Changeset - c87205ed6292
[Not reviewed]
0 10 0
MH - 4 years ago 2021-04-02 14:59:36
contact@maxhenger.nl
cleanup consume_type function name and rename ParseError
4 files changed:
0 comments (0 inline, 0 general)
src/protocol/inputsource.rs
Show inline comments
 
use std::fmt;
 
use std::fs::File;
 
use std::io;
 
use std::path::Path;
 

	
 
use backtrace::Backtrace;
 

	
 
#[derive(Debug, Clone, serde::Serialize, serde::Deserialize)]
 
pub struct InputSource {
 
    pub(crate) filename: String,
 
    pub(crate) input: Vec<u8>,
 
    line: usize,
 
    column: usize,
 
    offset: usize,
 
}
 

	
 
static STD_LIB_PDL: &'static [u8] = b"
 
primitive forward(in<msg> i, out<msg> o) {
 
    while(true) synchronous put(o, get(i));
 
}
 
primitive sync(in<msg> i, out<msg> o) {
 
    while(true) synchronous if(fires(i)) put(o, get(i));
 
}
 
primitive alternator(in<msg> i, out<msg> l, out<msg> r) {
 
    while(true) {
 
        synchronous if(fires(i)) put(l, get(i));
 
        synchronous if(fires(i)) put(r, get(i));
 
    }
 
}
 
primitive replicator(in<msg> i, out<msg> l, out<msg> r) {
 
    while(true) synchronous {
 
        if(fires(i)) {
 
            msg m = get(i);
 
            put(l, m);
 
            put(r, m);
 
        }
 
    }
 
}
 
primitive merger(in<msg> l, in<msg> r, out<msg> o) {
 
    while(true) synchronous {
 
        if(fires(l))      put(o, get(l));
 
        else if(fires(r)) put(o, get(r));
 
    }
 
}
 
";
 

	
 
impl InputSource {
 
    // Constructors
 
    pub fn new<R: io::Read, S: ToString>(filename: S, reader: &mut R) -> io::Result<InputSource> {
 
        let mut vec = Vec::new();
 
        reader.read_to_end(&mut vec)?;
 
        vec.extend(STD_LIB_PDL.to_vec());
 
        Ok(InputSource {
 
            filename: filename.to_string(),
 
            input: vec,
 
            line: 1,
 
            column: 1,
 
            offset: 0,
 
        })
 
    }
 
    // Constructor helpers
 
    pub fn from_file(path: &Path) -> io::Result<InputSource> {
 
        let filename = path.file_name();
 
        match filename {
 
            Some(filename) => {
 
                let mut f = File::open(path)?;
 
                InputSource::new(filename.to_string_lossy(), &mut f)
 
            }
 
            None => Err(io::Error::new(io::ErrorKind::NotFound, "Invalid path")),
 
        }
 
    }
 
    pub fn from_string(string: &str) -> io::Result<InputSource> {
 
        let buffer = Box::new(string);
 
        let mut bytes = buffer.as_bytes();
 
        InputSource::new(String::new(), &mut bytes)
 
    }
 
    pub fn from_buffer(buffer: &[u8]) -> io::Result<InputSource> {
 
        InputSource::new(String::new(), &mut Box::new(buffer))
 
    }
 
    // Internal methods
 
    pub fn pos(&self) -> InputPosition {
 
        InputPosition { line: self.line, column: self.column, offset: self.offset }
 
    }
 
    pub fn seek(&mut self, pos: InputPosition) {
 
        debug_assert!(pos.offset < self.input.len());
 
        self.line = pos.line;
 
        self.column = pos.column;
 
        self.offset = pos.offset;
 
    }
 
    // pub fn error<S: ToString>(&self, message: S) -> ParseError {
 
    //     self.pos().parse_error(message)
 
    // }
 
    pub fn is_eof(&self) -> bool {
 
        self.next() == None
 
    }
 

	
 
    pub fn next(&self) -> Option<u8> {
 
        if self.offset < self.input.len() {
 
            Some(self.input[self.offset])
 
        } else {
 
            None
 
        }
 
    }
 

	
 
    pub fn lookahead(&self, pos: usize) -> Option<u8> {
 
        let offset_pos = self.offset + pos;
 
        if offset_pos < self.input.len() {
 
            Some(self.input[offset_pos])
 
        } else {
 
            None
 
        }
 
    }
 

	
 
    pub fn has(&self, to_compare: &[u8]) -> bool {
 
        if self.offset + to_compare.len() <= self.input.len() {
 
            for idx in 0..to_compare.len() {
 
                if to_compare[idx] != self.input[self.offset + idx] {
 
                    return false;
 
                }
 
            }
 

	
 
            true
 
        } else {
 
            false
 
        }
 
    }
 

	
 
    pub fn consume(&mut self) {
 
        match self.next() {
 
            Some(x) if x == b'\r' && self.lookahead(1) != Some(b'\n') || x == b'\n' => {
 
                self.line += 1;
 
                self.offset += 1;
 
                self.column = 1;
 
            }
 
            Some(_) => {
 
                self.offset += 1;
 
                self.column += 1;
 
            }
 
            None => {}
 
        }
 
    }
 
}
 

	
 
impl fmt::Display for InputSource {
 
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
 
        self.pos().fmt(f)
 
    }
 
}
 

	
 
#[derive(Debug, Clone, Copy, serde::Serialize, serde::Deserialize)]
 
pub struct InputPosition {
 
    line: usize,
 
    column: usize,
 
    pub(crate) offset: usize,
 
}
 

	
 
impl InputPosition {
 
    fn context<'a>(&self, source: &'a InputSource) -> &'a [u8] {
 
        let start = self.offset - (self.column - 1);
 
        let mut end = self.offset;
 
        while end < source.input.len() {
 
            let cur = (*source.input)[end];
 
            if cur == b'\n' || cur == b'\r' {
 
                break;
 
            }
 
            end += 1;
 
        }
 
        &source.input[start..end]
 
    }
 
    // fn parse_error<S: ToString>(&self, message: S) -> ParseError {
 
    //     ParseError { position: *self, message: message.to_string(), backtrace: Backtrace::new() }
 
    // }
 
    fn eval_error<S: ToString>(&self, message: S) -> EvalError {
 
        EvalError { position: *self, message: message.to_string(), backtrace: Backtrace::new() }
 
    }
 

	
 
    pub(crate) fn col(&self) -> usize { self.column }
 
}
 

	
 
impl Default for InputPosition {
 
    fn default() -> Self {
 
        Self{ line: 1, column: 1, offset: 0 }
 
    }
 
}
 

	
 
impl fmt::Display for InputPosition {
 
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
 
        write!(f, "{}:{}", self.line, self.column)
 
    }
 
}
 

	
 
pub trait SyntaxElement {
 
    fn position(&self) -> InputPosition;
 
    fn error<S: ToString>(&self, message: S) -> EvalError {
 
        self.position().eval_error(message)
 
    }
 
}
 

	
 
#[derive(Debug)]
 
pub enum ParseErrorType {
 
    Info,
 
    Error
 
}
 

	
 
#[derive(Debug)]
 
pub struct ParseErrorStatement {
 
    pub(crate) error_type: ParseErrorType,
 
    pub(crate) position: InputPosition,
 
    pub(crate) filename: String,
 
    pub(crate) context: String,
 
    pub(crate) message: String,
 
}
 

	
 
impl ParseErrorStatement {
 
    fn from_source(error_type: ParseErrorType, source: &InputSource, position: InputPosition, msg: &str) -> Self {
 
        // Seek line start and end
 
        let line_start = position.offset - (position.column - 1);
 
        let mut line_end = position.offset;
 
        while line_end < source.input.len() && source.input[line_end] != b'\n' {
 
            line_end += 1;
 
        }
 

	
 
        // Compensate for '\r\n'
 
        if line_end > line_start && source.input[line_end - 1] == b'\r' {
 
            line_end -= 1;
 
        }
 

	
 
        Self{
 
            error_type,
 
            position,
 
            filename: source.filename.clone(),
 
            context: String::from_utf8_lossy(&source.input[line_start..line_end]).to_string(),
 
            message: msg.to_string()
 
        }
 
    }
 
}
 

	
 
impl fmt::Display for ParseErrorStatement {
 
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
 
        // Write message
 
        match self.error_type {
 
            ParseErrorType::Info => write!(f, " INFO: ")?,
 
            ParseErrorType::Error => write!(f, "ERROR: ")?,
 
        }
 
        writeln!(f, "{}", &self.message)?;
 

	
 
        // Write originating file/line/column
 
        if self.filename.is_empty() {
 
            writeln!(f, " +- at {}:{}", self.position.line, self.position.column)?;
 
        } else {
 
            writeln!(f, " +- at {}:{}:{}", self.filename, self.position.line, self.position.column)?;
 
        }
 

	
 
        // Write source context
 
        writeln!(f, " | ")?;
 
        writeln!(f, " | {}", self.context)?;
 

	
 
        // Write underline indicating where the error ocurred
 
        debug_assert!(self.position.column <= self.context.chars().count());
 
        let mut arrow = String::with_capacity(self.context.len() + 3);
 
        arrow.push_str(" | ");
 
        let mut char_col = 1;
 
        for char in self.context.chars() {
 
            if char_col == self.position.column { break; }
 
            if char == '\t' {
 
                arrow.push('\t');
 
            } else {
 
                arrow.push(' ');
 
            }
 

	
 
            char_col += 1;
 
        }
 
        arrow.push('^');
 
        writeln!(f, "{}", arrow)?;
 

	
 
        Ok(())
 
    }
 
}
 

	
 
#[derive(Debug)]
 
pub struct ParseError2 {
 
pub struct ParseError {
 
    pub(crate) statements: Vec<ParseErrorStatement>
 
}
 

	
 
impl fmt::Display for ParseError2 {
 
impl fmt::Display for ParseError {
 
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
 
        if self.statements.is_empty() {
 
            return Ok(())
 
        }
 

	
 
        self.statements[0].fmt(f)?;
 
        for statement in self.statements.iter().skip(1) {
 
            writeln!(f)?;
 
            statement.fmt(f)?;
 
        }
 

	
 
        Ok(())
 
    }
 
}
 

	
 
impl ParseError2 {
 
impl ParseError {
 
    pub fn empty() -> Self {
 
        Self{ statements: Vec::new() }
 
    }
 

	
 
    pub fn new_error(source: &InputSource, position: InputPosition, msg: &str) -> Self {
 
        Self{ statements: vec!(ParseErrorStatement::from_source(ParseErrorType::Error, source, position, msg))}
 
    }
 

	
 
    pub fn with_prefixed(mut self, error_type: ParseErrorType, source: &InputSource, position: InputPosition, msg: &str) -> Self {
 
        self.statements.insert(0, ParseErrorStatement::from_source(error_type, source, position, msg));
 
        self
 
    }
 

	
 
    pub fn with_postfixed(mut self, error_type: ParseErrorType, source: &InputSource, position: InputPosition, msg: &str) -> Self {
 
        self.statements.push(ParseErrorStatement::from_source(error_type, source, position, msg));
 
        self
 
    }
 

	
 
    pub fn with_postfixed_info(self, source: &InputSource, position: InputPosition, msg: &str) -> Self {
 
        self.with_postfixed(ParseErrorType::Info, source, position, msg)
 
    }
 
}
 

	
 
#[derive(Debug, Clone)]
 
pub struct EvalError {
 
    position: InputPosition,
 
    message: String,
 
    backtrace: Backtrace,
 
}
 

	
 
impl EvalError {
 
    pub fn new<S: ToString>(position: InputPosition, message: S) -> EvalError {
 
        EvalError { position, message: message.to_string(), backtrace: Backtrace::new() }
 
    }
 
    // Diagnostic methods
 
    pub fn write<A: io::Write>(&self, source: &InputSource, writer: &mut A) -> io::Result<()> {
 
        if !source.filename.is_empty() {
 
            writeln!(
 
                writer,
 
                "Evaluation error at {}:{}: {}",
 
                source.filename, self.position, self.message
 
            )?;
 
        } else {
 
            writeln!(writer, "Evaluation error at {}: {}", self.position, self.message)?;
 
        }
 
        let line = self.position.context(source);
 
        writeln!(writer, "{}", String::from_utf8_lossy(line))?;
 
        let mut arrow: Vec<u8> = Vec::new();
 
        for pos in 1..self.position.column {
 
            let c = line[pos - 1];
 
            if c == b'\t' {
 
                arrow.push(b'\t')
 
            } else {
 
                arrow.push(b' ')
 
            }
 
        }
 
        arrow.push(b'^');
 
        writeln!(writer, "{}", String::from_utf8_lossy(&arrow))
 
    }
 
    pub fn print(&self, source: &InputSource) {
 
        self.write(source, &mut std::io::stdout()).unwrap()
 
    }
 
    pub fn display<'a>(&'a self, source: &'a InputSource) -> DisplayEvalError<'a> {
 
        DisplayEvalError::new(self, source)
 
    }
 
}
 

	
 
impl From<EvalError> for io::Error {
 
    fn from(_: EvalError) -> io::Error {
 
        io::Error::new(io::ErrorKind::InvalidInput, "eval error")
 
    }
 
}
 

	
 
#[derive(Clone, Copy)]
 
pub struct DisplayEvalError<'a> {
 
    error: &'a EvalError,
 
    source: &'a InputSource,
 
}
 

	
 
impl DisplayEvalError<'_> {
 
    fn new<'a>(error: &'a EvalError, source: &'a InputSource) -> DisplayEvalError<'a> {
 
        DisplayEvalError { error, source }
 
    }
 
}
 

	
 
impl fmt::Display for DisplayEvalError<'_> {
 
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
 
        let mut vec: Vec<u8> = Vec::new();
 
        match self.error.write(self.source, &mut vec) {
 
            Err(_) => {
 
                return fmt::Result::Err(fmt::Error);
 
            }
 
            Ok(_) => {}
 
        }
 
        write!(f, "{}", String::from_utf8_lossy(&vec))
 
    }
 
}
 

	
 
// #[cfg(test)]
 
// mod tests {
 
//     use super::*;
 

	
 
//     #[test]
 
//     fn test_from_string() {
 
//         let mut is = InputSource::from_string("#version 100\n").unwrap();
 
//         assert!(is.input.len() == 13);
 
//         assert!(is.line == 1);
 
//         assert!(is.column == 1);
 
//         assert!(is.offset == 0);
 
//         let ps = is.pos();
 
//         assert!(ps.line == 1);
 
//         assert!(ps.column == 1);
 
//         assert!(ps.offset == 0);
 
//         assert!(is.next() == Some(b'#'));
 
//         is.consume();
 
//         assert!(is.next() == Some(b'v'));
 
//         assert!(is.lookahead(1) == Some(b'e'));
 
//         is.consume();
 
//         assert!(is.next() == Some(b'e'));
 
//         is.consume();
 
//         assert!(is.next() == Some(b'r'));
 
//         is.consume();
 
//         assert!(is.next() == Some(b's'));
 
//         is.consume();
 
//         assert!(is.next() == Some(b'i'));
 
//         is.consume();
 
//         {
 
//             let ps = is.pos();
 
//             assert_eq!(b"#version 100", ps.context(&is));
 
//             let er = is.error("hello world!");
 
//             let mut vec: Vec<u8> = Vec::new();
 
//             er.write(&is, &mut vec).unwrap();
 
//             assert_eq!(
 
//                 "Parse error at 1:7: hello world!\n#version 100\n      ^\n",
 
//                 String::from_utf8_lossy(&vec)
 
//             );
 
//         }
 
//         assert!(is.next() == Some(b'o'));
 
//         is.consume();
 
//         assert!(is.next() == Some(b'n'));
 
//         is.consume();
 
//         assert!(is.input.len() == 13);
 
//         assert!(is.line == 1);
 
//         assert!(is.column == 9);
 
//         assert!(is.offset == 8);
 
//         assert!(is.next() == Some(b' '));
 
//         is.consume();
 
//         assert!(is.next() == Some(b'1'));
 
//         is.consume();
 
//         assert!(is.next() == Some(b'0'));
 
//         is.consume();
 
//         assert!(is.next() == Some(b'0'));
 
//         is.consume();
 
//         assert!(is.input.len() == 13);
 
//         assert!(is.line == 1);
 
//         assert!(is.column == 13);
 
//         assert!(is.offset == 12);
 
//         assert!(is.next() == Some(b'\n'));
 
//         is.consume();
 
//         assert!(is.input.len() == 13);
 
//         assert!(is.line == 2);
 
//         assert!(is.column == 1);
 
//         assert!(is.offset == 13);
 
//         {
 
//             let ps = is.pos();
 
//             assert_eq!(b"", ps.context(&is));
 
//         }
 
//         assert!(is.next() == None);
 
//         is.consume();
 
//         assert!(is.next() == None);
 
//     }
 

	
 
//     #[test]
 
//     fn test_split() {
 
//         let mut is = InputSource::from_string("#version 100\n").unwrap();
 
//         let backup = is.clone();
 
//         assert!(is.next() == Some(b'#'));
 
//         is.consume();
 
//         assert!(is.next() == Some(b'v'));
 
//         is.consume();
 
//         assert!(is.next() == Some(b'e'));
 
//         is.consume();
 
//         is = backup;
 
//         assert!(is.next() == Some(b'#'));
 
//         is.consume();
 
//         assert!(is.next() == Some(b'v'));
 
//         is.consume();
 
//         assert!(is.next() == Some(b'e'));
 
//         is.consume();
 
//     }
 
// }
src/protocol/lexer.rs
Show inline comments
 
use crate::protocol::ast::*;
 
use crate::protocol::inputsource::*;
 

	
 
const MAX_LEVEL: usize = 128;
 
const MAX_NAMESPACES: u8 = 8; // only three levels are supported at the moment
 

	
 
macro_rules! debug_log {
 
    ($format:literal) => {
 
        enabled_debug_print!(true, "lexer", $format);
 
    };
 
    ($format:literal, $($args:expr),*) => {
 
        enabled_debug_print!(true, "lexer", $format, $($args),*);
 
    };
 
}
 

	
 
macro_rules! debug_line {
 
    ($source:expr) => {
 
        {
 
            let mut buffer = String::with_capacity(128);
 
            for idx in 0..buffer.capacity() {
 
                let next = $source.lookahead(idx);
 
                if next.is_none() || Some(b'\n') == next { break; }
 
                buffer.push(next.unwrap() as char);
 
            }
 
            buffer
 
        }
 
    };
 
}
 
fn is_vchar(x: Option<u8>) -> bool {
 
    if let Some(c) = x {
 
        c >= 0x21 && c <= 0x7E
 
    } else {
 
        false
 
    }
 
}
 

	
 
fn is_wsp(x: Option<u8>) -> bool {
 
    if let Some(c) = x {
 
        c == b' ' || c == b'\t'
 
    } else {
 
        false
 
    }
 
}
 

	
 
fn is_ident_start(x: Option<u8>) -> bool {
 
    if let Some(c) = x {
 
        c >= b'A' && c <= b'Z' || c >= b'a' && c <= b'z'
 
    } else {
 
        false
 
    }
 
}
 

	
 
fn is_ident_rest(x: Option<u8>) -> bool {
 
    if let Some(c) = x {
 
        c >= b'A' && c <= b'Z' || c >= b'a' && c <= b'z' || c >= b'0' && c <= b'9' || c == b'_'
 
    } else {
 
        false
 
    }
 
}
 

	
 
fn is_constant(x: Option<u8>) -> bool {
 
    if let Some(c) = x {
 
        c >= b'0' && c <= b'9' || c == b'\''
 
    } else {
 
        false
 
    }
 
}
 

	
 
fn is_integer_start(x: Option<u8>) -> bool {
 
    if let Some(c) = x {
 
        c >= b'0' && c <= b'9'
 
    } else {
 
        false
 
    }
 
}
 

	
 
fn is_integer_rest(x: Option<u8>) -> bool {
 
    if let Some(c) = x {
 
        c >= b'0' && c <= b'9'
 
            || c >= b'a' && c <= b'f'
 
            || c >= b'A' && c <= b'F'
 
            || c == b'x'
 
            || c == b'o'
 
    } else {
 
        false
 
    }
 
}
 

	
 
fn lowercase(x: u8) -> u8 {
 
    if x >= b'A' && x <= b'Z' {
 
        x - b'A' + b'a'
 
    } else {
 
        x
 
    }
 
}
 

	
 
fn identifier_as_namespaced(identifier: Identifier) -> NamespacedIdentifier {
 
    let identifier_len = identifier.value.len();
 
    debug_assert!(identifier_len < u16::max_value() as usize);
 
    NamespacedIdentifier{
 
        position: identifier.position,
 
        value: identifier.value,
 
        poly_args: Vec::new(),
 
        parts: vec![
 
            NamespacedIdentifierPart::Identifier{start: 0, end: identifier_len as u16}
 
        ],
 
    }
 
}
 

	
 
pub struct Lexer<'a> {
 
    source: &'a mut InputSource,
 
    level: usize,
 
}
 

	
 
impl Lexer<'_> {
 
    pub fn new(source: &mut InputSource) -> Lexer {
 
        Lexer { source, level: 0 }
 
    }
 
    fn error_at_pos(&self, msg: &str) -> ParseError2 {
 
        ParseError2::new_error(self.source, self.source.pos(), msg)
 
    fn error_at_pos(&self, msg: &str) -> ParseError {
 
        ParseError::new_error(self.source, self.source.pos(), msg)
 
    }
 
    fn consume_line(&mut self) -> Result<Vec<u8>, ParseError2> {
 
    fn consume_line(&mut self) -> Result<Vec<u8>, ParseError> {
 
        let mut result: Vec<u8> = Vec::new();
 
        let mut next = self.source.next();
 
        while next.is_some() && next != Some(b'\n') && next != Some(b'\r') {
 
            if !(is_vchar(next) || is_wsp(next)) {
 
                return Err(self.error_at_pos("Expected visible character or whitespace"));
 
            }
 
            result.push(next.unwrap());
 
            self.source.consume();
 
            next = self.source.next();
 
        }
 
        if next.is_some() {
 
            self.source.consume();
 
        }
 
        if next == Some(b'\r') && self.source.next() == Some(b'\n') {
 
            self.source.consume();
 
        }
 
        Ok(result)
 
    }
 
    fn consume_whitespace(&mut self, expected: bool) -> Result<(), ParseError2> {
 
    fn consume_whitespace(&mut self, expected: bool) -> Result<(), ParseError> {
 
        let mut found = false;
 
        let mut next = self.source.next();
 
        while next.is_some() {
 
            if next == Some(b' ')
 
                || next == Some(b'\t')
 
                || next == Some(b'\r')
 
                || next == Some(b'\n')
 
            {
 
                self.source.consume();
 
                next = self.source.next();
 
                found = true;
 
                continue;
 
            }
 
            if next == Some(b'/') {
 
                next = self.source.lookahead(1);
 
                if next == Some(b'/') {
 
                    self.source.consume(); // slash
 
                    self.source.consume(); // slash
 
                    self.consume_line()?;
 
                    next = self.source.next();
 
                    found = true;
 
                    continue;
 
                }
 
                if next == Some(b'*') {
 
                    self.source.consume(); // slash
 
                    self.source.consume(); // star
 
                    next = self.source.next();
 
                    while next.is_some() {
 
                        if next == Some(b'*') {
 
                            next = self.source.lookahead(1);
 
                            if next == Some(b'/') {
 
                                self.source.consume(); // star
 
                                self.source.consume(); // slash
 
                                break;
 
                            }
 
                        }
 
                        self.source.consume();
 
                        next = self.source.next();
 
                    }
 
                    next = self.source.next();
 
                    found = true;
 
                    continue;
 
                }
 
            }
 
            break;
 
        }
 
        if expected && !found {
 
            Err(self.error_at_pos("Expected whitespace"))
 
        } else {
 
            Ok(())
 
        }
 
    }
 
    fn consume_any_chars(&mut self) {
 
        if !is_ident_start(self.source.next()) { return }
 
        self.source.consume();
 
        while is_ident_rest(self.source.next()) {
 
            self.source.consume()
 
        }
 
    }
 
    fn has_keyword(&self, keyword: &[u8]) -> bool {
 
        if !self.source.has(keyword) {
 
            return false;
 
        }
 

	
 
        // Word boundary
 
        let next = self.source.lookahead(keyword.len());
 
        if next.is_none() { return true; }
 
        return !is_ident_rest(next);
 
    }
 
    fn consume_keyword(&mut self, keyword: &[u8]) -> Result<(), ParseError2> {
 
    fn consume_keyword(&mut self, keyword: &[u8]) -> Result<(), ParseError> {
 
        let len = keyword.len();
 
        for i in 0..len {
 
            let expected = Some(lowercase(keyword[i]));
 
            let next = self.source.next();
 
            if next != expected {
 
                return Err(self.error_at_pos(&format!("Expected keyword '{}'", String::from_utf8_lossy(keyword))));
 
            }
 
            self.source.consume();
 
        }
 
        if let Some(next) = self.source.next() {
 
            if next >= b'A' && next <= b'Z' || next >= b'a' && next <= b'z' || next >= b'0' && next <= b'9' {
 
                return Err(self.error_at_pos(&format!("Expected word boundary after '{}'", String::from_utf8_lossy(keyword))));
 
            }
 
        }
 
        Ok(())
 
    }
 
    fn has_string(&self, string: &[u8]) -> bool {
 
        self.source.has(string)
 
    }
 
    fn consume_string(&mut self, string: &[u8]) -> Result<(), ParseError2> {
 
    fn consume_string(&mut self, string: &[u8]) -> Result<(), ParseError> {
 
        let len = string.len();
 
        for i in 0..len {
 
            let expected = Some(string[i]);
 
            let next = self.source.next();
 
            if next != expected {
 
                return Err(self.error_at_pos(&format!("Expected {}", String::from_utf8_lossy(string))));
 
            }
 
            self.source.consume();
 
        }
 
        Ok(())
 
    }
 
    /// Generic comma-separated consumer. If opening delimiter is not found then
 
    /// `Ok(None)` will be returned. Otherwise will consume the comma separated
 
    /// values, allowing a trailing comma. If no comma is found and the closing
 
    /// delimiter is not found, then a parse error with `expected_end_msg` is
 
    /// returned.
 
    fn consume_comma_separated<T, F>(
 
        &mut self, h: &mut Heap, open: u8, close: u8, expected_end_msg: &str, func: F
 
    ) -> Result<Option<Vec<T>>, ParseError2>
 
        where F: Fn(&mut Lexer, &mut Heap) -> Result<T, ParseError2>
 
    ) -> Result<Option<Vec<T>>, ParseError>
 
        where F: Fn(&mut Lexer, &mut Heap) -> Result<T, ParseError>
 
    {
 
        if Some(open) != self.source.next() {
 
            return Ok(None)
 
        }
 

	
 
        self.source.consume();
 
        self.consume_whitespace(false)?;
 
        let mut elements = Vec::new();
 
        let mut had_comma = true;
 

	
 
        loop {
 
            if Some(close) == self.source.next() {
 
                self.source.consume();
 
                break;
 
            } else if !had_comma {
 
                return Err(ParseError2::new_error(
 
                return Err(ParseError::new_error(
 
                    &self.source, self.source.pos(), expected_end_msg
 
                ));
 
            }
 

	
 
            elements.push(func(self, h)?);
 
            self.consume_whitespace(false)?;
 

	
 
            had_comma = self.source.next() == Some(b',');
 
            if had_comma {
 
                self.source.consume();
 
                self.consume_whitespace(false)?;
 
            }
 
        }
 

	
 
        Ok(Some(elements))
 
    }
 
    /// Essentially the same as `consume_comma_separated`, but will not allocate
 
    /// memory. Will return `Ok(true)` and leave the input position at the end
 
    /// the comma-separated list if well formed and `Ok(false)` if the list is
 
    /// not present. Otherwise returns `Err(())` and leaves the input position 
 
    /// at a "random" position.
 
    fn consume_comma_separated_spilled_without_pos_recovery<F: Fn(&mut Lexer) -> bool>(
 
        &mut self, open: u8, close: u8, func: F
 
    ) -> Result<bool, ()> {
 
        if Some(open) != self.source.next() {
 
            return Ok(false);
 
        }
 

	
 
        self.source.consume();
 
        if self.consume_whitespace(false).is_err() { return Err(()) };
 
        let mut had_comma = true;
 
        loop {
 
            if Some(close) == self.source.next() {
 
                self.source.consume();
 
                return Ok(true);
 
            } else if !had_comma {
 
                return Err(());
 
            }
 

	
 
            if !func(self) { return Err(()); }
 
            if self.consume_whitespace(false).is_err() { return Err(()) };
 

	
 
            had_comma = self.source.next() == Some(b',');
 
            if had_comma {
 
                self.source.consume();
 
                if self.consume_whitespace(false).is_err() { return Err(()); }
 
            }
 
        }
 
    }
 
    fn consume_ident(&mut self) -> Result<Vec<u8>, ParseError2> {
 
    fn consume_ident(&mut self) -> Result<Vec<u8>, ParseError> {
 
        if !self.has_identifier() {
 
            return Err(self.error_at_pos("Expected identifier"));
 
        }
 
        let mut result = Vec::new();
 
        let mut next = self.source.next();
 
        result.push(next.unwrap());
 
        self.source.consume();
 
        next = self.source.next();
 
        while is_ident_rest(next) {
 
            result.push(next.unwrap());
 
            self.source.consume();
 
            next = self.source.next();
 
        }
 
        Ok(result)
 
    }
 
    fn has_integer(&mut self) -> bool {
 
        is_integer_start(self.source.next())
 
    }
 
    fn consume_integer(&mut self) -> Result<i64, ParseError2> {
 
    fn consume_integer(&mut self) -> Result<i64, ParseError> {
 
        let position = self.source.pos();
 
        let mut data = Vec::new();
 
        let mut next = self.source.next();
 
        while is_integer_rest(next) {
 
            data.push(next.unwrap());
 
            self.source.consume();
 
            next = self.source.next();
 
        }
 

	
 
        let data_len = data.len();
 
        debug_assert_ne!(data_len, 0);
 
        if data_len == 1 {
 
            debug_assert!(data[0] >= b'0' && data[0] <= b'9');
 
            return Ok((data[0] - b'0') as i64);
 
        } else {
 
            // TODO: Fix, u64 should be supported as well
 
            let parsed = if data[1] == b'b' {
 
                let data = String::from_utf8_lossy(&data[2..]);
 
                i64::from_str_radix(&data, 2)
 
            } else if data[1] == b'o' {
 
                let data = String::from_utf8_lossy(&data[2..]);
 
                i64::from_str_radix(&data, 8)
 
            } else if data[1] == b'x' {
 
                let data = String::from_utf8_lossy(&data[2..]);
 
                i64::from_str_radix(&data, 16)
 
            } else {
 
                // Assume decimal
 
                let data = String::from_utf8_lossy(&data);
 
                i64::from_str_radix(&data, 10)
 
            };
 

	
 
            if let Err(_err) = parsed {
 
                return Err(ParseError2::new_error(&self.source, position, "Invalid integer constant"));
 
                return Err(ParseError::new_error(&self.source, position, "Invalid integer constant"));
 
            }
 

	
 
            Ok(parsed.unwrap())
 
        }
 
    }
 

	
 
    // Statement keywords
 
    // TODO: Clean up these functions
 
    fn has_statement_keyword(&self) -> bool {
 
        self.has_keyword(b"channel")
 
            || self.has_keyword(b"skip")
 
            || self.has_keyword(b"if")
 
            || self.has_keyword(b"while")
 
            || self.has_keyword(b"break")
 
            || self.has_keyword(b"continue")
 
            || self.has_keyword(b"synchronous")
 
            || self.has_keyword(b"return")
 
            || self.has_keyword(b"assert")
 
            || self.has_keyword(b"goto")
 
            || self.has_keyword(b"new")
 
    }
 
    fn has_type_keyword(&self) -> bool {
 
        self.has_keyword(b"in")
 
            || self.has_keyword(b"out")
 
            || self.has_keyword(b"msg")
 
            || self.has_keyword(b"boolean")
 
            || self.has_keyword(b"byte")
 
            || self.has_keyword(b"short")
 
            || self.has_keyword(b"int")
 
            || self.has_keyword(b"long")
 
            || self.has_keyword(b"auto")
 
    }
 
    fn has_builtin_keyword(&self) -> bool {
 
        self.has_keyword(b"get")
 
            || self.has_keyword(b"fires")
 
            || self.has_keyword(b"create")
 
            || self.has_keyword(b"length")
 
    }
 
    fn has_reserved(&self) -> bool {
 
        self.has_statement_keyword()
 
            || self.has_type_keyword()
 
            || self.has_builtin_keyword()
 
            || self.has_keyword(b"let")
 
            || self.has_keyword(b"struct")
 
            || self.has_keyword(b"enum")
 
            || self.has_keyword(b"true")
 
            || self.has_keyword(b"false")
 
            || self.has_keyword(b"null")
 
    }
 

	
 
    // Identifiers
 

	
 
    fn has_identifier(&self) -> bool {
 
        if self.has_statement_keyword() || self.has_type_keyword() || self.has_builtin_keyword() {
 
            return false;
 
        }
 
        let next = self.source.next();
 
        is_ident_start(next)
 
    }
 
    fn consume_identifier(&mut self) -> Result<Identifier, ParseError2> {
 
    fn consume_identifier(&mut self) -> Result<Identifier, ParseError> {
 
        if self.has_statement_keyword() || self.has_type_keyword() || self.has_builtin_keyword() {
 
            return Err(self.error_at_pos("Expected identifier"));
 
        }
 
        let position = self.source.pos();
 
        let value = self.consume_ident()?;
 
        Ok(Identifier{ position, value })
 
    }
 
    fn consume_identifier_spilled(&mut self) -> Result<(), ParseError2> {
 
    fn consume_identifier_spilled(&mut self) -> Result<(), ParseError> {
 
        if self.has_statement_keyword() || self.has_type_keyword() || self.has_builtin_keyword() {
 
            return Err(self.error_at_pos("Expected identifier"));
 
        }
 
        self.consume_ident()?;
 
        Ok(())
 
    }
 

	
 
    fn consume_namespaced_identifier(&mut self, h: &mut Heap) -> Result<NamespacedIdentifier, ParseError2> {
 
    fn consume_namespaced_identifier(&mut self, h: &mut Heap) -> Result<NamespacedIdentifier, ParseError> {
 
        if self.has_reserved() {
 
            return Err(self.error_at_pos("Encountered reserved keyword"));
 
        }
 

	
 
        // Consumes a part of the namespaced identifier, returns a boolean
 
        // indicating whether polymorphic arguments were specified.
 
        // TODO: Continue here: if we fail to properly parse the polymorphic
 
        //  arguments, assume we have reached the end of the namespaced 
 
        //  identifier and are instead dealing with a less-than operator. Ugly?
 
        //  Yes. Needs tokenizer? Yes. 
 
        fn consume_part(
 
            l: &mut Lexer, h: &mut Heap, ident: &mut NamespacedIdentifier,
 
            backup_pos: &mut InputPosition
 
        ) -> Result<(), ParseError2> {
 
        ) -> Result<(), ParseError> {
 
            // Consume identifier
 
            if !ident.value.is_empty() {
 
                ident.value.extend(b"::");
 
            }
 
            let ident_start = ident.value.len();
 
            ident.value.extend(l.consume_ident()?);
 
            ident.parts.push(NamespacedIdentifierPart::Identifier{
 
                start: ident_start as u16,
 
                end: ident.value.len() as u16
 
            });
 

	
 
            // Maybe consume polymorphic args.
 
            *backup_pos = l.source.pos();
 
            l.consume_whitespace(false)?;
 
            match l.consume_polymorphic_args(h, true)? {
 
                Some(args) => {
 
                    let poly_start = ident.poly_args.len();
 
                    ident.poly_args.extend(args);
 

	
 
                    ident.parts.push(NamespacedIdentifierPart::PolyArgs{
 
                        start: poly_start as u16,
 
                        end: ident.poly_args.len() as u16,
 
                    });
 

	
 
                    *backup_pos = l.source.pos();
 
                },
 
                None => {}
 
            };
 

	
 
            Ok(())
 
        }
 

	
 
        let mut ident = NamespacedIdentifier{
 
            position: self.source.pos(),
 
            value: Vec::new(),
 
            poly_args: Vec::new(),
 
            parts: Vec::new(),
 
        };
 

	
 
        // Keep consume parts separted by "::". We don't consume the trailing
 
        // whitespace, hence we keep a backup position at the end of the last
 
        // valid part of the namespaced identifier (i.e. the last ident, or the
 
        // last encountered polymorphic arguments).
 
        let mut backup_pos = self.source.pos();
 
        consume_part(self, h, &mut ident, &mut backup_pos)?;
 
        self.consume_whitespace(false)?;
 
        while self.has_string(b"::") {
 
            self.consume_string(b"::")?;
 
            self.consume_whitespace(false)?;
 
            consume_part(self, h, &mut ident, &mut backup_pos)?;
 
            self.consume_whitespace(false)?;
 
        }
 

	
 
        self.source.seek(backup_pos);
 
        Ok(ident)
 
    }
 

	
 
    fn consume_namespaced_identifier_spilled(&mut self) -> Result<(), ParseError2> {
 
    fn consume_namespaced_identifier_spilled(&mut self) -> Result<(), ParseError> {
 
        if self.has_reserved() {
 
            return Err(self.error_at_pos("Encountered reserved keyword"));
 
        }
 

	
 
        debug_log!("consume_nsident2_spilled: {}", debug_line!(self.source));
 

	
 
        fn consume_part_spilled(l: &mut Lexer, backup_pos: &mut InputPosition) -> Result<(), ParseError2> {
 
        fn consume_part_spilled(l: &mut Lexer, backup_pos: &mut InputPosition) -> Result<(), ParseError> {
 
            l.consume_ident()?;
 
            *backup_pos = l.source.pos();
 
            l.consume_whitespace(false)?;
 
            match l.maybe_consume_poly_args_spilled_without_pos_recovery() {
 
                Ok(true) => { *backup_pos = l.source.pos(); },
 
                Ok(false) => {},
 
                Err(_) => { return Err(l.error_at_pos("Failed to parse poly args (spilled)")) },
 
            }
 
            Ok(())
 
        }
 

	
 
        let mut backup_pos = self.source.pos();
 
        consume_part_spilled(self, &mut backup_pos)?;
 
        self.consume_whitespace(false)?;
 
        while self.has_string(b"::") {
 
            self.consume_string(b"::")?;
 
            self.consume_whitespace(false)?;
 
            consume_part_spilled(self, &mut backup_pos)?;
 
            self.consume_whitespace(false)?;
 
        }
 

	
 
        self.source.seek(backup_pos);
 
        Ok(())
 
    }
 

	
 
    // Types and type annotations
 

	
 
    /// Consumes a type definition. When called the input position should be at
 
    /// the type specification. When done the input position will be at the end
 
    /// of the type specifications (hence may be at whitespace).
 
    fn consume_type2(&mut self, h: &mut Heap, allow_inference: bool) -> Result<ParserTypeId, ParseError2> {
 
    fn consume_type(&mut self, h: &mut Heap, allow_inference: bool) -> Result<ParserTypeId, ParseError> {
 
        // Small helper function to convert in/out polymorphic arguments. Not
 
        // pretty, but return boolean is true if the error is due to inference
 
        // not being allowed
 
        let reduce_port_poly_args = |
 
            heap: &mut Heap,
 
            port_pos: &InputPosition,
 
            args: Vec<ParserTypeId>,
 
        | -> Result<ParserTypeId, bool> {
 
            match args.len() {
 
                0 => if allow_inference {  
 
                    Ok(heap.alloc_parser_type(|this| ParserType{
 
                        this,
 
                        pos: port_pos.clone(),
 
                        variant: ParserTypeVariant::Inferred
 
                    }))
 
                } else {
 
                    Err(true)
 
                },
 
                1 => Ok(args[0]),
 
                _ => Err(false)
 
            }
 
        };
 

	
 
        // Consume the type
 
        debug_log!("consume_type2: {}", debug_line!(self.source));
 
        debug_log!("consume_type: {}", debug_line!(self.source));
 
        let pos = self.source.pos();
 
        let parser_type_variant = if self.has_keyword(b"msg") {
 
            self.consume_keyword(b"msg")?;
 
            ParserTypeVariant::Message
 
        } else if self.has_keyword(b"boolean") {
 
            self.consume_keyword(b"boolean")?;
 
            ParserTypeVariant::Bool
 
        } else if self.has_keyword(b"byte") {
 
            self.consume_keyword(b"byte")?;
 
            ParserTypeVariant::Byte
 
        } else if self.has_keyword(b"short") {
 
            self.consume_keyword(b"short")?;
 
            ParserTypeVariant::Short
 
        } else if self.has_keyword(b"int") {
 
            self.consume_keyword(b"int")?;
 
            ParserTypeVariant::Int
 
        } else if self.has_keyword(b"long") {
 
            self.consume_keyword(b"long")?;
 
            ParserTypeVariant::Long
 
        } else if self.has_keyword(b"str") {
 
            self.consume_keyword(b"str")?;
 
            ParserTypeVariant::String
 
        } else if self.has_keyword(b"auto") {
 
            if !allow_inference {
 
                return Err(ParseError2::new_error(
 
                return Err(ParseError::new_error(
 
                        &self.source, pos,
 
                        "Type inference is not allowed here"
 
                ));
 
            }
 

	
 
            self.consume_keyword(b"auto")?;
 
            ParserTypeVariant::Inferred
 
        } else if self.has_keyword(b"in") {
 
            // TODO: @cleanup: not particularly neat to have this special case
 
            //  where we enforce polyargs in the parser-phase
 
            self.consume_keyword(b"in")?;
 
            let poly_args = self.consume_polymorphic_args(h, allow_inference)?.unwrap_or_default();
 
            let poly_arg = reduce_port_poly_args(h, &pos, poly_args)
 
                .map_err(|infer_error|  {
 
                    let msg = if infer_error {
 
                        "Type inference is not allowed here"
 
                    } else {
 
                        "Type 'in' only allows for 1 polymorphic argument"
 
                    };
 
                    ParseError2::new_error(&self.source, pos, msg)
 
                    ParseError::new_error(&self.source, pos, msg)
 
                })?;
 
            ParserTypeVariant::Input(poly_arg)
 
        } else if self.has_keyword(b"out") {
 
            self.consume_keyword(b"out")?;
 
            let poly_args = self.consume_polymorphic_args(h, allow_inference)?.unwrap_or_default();
 
            let poly_arg = reduce_port_poly_args(h, &pos, poly_args)
 
                .map_err(|infer_error| {
 
                    let msg = if infer_error {
 
                        "Type inference is not allowed here"
 
                    } else {
 
                        "Type 'out' only allows for 1 polymorphic argument, but {} were specified"
 
                    };
 
                    ParseError2::new_error(&self.source, pos, msg)
 
                    ParseError::new_error(&self.source, pos, msg)
 
                })?;
 
            ParserTypeVariant::Output(poly_arg)
 
        } else {
 
            // Must be a symbolic type
 
            let identifier = self.consume_namespaced_identifier(h)?;
 
            ParserTypeVariant::Symbolic(SymbolicParserType{identifier, variant: None, poly_args2: Vec::new()})
 
        };
 

	
 
        // If the type was a basic type (not supporting polymorphic type
 
        // arguments), then we make sure the user did not specify any of them.
 
        let mut backup_pos = self.source.pos();
 
        if !parser_type_variant.supports_polymorphic_args() {
 
            self.consume_whitespace(false)?;
 
            if let Some(b'<') = self.source.next() {
 
                return Err(ParseError2::new_error(
 
                return Err(ParseError::new_error(
 
                    &self.source, self.source.pos(),
 
                    "This type does not allow polymorphic arguments"
 
                ));
 
            }
 

	
 
            self.source.seek(backup_pos);
 
        }
 

	
 
        let mut parser_type_id = h.alloc_parser_type(|this| ParserType{
 
            this, pos, variant: parser_type_variant
 
        });
 

	
 
        // If we're dealing with arrays, then we need to wrap the currently
 
        // parsed type in array types
 
        self.consume_whitespace(false)?;
 
        while let Some(b'[') = self.source.next() {
 
            let pos = self.source.pos();
 
            self.source.consume();
 
            self.consume_whitespace(false)?;
 
            if let Some(b']') = self.source.next() {
 
                // Type is wrapped in an array
 
                self.source.consume();
 
                parser_type_id = h.alloc_parser_type(|this| ParserType{
 
                    this, pos, variant: ParserTypeVariant::Array(parser_type_id)
 
                });
 
                backup_pos = self.source.pos();
 

	
 
                // In case we're dealing with another array
 
                self.consume_whitespace(false)?;
 
            } else {
 
                return Err(ParseError2::new_error(
 
                return Err(ParseError::new_error(
 
                    &self.source, pos,
 
                    "Expected a closing ']'"
 
                ));
 
            }
 
        }
 

	
 
        self.source.seek(backup_pos);
 
        Ok(parser_type_id)
 
    }
 

	
 
    /// Attempts to consume a type without returning it. If it doesn't encounter
 
    /// a well-formed type, then the input position is left at a "random"
 
    /// position.
 
    fn maybe_consume_type_spilled_without_pos_recovery(&mut self) -> bool {
 
        // Consume type identifier
 
        debug_log!("maybe_consume_type_spilled_...: {}", debug_line!(self.source));
 
        if self.has_type_keyword() {
 
            self.consume_any_chars();
 
        } else {
 
            let ident = self.consume_namespaced_identifier_spilled();
 
            if ident.is_err() { return false; }
 
        }
 

	
 
        // Consume any polymorphic arguments that follow the type identifier
 
        let mut backup_pos = self.source.pos();
 
        if self.consume_whitespace(false).is_err() { return false; }
 
        
 
        // Consume any array specifiers. Make sure we always leave the input
 
        // position at the end of the last array specifier if we do find a
 
        // valid type
 
        if self.consume_whitespace(false).is_err() { return false; }
 
        while let Some(b'[') = self.source.next() {
 
            self.source.consume();
 
            if self.consume_whitespace(false).is_err() { return false; }
 
            if self.source.next() != Some(b']') { return false; }
 
            self.source.consume();
 
            backup_pos = self.source.pos();
 
            if self.consume_whitespace(false).is_err() { return false; }
 
        }
 

	
 
        self.source.seek(backup_pos);
 
        return true;
 
    }
 

	
 
    fn maybe_consume_type_spilled(&mut self) -> bool {
 
        let backup_pos = self.source.pos();
 
        if !self.maybe_consume_type_spilled_without_pos_recovery() {
 
            self.source.seek(backup_pos);
 
            return false;
 
        }
 

	
 
        return true;
 
    }
 

	
 
    /// Attempts to consume polymorphic arguments without returning them. If it
 
    /// doesn't encounter well-formed polymorphic arguments, then the input
 
    /// position is left at a "random" position. Returns a boolean indicating if
 
    /// the poly_args list was present.
 
    fn maybe_consume_poly_args_spilled_without_pos_recovery(&mut self) -> Result<bool, ()> {
 
        debug_log!("maybe_consume_poly_args_spilled_...: {}", debug_line!(self.source));
 
        self.consume_comma_separated_spilled_without_pos_recovery(
 
            b'<', b'>', |lexer| {
 
                lexer.maybe_consume_type_spilled_without_pos_recovery()
 
            })
 
    }
 

	
 
    /// Consumes polymorphic arguments and its delimiters if specified. If
 
    /// polyargs are present then the args are consumed and the input position
 
    /// will be placed after the polyarg list. If polyargs are not present then
 
    /// the input position will remain unmodified and an empty vector will be
 
    /// returned.
 
    ///
 
    /// Polymorphic arguments represent the specification of the parametric
 
    /// types of a polymorphic type: they specify the value of the polymorphic
 
    /// type's polymorphic variables.
 
    fn consume_polymorphic_args(&mut self, h: &mut Heap, allow_inference: bool) -> Result<Option<Vec<ParserTypeId>>, ParseError2> {
 
    fn consume_polymorphic_args(&mut self, h: &mut Heap, allow_inference: bool) -> Result<Option<Vec<ParserTypeId>>, ParseError> {
 
        self.consume_comma_separated(
 
            h, b'<', b'>', "Expected the end of the polymorphic argument list",
 
            |lexer, heap| lexer.consume_type2(heap, allow_inference)
 
            |lexer, heap| lexer.consume_type(heap, allow_inference)
 
        )
 
    }
 

	
 
    /// Consumes polymorphic variables. These are identifiers that are used
 
    /// within polymorphic types. The input position may be at whitespace. If
 
    /// polymorphic variables are present then the whitespace, wrapping
 
    /// delimiters and the polymorphic variables are consumed. Otherwise the
 
    /// input position will stay where it is. If no polymorphic variables are
 
    /// present then an empty vector will be returned.
 
    fn consume_polymorphic_vars(&mut self, h: &mut Heap) -> Result<Vec<Identifier>, ParseError2> {
 
    fn consume_polymorphic_vars(&mut self, h: &mut Heap) -> Result<Vec<Identifier>, ParseError> {
 
        let backup_pos = self.source.pos();
 
        match self.consume_comma_separated(
 
            h, b'<', b'>', "Expected the end of the polymorphic variable list",
 
            |lexer, _heap| lexer.consume_identifier()
 
        )? {
 
            Some(poly_vars) => Ok(poly_vars),
 
            None => {
 
                self.source.seek(backup_pos);
 
                Ok(vec!())
 
            }
 
        }
 
    }
 

	
 
    // Parameters
 

	
 
    fn consume_parameter(&mut self, h: &mut Heap) -> Result<ParameterId, ParseError2> {
 
        let parser_type = self.consume_type2(h, false)?;
 
    fn consume_parameter(&mut self, h: &mut Heap) -> Result<ParameterId, ParseError> {
 
        let parser_type = self.consume_type(h, false)?;
 
        self.consume_whitespace(true)?;
 
        let position = self.source.pos();
 
        let identifier = self.consume_identifier()?;
 
        let id =
 
            h.alloc_parameter(|this| Parameter { this, position, parser_type, identifier });
 
        Ok(id)
 
    }
 
    fn consume_parameters(&mut self, h: &mut Heap) -> Result<Vec<ParameterId>, ParseError2> {
 
    fn consume_parameters(&mut self, h: &mut Heap) -> Result<Vec<ParameterId>, ParseError> {
 
        match self.consume_comma_separated(
 
            h, b'(', b')', "Expected the end of the parameter list",
 
            |lexer, heap| lexer.consume_parameter(heap)
 
        )? {
 
            Some(params) => Ok(params),
 
            None => {
 
                Err(ParseError2::new_error(
 
                Err(ParseError::new_error(
 
                    &self.source, self.source.pos(),
 
                    "Expected a parameter list"
 
                ))
 
            }
 
        }
 
    }
 

	
 
    // ====================
 
    // Expressions
 
    // ====================
 

	
 
    fn consume_paren_expression(&mut self, h: &mut Heap) -> Result<ExpressionId, ParseError2> {
 
    fn consume_paren_expression(&mut self, h: &mut Heap) -> Result<ExpressionId, ParseError> {
 
        self.consume_string(b"(")?;
 
        self.consume_whitespace(false)?;
 
        let result = self.consume_expression(h)?;
 
        self.consume_whitespace(false)?;
 
        self.consume_string(b")")?;
 
        Ok(result)
 
    }
 
    fn consume_expression(&mut self, h: &mut Heap) -> Result<ExpressionId, ParseError2> {
 
    fn consume_expression(&mut self, h: &mut Heap) -> Result<ExpressionId, ParseError> {
 
        if self.level >= MAX_LEVEL {
 
            return Err(self.error_at_pos("Too deeply nested expression"));
 
        }
 
        self.level += 1;
 
        let result = self.consume_assignment_expression(h);
 
        self.level -= 1;
 
        result
 
    }
 
    fn consume_assignment_expression(&mut self, h: &mut Heap) -> Result<ExpressionId, ParseError2> {
 
    fn consume_assignment_expression(&mut self, h: &mut Heap) -> Result<ExpressionId, ParseError> {
 
        let result = self.consume_conditional_expression(h)?;
 
        self.consume_whitespace(false)?;
 
        if self.has_assignment_operator() {
 
            let position = self.source.pos();
 
            let left = result;
 
            let operation = self.consume_assignment_operator()?;
 
            self.consume_whitespace(false)?;
 
            let right = self.consume_expression(h)?;
 
            Ok(h.alloc_assignment_expression(|this| AssignmentExpression {
 
                this,
 
                position,
 
                left,
 
                operation,
 
                right,
 
                parent: ExpressionParent::None,
 
                concrete_type: ConcreteType::default(),
 
            })
 
            .upcast())
 
        } else {
 
            Ok(result)
 
        }
 
    }
 
    fn has_assignment_operator(&self) -> bool {
 
        self.has_string(b"=")
 
            || self.has_string(b"*=")
 
            || self.has_string(b"/=")
 
            || self.has_string(b"%=")
 
            || self.has_string(b"+=")
 
            || self.has_string(b"-=")
 
            || self.has_string(b"<<=")
 
            || self.has_string(b">>=")
 
            || self.has_string(b"&=")
 
            || self.has_string(b"^=")
 
            || self.has_string(b"|=")
 
    }
 
    fn consume_assignment_operator(&mut self) -> Result<AssignmentOperator, ParseError2> {
 
    fn consume_assignment_operator(&mut self) -> Result<AssignmentOperator, ParseError> {
 
        if self.has_string(b"=") {
 
            self.consume_string(b"=")?;
 
            Ok(AssignmentOperator::Set)
 
        } else if self.has_string(b"*=") {
 
            self.consume_string(b"*=")?;
 
            Ok(AssignmentOperator::Multiplied)
 
        } else if self.has_string(b"/=") {
 
            self.consume_string(b"/=")?;
 
            Ok(AssignmentOperator::Divided)
 
        } else if self.has_string(b"%=") {
 
            self.consume_string(b"%=")?;
 
            Ok(AssignmentOperator::Remained)
 
        } else if self.has_string(b"+=") {
 
            self.consume_string(b"+=")?;
 
            Ok(AssignmentOperator::Added)
 
        } else if self.has_string(b"-=") {
 
            self.consume_string(b"-=")?;
 
            Ok(AssignmentOperator::Subtracted)
 
        } else if self.has_string(b"<<=") {
 
            self.consume_string(b"<<=")?;
 
            Ok(AssignmentOperator::ShiftedLeft)
 
        } else if self.has_string(b">>=") {
 
            self.consume_string(b">>=")?;
 
            Ok(AssignmentOperator::ShiftedRight)
 
        } else if self.has_string(b"&=") {
 
            self.consume_string(b"&=")?;
 
            Ok(AssignmentOperator::BitwiseAnded)
 
        } else if self.has_string(b"^=") {
 
            self.consume_string(b"^=")?;
 
            Ok(AssignmentOperator::BitwiseXored)
 
        } else if self.has_string(b"|=") {
 
            self.consume_string(b"|=")?;
 
            Ok(AssignmentOperator::BitwiseOred)
 
        } else {
 
            Err(self.error_at_pos("Expected assignment operator"))
 
        }
 
    }
 
    fn consume_conditional_expression(&mut self, h: &mut Heap) -> Result<ExpressionId, ParseError2> {
 
    fn consume_conditional_expression(&mut self, h: &mut Heap) -> Result<ExpressionId, ParseError> {
 
        let result = self.consume_concat_expression(h)?;
 
        self.consume_whitespace(false)?;
 
        if self.has_string(b"?") {
 
            let position = self.source.pos();
 
            let test = result;
 
            self.consume_string(b"?")?;
 
            self.consume_whitespace(false)?;
 
            let true_expression = self.consume_expression(h)?;
 
            self.consume_whitespace(false)?;
 
            self.consume_string(b":")?;
 
            self.consume_whitespace(false)?;
 
            let false_expression = self.consume_expression(h)?;
 
            Ok(h.alloc_conditional_expression(|this| ConditionalExpression {
 
                this,
 
                position,
 
                test,
 
                true_expression,
 
                false_expression,
 
                parent: ExpressionParent::None,
 
                concrete_type: ConcreteType::default(),
 
            })
 
            .upcast())
 
        } else {
 
            Ok(result)
 
        }
 
    }
 
    fn consume_concat_expression(&mut self, h: &mut Heap) -> Result<ExpressionId, ParseError2> {
 
    fn consume_concat_expression(&mut self, h: &mut Heap) -> Result<ExpressionId, ParseError> {
 
        let mut result = self.consume_lor_expression(h)?;
 
        self.consume_whitespace(false)?;
 
        while self.has_string(b"@") {
 
            let position = self.source.pos();
 
            let left = result;
 
            self.consume_string(b"@")?;
 
            let operation = BinaryOperator::Concatenate;
 
            self.consume_whitespace(false)?;
 
            let right = self.consume_lor_expression(h)?;
 
            self.consume_whitespace(false)?;
 
            result = h
 
                .alloc_binary_expression(|this| BinaryExpression {
 
                    this,
 
                    position,
 
                    left,
 
                    operation,
 
                    right,
 
                    parent: ExpressionParent::None,
 
                    concrete_type: ConcreteType::default(),
 
                })
 
                .upcast();
 
        }
 
        Ok(result)
 
    }
 
    fn consume_lor_expression(&mut self, h: &mut Heap) -> Result<ExpressionId, ParseError2> {
 
    fn consume_lor_expression(&mut self, h: &mut Heap) -> Result<ExpressionId, ParseError> {
 
        let mut result = self.consume_land_expression(h)?;
 
        self.consume_whitespace(false)?;
 
        while self.has_string(b"||") {
 
            let position = self.source.pos();
 
            let left = result;
 
            self.consume_string(b"||")?;
 
            let operation = BinaryOperator::LogicalOr;
 
            self.consume_whitespace(false)?;
 
            let right = self.consume_land_expression(h)?;
 
            self.consume_whitespace(false)?;
 
            result = h
 
                .alloc_binary_expression(|this| BinaryExpression {
 
                    this,
 
                    position,
 
                    left,
 
                    operation,
 
                    right,
 
                    parent: ExpressionParent::None,
 
                    concrete_type: ConcreteType::default(),
 
                })
 
                .upcast();
 
        }
 
        Ok(result)
 
    }
 
    fn consume_land_expression(&mut self, h: &mut Heap) -> Result<ExpressionId, ParseError2> {
 
    fn consume_land_expression(&mut self, h: &mut Heap) -> Result<ExpressionId, ParseError> {
 
        let mut result = self.consume_bor_expression(h)?;
 
        self.consume_whitespace(false)?;
 
        while self.has_string(b"&&") {
 
            let position = self.source.pos();
 
            let left = result;
 
            self.consume_string(b"&&")?;
 
            let operation = BinaryOperator::LogicalAnd;
 
            self.consume_whitespace(false)?;
 
            let right = self.consume_bor_expression(h)?;
 
            self.consume_whitespace(false)?;
 
            result = h
 
                .alloc_binary_expression(|this| BinaryExpression {
 
                    this,
 
                    position,
 
                    left,
 
                    operation,
 
                    right,
 
                    parent: ExpressionParent::None,
 
                    concrete_type: ConcreteType::default(),
 
                })
 
                .upcast();
 
        }
 
        Ok(result)
 
    }
 
    fn consume_bor_expression(&mut self, h: &mut Heap) -> Result<ExpressionId, ParseError2> {
 
    fn consume_bor_expression(&mut self, h: &mut Heap) -> Result<ExpressionId, ParseError> {
 
        let mut result = self.consume_xor_expression(h)?;
 
        self.consume_whitespace(false)?;
 
        while self.has_string(b"|") && !self.has_string(b"||") && !self.has_string(b"|=") {
 
            let position = self.source.pos();
 
            let left = result;
 
            self.consume_string(b"|")?;
 
            let operation = BinaryOperator::BitwiseOr;
 
            self.consume_whitespace(false)?;
 
            let right = self.consume_xor_expression(h)?;
 
            self.consume_whitespace(false)?;
 
            result = h
 
                .alloc_binary_expression(|this| BinaryExpression {
 
                    this,
 
                    position,
 
                    left,
 
                    operation,
 
                    right,
 
                    parent: ExpressionParent::None,
 
                    concrete_type: ConcreteType::default(),
 
                })
 
                .upcast();
 
        }
 
        Ok(result)
 
    }
 
    fn consume_xor_expression(&mut self, h: &mut Heap) -> Result<ExpressionId, ParseError2> {
 
    fn consume_xor_expression(&mut self, h: &mut Heap) -> Result<ExpressionId, ParseError> {
 
        let mut result = self.consume_band_expression(h)?;
 
        self.consume_whitespace(false)?;
 
        while self.has_string(b"^") && !self.has_string(b"^=") {
 
            let position = self.source.pos();
 
            let left = result;
 
            self.consume_string(b"^")?;
 
            let operation = BinaryOperator::BitwiseXor;
 
            self.consume_whitespace(false)?;
 
            let right = self.consume_band_expression(h)?;
 
            self.consume_whitespace(false)?;
 
            result = h
 
                .alloc_binary_expression(|this| BinaryExpression {
 
                    this,
 
                    position,
 
                    left,
 
                    operation,
 
                    right,
 
                    parent: ExpressionParent::None,
 
                    concrete_type: ConcreteType::default(),
 
                })
 
                .upcast();
 
        }
 
        Ok(result)
 
    }
 
    fn consume_band_expression(&mut self, h: &mut Heap) -> Result<ExpressionId, ParseError2> {
 
    fn consume_band_expression(&mut self, h: &mut Heap) -> Result<ExpressionId, ParseError> {
 
        let mut result = self.consume_eq_expression(h)?;
 
        self.consume_whitespace(false)?;
 
        while self.has_string(b"&") && !self.has_string(b"&&") && !self.has_string(b"&=") {
 
            let position = self.source.pos();
 
            let left = result;
 
            self.consume_string(b"&")?;
 
            let operation = BinaryOperator::BitwiseAnd;
 
            self.consume_whitespace(false)?;
 
            let right = self.consume_eq_expression(h)?;
 
            self.consume_whitespace(false)?;
 
            result = h
 
                .alloc_binary_expression(|this| BinaryExpression {
 
                    this,
 
                    position,
 
                    left,
 
                    operation,
 
                    right,
 
                    parent: ExpressionParent::None,
 
                    concrete_type: ConcreteType::default(),
 
                })
 
                .upcast();
 
        }
 
        Ok(result)
 
    }
 
    fn consume_eq_expression(&mut self, h: &mut Heap) -> Result<ExpressionId, ParseError2> {
 
    fn consume_eq_expression(&mut self, h: &mut Heap) -> Result<ExpressionId, ParseError> {
 
        let mut result = self.consume_rel_expression(h)?;
 
        self.consume_whitespace(false)?;
 
        while self.has_string(b"==") || self.has_string(b"!=") {
 
            let position = self.source.pos();
 
            let left = result;
 
            let operation;
 
            if self.has_string(b"==") {
 
                self.consume_string(b"==")?;
 
                operation = BinaryOperator::Equality;
 
            } else {
 
                self.consume_string(b"!=")?;
 
                operation = BinaryOperator::Inequality;
 
            }
 
            self.consume_whitespace(false)?;
 
            let right = self.consume_rel_expression(h)?;
 
            self.consume_whitespace(false)?;
 
            result = h
 
                .alloc_binary_expression(|this| BinaryExpression {
 
                    this,
 
                    position,
 
                    left,
 
                    operation,
 
                    right,
 
                    parent: ExpressionParent::None,
 
                    concrete_type: ConcreteType::default(),
 
                })
 
                .upcast();
 
        }
 
        Ok(result)
 
    }
 
    fn consume_rel_expression(&mut self, h: &mut Heap) -> Result<ExpressionId, ParseError2> {
 
    fn consume_rel_expression(&mut self, h: &mut Heap) -> Result<ExpressionId, ParseError> {
 
        let mut result = self.consume_shift_expression(h)?;
 
        self.consume_whitespace(false)?;
 
        while self.has_string(b"<=")
 
            || self.has_string(b">=")
 
            || self.has_string(b"<") && !self.has_string(b"<<=")
 
            || self.has_string(b">") && !self.has_string(b">>=")
 
        {
 
            let position = self.source.pos();
 
            let left = result;
 
            let operation;
 
            if self.has_string(b"<=") {
 
                self.consume_string(b"<=")?;
 
                operation = BinaryOperator::LessThanEqual;
 
            } else if self.has_string(b">=") {
 
                self.consume_string(b">=")?;
 
                operation = BinaryOperator::GreaterThanEqual;
 
            } else if self.has_string(b"<") {
 
                self.consume_string(b"<")?;
 
                operation = BinaryOperator::LessThan;
 
            } else {
 
                self.consume_string(b">")?;
 
                operation = BinaryOperator::GreaterThan;
 
            }
 
            self.consume_whitespace(false)?;
 
            let right = self.consume_shift_expression(h)?;
 
            self.consume_whitespace(false)?;
 
            result = h
 
                .alloc_binary_expression(|this| BinaryExpression {
 
                    this,
 
                    position,
 
                    left,
 
                    operation,
 
                    right,
 
                    parent: ExpressionParent::None,
 
                    concrete_type: ConcreteType::default(),
 
                })
 
                .upcast();
 
        }
 
        Ok(result)
 
    }
 
    fn consume_shift_expression(&mut self, h: &mut Heap) -> Result<ExpressionId, ParseError2> {
 
    fn consume_shift_expression(&mut self, h: &mut Heap) -> Result<ExpressionId, ParseError> {
 
        let mut result = self.consume_add_expression(h)?;
 
        self.consume_whitespace(false)?;
 
        while self.has_string(b"<<") && !self.has_string(b"<<=")
 
            || self.has_string(b">>") && !self.has_string(b">>=")
 
        {
 
            let position = self.source.pos();
 
            let left = result;
 
            let operation;
 
            if self.has_string(b"<<") {
 
                self.consume_string(b"<<")?;
 
                operation = BinaryOperator::ShiftLeft;
 
            } else {
 
                self.consume_string(b">>")?;
 
                operation = BinaryOperator::ShiftRight;
 
            }
 
            self.consume_whitespace(false)?;
 
            let right = self.consume_add_expression(h)?;
 
            self.consume_whitespace(false)?;
 
            result = h
 
                .alloc_binary_expression(|this| BinaryExpression {
 
                    this,
 
                    position,
 
                    left,
 
                    operation,
 
                    right,
 
                    parent: ExpressionParent::None,
 
                    concrete_type: ConcreteType::default(),
 
                })
 
                .upcast();
 
        }
 
        Ok(result)
 
    }
 
    fn consume_add_expression(&mut self, h: &mut Heap) -> Result<ExpressionId, ParseError2> {
 
    fn consume_add_expression(&mut self, h: &mut Heap) -> Result<ExpressionId, ParseError> {
 
        let mut result = self.consume_mul_expression(h)?;
 
        self.consume_whitespace(false)?;
 
        while self.has_string(b"+") && !self.has_string(b"+=")
 
            || self.has_string(b"-") && !self.has_string(b"-=")
 
        {
 
            let position = self.source.pos();
 
            let left = result;
 
            let operation;
 
            if self.has_string(b"+") {
 
                self.consume_string(b"+")?;
 
                operation = BinaryOperator::Add;
 
            } else {
 
                self.consume_string(b"-")?;
 
                operation = BinaryOperator::Subtract;
 
            }
 
            self.consume_whitespace(false)?;
 
            let right = self.consume_mul_expression(h)?;
 
            self.consume_whitespace(false)?;
 
            result = h
 
                .alloc_binary_expression(|this| BinaryExpression {
 
                    this,
 
                    position,
 
                    left,
 
                    operation,
 
                    right,
 
                    parent: ExpressionParent::None,
 
                    concrete_type: ConcreteType::default(),
 
                })
 
                .upcast();
 
        }
 
        Ok(result)
 
    }
 
    fn consume_mul_expression(&mut self, h: &mut Heap) -> Result<ExpressionId, ParseError2> {
 
    fn consume_mul_expression(&mut self, h: &mut Heap) -> Result<ExpressionId, ParseError> {
 
        let mut result = self.consume_prefix_expression(h)?;
 
        self.consume_whitespace(false)?;
 
        while self.has_string(b"*") && !self.has_string(b"*=")
 
            || self.has_string(b"/") && !self.has_string(b"/=")
 
            || self.has_string(b"%") && !self.has_string(b"%=")
 
        {
 
            let position = self.source.pos();
 
            let left = result;
 
            let operation;
 
            if self.has_string(b"*") {
 
                self.consume_string(b"*")?;
 
                operation = BinaryOperator::Multiply;
 
            } else if self.has_string(b"/") {
 
                self.consume_string(b"/")?;
 
                operation = BinaryOperator::Divide;
 
            } else {
 
                self.consume_string(b"%")?;
 
                operation = BinaryOperator::Remainder;
 
            }
 
            self.consume_whitespace(false)?;
 
            let right = self.consume_prefix_expression(h)?;
 
            self.consume_whitespace(false)?;
 
            result = h
 
                .alloc_binary_expression(|this| BinaryExpression {
 
                    this,
 
                    position,
 
                    left,
 
                    operation,
 
                    right,
 
                    parent: ExpressionParent::None,
 
                    concrete_type: ConcreteType::default(),
 
                })
 
                .upcast();
 
        }
 
        Ok(result)
 
    }
 
    fn consume_prefix_expression(&mut self, h: &mut Heap) -> Result<ExpressionId, ParseError2> {
 
    fn consume_prefix_expression(&mut self, h: &mut Heap) -> Result<ExpressionId, ParseError> {
 
        if self.has_string(b"+")
 
            || self.has_string(b"-")
 
            || self.has_string(b"~")
 
            || self.has_string(b"!")
 
        {
 
            let position = self.source.pos();
 
            let operation;
 
            if self.has_string(b"+") {
 
                self.consume_string(b"+")?;
 
                if self.has_string(b"+") {
 
                    self.consume_string(b"+")?;
 
                    operation = UnaryOperation::PreIncrement;
 
                } else {
 
                    operation = UnaryOperation::Positive;
 
                }
 
            } else if self.has_string(b"-") {
 
                self.consume_string(b"-")?;
 
                if self.has_string(b"-") {
 
                    self.consume_string(b"-")?;
 
                    operation = UnaryOperation::PreDecrement;
 
                } else {
 
                    operation = UnaryOperation::Negative;
 
                }
 
            } else if self.has_string(b"~") {
 
                self.consume_string(b"~")?;
 
                operation = UnaryOperation::BitwiseNot;
 
            } else {
 
                self.consume_string(b"!")?;
 
                operation = UnaryOperation::LogicalNot;
 
            }
 
            self.consume_whitespace(false)?;
 
            if self.level >= MAX_LEVEL {
 
                return Err(self.error_at_pos("Too deeply nested expression"));
 
            }
 
            self.level += 1;
 
            let result = self.consume_prefix_expression(h);
 
            self.level -= 1;
 
            let expression = result?;
 
            return Ok(h
 
                .alloc_unary_expression(|this| UnaryExpression {
 
                    this,
 
                    position,
 
                    operation,
 
                    expression,
 
                    parent: ExpressionParent::None,
 
                    concrete_type: ConcreteType::default(),
 
                })
 
                .upcast());
 
        }
 
        self.consume_postfix_expression(h)
 
    }
 
    fn consume_postfix_expression(&mut self, h: &mut Heap) -> Result<ExpressionId, ParseError2> {
 
    fn consume_postfix_expression(&mut self, h: &mut Heap) -> Result<ExpressionId, ParseError> {
 
        let mut result = self.consume_primary_expression(h)?;
 
        self.consume_whitespace(false)?;
 
        while self.has_string(b"++")
 
            || self.has_string(b"--")
 
            || self.has_string(b"[")
 
            || (self.has_string(b".") && !self.has_string(b".."))
 
        {
 
            let mut position = self.source.pos();
 
            if self.has_string(b"++") {
 
                self.consume_string(b"++")?;
 
                let operation = UnaryOperation::PostIncrement;
 
                let expression = result;
 
                self.consume_whitespace(false)?;
 
                result = h
 
                    .alloc_unary_expression(|this| UnaryExpression {
 
                        this,
 
                        position,
 
                        operation,
 
                        expression,
 
                        parent: ExpressionParent::None,
 
                        concrete_type: ConcreteType::default(),
 
                    })
 
                    .upcast();
 
            } else if self.has_string(b"--") {
 
                self.consume_string(b"--")?;
 
                let operation = UnaryOperation::PostDecrement;
 
                let expression = result;
 
                self.consume_whitespace(false)?;
 
                result = h
 
                    .alloc_unary_expression(|this| UnaryExpression {
 
                        this,
 
                        position,
 
                        operation,
 
                        expression,
 
                        parent: ExpressionParent::None,
 
                        concrete_type: ConcreteType::default(),
 
                    })
 
                    .upcast();
 
            } else if self.has_string(b"[") {
 
                self.consume_string(b"[")?;
 
                self.consume_whitespace(false)?;
 
                let subject = result;
 
                let index = self.consume_expression(h)?;
 
                self.consume_whitespace(false)?;
 
                if self.has_string(b"..") || self.has_string(b":") {
 
                    position = self.source.pos();
 
                    if self.has_string(b"..") {
 
                        self.consume_string(b"..")?;
 
                    } else {
 
                        self.consume_string(b":")?;
 
                    }
 
                    self.consume_whitespace(false)?;
 
                    let to_index = self.consume_expression(h)?;
 
                    self.consume_whitespace(false)?;
 
                    result = h
 
                        .alloc_slicing_expression(|this| SlicingExpression {
 
                            this,
 
                            position,
 
                            subject,
 
                            from_index: index,
 
                            to_index,
 
                            parent: ExpressionParent::None,
 
                            concrete_type: ConcreteType::default(),
 
                        })
 
                        .upcast();
 
                } else {
 
                    result = h
 
                        .alloc_indexing_expression(|this| IndexingExpression {
 
                            this,
 
                            position,
 
                            subject,
 
                            index,
 
                            parent: ExpressionParent::None,
 
                            concrete_type: ConcreteType::default(),
 
                        })
 
                        .upcast();
 
                }
 
                self.consume_string(b"]")?;
 
                self.consume_whitespace(false)?;
 
            } else {
 
                assert!(self.has_string(b"."));
 
                self.consume_string(b".")?;
 
                self.consume_whitespace(false)?;
 
                let subject = result;
 
                let field;
 
                if self.has_keyword(b"length") {
 
                    self.consume_keyword(b"length")?;
 
                    field = Field::Length;
 
                } else {
 
                    let identifier = self.consume_identifier()?;
 
                    field = Field::Symbolic(FieldSymbolic{
 
                        identifier,
 
                        definition: None,
 
                        field_idx: 0,
 
                    });
 
                }
 
                result = h
 
                    .alloc_select_expression(|this| SelectExpression {
 
                        this,
 
                        position,
 
                        subject,
 
                        field,
 
                        parent: ExpressionParent::None,
 
                        concrete_type: ConcreteType::default(),
 
                    })
 
                    .upcast();
 
            }
 
        }
 
        Ok(result)
 
    }
 
    fn consume_primary_expression(&mut self, h: &mut Heap) -> Result<ExpressionId, ParseError2> {
 
    fn consume_primary_expression(&mut self, h: &mut Heap) -> Result<ExpressionId, ParseError> {
 
        if self.has_string(b"(") {
 
            return self.consume_paren_expression(h);
 
        }
 
        if self.has_string(b"{") {
 
            return Ok(self.consume_array_expression(h)?.upcast());
 
        }
 
        if self.has_builtin_literal() {
 
            return Ok(self.consume_builtin_literal_expression(h)?.upcast());
 
        }
 
        if self.has_struct_literal() {
 
            return Ok(self.consume_struct_literal_expression(h)?.upcast());
 
        }
 
        if self.has_call_expression() {
 
            return Ok(self.consume_call_expression(h)?.upcast());
 
        }
 
        Ok(self.consume_variable_expression(h)?.upcast())
 
    }
 
    fn consume_array_expression(&mut self, h: &mut Heap) -> Result<ArrayExpressionId, ParseError2> {
 
    fn consume_array_expression(&mut self, h: &mut Heap) -> Result<ArrayExpressionId, ParseError> {
 
        let position = self.source.pos();
 
        let mut elements = Vec::new();
 
        self.consume_string(b"{")?;
 
        self.consume_whitespace(false)?;
 
        if !self.has_string(b"}") {
 
            while self.source.next().is_some() {
 
                elements.push(self.consume_expression(h)?);
 
                self.consume_whitespace(false)?;
 
                if self.has_string(b"}") {
 
                    break;
 
                }
 
                self.consume_string(b",")?;
 
                self.consume_whitespace(false)?;
 
            }
 
        }
 
        self.consume_string(b"}")?;
 
        Ok(h.alloc_array_expression(|this| ArrayExpression {
 
            this,
 
            position,
 
            elements,
 
            parent: ExpressionParent::None,
 
            concrete_type: ConcreteType::default(),
 
        }))
 
    }
 
    fn has_builtin_literal(&self) -> bool {
 
        is_constant(self.source.next())
 
            || self.has_keyword(b"null")
 
            || self.has_keyword(b"true")
 
            || self.has_keyword(b"false")
 
    }
 
    fn consume_builtin_literal_expression(
 
        &mut self,
 
        h: &mut Heap,
 
    ) -> Result<LiteralExpressionId, ParseError2> {
 
    ) -> Result<LiteralExpressionId, ParseError> {
 
        let position = self.source.pos();
 
        let value;
 
        if self.has_keyword(b"null") {
 
            self.consume_keyword(b"null")?;
 
            value = Literal::Null;
 
        } else if self.has_keyword(b"true") {
 
            self.consume_keyword(b"true")?;
 
            value = Literal::True;
 
        } else if self.has_keyword(b"false") {
 
            self.consume_keyword(b"false")?;
 
            value = Literal::False;
 
        } else if self.source.next() == Some(b'\'') {
 
            self.source.consume();
 
            let mut data = Vec::new();
 
            let mut next = self.source.next();
 
            while next != Some(b'\'') && (is_vchar(next) || next == Some(b' ')) {
 
                data.push(next.unwrap());
 
                self.source.consume();
 
                next = self.source.next();
 
            }
 
            if next != Some(b'\'') || data.is_empty() {
 
                return Err(self.error_at_pos("Expected character constant"));
 
            }
 
            self.source.consume();
 
            value = Literal::Character(data);
 
        } else {
 
            if !self.has_integer() {
 
                return Err(self.error_at_pos("Expected integer constant"));
 
            }
 

	
 
            value = Literal::Integer(self.consume_integer()?);
 
        }
 
        Ok(h.alloc_literal_expression(|this| LiteralExpression {
 
            this,
 
            position,
 
            value,
 
            parent: ExpressionParent::None,
 
            concrete_type: ConcreteType::default(),
 
        }))
 
    }
 

	
 
    fn has_struct_literal(&mut self) -> bool {
 
        // A struct literal is written as:
 
        //      namespace::StructName<maybe_one_of_these, auto>{ field: expr }
 
        // We will parse up until the opening brace to see if we're dealing with
 
        // a struct literal.
 
        let backup_pos = self.source.pos();
 
        let result = self.consume_namespaced_identifier_spilled().is_ok() &&
 
            self.consume_whitespace(false).is_ok() &&
 
            self.source.next() == Some(b'{');
 

	
 
        self.source.seek(backup_pos);
 
        return result;
 
    }
 

	
 
    fn consume_struct_literal_expression(&mut self, h: &mut Heap) -> Result<LiteralExpressionId, ParseError2> {
 
    fn consume_struct_literal_expression(&mut self, h: &mut Heap) -> Result<LiteralExpressionId, ParseError> {
 
        // Consume identifier and polymorphic arguments
 
        debug_log!("consume_struct_literal_expression: {}", debug_line!(self.source));
 
        let position = self.source.pos();
 
        let identifier = self.consume_namespaced_identifier(h)?;
 
        self.consume_whitespace(false)?;
 

	
 
        // Consume fields
 
        let fields = match self.consume_comma_separated(
 
            h, b'{', b'}', "Expected the end of the list of struct fields",
 
            |lexer, heap| {
 
                let identifier = lexer.consume_identifier()?;
 
                lexer.consume_whitespace(false)?;
 
                lexer.consume_string(b":")?;
 
                lexer.consume_whitespace(false)?;
 
                let value = lexer.consume_expression(heap)?;
 

	
 
                Ok(LiteralStructField{ identifier, value, field_idx: 0 })
 
            }
 
        )? {
 
            Some(fields) => fields,
 
            None => return Err(ParseError2::new_error(
 
            None => return Err(ParseError::new_error(
 
                self.source, self.source.pos(),
 
                "A struct literal must be followed by its field values"
 
            ))
 
        };
 

	
 
        Ok(h.alloc_literal_expression(|this| LiteralExpression{
 
            this,
 
            position,
 
            value: Literal::Struct(LiteralStruct{
 
                identifier,
 
                fields,
 
                poly_args2: Vec::new(),
 
                definition: None,
 
            }),
 
            parent: ExpressionParent::None,
 
            concrete_type: Default::default()
 
        }))
 
    }
 

	
 
    fn has_call_expression(&mut self) -> bool {
 
        // We need to prevent ambiguity with various operators (because we may
 
        // be specifying polymorphic variables) and variables.
 
        if self.has_builtin_keyword() {
 
            return true;
 
        }
 

	
 
        let backup_pos = self.source.pos();
 
        let mut result = false;
 

	
 
        if self.consume_namespaced_identifier_spilled().is_ok() &&
 
            self.consume_whitespace(false).is_ok() &&
 
            self.source.next() == Some(b'(') {
 
            // Seems like we have a function call or an enum literal
 
            result = true;
 
        }
 

	
 
        self.source.seek(backup_pos);
 
        return result;
 
    }
 
    fn consume_call_expression(&mut self, h: &mut Heap) -> Result<CallExpressionId, ParseError2> {
 
    fn consume_call_expression(&mut self, h: &mut Heap) -> Result<CallExpressionId, ParseError> {
 
        let position = self.source.pos();
 

	
 
        // Consume method identifier
 
        // TODO: @token Replace this conditional polymorphic arg parsing once we have a tokenizer.
 
        debug_log!("consume_call_expression: {}", debug_line!(self.source));
 
        let method;
 
        let mut consume_poly_args_explicitly = true;
 
        if self.has_keyword(b"get") {
 
            self.consume_keyword(b"get")?;
 
            method = Method::Get;
 
        } else if self.has_keyword(b"put") {
 
            self.consume_keyword(b"put")?;
 
            method = Method::Put;
 
        } else if self.has_keyword(b"fires") {
 
            self.consume_keyword(b"fires")?;
 
            method = Method::Fires;
 
        } else if self.has_keyword(b"create") {
 
            self.consume_keyword(b"create")?;
 
            method = Method::Create;
 
        } else {
 
            let identifier = self.consume_namespaced_identifier(h)?;
 
            method = Method::Symbolic(MethodSymbolic{
 
                identifier,
 
                definition: None
 
            });
 
            consume_poly_args_explicitly = false;
 
        };
 

	
 
        // Consume polymorphic arguments
 
        let poly_args = if consume_poly_args_explicitly {
 
            self.consume_whitespace(false)?;
 
            self.consume_polymorphic_args(h, true)?.unwrap_or_default()
 
        } else {
 
            Vec::new()
 
        };
 

	
 
        // Consume arguments to call
 
        self.consume_whitespace(false)?;
 
        let mut arguments = Vec::new();
 
        self.consume_string(b"(")?;
 
        self.consume_whitespace(false)?;
 
        if !self.has_string(b")") {
 
            // TODO: allow trailing comma
 
            while self.source.next().is_some() {
 
                arguments.push(self.consume_expression(h)?);
 
                self.consume_whitespace(false)?;
 
                if self.has_string(b")") {
 
                    break;
 
                }
 
                self.consume_string(b",")?;
 
                self.consume_whitespace(false)?
 
            }
 
        }
 
        self.consume_string(b")")?;
 
        Ok(h.alloc_call_expression(|this| CallExpression {
 
            this,
 
            position,
 
            method,
 
            arguments,
 
            poly_args,
 
            parent: ExpressionParent::None,
 
            concrete_type: ConcreteType::default(),
 
        }))
 
    }
 
    fn consume_variable_expression(
 
        &mut self,
 
        h: &mut Heap,
 
    ) -> Result<VariableExpressionId, ParseError2> {
 
    ) -> Result<VariableExpressionId, ParseError> {
 
        let position = self.source.pos();
 
        debug_log!("consume_variable_expression: {}", debug_line!(self.source));
 

	
 
        // TODO: @token Reimplement when tokenizer is implemented, prevent ambiguities
 
        let identifier = identifier_as_namespaced(self.consume_identifier()?);
 

	
 
        Ok(h.alloc_variable_expression(|this| VariableExpression {
 
            this,
 
            position,
 
            identifier,
 
            declaration: None,
 
            parent: ExpressionParent::None,
 
            concrete_type: ConcreteType::default(),
 
        }))
 
    }
 

	
 
    // ====================
 
    // Statements
 
    // ====================
 

	
 
    /// Consumes any kind of statement from the source and will error if it
 
    /// did not encounter a statement. Will also return an error if the
 
    /// statement is nested too deeply.
 
    ///
 
    /// `wrap_in_block` may be set to true to ensure that the parsed statement
 
    /// will be wrapped in a block statement if it is not already a block
 
    /// statement. This is used to ensure that all `if`, `while` and `sync`
 
    /// statements have a block statement as body.
 
    fn consume_statement(&mut self, h: &mut Heap, wrap_in_block: bool) -> Result<StatementId, ParseError2> {
 
    fn consume_statement(&mut self, h: &mut Heap, wrap_in_block: bool) -> Result<StatementId, ParseError> {
 
        if self.level >= MAX_LEVEL {
 
            return Err(self.error_at_pos("Too deeply nested statement"));
 
        }
 
        self.level += 1;
 
        let result = self.consume_statement_impl(h, wrap_in_block);
 
        self.level -= 1;
 
        result
 
    }
 
    fn has_label(&mut self) -> bool {
 
        // To prevent ambiguity with expression statements consisting only of an
 
        // identifier or a namespaced identifier, we look ahead and match on the
 
        // *single* colon that signals a labeled statement.
 
        let backup_pos = self.source.pos();
 
        let mut result = false;
 
        if self.consume_identifier_spilled().is_ok() {
 
            // next character is ':', second character is NOT ':'
 
            result = Some(b':') == self.source.next() && Some(b':') != self.source.lookahead(1)
 
        }
 
        self.source.seek(backup_pos);
 
        return result;
 
    }
 
    fn consume_statement_impl(&mut self, h: &mut Heap, wrap_in_block: bool) -> Result<StatementId, ParseError2> {
 
    fn consume_statement_impl(&mut self, h: &mut Heap, wrap_in_block: bool) -> Result<StatementId, ParseError> {
 
        // Parse and allocate statement
 
        let mut must_wrap = true;
 
        let mut stmt_id = if self.has_string(b"{") {
 
            must_wrap = false;
 
            self.consume_block_statement(h)?
 
        } else if self.has_keyword(b"skip") {
 
            must_wrap = false;
 
            self.consume_skip_statement(h)?.upcast()
 
        } else if self.has_keyword(b"if") {
 
            self.consume_if_statement(h)?.upcast()
 
        } else if self.has_keyword(b"while") {
 
            self.consume_while_statement(h)?.upcast()
 
        } else if self.has_keyword(b"break") {
 
            self.consume_break_statement(h)?.upcast()
 
        } else if self.has_keyword(b"continue") {
 
            self.consume_continue_statement(h)?.upcast()
 
        } else if self.has_keyword(b"synchronous") {
 
            self.consume_synchronous_statement(h)?.upcast()
 
        } else if self.has_keyword(b"return") {
 
            self.consume_return_statement(h)?.upcast()
 
        } else if self.has_keyword(b"assert") {
 
            self.consume_assert_statement(h)?.upcast()
 
        } else if self.has_keyword(b"goto") {
 
            self.consume_goto_statement(h)?.upcast()
 
        } else if self.has_keyword(b"new") {
 
            self.consume_new_statement(h)?.upcast()
 
        } else if self.has_label() {
 
            self.consume_labeled_statement(h)?.upcast()
 
        } else {
 
            self.consume_expression_statement(h)?.upcast()
 
        };
 

	
 
        // Wrap if desired and if needed
 
        if must_wrap && wrap_in_block {
 
            let position = h[stmt_id].position();
 
            let block_wrapper = h.alloc_block_statement(|this| BlockStatement{
 
                this,
 
                position,
 
                statements: vec![stmt_id],
 
                parent_scope: None,
 
                relative_pos_in_parent: 0,
 
                locals: Vec::new(),
 
                labels: Vec::new()
 
            });
 

	
 
            stmt_id = block_wrapper.upcast();
 
        }
 

	
 
        Ok(stmt_id)
 
    }
 
    fn has_local_statement(&mut self) -> bool {
 
        /* To avoid ambiguity, we look ahead to find either the
 
        channel keyword that signals a variable declaration, or
 
        a type annotation followed by another identifier.
 
        Example:
 
          my_type[] x = {5}; // memory statement
 
          my_var[5] = x; // assignment expression, expression statement
 
        Note how both the local and the assignment
 
        start with arbitrary identifier followed by [. */
 
        if self.has_keyword(b"channel") {
 
            return true;
 
        }
 
        if self.has_statement_keyword() {
 
            return false;
 
        }
 
        let backup_pos = self.source.pos();
 
        let mut result = false;
 
        if self.maybe_consume_type_spilled_without_pos_recovery() {
 
            // We seem to have a valid type, do we now have an identifier?
 
            if self.consume_whitespace(true).is_ok() {
 
                result = self.has_identifier();
 
            }
 
        }
 

	
 
        self.source.seek(backup_pos);
 
        return result;
 
    }
 
    fn consume_block_statement(&mut self, h: &mut Heap) -> Result<StatementId, ParseError2> {
 
    fn consume_block_statement(&mut self, h: &mut Heap) -> Result<StatementId, ParseError> {
 
        let position = self.source.pos();
 
        let mut statements = Vec::new();
 
        self.consume_string(b"{")?;
 
        self.consume_whitespace(false)?;
 
        while self.has_local_statement() {
 
            let (local_id, stmt_id) = self.consume_local_statement(h)?;
 
            statements.push(local_id.upcast());
 
            if let Some(stmt_id) = stmt_id {
 
                statements.push(stmt_id.upcast());
 
            }
 
            self.consume_whitespace(false)?;
 
        }
 
        while !self.has_string(b"}") {
 
            statements.push(self.consume_statement(h, false)?);
 
            self.consume_whitespace(false)?;
 
        }
 
        self.consume_string(b"}")?;
 
        if statements.is_empty() {
 
            Ok(h.alloc_skip_statement(|this| SkipStatement { this, position, next: None }).upcast())
 
        } else {
 
            Ok(h.alloc_block_statement(|this| BlockStatement {
 
                this,
 
                position,
 
                statements,
 
                parent_scope: None,
 
                relative_pos_in_parent: 0,
 
                locals: Vec::new(),
 
                labels: Vec::new(),
 
            })
 
            .upcast())
 
        }
 
    }
 
    fn consume_local_statement(&mut self, h: &mut Heap) -> Result<(LocalStatementId, Option<ExpressionStatementId>), ParseError2> {
 
    fn consume_local_statement(&mut self, h: &mut Heap) -> Result<(LocalStatementId, Option<ExpressionStatementId>), ParseError> {
 
        if self.has_keyword(b"channel") {
 
            let local_id = self.consume_channel_statement(h)?.upcast();
 
            Ok((local_id, None))
 
        } else {
 
            let (memory_id, stmt_id) = self.consume_memory_statement(h)?;
 
            Ok((memory_id.upcast(), Some(stmt_id)))
 
        }
 
    }
 
    fn consume_channel_statement(
 
        &mut self,
 
        h: &mut Heap,
 
    ) -> Result<ChannelStatementId, ParseError2> {
 
    ) -> Result<ChannelStatementId, ParseError> {
 
        // Consume channel statement and polymorphic argument if specified.
 
        // Needs a tiny bit of special parsing to ensure the right amount of
 
        // whitespace is present.
 
        let position = self.source.pos();
 
        self.consume_keyword(b"channel")?;
 

	
 
        let expect_whitespace = self.source.next() != Some(b'<');
 
        self.consume_whitespace(expect_whitespace)?;
 
        let poly_args = self.consume_polymorphic_args(h, true)?.unwrap_or_default();
 
        let poly_arg_id = match poly_args.len() {
 
            0 => h.alloc_parser_type(|this| ParserType{
 
                this, pos: position.clone(), variant: ParserTypeVariant::Inferred,
 
            }),
 
            1 => poly_args[0],
 
            _ => return Err(ParseError2::new_error(
 
            _ => return Err(ParseError::new_error(
 
                &self.source, self.source.pos(),
 
                "port construction using 'channel' accepts up to 1 polymorphic argument"
 
            ))
 
        };
 
        self.consume_whitespace(false)?;
 

	
 
        // Consume the output port
 
        let out_parser_type = h.alloc_parser_type(|this| ParserType{
 
            this, pos: position.clone(), variant: ParserTypeVariant::Output(poly_arg_id)
 
        });
 
        let out_identifier = self.consume_identifier()?;
 

	
 
        // Consume the "->" syntax
 
        self.consume_whitespace(false)?;
 
        self.consume_string(b"->")?;
 
        self.consume_whitespace(false)?;
 

	
 
        // Consume the input port
 
        let in_parser_type = h.alloc_parser_type(|this| ParserType{
 
            this, pos: position.clone(), variant: ParserTypeVariant::Input(poly_arg_id)
 
        });
 
        let in_identifier = self.consume_identifier()?;
 
        self.consume_whitespace(false)?;
 
        self.consume_string(b";")?;
 
        let out_port = h.alloc_local(|this| Local {
 
            this,
 
            position,
 
            parser_type: out_parser_type,
 
            identifier: out_identifier,
 
            relative_pos_in_block: 0
 
        });
 
        let in_port = h.alloc_local(|this| Local {
 
            this,
 
            position,
 
            parser_type: in_parser_type,
 
            identifier: in_identifier,
 
            relative_pos_in_block: 0
 
        });
 
        Ok(h.alloc_channel_statement(|this| ChannelStatement {
 
            this,
 
            position,
 
            from: out_port,
 
            to: in_port,
 
            relative_pos_in_block: 0,
 
            next: None,
 
        }))
 
    }
 
    fn consume_memory_statement(&mut self, h: &mut Heap) -> Result<(MemoryStatementId, ExpressionStatementId), ParseError2> {
 
    fn consume_memory_statement(&mut self, h: &mut Heap) -> Result<(MemoryStatementId, ExpressionStatementId), ParseError> {
 
        let position = self.source.pos();
 
        let parser_type = self.consume_type2(h, true)?;
 
        let parser_type = self.consume_type(h, true)?;
 
        self.consume_whitespace(true)?;
 
        let identifier = self.consume_identifier()?;
 
        self.consume_whitespace(false)?;
 
        let assignment_position = self.source.pos();
 
        self.consume_string(b"=")?;
 
        self.consume_whitespace(false)?;
 
        let initial = self.consume_expression(h)?;
 
        let variable = h.alloc_local(|this| Local {
 
            this,
 
            position,
 
            parser_type,
 
            identifier: identifier.clone(),
 
            relative_pos_in_block: 0
 
        });
 
        self.consume_whitespace(false)?;
 
        self.consume_string(b";")?;
 

	
 
        // Transform into the variable declaration, followed by an assignment
 
        let memory_stmt_id = h.alloc_memory_statement(|this| MemoryStatement {
 
            this,
 
            position,
 
            variable,
 
            next: None,
 
        });
 
        let variable_expr_id = h.alloc_variable_expression(|this| VariableExpression{
 
            this,
 
            position: identifier.position.clone(),
 
            identifier: identifier_as_namespaced(identifier),
 
            declaration: None,
 
            parent: ExpressionParent::None,
 
            concrete_type: Default::default()
 
        });
 
        let assignment_expr_id = h.alloc_assignment_expression(|this| AssignmentExpression{
 
            this,
 
            position: assignment_position,
 
            left: variable_expr_id.upcast(),
 
            operation: AssignmentOperator::Set,
 
            right: initial,
 
            parent: ExpressionParent::None,
 
            concrete_type: Default::default()
 
        });
 
        let assignment_stmt_id = h.alloc_expression_statement(|this| ExpressionStatement{
 
            this,
 
            position,
 
            expression: assignment_expr_id.upcast(),
 
            next: None
 
        });
 
        Ok((memory_stmt_id, assignment_stmt_id))
 
    }
 
    fn consume_labeled_statement(
 
        &mut self,
 
        h: &mut Heap,
 
    ) -> Result<LabeledStatementId, ParseError2> {
 
    ) -> Result<LabeledStatementId, ParseError> {
 
        let position = self.source.pos();
 
        let label = self.consume_identifier()?;
 
        self.consume_whitespace(false)?;
 
        self.consume_string(b":")?;
 
        self.consume_whitespace(false)?;
 
        let body = self.consume_statement(h, false)?;
 
        Ok(h.alloc_labeled_statement(|this| LabeledStatement {
 
            this,
 
            position,
 
            label,
 
            body,
 
            relative_pos_in_block: 0,
 
            in_sync: None,
 
        }))
 
    }
 
    fn consume_skip_statement(&mut self, h: &mut Heap) -> Result<SkipStatementId, ParseError2> {
 
    fn consume_skip_statement(&mut self, h: &mut Heap) -> Result<SkipStatementId, ParseError> {
 
        let position = self.source.pos();
 
        self.consume_keyword(b"skip")?;
 
        self.consume_whitespace(false)?;
 
        self.consume_string(b";")?;
 
        Ok(h.alloc_skip_statement(|this| SkipStatement { this, position, next: None }))
 
    }
 
    fn consume_if_statement(&mut self, h: &mut Heap) -> Result<IfStatementId, ParseError2> {
 
    fn consume_if_statement(&mut self, h: &mut Heap) -> Result<IfStatementId, ParseError> {
 
        let position = self.source.pos();
 
        self.consume_keyword(b"if")?;
 
        self.consume_whitespace(false)?;
 
        let test = self.consume_paren_expression(h)?;
 
        self.consume_whitespace(false)?;
 
        let true_body = self.consume_statement(h, true)?;
 
        self.consume_whitespace(false)?;
 
        let false_body = if self.has_keyword(b"else") {
 
            self.consume_keyword(b"else")?;
 
            self.consume_whitespace(false)?;
 
            self.consume_statement(h, true)?
 
        } else {
 
            h.alloc_skip_statement(|this| SkipStatement { this, position, next: None }).upcast()
 
        };
 
        Ok(h.alloc_if_statement(|this| IfStatement { this, position, test, true_body, false_body, end_if: None }))
 
    }
 
    fn consume_while_statement(&mut self, h: &mut Heap) -> Result<WhileStatementId, ParseError2> {
 
    fn consume_while_statement(&mut self, h: &mut Heap) -> Result<WhileStatementId, ParseError> {
 
        let position = self.source.pos();
 
        self.consume_keyword(b"while")?;
 
        self.consume_whitespace(false)?;
 
        let test = self.consume_paren_expression(h)?;
 
        self.consume_whitespace(false)?;
 
        let body = self.consume_statement(h, true)?;
 
        Ok(h.alloc_while_statement(|this| WhileStatement {
 
            this,
 
            position,
 
            test,
 
            body,
 
            end_while: None,
 
            in_sync: None,
 
        }))
 
    }
 
    fn consume_break_statement(&mut self, h: &mut Heap) -> Result<BreakStatementId, ParseError2> {
 
    fn consume_break_statement(&mut self, h: &mut Heap) -> Result<BreakStatementId, ParseError> {
 
        let position = self.source.pos();
 
        self.consume_keyword(b"break")?;
 
        self.consume_whitespace(false)?;
 
        let label;
 
        if self.has_identifier() {
 
            label = Some(self.consume_identifier()?);
 
            self.consume_whitespace(false)?;
 
        } else {
 
            label = None;
 
        }
 
        self.consume_string(b";")?;
 
        Ok(h.alloc_break_statement(|this| BreakStatement { this, position, label, target: None }))
 
    }
 
    fn consume_continue_statement(
 
        &mut self,
 
        h: &mut Heap,
 
    ) -> Result<ContinueStatementId, ParseError2> {
 
    ) -> Result<ContinueStatementId, ParseError> {
 
        let position = self.source.pos();
 
        self.consume_keyword(b"continue")?;
 
        self.consume_whitespace(false)?;
 
        let label;
 
        if self.has_identifier() {
 
            label = Some(self.consume_identifier()?);
 
            self.consume_whitespace(false)?;
 
        } else {
 
            label = None;
 
        }
 
        self.consume_string(b";")?;
 
        Ok(h.alloc_continue_statement(|this| ContinueStatement {
 
            this,
 
            position,
 
            label,
 
            target: None,
 
        }))
 
    }
 
    fn consume_synchronous_statement(
 
        &mut self,
 
        h: &mut Heap,
 
    ) -> Result<SynchronousStatementId, ParseError2> {
 
    ) -> Result<SynchronousStatementId, ParseError> {
 
        let position = self.source.pos();
 
        self.consume_keyword(b"synchronous")?;
 
        self.consume_whitespace(false)?;
 
        // TODO: What was the purpose of this? Seems superfluous and confusing?
 
        // let mut parameters = Vec::new();
 
        // if self.has_string(b"(") {
 
        //     self.consume_parameters(h, &mut parameters)?;
 
        //     self.consume_whitespace(false)?;
 
        // } else if !self.has_keyword(b"skip") && !self.has_string(b"{") {
 
        //     return Err(self.error_at_pos("Expected block statement"));
 
        // }
 
        let body = self.consume_statement(h, true)?;
 
        Ok(h.alloc_synchronous_statement(|this| SynchronousStatement {
 
            this,
 
            position,
 
            body,
 
            end_sync: None,
 
            parent_scope: None,
 
        }))
 
    }
 
    fn consume_return_statement(&mut self, h: &mut Heap) -> Result<ReturnStatementId, ParseError2> {
 
    fn consume_return_statement(&mut self, h: &mut Heap) -> Result<ReturnStatementId, ParseError> {
 
        let position = self.source.pos();
 
        self.consume_keyword(b"return")?;
 
        self.consume_whitespace(false)?;
 
        let expression = if self.has_string(b"(") {
 
            self.consume_paren_expression(h)
 
        } else {
 
            self.consume_expression(h)
 
        }?;
 
        self.consume_whitespace(false)?;
 
        self.consume_string(b";")?;
 
        Ok(h.alloc_return_statement(|this| ReturnStatement { this, position, expression }))
 
    }
 
    fn consume_assert_statement(&mut self, h: &mut Heap) -> Result<AssertStatementId, ParseError2> {
 
    fn consume_assert_statement(&mut self, h: &mut Heap) -> Result<AssertStatementId, ParseError> {
 
        let position = self.source.pos();
 
        self.consume_keyword(b"assert")?;
 
        self.consume_whitespace(false)?;
 
        let expression = if self.has_string(b"(") {
 
            self.consume_paren_expression(h)
 
        } else {
 
            self.consume_expression(h)
 
        }?;
 
        self.consume_whitespace(false)?;
 
        self.consume_string(b";")?;
 
        Ok(h.alloc_assert_statement(|this| AssertStatement {
 
            this,
 
            position,
 
            expression,
 
            next: None,
 
        }))
 
    }
 
    fn consume_goto_statement(&mut self, h: &mut Heap) -> Result<GotoStatementId, ParseError2> {
 
    fn consume_goto_statement(&mut self, h: &mut Heap) -> Result<GotoStatementId, ParseError> {
 
        let position = self.source.pos();
 
        self.consume_keyword(b"goto")?;
 
        self.consume_whitespace(false)?;
 
        let label = self.consume_identifier()?;
 
        self.consume_whitespace(false)?;
 
        self.consume_string(b";")?;
 
        Ok(h.alloc_goto_statement(|this| GotoStatement { this, position, label, target: None }))
 
    }
 
    fn consume_new_statement(&mut self, h: &mut Heap) -> Result<NewStatementId, ParseError2> {
 
    fn consume_new_statement(&mut self, h: &mut Heap) -> Result<NewStatementId, ParseError> {
 
        let position = self.source.pos();
 
        self.consume_keyword(b"new")?;
 
        self.consume_whitespace(false)?;
 
        let expression = self.consume_call_expression(h)?;
 
        self.consume_whitespace(false)?;
 
        self.consume_string(b";")?;
 
        Ok(h.alloc_new_statement(|this| NewStatement { this, position, expression, next: None }))
 
    }
 
    fn consume_expression_statement(
 
        &mut self,
 
        h: &mut Heap,
 
    ) -> Result<ExpressionStatementId, ParseError2> {
 
    ) -> Result<ExpressionStatementId, ParseError> {
 
        let position = self.source.pos();
 
        let expression = self.consume_expression(h)?;
 
        self.consume_whitespace(false)?;
 
        self.consume_string(b";")?;
 
        Ok(h.alloc_expression_statement(|this| ExpressionStatement {
 
            this,
 
            position,
 
            expression,
 
            next: None,
 
        }))
 
    }
 

	
 
    // ====================
 
    // Symbol definitions
 
    // ====================
 

	
 
    fn has_symbol_definition(&self) -> bool {
 
        self.has_keyword(b"composite")
 
            || self.has_keyword(b"primitive")
 
            || self.has_type_keyword()
 
            || self.has_identifier()
 
    }
 
    fn consume_symbol_definition(&mut self, h: &mut Heap) -> Result<DefinitionId, ParseError2> {
 
    fn consume_symbol_definition(&mut self, h: &mut Heap) -> Result<DefinitionId, ParseError> {
 
        if self.has_keyword(b"struct") {
 
            Ok(self.consume_struct_definition(h)?.upcast())
 
        } else if self.has_keyword(b"enum") {
 
            Ok(self.consume_enum_definition(h)?.upcast())
 
        } else if self.has_keyword(b"composite") || self.has_keyword(b"primitive") {
 
            Ok(self.consume_component_definition(h)?.upcast())
 
        } else {
 
            Ok(self.consume_function_definition(h)?.upcast())
 
        }
 
    }
 
    fn consume_struct_definition(&mut self, h: &mut Heap) -> Result<StructId, ParseError2> {
 
    fn consume_struct_definition(&mut self, h: &mut Heap) -> Result<StructId, ParseError> {
 
        // Parse "struct" keyword, optional polyvars and its identifier
 
        let struct_pos = self.source.pos();
 
        self.consume_keyword(b"struct")?;
 
        self.consume_whitespace(true)?;
 
        let struct_ident = self.consume_identifier()?;
 
        self.consume_whitespace(false)?;
 
        let poly_vars = self.consume_polymorphic_vars(h)?;
 
        self.consume_whitespace(false)?;
 

	
 
        // Parse struct fields
 
        let fields = match self.consume_comma_separated(
 
            h, b'{', b'}', "Expected the end of the list of struct fields",
 
            |lexer, heap| {
 
                let position = lexer.source.pos();
 
                let parser_type = lexer.consume_type2(heap, false)?;
 
                let parser_type = lexer.consume_type(heap, false)?;
 
                lexer.consume_whitespace(true)?;
 
                let field = lexer.consume_identifier()?;
 

	
 
                Ok(StructFieldDefinition{ position, field, parser_type })
 
            }
 
        )? {
 
            Some(fields) => fields,
 
            None => return Err(ParseError2::new_error(
 
            None => return Err(ParseError::new_error(
 
                self.source, struct_pos,
 
                "An struct definition must be followed by its fields"
 
            )),
 
        };
 

	
 
        // Valid struct definition
 
        Ok(h.alloc_struct_definition(|this| StructDefinition{
 
            this,
 
            position: struct_pos,
 
            identifier: struct_ident,
 
            poly_vars,
 
            fields,
 
        }))
 
    }
 
    fn consume_enum_definition(&mut self, h: &mut Heap) -> Result<EnumId, ParseError2> {
 
    fn consume_enum_definition(&mut self, h: &mut Heap) -> Result<EnumId, ParseError> {
 
        // Parse "enum" keyword, optional polyvars and its identifier
 
        let enum_pos = self.source.pos();
 
        self.consume_keyword(b"enum")?;
 
        self.consume_whitespace(true)?;
 
        let enum_ident = self.consume_identifier()?;
 
        self.consume_whitespace(false)?;
 
        let poly_vars = self.consume_polymorphic_vars(h)?;
 
        self.consume_whitespace(false)?;
 

	
 
        let variants = match self.consume_comma_separated(
 
            h, b'{', b'}', "Expected end of enum variant list",
 
            |lexer, heap| {
 
                // Variant identifier
 
                let position = lexer.source.pos();
 
                let identifier = lexer.consume_identifier()?;
 
                lexer.consume_whitespace(false)?;
 

	
 
                // Optional variant value/type
 
                let next = lexer.source.next();
 
                let value = match next {
 
                    Some(b',') => {
 
                        // Do not consume, let `consume_comma_separated` handle
 
                        // the next item
 
                        EnumVariantValue::None
 
                    },
 
                    Some(b'=') => {
 
                        // Integer value
 
                        lexer.source.consume();
 
                        lexer.consume_whitespace(false)?;
 
                        if !lexer.has_integer() {
 
                            return Err(lexer.error_at_pos("expected integer"))
 
                        }
 
                        let value = lexer.consume_integer()?;
 
                        EnumVariantValue::Integer(value)
 
                    },
 
                    Some(b'(') => {
 
                        // Embedded type
 
                        lexer.source.consume();
 
                        lexer.consume_whitespace(false)?;
 
                        let embedded_type = lexer.consume_type2(heap, false)?;
 
                        let embedded_type = lexer.consume_type(heap, false)?;
 
                        lexer.consume_whitespace(false)?;
 
                        lexer.consume_string(b")")?;
 
                        EnumVariantValue::Type(embedded_type)
 
                    },
 
                    _ => {
 
                        return Err(lexer.error_at_pos("Expected ',', '=', or '('"));
 
                    }
 
                };
 

	
 
                Ok(EnumVariantDefinition{ position, identifier, value })
 
            }
 
        )? {
 
            Some(variants) => variants,
 
            None => return Err(ParseError2::new_error(
 
            None => return Err(ParseError::new_error(
 
                self.source, enum_pos,
 
                "An enum definition must be followed by its variants"
 
            )),
 
        };
 

	
 
        Ok(h.alloc_enum_definition(|this| EnumDefinition{
 
            this,
 
            position: enum_pos,
 
            identifier: enum_ident,
 
            poly_vars,
 
            variants,
 
        }))
 
    }
 
    fn consume_component_definition(&mut self, h: &mut Heap) -> Result<ComponentId, ParseError2> {
 
    fn consume_component_definition(&mut self, h: &mut Heap) -> Result<ComponentId, ParseError> {
 
        // TODO: Cleanup
 
        if self.has_keyword(b"composite") {
 
            Ok(self.consume_composite_definition(h)?)
 
        } else {
 
            Ok(self.consume_primitive_definition(h)?)
 
        }
 
    }
 
    fn consume_composite_definition(&mut self, h: &mut Heap) -> Result<ComponentId, ParseError2> {
 
    fn consume_composite_definition(&mut self, h: &mut Heap) -> Result<ComponentId, ParseError> {
 
        // Parse keyword, optional polyvars and the identifier
 
        let position = self.source.pos();
 
        self.consume_keyword(b"composite")?;
 
        self.consume_whitespace(true)?;
 
        let identifier = self.consume_identifier()?;
 
        self.consume_whitespace(false)?;
 
        let poly_vars = self.consume_polymorphic_vars(h)?;
 
        self.consume_whitespace(false)?;
 

	
 
        // Consume parameters
 
        let parameters = self.consume_parameters(h)?;
 
        self.consume_whitespace(false)?;
 

	
 
        // Parse body
 
        let body = self.consume_block_statement(h)?;
 
        Ok(h.alloc_component(|this| Component { 
 
            this,
 
            variant: ComponentVariant::Composite,
 
            position,
 
            identifier,
 
            poly_vars,
 
            parameters,
 
            body
 
        }))
 
    }
 
    fn consume_primitive_definition(&mut self, h: &mut Heap) -> Result<ComponentId, ParseError2> {
 
    fn consume_primitive_definition(&mut self, h: &mut Heap) -> Result<ComponentId, ParseError> {
 
        // Consume keyword, optional polyvars and identifier
 
        let position = self.source.pos();
 
        self.consume_keyword(b"primitive")?;
 
        self.consume_whitespace(true)?;
 
        let identifier = self.consume_identifier()?;
 
        self.consume_whitespace(false)?;
 
        let poly_vars = self.consume_polymorphic_vars(h)?;
 
        self.consume_whitespace(false)?;
 

	
 
        // Consume parameters
 
        let parameters = self.consume_parameters(h)?;
 
        self.consume_whitespace(false)?;
 

	
 
        // Consume body
 
        let body = self.consume_block_statement(h)?;
 
        Ok(h.alloc_component(|this| Component { 
 
            this,
 
            variant: ComponentVariant::Primitive,
 
            position,
 
            identifier,
 
            poly_vars,
 
            parameters,
 
            body
 
        }))
 
    }
 
    fn consume_function_definition(&mut self, h: &mut Heap) -> Result<FunctionId, ParseError2> {
 
    fn consume_function_definition(&mut self, h: &mut Heap) -> Result<FunctionId, ParseError> {
 
        // Consume return type, optional polyvars and identifier
 
        let position = self.source.pos();
 
        let return_type = self.consume_type2(h, false)?;
 
        let return_type = self.consume_type(h, false)?;
 
        self.consume_whitespace(true)?;
 
        let identifier = self.consume_identifier()?;
 
        self.consume_whitespace(false)?;
 
        let poly_vars = self.consume_polymorphic_vars(h)?;
 
        self.consume_whitespace(false)?;
 

	
 
        // Consume parameters
 
        let parameters = self.consume_parameters(h)?;
 
        self.consume_whitespace(false)?;
 

	
 
        // Consume body
 
        let body = self.consume_block_statement(h)?;
 
        Ok(h.alloc_function(|this| Function {
 
            this,
 
            position,
 
            return_type,
 
            identifier,
 
            poly_vars,
 
            parameters,
 
            body,
 
        }))
 
    }
 
    fn has_pragma(&self) -> bool {
 
        if let Some(c) = self.source.next() {
 
            c == b'#'
 
        } else {
 
            false
 
        }
 
    }
 
    fn consume_pragma(&mut self, h: &mut Heap) -> Result<PragmaId, ParseError2> {
 
    fn consume_pragma(&mut self, h: &mut Heap) -> Result<PragmaId, ParseError> {
 
        let position = self.source.pos();
 
        let next = self.source.next();
 
        if next != Some(b'#') {
 
            return Err(self.error_at_pos("Expected pragma"));
 
        }
 
        self.source.consume();
 
        if !is_vchar(self.source.next()) {
 
            return Err(self.error_at_pos("Expected pragma"));
 
        }
 
        if self.has_string(b"version") {
 
            self.consume_string(b"version")?;
 
            self.consume_whitespace(true)?;
 
            if !self.has_integer() {
 
                return Err(self.error_at_pos("Expected integer constant"));
 
            }
 
            let version = self.consume_integer()?;
 
            debug_assert!(version >= 0);
 
            return Ok(h.alloc_pragma(|this| Pragma::Version(PragmaVersion{
 
                this, position, version: version as u64
 
            })))
 
        } else if self.has_string(b"module") {
 
            self.consume_string(b"module")?;
 
            self.consume_whitespace(true)?;
 
            if !self.has_identifier() {
 
                return Err(self.error_at_pos("Expected identifier"));
 
            }
 
            let mut value = Vec::new();
 
            let mut ident = self.consume_ident()?;
 
            value.append(&mut ident);
 
            while self.has_string(b".") {
 
                self.consume_string(b".")?;
 
                value.push(b'.');
 
                ident = self.consume_ident()?;
 
                value.append(&mut ident);
 
            }
 
            return Ok(h.alloc_pragma(|this| Pragma::Module(PragmaModule{
 
                this, position, value
 
            })));
 
        } else {
 
            return Err(self.error_at_pos("Unknown pragma"));
 
        }
 
    }
 

	
 
    fn has_import(&self) -> bool {
 
        self.has_keyword(b"import")
 
    }
 
    fn consume_import(&mut self, h: &mut Heap) -> Result<ImportId, ParseError2> {
 
    fn consume_import(&mut self, h: &mut Heap) -> Result<ImportId, ParseError> {
 
        // Parse the word "import" and the name of the module
 
        let position = self.source.pos();
 
        self.consume_keyword(b"import")?;
 
        self.consume_whitespace(true)?;
 
        let mut value = Vec::new();
 
        let mut last_ident_pos = self.source.pos();
 
        let mut ident = self.consume_ident()?;
 
        value.append(&mut ident);
 
        let mut last_ident_start = 0;
 

	
 
        while self.has_string(b".") {
 
            self.consume_string(b".")?;
 
            value.push(b'.');
 
            last_ident_pos = self.source.pos();
 
            ident = self.consume_ident()?;
 
            last_ident_start = value.len();
 
            value.append(&mut ident);
 
        }
 

	
 

	
 
        self.consume_whitespace(false)?;
 

	
 
        // Check for the potential aliasing or specific module imports
 
        let import = if self.has_string(b"as") {
 
            self.consume_string(b"as")?;
 
            self.consume_whitespace(true)?;
 
            let alias = self.consume_identifier()?;
 

	
 
            h.alloc_import(|this| Import::Module(ImportModule{
 
                this,
 
                position,
 
                module_name: value,
 
                alias,
 
                module_id: None,
 
            }))
 
        } else if self.has_string(b"::") {
 
            self.consume_string(b"::")?;
 
            self.consume_whitespace(false)?;
 

	
 
            let next = self.source.next();
 
            if Some(b'{') == next {
 
                let symbols = match self.consume_comma_separated(
 
                    h, b'{', b'}', "Expected end of import list",
 
                    |lexer, _heap| {
 
                        // Symbol name
 
                        let position = lexer.source.pos();
 
                        let name = lexer.consume_identifier()?;
 
                        lexer.consume_whitespace(false)?;
 

	
 
                        // Symbol alias
 
                        if lexer.has_string(b"as") {
 
                            // With alias
 
                            lexer.consume_string(b"as")?;
 
                            lexer.consume_whitespace(true)?;
 
                            let alias = lexer.consume_identifier()?;
 

	
 
                            Ok(AliasedSymbol{
 
                                position,
 
                                name,
 
                                alias,
 
                                definition_id: None
 
                            })
 
                        } else {
 
                            // Without alias
 
                            Ok(AliasedSymbol{
 
                                position,
 
                                name: name.clone(),
 
                                alias: name,
 
                                definition_id: None
 
                            })
 
                        }
 
                    }
 
                )? {
 
                    Some(symbols) => symbols,
 
                    None => unreachable!(), // because we checked for opening '{'
 
                };
 

	
 
                h.alloc_import(|this| Import::Symbols(ImportSymbols{
 
                    this,
 
                    position,
 
                    module_name: value,
 
                    module_id: None,
 
                    symbols,
 
                }))
 
            } else if Some(b'*') == next {
 
                self.source.consume();
 
                h.alloc_import(|this| Import::Symbols(ImportSymbols{
 
                    this,
 
                    position,
 
                    module_name: value,
 
                    module_id: None,
 
                    symbols: Vec::new()
 
                }))
 
            } else if self.has_identifier() {
 
                let position = self.source.pos();
 
                let name = self.consume_identifier()?;
 
                self.consume_whitespace(false)?;
 
                let alias = if self.has_string(b"as") {
 
                    self.consume_string(b"as")?;
 
                    self.consume_whitespace(true)?;
 
                    self.consume_identifier()?
 
                } else {
 
                    name.clone()
 
                };
 

	
 
                h.alloc_import(|this| Import::Symbols(ImportSymbols{
 
                    this,
 
                    position,
 
                    module_name: value,
 
                    module_id: None,
 
                    symbols: vec![AliasedSymbol{
 
                        position,
 
                        name,
 
                        alias,
 
                        definition_id: None
 
                    }]
 
                }))
 
            } else {
 
                return Err(self.error_at_pos("Expected '*', '{' or a symbol name"));
 
            }
 
        } else {
 
            // No explicit alias or subimports, so implicit alias
 
            let alias_value = Vec::from(&value[last_ident_start..]);
 
            h.alloc_import(|this| Import::Module(ImportModule{
 
                this,
 
                position,
 
                module_name: value,
 
                alias: Identifier{
 
                    position: last_ident_pos,
 
                    value: Vec::from(alias_value),
 
                },
 
                module_id: None,
 
            }))
 
        };
 

	
 
        self.consume_whitespace(false)?;
 
        self.consume_string(b";")?;
 
        Ok(import)
 
    }
 
    pub fn consume_protocol_description(&mut self, h: &mut Heap) -> Result<RootId, ParseError2> {
 
    pub fn consume_protocol_description(&mut self, h: &mut Heap) -> Result<RootId, ParseError> {
 
        let position = self.source.pos();
 
        let mut pragmas = Vec::new();
 
        let mut imports = Vec::new();
 
        let mut definitions = Vec::new();
 
        self.consume_whitespace(false)?;
 
        while self.has_pragma() {
 
            let pragma = self.consume_pragma(h)?;
 
            pragmas.push(pragma);
 
            self.consume_whitespace(false)?;
 
        }
 
        while self.has_import() {
 
            let import = self.consume_import(h)?;
 
            imports.push(import);
 
            self.consume_whitespace(false)?;
 
        }
 
        while self.has_symbol_definition() {
 
            let def = self.consume_symbol_definition(h)?;
 
            definitions.push(def);
 
            self.consume_whitespace(false)?;
 
        }
 
        // end of file
 
        if !self.source.is_eof() {
 
            return Err(self.error_at_pos("Expected end of file"));
 
        }
 
        Ok(h.alloc_protocol_description(|this| Root {
 
            this,
 
            position,
 
            pragmas,
 
            imports,
 
            definitions,
 
        }))
 
    }
 
}
src/protocol/parser/mod.rs
Show inline comments
 
mod depth_visitor;
 
pub(crate) mod symbol_table;
 
pub(crate) mod type_table;
 
mod type_resolver;
 
mod visitor;
 
mod visitor_linker;
 
mod utils;
 

	
 
use depth_visitor::*;
 
use symbol_table::SymbolTable;
 
use visitor::Visitor2;
 
use visitor_linker::ValidityAndLinkerVisitor;
 
use type_resolver::{TypeResolvingVisitor, ResolveQueue};
 
use type_table::{TypeTable, TypeCtx};
 

	
 
use crate::protocol::ast::*;
 
use crate::protocol::inputsource::*;
 
use crate::protocol::lexer::*;
 

	
 
use std::collections::HashMap;
 
use crate::protocol::ast_printer::ASTWriter;
 

	
 
// TODO: @fixme, pub qualifier
 
pub(crate) struct LexedModule {
 
    pub(crate) source: InputSource,
 
    module_name: Vec<u8>,
 
    version: Option<u64>,
 
    pub(crate) root_id: RootId,
 
}
 

	
 
pub struct Parser {
 
    pub(crate) heap: Heap,
 
    pub(crate) modules: Vec<LexedModule>,
 
    pub(crate) module_lookup: HashMap<Vec<u8>, usize>, // from (optional) module name to `modules` idx
 
    pub(crate) symbol_table: SymbolTable,
 
    pub(crate) type_table: TypeTable,
 
}
 

	
 
impl Parser {
 
    pub fn new() -> Self {
 
        Parser{
 
            heap: Heap::new(),
 
            modules: Vec::new(),
 
            module_lookup: HashMap::new(),
 
            symbol_table: SymbolTable::new(),
 
            type_table: TypeTable::new(),
 
        }
 
    }
 

	
 
    pub fn feed(&mut self, mut source: InputSource) -> Result<RootId, ParseError2> {
 
    pub fn feed(&mut self, mut source: InputSource) -> Result<RootId, ParseError> {
 
        // Lex the input source
 
        let mut lex = Lexer::new(&mut source);
 
        let pd = lex.consume_protocol_description(&mut self.heap)?;
 

	
 
        // Seek the module name and version
 
        let root = &self.heap[pd];
 
        let mut module_name_pos = InputPosition::default();
 
        let mut module_name = Vec::new();
 
        let mut module_version_pos = InputPosition::default();
 
        let mut module_version = None;
 

	
 
        for pragma in &root.pragmas {
 
            match &self.heap[*pragma] {
 
                Pragma::Module(module) => {
 
                    if !module_name.is_empty() {
 
                        return Err(
 
                            ParseError2::new_error(&source, module.position, "Double definition of module name in the same file")
 
                            ParseError::new_error(&source, module.position, "Double definition of module name in the same file")
 
                                .with_postfixed_info(&source, module_name_pos, "Previous definition was here")
 
                        )
 
                    }
 

	
 
                    module_name_pos = module.position.clone();
 
                    module_name = module.value.clone();
 
                },
 
                Pragma::Version(version) => {
 
                    if module_version.is_some() {
 
                        return Err(
 
                            ParseError2::new_error(&source, version.position, "Double definition of module version")
 
                            ParseError::new_error(&source, version.position, "Double definition of module version")
 
                                .with_postfixed_info(&source, module_version_pos, "Previous definition was here")
 
                        )
 
                    }
 

	
 
                    module_version_pos = version.position.clone();
 
                    module_version = Some(version.version);
 
                },
 
            }
 
        }
 

	
 
        // Add module to list of modules and prevent naming conflicts
 
        let cur_module_idx = self.modules.len();
 
        if let Some(prev_module_idx) = self.module_lookup.get(&module_name) {
 
            // Find `#module` statement in other module again
 
            let prev_module = &self.modules[*prev_module_idx];
 
            let prev_module_pos = self.heap[prev_module.root_id].pragmas
 
                .iter()
 
                .find_map(|p| {
 
                    match &self.heap[*p] {
 
                        Pragma::Module(module) => Some(module.position.clone()),
 
                        _ => None
 
                    }
 
                })
 
                .unwrap_or(InputPosition::default());
 

	
 
            let module_name_msg = if module_name.is_empty() {
 
                format!("a nameless module")
 
            } else {
 
                format!("module '{}'", String::from_utf8_lossy(&module_name))
 
            };
 

	
 
            return Err(
 
                ParseError2::new_error(&source, module_name_pos, &format!("Double definition of {} across files", module_name_msg))
 
                ParseError::new_error(&source, module_name_pos, &format!("Double definition of {} across files", module_name_msg))
 
                    .with_postfixed_info(&prev_module.source, prev_module_pos, "Other definition was here")
 
            );
 
        }
 

	
 
        self.modules.push(LexedModule{
 
            source,
 
            module_name: module_name.clone(),
 
            version: module_version,
 
            root_id: pd
 
        });
 
        self.module_lookup.insert(module_name, cur_module_idx);
 
        Ok(pd)
 
    }
 

	
 
    fn resolve_symbols_and_types(&mut self) -> Result<(), ParseError2> {
 
    fn resolve_symbols_and_types(&mut self) -> Result<(), ParseError> {
 
        // Construct the symbol table to resolve any imports and/or definitions,
 
        // then use the symbol table to actually annotate all of the imports.
 
        // If the type table is constructed correctly then all imports MUST be
 
        // resolvable.
 
        self.symbol_table.build(&self.heap, &self.modules)?;
 

	
 
        // Not pretty, but we need to work around rust's borrowing rules, it is
 
        // totally safe to mutate the contents of an AST element that we are
 
        // not borrowing anywhere else.
 
        let mut module_index = 0;
 
        let mut import_index = 0;
 
        loop {
 
            if module_index >= self.modules.len() {
 
                break;
 
            }
 

	
 
            let module_root_id = self.modules[module_index].root_id;
 
            let import_id = {
 
                let root = &self.heap[module_root_id];
 
                if import_index >= root.imports.len() {
 
                    module_index += 1;
 
                    import_index = 0;
 
                    continue
 
                }
 
                root.imports[import_index]
 
            };
 

	
 
            let import = &mut self.heap[import_id];
 
            match import {
 
                Import::Module(import) => {
 
                    debug_assert!(import.module_id.is_none(), "module import already resolved");
 
                    let target_module_id = self.symbol_table.resolve_module(&import.module_name)
 
                        .expect("module import is resolved by symbol table");
 
                    import.module_id = Some(target_module_id)
 
                },
 
                Import::Symbols(import) => {
 
                    debug_assert!(import.module_id.is_none(), "module of symbol import already resolved");
 
                    let target_module_id = self.symbol_table.resolve_module(&import.module_name)
 
                        .expect("symbol import's module is resolved by symbol table");
 
                    import.module_id = Some(target_module_id);
 

	
 
                    for symbol in &mut import.symbols {
 
                        debug_assert!(symbol.definition_id.is_none(), "symbol import already resolved");
 
                        let (_, target_definition_id) = self.symbol_table.resolve_identifier(module_root_id, &symbol.alias)
 
                            .expect("symbol import is resolved by symbol table")
 
                            .as_definition()
 
                            .expect("symbol import does not resolve to namespace symbol");
 
                        symbol.definition_id = Some(target_definition_id);
 
                    }
 
                }
 
            }
 

	
 
            import_index += 1;
 
        }
 

	
 
        // All imports in the AST are now annotated. We now use the symbol table
 
        // to construct the type table.
 
        let mut type_ctx = TypeCtx::new(&self.symbol_table, &mut self.heap, &self.modules);
 
        self.type_table.build_base_types(&mut type_ctx)?;
 

	
 
        Ok(())
 
    }
 

	
 
    pub fn parse(&mut self) -> Result<(), ParseError2> {
 
    pub fn parse(&mut self) -> Result<(), ParseError> {
 
        self.resolve_symbols_and_types()?;
 

	
 
        // Validate and link all modules
 
        let mut visit = ValidityAndLinkerVisitor::new();
 
        for module in &self.modules {
 
            let mut ctx = visitor::Ctx{
 
                heap: &mut self.heap,
 
                module,
 
                symbols: &mut self.symbol_table,
 
                types: &mut self.type_table,
 
            };
 
            visit.visit_module(&mut ctx)?;
 
        }
 

	
 
        // Perform typechecking on all modules
 
        let mut visit = TypeResolvingVisitor::new();
 
        let mut queue = ResolveQueue::new();
 
        for module in &self.modules {
 
            let ctx = visitor::Ctx{
 
                heap: &mut self.heap,
 
                module,
 
                symbols: &mut self.symbol_table,
 
                types: &mut self.type_table,
 
            };
 
            TypeResolvingVisitor::queue_module_definitions(&ctx, &mut queue);   
 
        };
 
        while !queue.is_empty() {
 
            let top = queue.pop().unwrap();
 
            let mut ctx = visitor::Ctx{
 
                heap: &mut self.heap,
 
                module: &self.modules[top.root_id.index as usize],
 
                symbols: &mut self.symbol_table,
 
                types: &mut self.type_table,
 
            };
 
            visit.handle_module_definition(&mut ctx, &mut queue, top)?;
 
        }
 

	
 
        // Perform remaining steps
 
        // TODO: Phase out at some point
 
        for module in &self.modules {
 
            let root_id = module.root_id;
 
            if let Err((position, message)) = Self::parse_inner(&mut self.heap, root_id) {
 
                return Err(ParseError2::new_error(&self.modules[0].source, position, &message))
 
                return Err(ParseError::new_error(&self.modules[0].source, position, &message))
 
            }
 
        }
 

	
 
        // let mut writer = ASTWriter::new();
 
        // let mut file = std::fs::File::create(std::path::Path::new("ast.txt")).unwrap();
 
        // writer.write_ast(&mut file, &self.heap);
 

	
 
        Ok(())
 
    }
 

	
 
    pub fn parse_inner(h: &mut Heap, pd: RootId) -> VisitorResult {
 
        // TODO: @cleanup, slowly phasing out old compiler
 
        // NestedSynchronousStatements::new().visit_protocol_description(h, pd)?;
 
        // ChannelStatementOccurrences::new().visit_protocol_description(h, pd)?;
 
        // FunctionStatementReturns::new().visit_protocol_description(h, pd)?;
 
        // ComponentStatementReturnNew::new().visit_protocol_description(h, pd)?;
 
        // CheckBuiltinOccurrences::new().visit_protocol_description(h, pd)?;
 
        // BuildSymbolDeclarations::new().visit_protocol_description(h, pd)?;
 
        // LinkCallExpressions::new().visit_protocol_description(h, pd)?;
 
        // BuildScope::new().visit_protocol_description(h, pd)?;
 
        // ResolveVariables::new().visit_protocol_description(h, pd)?;
 
        LinkStatements::new().visit_protocol_description(h, pd)?;
 
        // BuildLabels::new().visit_protocol_description(h, pd)?;
 
        // ResolveLabels::new().visit_protocol_description(h, pd)?;
 
        AssignableExpressions::new().visit_protocol_description(h, pd)?;
 
        IndexableExpressions::new().visit_protocol_description(h, pd)?;
 
        SelectableExpressions::new().visit_protocol_description(h, pd)?;
 

	
 
        Ok(())
 
    }
 
}
 
\ No newline at end of file
src/protocol/parser/symbol_table.rs
Show inline comments
 
// TODO: Maybe allow namespaced-aliased imports. It is currently not possible
 
//  to express the following:
 
//      import Module.Submodule as SubMod
 
//      import SubMod::{Symbol}
 
//  And it is especially not possible to express the following:
 
//      import SubMod::{Symbol}
 
//      import Module.Submodule as SubMod
 
use crate::protocol::ast::*;
 
use crate::protocol::inputsource::*;
 

	
 
use std::collections::{HashMap, hash_map::Entry};
 
use crate::protocol::parser::LexedModule;
 

	
 
#[derive(PartialEq, Eq, Hash)]
 
struct SymbolKey {
 
    module_id: RootId,
 
    symbol_name: Vec<u8>,
 
}
 

	
 
impl SymbolKey {
 
    fn from_identifier(module_id: RootId, symbol: &Identifier) -> Self {
 
        Self{ module_id, symbol_name: symbol.value.clone() }
 
    }
 

	
 
    fn from_namespaced_identifier(module_id: RootId, symbol: &NamespacedIdentifier) -> Self {
 
        Self{ module_id, symbol_name: symbol.strip_poly_args() }
 
    }
 
}
 

	
 
pub(crate) enum Symbol {
 
    Namespace(RootId),
 
    Definition((RootId, DefinitionId)),
 
}
 

	
 
pub(crate) struct SymbolValue {
 
    // Position is the place where the symbol is introduced to a module (this
 
    // position always corresponds to the module whose RootId is stored in the
 
    // `SymbolKey` associated with this `SymbolValue`). For a definition this
 
    // is the position where the symbol is defined, for an import this is the
 
    // position of the import statement.
 
    pub(crate) position: InputPosition,
 
    pub(crate) symbol: Symbol,
 
}
 

	
 
impl SymbolValue {
 
    pub(crate) fn is_namespace(&self) -> bool {
 
        match &self.symbol {
 
            Symbol::Namespace(_) => true,
 
            _ => false
 
        }
 
    }
 
    pub(crate) fn as_namespace(&self) -> Option<RootId> {
 
        match &self.symbol {
 
            Symbol::Namespace(root_id) => Some(*root_id),
 
            _ => None,
 
        }
 
    }
 

	
 
    pub(crate) fn as_definition(&self) -> Option<(RootId, DefinitionId)> {
 
        match &self.symbol {
 
            Symbol::Definition((root_id, definition_id)) => Some((*root_id, *definition_id)),
 
            _ => None,
 
        }
 
    }
 
}
 
/// `SymbolTable` is responsible for two parts of the parsing process: firstly
 
/// it ensures that there are no clashing symbol definitions within each file,
 
/// and secondly it will resolve all symbols within a module to their
 
/// appropriate definitions (in case of enums, functions, etc.) and namespaces
 
/// (currently only external modules can act as namespaces). If a symbol clashes
 
/// or if a symbol cannot be resolved this will be an error.
 
///
 
/// Within the compilation process the symbol table is responsible for resolving
 
/// namespaced identifiers (e.g. Module::Enum::EnumVariant) to the appropriate
 
/// definition (i.e. not namespaces; as the language has no way to use
 
/// namespaces except for using them in namespaced identifiers).
 
pub(crate) struct SymbolTable {
 
    // Lookup from module name (not any aliases) to the root id
 
    module_lookup: HashMap<Vec<u8>, RootId>,
 
    // Lookup from within a module, to a particular imported (potentially
 
    // aliased) or defined symbol. Basically speaking: if the source code of a
 
    // module contains correctly imported/defined symbols, then this lookup
 
    // will always return the corresponding definition
 
    symbol_lookup: HashMap<SymbolKey, SymbolValue>,
 
}
 

	
 
impl SymbolTable {
 
    pub(crate) fn new() -> Self {
 
        Self{ module_lookup: HashMap::new(), symbol_lookup: HashMap::new() }
 
    }
 

	
 
    pub(crate) fn build(&mut self, heap: &Heap, modules: &[LexedModule]) -> Result<(), ParseError2> {
 
    pub(crate) fn build(&mut self, heap: &Heap, modules: &[LexedModule]) -> Result<(), ParseError> {
 
        // Sanity checks
 
        debug_assert!(self.module_lookup.is_empty());
 
        debug_assert!(self.symbol_lookup.is_empty());
 
        if cfg!(debug_assertions) {
 
            for (index, module) in modules.iter().enumerate() {
 
                debug_assert_eq!(
 
                    index, module.root_id.index as usize,
 
                    "module RootId does not correspond to LexedModule index"
 
                )
 
            }
 
        }
 

	
 
        // Preparation: create a lookup from module name to root id. This does
 
        // not take aliasing into account.
 
        self.module_lookup.reserve(modules.len());
 
        for module in modules {
 
            // TODO: Maybe put duplicate module name checking here?
 
            // TODO: @string
 
            self.module_lookup.insert(module.module_name.clone(), module.root_id);
 
        }
 

	
 
        // Preparation: determine total number of imports we will be inserting
 
        // into the lookup table. We could just iterate over the arena, but then
 
        // we don't know the source file the import belongs to.
 
        let mut lookup_reserve_size = 0;
 
        for module in modules {
 
            let module_root = &heap[module.root_id];
 
            for import_id in &module_root.imports {
 
                match &heap[*import_id] {
 
                    Import::Module(_) => lookup_reserve_size += 1,
 
                    Import::Symbols(import) => {
 
                        if import.symbols.is_empty() {
 
                            // Add all symbols from the other module
 
                            match self.module_lookup.get(&import.module_name) {
 
                                Some(target_module_id) => {
 
                                    lookup_reserve_size += heap[*target_module_id].definitions.len()
 
                                },
 
                                None => {
 
                                    return Err(
 
                                        ParseError2::new_error(&module.source, import.position, "Cannot resolve module")
 
                                        ParseError::new_error(&module.source, import.position, "Cannot resolve module")
 
                                    );
 
                                }
 
                            }
 
                        } else {
 
                            lookup_reserve_size += import.symbols.len();
 
                        }
 
                    }
 
                }
 
            }
 

	
 
            lookup_reserve_size += module_root.definitions.len();
 
        }
 

	
 
        self.symbol_lookup.reserve(lookup_reserve_size);
 

	
 
        // First pass: we go through all of the modules and add lookups to
 
        // symbols that are defined within that module. Cross-module imports are
 
        // not yet resolved
 
        for module in modules {
 
            let root = &heap[module.root_id];
 
            for definition_id in &root.definitions {
 
                let definition = &heap[*definition_id];
 
                let identifier = definition.identifier();
 
                if let Err(previous_position) = self.add_definition_symbol(
 
                    identifier.position, SymbolKey::from_identifier(module.root_id, &identifier),
 
                    module.root_id, *definition_id
 
                ) {
 
                    return Err(
 
                        ParseError2::new_error(&module.source, definition.position(), "Symbol is multiply defined")
 
                        ParseError::new_error(&module.source, definition.position(), "Symbol is multiply defined")
 
                            .with_postfixed_info(&module.source, previous_position, "Previous definition was here")
 
                    )
 
                }
 
            }
 
        }
 

	
 
        // Second pass: now that we can find symbols in modules, we can resolve
 
        // all imports (if they're correct, that is)
 
        for module in modules {
 
            let root = &heap[module.root_id];
 
            for import_id in &root.imports {
 
                let import = &heap[*import_id];
 
                match import {
 
                    Import::Module(import) => {
 
                        // Find the module using its name
 
                        let target_root_id = self.resolve_module(&import.module_name);
 
                        if target_root_id.is_none() {
 
                            return Err(ParseError2::new_error(&module.source, import.position, "Could not resolve module"));
 
                            return Err(ParseError::new_error(&module.source, import.position, "Could not resolve module"));
 
                        }
 
                        let target_root_id = target_root_id.unwrap();
 
                        if target_root_id == module.root_id {
 
                            return Err(ParseError2::new_error(&module.source, import.position, "Illegal import of self"));
 
                            return Err(ParseError::new_error(&module.source, import.position, "Illegal import of self"));
 
                        }
 

	
 
                        // Add the target module under its alias
 
                        if let Err(previous_position) = self.add_namespace_symbol(
 
                            import.position, SymbolKey::from_identifier(module.root_id, &import.alias),
 
                            target_root_id
 
                        ) {
 
                            return Err(
 
                                ParseError2::new_error(&module.source, import.position, "Symbol is multiply defined")
 
                                ParseError::new_error(&module.source, import.position, "Symbol is multiply defined")
 
                                    .with_postfixed_info(&module.source, previous_position, "Previous definition was here")
 
                            );
 
                        }
 
                    },
 
                    Import::Symbols(import) => {
 
                        // Find the target module using its name
 
                        let target_root_id = self.resolve_module(&import.module_name);
 
                        if target_root_id.is_none() {
 
                            return Err(ParseError2::new_error(&module.source, import.position, "Could not resolve module of symbol imports"));
 
                            return Err(ParseError::new_error(&module.source, import.position, "Could not resolve module of symbol imports"));
 
                        }
 
                        let target_root_id = target_root_id.unwrap();
 
                        if target_root_id == module.root_id {
 
                            return Err(ParseError2::new_error(&module.source, import.position, "Illegal import of self"));
 
                            return Err(ParseError::new_error(&module.source, import.position, "Illegal import of self"));
 
                        }
 

	
 
                        // Determine which symbols to import
 
                        if import.symbols.is_empty() {
 
                            // Import of all symbols, not using any aliases
 
                            for definition_id in &heap[target_root_id].definitions {
 
                                let definition = &heap[*definition_id];
 
                                let identifier = definition.identifier();
 
                                if let Err(previous_position) = self.add_definition_symbol(
 
                                    import.position, SymbolKey::from_identifier(module.root_id, identifier),
 
                                    target_root_id, *definition_id
 
                                ) {
 
                                    return Err(
 
                                        ParseError2::new_error(
 
                                        ParseError::new_error(
 
                                            &module.source, import.position,
 
                                            &format!("Imported symbol '{}' is already defined", String::from_utf8_lossy(&identifier.value))
 
                                        )
 
                                        .with_postfixed_info(
 
                                            &modules[target_root_id.index as usize].source,
 
                                            definition.position(),
 
                                            "The imported symbol is defined here"
 
                                        )
 
                                        .with_postfixed_info(
 
                                            &module.source, previous_position, "And is previously defined here"
 
                                        )
 
                                    )
 
                                }
 
                            }
 
                        } else {
 
                            // Import of specific symbols, optionally using aliases
 
                            for symbol in &import.symbols {
 
                                // Because we have already added per-module definitions, we can use
 
                                // the table to lookup this particular symbol. Note: within a single
 
                                // module a namespace-import and a symbol-import may not collide.
 
                                // Hence per-module symbols are unique.
 
                                // However: if we import a symbol from another module, we don't want
 
                                // to "import a module's imported symbol". And so if we do find
 
                                // a symbol match, we need to make sure it is a definition from
 
                                // within that module by checking `source_root_id == target_root_id`
 
                                let key = SymbolKey::from_identifier(target_root_id, &symbol.name);
 
                                let target_symbol = self.symbol_lookup.get(&key);
 
                                let symbol_definition_id = match target_symbol {
 
                                    Some(target_symbol) => {
 
                                        match target_symbol.symbol {
 
                                            Symbol::Definition((symbol_root_id, symbol_definition_id)) => {
 
                                                if symbol_root_id == target_root_id {
 
                                                    Some(symbol_definition_id)
 
                                                } else {
 
                                                    // This is imported within the target module, and not
 
                                                    // defined within the target module
 
                                                    None
 
                                                }
 
                                            },
 
                                            Symbol::Namespace(_) => {
 
                                                // We don't import a module's "module import"
 
                                                None
 
                                            }
 
                                        }
 
                                    },
 
                                    None => None
 
                                };
 

	
 
                                if symbol_definition_id.is_none() {
 
                                    return Err(
 
                                        ParseError2::new_error(&module.source, symbol.position, "Could not resolve symbol")
 
                                        ParseError::new_error(&module.source, symbol.position, "Could not resolve symbol")
 
                                    )
 
                                }
 
                                let symbol_definition_id = symbol_definition_id.unwrap();
 

	
 
                                if let Err(previous_position) = self.add_definition_symbol(
 
                                    symbol.position, SymbolKey::from_identifier(module.root_id, &symbol.alias),
 
                                    target_root_id, symbol_definition_id
 
                                ) {
 
                                    return Err(
 
                                        ParseError2::new_error(&module.source, symbol.position, "Symbol is multiply defined")
 
                                        ParseError::new_error(&module.source, symbol.position, "Symbol is multiply defined")
 
                                            .with_postfixed_info(&module.source, previous_position, "Previous definition was here")
 
                                    )
 
                                }
 
                            }
 
                        }
 
                    }
 
                }
 
            }
 
        }
 
        fn find_name(heap: &Heap, root_id: RootId) -> String {
 
            let root = &heap[root_id];
 
            for pragma_id in &root.pragmas {
 
                match &heap[*pragma_id] {
 
                    Pragma::Module(module) => {
 
                        return String::from_utf8_lossy(&module.value).to_string()
 
                    },
 
                    _ => {},
 
                }
 
            }
 

	
 
            return String::from("Unknown")
 
        }
 

	
 
        debug_assert_eq!(
 
            self.symbol_lookup.len(), lookup_reserve_size,
 
            "miscalculated reserved size for symbol lookup table"
 
        );
 
        Ok(())
 
    }
 

	
 
    /// Resolves a module by its defined name
 
    pub(crate) fn resolve_module(&self, identifier: &Vec<u8>) -> Option<RootId> {
 
        self.module_lookup.get(identifier).map(|v| *v)
 
    }
 

	
 
    pub(crate) fn resolve_symbol<'t>(
 
        &'t self, root_module_id: RootId, identifier: &[u8]
 
    ) -> Option<&'t SymbolValue> {
 
        let lookup_key = SymbolKey{ module_id: root_module_id, symbol_name: Vec::from(identifier) };
 
        self.symbol_lookup.get(&lookup_key)
 
    }
 

	
 
    pub(crate) fn resolve_identifier<'t>(
 
        &'t self, root_module_id: RootId, identifier: &Identifier
 
    ) -> Option<&'t SymbolValue> {
 
        let lookup_key = SymbolKey::from_identifier(root_module_id, identifier);
 
        self.symbol_lookup.get(&lookup_key)
 
    }
 

	
 
    /// Resolves a namespaced symbol. This method will go as far as possible in
 
    /// going to the right symbol. It will halt the search when:
 
    /// 1. Polymorphic arguments are encountered on the identifier.
 
    /// 2. A non-namespace symbol is encountered.
 
    /// 3. A part of the identifier couldn't be resolved to anything
 
    /// The returned iterator will always point to the next symbol (even if 
 
    /// nothing was found)
 
    pub(crate) fn resolve_namespaced_identifier<'t, 'i>(
 
        &'t self, root_module_id: RootId, identifier: &'i NamespacedIdentifier
 
    ) -> (Option<&'t SymbolValue>, NamespacedIdentifierIter<'i>) {
 
        let mut iter = identifier.iter();
 
        let mut symbol: Option<&SymbolValue> = None;
 
        let mut within_module_id = root_module_id;
 

	
 
        while let Some((partial, poly_args)) = iter.next() {
 
            // Lookup the symbol within the currently iterated upon module
 
            let lookup_key = SymbolKey{ module_id: within_module_id, symbol_name: Vec::from(partial) };
 
            let new_symbol = self.symbol_lookup.get(&lookup_key);
 
            
 
            match new_symbol {
 
                None => {
 
                    // Can't find anything
 
                    symbol = None;
 
                    break;
 
                },
 
                Some(new_symbol) => {
 
                    // Found something, but if we already moved to another
 
                    // module then we don't want to keep jumping across modules,
 
                    // we're only interested in symbols defined within that
 
                    // module.
 
                    match &new_symbol.symbol {
 
                        Symbol::Namespace(new_root_id) => {
 
                            if root_module_id != within_module_id {
 
                                // This new symbol is imported by a foreign
 
                                // module, so this is an error
 
                                debug_assert!(symbol.is_some());
 
                                debug_assert!(symbol.unwrap().is_namespace());
 
                                debug_assert!(iter.num_returned() > 1);
 
                                symbol = None;
 
                                break;
 
                            }
 
                            within_module_id = *new_root_id;
 
                            symbol = Some(new_symbol);
 
                        },
 
                        Symbol::Definition((definition_root_id, _)) => {
 
                            // Found a definition, but if we already jumped
 
                            // modules, then this must be defined within that
 
                            // module.
 
                            if root_module_id != within_module_id && within_module_id != *definition_root_id {
 
                                // This is an imported definition within the module
 
                                // So keep the old 
 
                                debug_assert!(symbol.is_some());
 
                                debug_assert!(symbol.unwrap().is_namespace());
 
                                debug_assert!(iter.num_returned() > 1);
 
                                symbol = None;
 
                                break;
 
                            }
 
                            symbol = Some(new_symbol);
 
                            break;
 
                        }
 
                    }
 
                }
 
            }
 

	
 
            if poly_args.is_some() {
 
                // Polymorphic argument specification should also be a fully 
 
                // resolved result.
 
                break;
 
            }
 
        }
 

	
 
        match symbol {
 
            None => (None, iter),
 
            Some(symbol) => (Some(symbol), iter)
 
        }
 
    }
 

	
 
    /// Attempts to add a namespace symbol. Returns `Ok` if the symbol was
 
    /// inserted. If the symbol already exists then `Err` will be returned
 
    /// together with the previous definition's source position (in the origin
 
    /// module's source file).
 
    // Note: I would love to return a reference to the value, but Rust is
 
    // preventing me from doing so... That, or I'm not smart enough...
 
    fn add_namespace_symbol(
 
        &mut self, origin_position: InputPosition, key: SymbolKey, target_module_id: RootId
 
    ) -> Result<(), InputPosition> {
 
        match self.symbol_lookup.entry(key) {
 
            Entry::Occupied(o) => Err(o.get().position),
 
            Entry::Vacant(v) => {
 
                v.insert(SymbolValue{
 
                    position: origin_position,
 
                    symbol: Symbol::Namespace(target_module_id)
 
                });
 
                Ok(())
 
            }
 
        }
 
    }
 

	
 
    /// Attempts to add a definition symbol. Returns `Ok` if the symbol was
 
    /// inserted. If the symbol already exists then `Err` will be returned
 
    /// together with the previous definition's source position (in the origin
 
    /// module's source file).
 
    fn add_definition_symbol(
 
        &mut self, origin_position: InputPosition, key: SymbolKey,
 
        target_module_id: RootId, target_definition_id: DefinitionId,
 
    ) -> Result<(), InputPosition> {
 
        match self.symbol_lookup.entry(key) {
 
            Entry::Occupied(o) => Err(o.get().position),
 
            Entry::Vacant(v) => {
 
                v.insert(SymbolValue {
 
                    position: origin_position,
 
                    symbol: Symbol::Definition((target_module_id, target_definition_id))
 
                });
 
                Ok(())
 
            }
 
        }
 
    }
 
}
 
\ No newline at end of file

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