Changeset - fbd1526bae2c
examples/make.py
Show inline comments
 
modified file chmod 100644 => 100755
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 {
 
    filename: String,
 
    input: Vec<u8>,
 
    pub input: Vec<u8>,
 
    line: usize,
 
    column: usize,
 
    offset: usize,
 
}
 

	
 
static STD_LIB_PDL: &'static [u8] = b"
 
primitive forward(in i, out o) {
 
    while(true) synchronous() put(o, get(i));
 
}
 
primitive sync(in i, out o) {
 
    while(true) synchronous() if(fires(i)) put(o, get(i));
 
}
 
primitive alternator(in i, out l, out r) {
 
    while(true) {
 
        synchronous() if(fires(i)) put(l, get(i));
 
        synchronous() if(fires(i)) put(r, get(i));
 
    }
 
}
 
primitive replicator(in i, out l, out r) {
 
    while(true) synchronous {
 
        if(fires(i)) {
 
            msg m = get(i);
 
            put(l, m);
 
            put(r, m);
 
        }
 
    }
 
}
 
primitive merger(in l, in r, out 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 = STD_LIB_PDL.to_vec();
 
        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 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> {
 
        if let Some(x) = usize::checked_add(self.offset, pos) {
 
            if x < self.input.len() {
 
                return Some((*self.input)[x]);
 
            }
 
        }
 
        None
 
    }
 
    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, Default, serde::Serialize, serde::Deserialize)]
 
pub struct InputPosition {
 
    line: usize,
 
    column: usize,
 
    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() }
 
    }
 
}
 

	
 
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, Clone)]
 
pub struct ParseError {
 
    position: InputPosition,
 
    message: String,
 
    backtrace: Backtrace,
 
}
 

	
 
impl ParseError {
 
    pub fn new<S: ToString>(position: InputPosition, message: S) -> ParseError {
 
        ParseError { 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,
 
                "Parse error at {}:{}: {}",
 
                source.filename, self.position, self.message
 
            )?;
 
        } else {
 
            writeln!(writer, "Parse 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) -> DisplayParseError<'a> {
 
        DisplayParseError::new(self, source)
 
    }
 
}
 

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

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

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

	
 
impl fmt::Display for DisplayParseError<'_> {
 
    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))
 
    }
 
}
 

	
 
#[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/mod.rs
Show inline comments
 
mod arena;
 
mod ast;
 
mod eval;
 
pub(crate) mod inputsource;
 
mod lexer;
 
// mod library;
 
mod library;
 
mod parser;
 

	
 
lazy_static::lazy_static! {
 
    /// Conveniently-provided protocol description initialized with a zero-length PDL string.
 
    /// Exposed to minimize repeated initializations of this common protocol description.
 
    pub static ref TRIVIAL_PD: std::sync::Arc<ProtocolDescription> = {
 
        std::sync::Arc::new(ProtocolDescription::parse(b"").unwrap())
 
    };
 
}
 

	
 
use crate::common::*;
 
use crate::protocol::ast::*;
 
use crate::protocol::eval::*;
 
use crate::protocol::inputsource::*;
 
use crate::protocol::parser::*;
 

	
 
/// Description of a protocol object, used to configure new connectors.
 
/// (De)serializable.
 
#[derive(serde::Serialize, serde::Deserialize)]
 
#[repr(C)]
 
pub struct ProtocolDescription {
 
    heap: Heap,
 
    source: InputSource,
 
    root: RootId,
 
}
 
#[derive(Debug, Clone, serde::Serialize, serde::Deserialize)]
 
pub(crate) struct ComponentState {
 
    prompt: Prompt,
 
}
 
pub(crate) enum EvalContext<'a> {
 
    Nonsync(&'a mut NonsyncProtoContext<'a>),
 
    Sync(&'a mut SyncProtoContext<'a>),
 
    // None,
 
}
 
//////////////////////////////////////////////
 

	
 
impl std::fmt::Debug for ProtocolDescription {
 
    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
 
        write!(f, "(An opaque protocol description)")
 
    }
 
}
 
impl ProtocolDescription {
 
    pub fn parse(buffer: &[u8]) -> Result<Self, String> {
 
        let mut heap = Heap::new();
 
        let mut source = InputSource::from_buffer(buffer).unwrap();
 
        let mut parser = Parser::new(&mut source);
 
        match parser.parse(&mut heap) {
 
            Ok(root) => {
 
                return Ok(ProtocolDescription { heap, source, root });
 
            }
 
            Err(err) => {
 
                let mut vec: Vec<u8> = Vec::new();
 
                err.write(&source, &mut vec).unwrap();
 
                Err(String::from_utf8_lossy(&vec).to_string())
 
            }
 
        }
 
    }
 
    pub(crate) fn component_polarities(
 
        &self,
 
        identifier: &[u8],
 
    ) -> Result<Vec<Polarity>, AddComponentError> {
 
        use AddComponentError::*;
 
        let h = &self.heap;
 
        let root = &h[self.root];
 
        let def = root.get_definition_ident(h, identifier);
 
        if def.is_none() {
 
            return Err(NoSuchComponent);
 
        }
 
        let def = &h[def.unwrap()];
 
        if !def.is_component() {
 
            return Err(NoSuchComponent);
 
        }
 
        for &param in def.parameters().iter() {
 
            let param = &h[param];
 
            let type_annot = &h[param.type_annotation];
 
            if type_annot.the_type.array {
 
                return Err(NonPortTypeParameters);
 
            }
 
            match type_annot.the_type.primitive {
 
                PrimitiveType::Input | PrimitiveType::Output => continue,
 
                _ => {
 
                    return Err(NonPortTypeParameters);
 
                }
 
            }
 
        }
 
        let mut result = Vec::new();
 
        for &param in def.parameters().iter() {
 
            let param = &h[param];
 
            let type_annot = &h[param.type_annotation];
 
            let ptype = &type_annot.the_type.primitive;
 
            if ptype == &PrimitiveType::Input {
 
                result.push(Polarity::Getter)
 
            } else if ptype == &PrimitiveType::Output {
 
                result.push(Polarity::Putter)
 
            } else {
 
                unreachable!()
 
            }
 
        }
 
        Ok(result)
 
    }
 
    // expects port polarities to be correct
 
    pub(crate) fn new_component(&self, identifier: &[u8], ports: &[PortId]) -> ComponentState {
 
        let mut args = Vec::new();
 
        for (&x, y) in ports.iter().zip(self.component_polarities(identifier).unwrap()) {
 
            match y {
 
                Polarity::Getter => args.push(Value::Input(InputValue(x))),
 
                Polarity::Putter => args.push(Value::Output(OutputValue(x))),
 
            }
 
        }
 
        let h = &self.heap;
 
        let root = &h[self.root];
 
        let def = root.get_definition_ident(h, identifier).unwrap();
 
        ComponentState { prompt: Prompt::new(h, def, &args) }
 
    }
 
}
 
impl ComponentState {
 
    pub(crate) fn nonsync_run<'a: 'b, 'b>(
 
        &'a mut self,
 
        context: &'b mut NonsyncProtoContext<'b>,
 
        pd: &'a ProtocolDescription,
 
    ) -> NonsyncBlocker {
 
        let mut context = EvalContext::Nonsync(context);
 
        loop {
 
            let result = self.prompt.step(&pd.heap, &mut context);
 
            match result {
 
                // In component definitions, there are no return statements
 
                Ok(_) => unreachable!(),
 
                Err(cont) => match cont {
 
                    EvalContinuation::Stepping => continue,
 
                    EvalContinuation::Inconsistent => return NonsyncBlocker::Inconsistent,
 
                    EvalContinuation::Terminal => return NonsyncBlocker::ComponentExit,
 
                    EvalContinuation::SyncBlockStart => return NonsyncBlocker::SyncBlockStart,
 
                    // Not possible to end sync block if never entered one
 
                    EvalContinuation::SyncBlockEnd => unreachable!(),
 
                    EvalContinuation::NewComponent(decl, args) => {
 
                        // Look up definition (TODO for now, assume it is a definition)
 
                        let h = &pd.heap;
 
                        let def = h[decl].as_defined().definition;
 
                        let init_state = ComponentState { prompt: Prompt::new(h, def, &args) };
 
                        context.new_component(&args, init_state);
 
                        // Continue stepping
 
                        continue;
 
                    }
 
                    // Outside synchronous blocks, no fires/get/put happens
 
                    EvalContinuation::BlockFires(_) => unreachable!(),
 
                    EvalContinuation::BlockGet(_) => unreachable!(),
 
                    EvalContinuation::Put(_, _) => unreachable!(),
 
                },
 
            }
 
        }
 
    }
 

	
 
    pub(crate) fn sync_run<'a: 'b, 'b>(
 
        &'a mut self,
 
        context: &'b mut SyncProtoContext<'b>,
 
        pd: &'a ProtocolDescription,
 
    ) -> SyncBlocker {
 
        let mut context = EvalContext::Sync(context);
 
        loop {
 
            let result = self.prompt.step(&pd.heap, &mut context);
 
            match result {
 
                // Inside synchronous blocks, there are no return statements
 
                Ok(_) => unreachable!(),
 
                Err(cont) => match cont {
 
                    EvalContinuation::Stepping => continue,
 
                    EvalContinuation::Inconsistent => return SyncBlocker::Inconsistent,
 
                    // First need to exit synchronous block before definition may end
 
                    EvalContinuation::Terminal => unreachable!(),
 
                    // No nested synchronous blocks
 
                    EvalContinuation::SyncBlockStart => unreachable!(),
 
                    EvalContinuation::SyncBlockEnd => return SyncBlocker::SyncBlockEnd,
 
                    // Not possible to create component in sync block
 
                    EvalContinuation::NewComponent(_, _) => unreachable!(),
 
                    EvalContinuation::BlockFires(port) => match port {
 
                        Value::Output(OutputValue(port)) => {
 
                            return SyncBlocker::CouldntCheckFiring(port);
 
                        }
 
                        Value::Input(InputValue(port)) => {
 
                            return SyncBlocker::CouldntCheckFiring(port);
 
                        }
 
                        _ => unreachable!(),
 
                    },
 
                    EvalContinuation::BlockGet(port) => match port {
 
                        Value::Output(OutputValue(port)) => {
 
                            return SyncBlocker::CouldntReadMsg(port);
 
                        }
 
                        Value::Input(InputValue(port)) => {
 
                            return SyncBlocker::CouldntReadMsg(port);
 
                        }
 
                        _ => unreachable!(),
 
                    },
 
                    EvalContinuation::Put(port, message) => {
 
                        let value;
 
                        match port {
 
                            Value::Output(OutputValue(port_value)) => {
 
                                value = port_value;
 
                            }
 
                            Value::Input(InputValue(port_value)) => {
 
                                value = port_value;
 
                            }
 
                            _ => unreachable!(),
 
                        }
 
                        let payload;
 
                        match message {
 
                            Value::Message(MessageValue(None)) => {
 
                                // Putting a null message is inconsistent
 
                                return SyncBlocker::Inconsistent;
 
                            }
 
                            Value::Message(MessageValue(Some(buffer))) => {
 
                                // Create a copy of the payload
 
                                payload = buffer;
 
                            }
 
                            _ => unreachable!(),
 
                        }
 
                        return SyncBlocker::PutMsg(value, payload);
 
                    }
 
                },
 
            }
 
        }
 
    }
 
}
 
impl EvalContext<'_> {
 
    // fn random(&mut self) -> LongValue {
 
    //     match self {
 
    //         // EvalContext::None => unreachable!(),
 
    //         EvalContext::Nonsync(_context) => todo!(),
 
    //         EvalContext::Sync(_) => unreachable!(),
 
    //     }
 
    // }
 
    fn new_component(&mut self, args: &[Value], init_state: ComponentState) -> () {
 
        match self {
 
            // EvalContext::None => unreachable!(),
 
            EvalContext::Nonsync(context) => {
 
                let mut moved_ports = HashSet::new();
 
                for arg in args.iter() {
 
                    match arg {
 
                        Value::Output(OutputValue(port)) => {
 
                            moved_ports.insert(*port);
 
                        }
 
                        Value::Input(InputValue(port)) => {
 
                            moved_ports.insert(*port);
 
                        }
 
                        _ => {}
 
                    }
 
                }
 
                context.new_component(moved_ports, init_state)
 
            }
 
            EvalContext::Sync(_) => unreachable!(),
 
        }
 
    }
 
    fn new_channel(&mut self) -> [Value; 2] {
 
        match self {
 
            // EvalContext::None => unreachable!(),
 
            EvalContext::Nonsync(context) => {
 
                let [from, to] = context.new_port_pair();
 
                let from = Value::Output(OutputValue(from));
 
                let to = Value::Input(InputValue(to));
 
                return [from, to];
 
            }
 
            EvalContext::Sync(_) => unreachable!(),
 
        }
 
    }
 
    fn fires(&mut self, port: Value) -> Option<Value> {
 
        match self {
 
            // EvalContext::None => unreachable!(),
 
            EvalContext::Nonsync(_) => unreachable!(),
 
            EvalContext::Sync(context) => match port {
 
                Value::Output(OutputValue(port)) => context.is_firing(port).map(Value::from),
 
                Value::Input(InputValue(port)) => context.is_firing(port).map(Value::from),
 
                _ => unreachable!(),
 
            },
 
        }
 
    }
 
    fn get(&mut self, port: Value) -> Option<Value> {
 
        match self {
 
            // EvalContext::None => unreachable!(),
 
            EvalContext::Nonsync(_) => unreachable!(),
 
            EvalContext::Sync(context) => match port {
 
                Value::Output(OutputValue(port)) => {
 
                    context.read_msg(port).map(Value::receive_message)
 
                }
 
                Value::Input(InputValue(port)) => {
 
                    context.read_msg(port).map(Value::receive_message)
 
                }
 
                _ => unreachable!(),
 
            },
 
        }
 
    }
 
}
src/protocol/parser.rs
Show inline comments
 
use crate::protocol::ast::*;
 
use crate::protocol::inputsource::*;
 
use crate::protocol::lexer::*;
 
// use crate::protocol::library;
 
use crate::protocol::library;
 

	
 
// The following indirection is needed due to a bug in the cbindgen tool.
 
type Unit = ();
 
type VisitorResult = Result<Unit, ParseError>;
 

	
 
trait Visitor: Sized {
 
    fn visit_protocol_description(&mut self, h: &mut Heap, pd: RootId) -> VisitorResult {
 
        recursive_protocol_description(self, h, pd)
 
    }
 
    fn visit_pragma(&mut self, _h: &mut Heap, _pragma: PragmaId) -> VisitorResult {
 
        Ok(())
 
    }
 
    fn visit_import(&mut self, _h: &mut Heap, _import: ImportId) -> VisitorResult {
 
        Ok(())
 
    }
 

	
 
    fn visit_symbol_definition(&mut self, h: &mut Heap, def: DefinitionId) -> VisitorResult {
 
        recursive_symbol_definition(self, h, def)
 
    }
 
    fn visit_component_definition(&mut self, h: &mut Heap, def: ComponentId) -> VisitorResult {
 
        recursive_component_definition(self, h, def)
 
    }
 
    fn visit_composite_definition(&mut self, h: &mut Heap, def: CompositeId) -> VisitorResult {
 
        recursive_composite_definition(self, h, def)
 
    }
 
    fn visit_primitive_definition(&mut self, h: &mut Heap, def: PrimitiveId) -> VisitorResult {
 
        recursive_primitive_definition(self, h, def)
 
    }
 
    fn visit_function_definition(&mut self, h: &mut Heap, def: FunctionId) -> VisitorResult {
 
        recursive_function_definition(self, h, def)
 
    }
 

	
 
    fn visit_variable_declaration(&mut self, h: &mut Heap, decl: VariableId) -> VisitorResult {
 
        recursive_variable_declaration(self, h, decl)
 
    }
 
    fn visit_parameter_declaration(&mut self, _h: &mut Heap, _decl: ParameterId) -> VisitorResult {
 
        Ok(())
 
    }
 
    fn visit_local_declaration(&mut self, _h: &mut Heap, _decl: LocalId) -> VisitorResult {
 
        Ok(())
 
    }
 

	
 
    fn visit_statement(&mut self, h: &mut Heap, stmt: StatementId) -> VisitorResult {
 
        recursive_statement(self, h, stmt)
 
    }
 
    fn visit_local_statement(&mut self, h: &mut Heap, stmt: LocalStatementId) -> VisitorResult {
 
        recursive_local_statement(self, h, stmt)
 
    }
 
    fn visit_memory_statement(&mut self, h: &mut Heap, stmt: MemoryStatementId) -> VisitorResult {
 
        recursive_memory_statement(self, h, stmt)
 
    }
 
    fn visit_channel_statement(
 
        &mut self,
 
        _h: &mut Heap,
 
        _stmt: ChannelStatementId,
 
    ) -> VisitorResult {
 
        Ok(())
 
    }
 
    fn visit_block_statement(&mut self, h: &mut Heap, stmt: BlockStatementId) -> VisitorResult {
 
        recursive_block_statement(self, h, stmt)
 
    }
 
    fn visit_labeled_statement(&mut self, h: &mut Heap, stmt: LabeledStatementId) -> VisitorResult {
 
        recursive_labeled_statement(self, h, stmt)
 
    }
 
    fn visit_skip_statement(&mut self, _h: &mut Heap, _stmt: SkipStatementId) -> VisitorResult {
 
        Ok(())
 
    }
 
    fn visit_if_statement(&mut self, h: &mut Heap, stmt: IfStatementId) -> VisitorResult {
 
        recursive_if_statement(self, h, stmt)
 
    }
 
    fn visit_while_statement(&mut self, h: &mut Heap, stmt: WhileStatementId) -> VisitorResult {
 
        recursive_while_statement(self, h, stmt)
 
    }
 
    fn visit_break_statement(&mut self, _h: &mut Heap, _stmt: BreakStatementId) -> VisitorResult {
 
        Ok(())
 
    }
 
    fn visit_continue_statement(
 
        &mut self,
 
        _h: &mut Heap,
 
        _stmt: ContinueStatementId,
 
    ) -> VisitorResult {
 
        Ok(())
 
    }
 
    fn visit_synchronous_statement(
 
        &mut self,
 
        h: &mut Heap,
 
        stmt: SynchronousStatementId,
 
    ) -> VisitorResult {
 
        recursive_synchronous_statement(self, h, stmt)
 
    }
 
    fn visit_return_statement(&mut self, h: &mut Heap, stmt: ReturnStatementId) -> VisitorResult {
 
        recursive_return_statement(self, h, stmt)
 
    }
 
    fn visit_assert_statement(&mut self, h: &mut Heap, stmt: AssertStatementId) -> VisitorResult {
 
        recursive_assert_statement(self, h, stmt)
 
    }
 
    fn visit_goto_statement(&mut self, _h: &mut Heap, _stmt: GotoStatementId) -> VisitorResult {
 
        Ok(())
 
    }
 
    fn visit_new_statement(&mut self, h: &mut Heap, stmt: NewStatementId) -> VisitorResult {
 
        recursive_new_statement(self, h, stmt)
 
    }
 
    fn visit_put_statement(&mut self, h: &mut Heap, stmt: PutStatementId) -> VisitorResult {
 
        recursive_put_statement(self, h, stmt)
 
    }
 
    fn visit_expression_statement(
 
        &mut self,
 
        h: &mut Heap,
 
        stmt: ExpressionStatementId,
 
    ) -> VisitorResult {
 
        recursive_expression_statement(self, h, stmt)
 
    }
 

	
 
    fn visit_expression(&mut self, h: &mut Heap, expr: ExpressionId) -> VisitorResult {
 
        recursive_expression(self, h, expr)
 
    }
 
    fn visit_assignment_expression(
 
        &mut self,
 
        h: &mut Heap,
 
        expr: AssignmentExpressionId,
 
    ) -> VisitorResult {
 
        recursive_assignment_expression(self, h, expr)
 
    }
 
    fn visit_conditional_expression(
 
        &mut self,
 
        h: &mut Heap,
 
        expr: ConditionalExpressionId,
 
    ) -> VisitorResult {
 
        recursive_conditional_expression(self, h, expr)
 
    }
 
    fn visit_binary_expression(&mut self, h: &mut Heap, expr: BinaryExpressionId) -> VisitorResult {
 
        recursive_binary_expression(self, h, expr)
 
    }
 
    fn visit_unary_expression(&mut self, h: &mut Heap, expr: UnaryExpressionId) -> VisitorResult {
 
        recursive_unary_expression(self, h, expr)
 
    }
 
    fn visit_indexing_expression(
 
        &mut self,
 
        h: &mut Heap,
 
        expr: IndexingExpressionId,
 
    ) -> VisitorResult {
 
        recursive_indexing_expression(self, h, expr)
 
    }
 
    fn visit_slicing_expression(
 
        &mut self,
 
        h: &mut Heap,
 
        expr: SlicingExpressionId,
 
    ) -> VisitorResult {
 
        recursive_slicing_expression(self, h, expr)
 
    }
 
    fn visit_select_expression(&mut self, h: &mut Heap, expr: SelectExpressionId) -> VisitorResult {
 
        recursive_select_expression(self, h, expr)
 
    }
 
    fn visit_array_expression(&mut self, h: &mut Heap, expr: ArrayExpressionId) -> VisitorResult {
 
        recursive_array_expression(self, h, expr)
 
    }
 
    fn visit_call_expression(&mut self, h: &mut Heap, expr: CallExpressionId) -> VisitorResult {
 
        recursive_call_expression(self, h, expr)
 
    }
 
    fn visit_constant_expression(
 
        &mut self,
 
        _h: &mut Heap,
 
        _expr: ConstantExpressionId,
 
    ) -> VisitorResult {
 
        Ok(())
 
    }
 
    fn visit_variable_expression(
 
        &mut self,
 
        _h: &mut Heap,
 
        _expr: VariableExpressionId,
 
    ) -> VisitorResult {
 
        Ok(())
 
    }
 
}
 

	
 
// Bubble-up helpers
 
fn recursive_parameter_as_variable<T: Visitor>(
 
    this: &mut T,
 
    h: &mut Heap,
 
    param: ParameterId,
 
) -> VisitorResult {
 
    this.visit_variable_declaration(h, param.upcast())
 
}
 

	
 
fn recursive_local_as_variable<T: Visitor>(
 
    this: &mut T,
 
    h: &mut Heap,
 
    local: LocalId,
 
) -> VisitorResult {
 
    this.visit_variable_declaration(h, local.upcast())
 
}
 

	
 
fn recursive_call_expression_as_expression<T: Visitor>(
 
    this: &mut T,
 
    h: &mut Heap,
 
    call: CallExpressionId,
 
) -> VisitorResult {
 
    this.visit_expression(h, call.upcast())
 
}
 

	
 
// Recursive procedures
 
fn recursive_protocol_description<T: Visitor>(
 
    this: &mut T,
 
    h: &mut Heap,
 
    pd: RootId,
 
) -> VisitorResult {
 
    for &pragma in h[pd].pragmas.clone().iter() {
 
        this.visit_pragma(h, pragma)?;
 
    }
 
    for &import in h[pd].imports.clone().iter() {
 
        this.visit_import(h, import)?;
 
    }
 
    for &def in h[pd].definitions.clone().iter() {
 
        this.visit_symbol_definition(h, def)?;
 
    }
 
    Ok(())
 
}
 

	
 
fn recursive_symbol_definition<T: Visitor>(
 
    this: &mut T,
 
    h: &mut Heap,
 
    def: DefinitionId,
 
) -> VisitorResult {
 
    // We clone the definition in case it is modified
 
    match h[def].clone() {
 
        Definition::Component(cdef) => this.visit_component_definition(h, cdef.this()),
 
        Definition::Function(fdef) => this.visit_function_definition(h, fdef.this),
 
    }
 
}
 

	
 
fn recursive_component_definition<T: Visitor>(
 
    this: &mut T,
 
    h: &mut Heap,
 
    def: ComponentId,
 
) -> VisitorResult {
 
    match h[def].clone() {
 
        Component::Composite(cdef) => this.visit_composite_definition(h, cdef.this),
 
        Component::Primitive(pdef) => this.visit_primitive_definition(h, pdef.this),
 
    }
 
}
 

	
 
fn recursive_composite_definition<T: Visitor>(
 
    this: &mut T,
 
    h: &mut Heap,
 
    def: CompositeId,
 
) -> VisitorResult {
 
    for &param in h[def].parameters.clone().iter() {
 
        recursive_parameter_as_variable(this, h, param)?;
 
    }
 
    this.visit_statement(h, h[def].body)
 
}
 

	
 
fn recursive_primitive_definition<T: Visitor>(
 
    this: &mut T,
 
    h: &mut Heap,
 
    def: PrimitiveId,
 
) -> VisitorResult {
 
    for &param in h[def].parameters.clone().iter() {
 
        recursive_parameter_as_variable(this, h, param)?;
 
    }
 
    this.visit_statement(h, h[def].body)
 
}
 

	
 
fn recursive_function_definition<T: Visitor>(
 
    this: &mut T,
 
    h: &mut Heap,
 
    def: FunctionId,
 
) -> VisitorResult {
 
    for &param in h[def].parameters.clone().iter() {
 
        recursive_parameter_as_variable(this, h, param)?;
 
    }
 
    this.visit_statement(h, h[def].body)
 
}
 

	
 
fn recursive_variable_declaration<T: Visitor>(
 
    this: &mut T,
 
    h: &mut Heap,
 
    decl: VariableId,
 
) -> VisitorResult {
 
    match h[decl].clone() {
 
        Variable::Parameter(decl) => this.visit_parameter_declaration(h, decl.this),
 
        Variable::Local(decl) => this.visit_local_declaration(h, decl.this),
 
    }
 
}
 

	
 
fn recursive_statement<T: Visitor>(this: &mut T, h: &mut Heap, stmt: StatementId) -> VisitorResult {
 
    match h[stmt].clone() {
 
        Statement::Block(stmt) => this.visit_block_statement(h, stmt.this),
 
        Statement::Local(stmt) => this.visit_local_statement(h, stmt.this()),
 
        Statement::Skip(stmt) => this.visit_skip_statement(h, stmt.this),
 
        Statement::Labeled(stmt) => this.visit_labeled_statement(h, stmt.this),
 
        Statement::If(stmt) => this.visit_if_statement(h, stmt.this),
 
        Statement::While(stmt) => this.visit_while_statement(h, stmt.this),
 
        Statement::Break(stmt) => this.visit_break_statement(h, stmt.this),
 
        Statement::Continue(stmt) => this.visit_continue_statement(h, stmt.this),
 
        Statement::Synchronous(stmt) => this.visit_synchronous_statement(h, stmt.this),
 
        Statement::Return(stmt) => this.visit_return_statement(h, stmt.this),
 
        Statement::Assert(stmt) => this.visit_assert_statement(h, stmt.this),
 
        Statement::Goto(stmt) => this.visit_goto_statement(h, stmt.this),
 
        Statement::New(stmt) => this.visit_new_statement(h, stmt.this),
 
        Statement::Put(stmt) => this.visit_put_statement(h, stmt.this),
 
        Statement::Expression(stmt) => this.visit_expression_statement(h, stmt.this),
 
        Statement::EndSynchronous(_) | Statement::EndWhile(_) | Statement::EndIf(_) => {
 
            unreachable!() // pseudo-statement
 
        }
 
    }
 
}
 

	
 
fn recursive_block_statement<T: Visitor>(
 
    this: &mut T,
 
    h: &mut Heap,
 
    block: BlockStatementId,
 
) -> VisitorResult {
 
    for &local in h[block].locals.clone().iter() {
 
        recursive_local_as_variable(this, h, local)?;
 
    }
 
    for &stmt in h[block].statements.clone().iter() {
 
        this.visit_statement(h, stmt)?;
 
    }
 
    Ok(())
 
}
 

	
 
fn recursive_local_statement<T: Visitor>(
 
    this: &mut T,
 
    h: &mut Heap,
 
    stmt: LocalStatementId,
 
) -> VisitorResult {
 
    match h[stmt].clone() {
 
        LocalStatement::Channel(stmt) => this.visit_channel_statement(h, stmt.this),
 
        LocalStatement::Memory(stmt) => this.visit_memory_statement(h, stmt.this),
 
    }
 
}
 

	
 
fn recursive_memory_statement<T: Visitor>(
 
    this: &mut T,
 
    h: &mut Heap,
 
    stmt: MemoryStatementId,
 
) -> VisitorResult {
 
    this.visit_expression(h, h[stmt].initial)
 
}
 

	
 
fn recursive_labeled_statement<T: Visitor>(
 
    this: &mut T,
 
    h: &mut Heap,
 
    stmt: LabeledStatementId,
 
) -> VisitorResult {
 
    this.visit_statement(h, h[stmt].body)
 
}
 

	
 
fn recursive_if_statement<T: Visitor>(
 
    this: &mut T,
 
    h: &mut Heap,
 
    stmt: IfStatementId,
 
) -> VisitorResult {
 
    this.visit_expression(h, h[stmt].test)?;
 
    this.visit_statement(h, h[stmt].true_body)?;
 
    this.visit_statement(h, h[stmt].false_body)
 
}
 

	
 
fn recursive_while_statement<T: Visitor>(
 
    this: &mut T,
 
    h: &mut Heap,
 
    stmt: WhileStatementId,
 
) -> VisitorResult {
 
    this.visit_expression(h, h[stmt].test)?;
 
    this.visit_statement(h, h[stmt].body)
 
}
 

	
 
fn recursive_synchronous_statement<T: Visitor>(
 
    this: &mut T,
 
    h: &mut Heap,
 
    stmt: SynchronousStatementId,
 
) -> VisitorResult {
 
    for &param in h[stmt].parameters.clone().iter() {
 
        recursive_parameter_as_variable(this, h, param)?;
 
    }
 
    this.visit_statement(h, h[stmt].body)
 
}
 

	
 
fn recursive_return_statement<T: Visitor>(
 
    this: &mut T,
 
    h: &mut Heap,
 
    stmt: ReturnStatementId,
 
) -> VisitorResult {
 
@@ -415,776 +415,776 @@ fn recursive_put_statement<T: Visitor>(
 
}
 

	
 
fn recursive_expression_statement<T: Visitor>(
 
    this: &mut T,
 
    h: &mut Heap,
 
    stmt: ExpressionStatementId,
 
) -> VisitorResult {
 
    this.visit_expression(h, h[stmt].expression)
 
}
 

	
 
fn recursive_expression<T: Visitor>(
 
    this: &mut T,
 
    h: &mut Heap,
 
    expr: ExpressionId,
 
) -> VisitorResult {
 
    match h[expr].clone() {
 
        Expression::Assignment(expr) => this.visit_assignment_expression(h, expr.this),
 
        Expression::Conditional(expr) => this.visit_conditional_expression(h, expr.this),
 
        Expression::Binary(expr) => this.visit_binary_expression(h, expr.this),
 
        Expression::Unary(expr) => this.visit_unary_expression(h, expr.this),
 
        Expression::Indexing(expr) => this.visit_indexing_expression(h, expr.this),
 
        Expression::Slicing(expr) => this.visit_slicing_expression(h, expr.this),
 
        Expression::Select(expr) => this.visit_select_expression(h, expr.this),
 
        Expression::Array(expr) => this.visit_array_expression(h, expr.this),
 
        Expression::Constant(expr) => this.visit_constant_expression(h, expr.this),
 
        Expression::Call(expr) => this.visit_call_expression(h, expr.this),
 
        Expression::Variable(expr) => this.visit_variable_expression(h, expr.this),
 
    }
 
}
 

	
 
fn recursive_assignment_expression<T: Visitor>(
 
    this: &mut T,
 
    h: &mut Heap,
 
    expr: AssignmentExpressionId,
 
) -> VisitorResult {
 
    this.visit_expression(h, h[expr].left)?;
 
    this.visit_expression(h, h[expr].right)
 
}
 

	
 
fn recursive_conditional_expression<T: Visitor>(
 
    this: &mut T,
 
    h: &mut Heap,
 
    expr: ConditionalExpressionId,
 
) -> VisitorResult {
 
    this.visit_expression(h, h[expr].test)?;
 
    this.visit_expression(h, h[expr].true_expression)?;
 
    this.visit_expression(h, h[expr].false_expression)
 
}
 

	
 
fn recursive_binary_expression<T: Visitor>(
 
    this: &mut T,
 
    h: &mut Heap,
 
    expr: BinaryExpressionId,
 
) -> VisitorResult {
 
    this.visit_expression(h, h[expr].left)?;
 
    this.visit_expression(h, h[expr].right)
 
}
 

	
 
fn recursive_unary_expression<T: Visitor>(
 
    this: &mut T,
 
    h: &mut Heap,
 
    expr: UnaryExpressionId,
 
) -> VisitorResult {
 
    this.visit_expression(h, h[expr].expression)
 
}
 

	
 
fn recursive_indexing_expression<T: Visitor>(
 
    this: &mut T,
 
    h: &mut Heap,
 
    expr: IndexingExpressionId,
 
) -> VisitorResult {
 
    this.visit_expression(h, h[expr].subject)?;
 
    this.visit_expression(h, h[expr].index)
 
}
 

	
 
fn recursive_slicing_expression<T: Visitor>(
 
    this: &mut T,
 
    h: &mut Heap,
 
    expr: SlicingExpressionId,
 
) -> VisitorResult {
 
    this.visit_expression(h, h[expr].subject)?;
 
    this.visit_expression(h, h[expr].from_index)?;
 
    this.visit_expression(h, h[expr].to_index)
 
}
 

	
 
fn recursive_select_expression<T: Visitor>(
 
    this: &mut T,
 
    h: &mut Heap,
 
    expr: SelectExpressionId,
 
) -> VisitorResult {
 
    this.visit_expression(h, h[expr].subject)
 
}
 

	
 
fn recursive_array_expression<T: Visitor>(
 
    this: &mut T,
 
    h: &mut Heap,
 
    expr: ArrayExpressionId,
 
) -> VisitorResult {
 
    for &expr in h[expr].elements.clone().iter() {
 
        this.visit_expression(h, expr)?;
 
    }
 
    Ok(())
 
}
 

	
 
fn recursive_call_expression<T: Visitor>(
 
    this: &mut T,
 
    h: &mut Heap,
 
    expr: CallExpressionId,
 
) -> VisitorResult {
 
    for &expr in h[expr].arguments.clone().iter() {
 
        this.visit_expression(h, expr)?;
 
    }
 
    Ok(())
 
}
 

	
 
// ====================
 
// Grammar Rules
 
// ====================
 

	
 
struct NestedSynchronousStatements {
 
    illegal: bool,
 
}
 

	
 
impl NestedSynchronousStatements {
 
    fn new() -> Self {
 
        NestedSynchronousStatements { illegal: false }
 
    }
 
}
 

	
 
impl Visitor for NestedSynchronousStatements {
 
    fn visit_composite_definition(&mut self, h: &mut Heap, def: CompositeId) -> VisitorResult {
 
        assert!(!self.illegal);
 
        self.illegal = true;
 
        recursive_composite_definition(self, h, def)?;
 
        self.illegal = false;
 
        Ok(())
 
    }
 
    fn visit_function_definition(&mut self, h: &mut Heap, def: FunctionId) -> VisitorResult {
 
        assert!(!self.illegal);
 
        self.illegal = true;
 
        recursive_function_definition(self, h, def)?;
 
        self.illegal = false;
 
        Ok(())
 
    }
 
    fn visit_synchronous_statement(
 
        &mut self,
 
        h: &mut Heap,
 
        stmt: SynchronousStatementId,
 
    ) -> VisitorResult {
 
        if self.illegal {
 
            return Err(ParseError::new(
 
                h[stmt].position(),
 
                "Illegal nested synchronous statement",
 
            ));
 
        }
 
        self.illegal = true;
 
        recursive_synchronous_statement(self, h, stmt)?;
 
        self.illegal = false;
 
        Ok(())
 
    }
 
    fn visit_expression(&mut self, _h: &mut Heap, _expr: ExpressionId) -> VisitorResult {
 
        Ok(())
 
    }
 
}
 

	
 
struct ChannelStatementOccurrences {
 
    illegal: bool,
 
}
 

	
 
impl ChannelStatementOccurrences {
 
    fn new() -> Self {
 
        ChannelStatementOccurrences { illegal: false }
 
    }
 
}
 

	
 
impl Visitor for ChannelStatementOccurrences {
 
    fn visit_primitive_definition(&mut self, h: &mut Heap, def: PrimitiveId) -> VisitorResult {
 
        assert!(!self.illegal);
 
        self.illegal = true;
 
        recursive_primitive_definition(self, h, def)?;
 
        self.illegal = false;
 
        Ok(())
 
    }
 
    fn visit_function_definition(&mut self, h: &mut Heap, def: FunctionId) -> VisitorResult {
 
        assert!(!self.illegal);
 
        self.illegal = true;
 
        recursive_function_definition(self, h, def)?;
 
        self.illegal = false;
 
        Ok(())
 
    }
 
    fn visit_channel_statement(&mut self, h: &mut Heap, stmt: ChannelStatementId) -> VisitorResult {
 
        if self.illegal {
 
            return Err(ParseError::new(h[stmt].position(), "Illegal channel delcaration"));
 
        }
 
        Ok(())
 
    }
 
    fn visit_expression(&mut self, _h: &mut Heap, _expr: ExpressionId) -> VisitorResult {
 
        Ok(())
 
    }
 
}
 

	
 
struct FunctionStatementReturns {}
 

	
 
impl FunctionStatementReturns {
 
    fn new() -> Self {
 
        FunctionStatementReturns {}
 
    }
 
    fn function_error(&self, position: InputPosition) -> VisitorResult {
 
        Err(ParseError::new(position, "Function definition must return"))
 
    }
 
}
 

	
 
impl Visitor for FunctionStatementReturns {
 
    fn visit_component_definition(&mut self, _h: &mut Heap, _def: ComponentId) -> VisitorResult {
 
        Ok(())
 
    }
 
    fn visit_variable_declaration(&mut self, _h: &mut Heap, _decl: VariableId) -> VisitorResult {
 
        Ok(())
 
    }
 
    fn visit_block_statement(&mut self, h: &mut Heap, block: BlockStatementId) -> VisitorResult {
 
        let len = h[block].statements.len();
 
        assert!(len > 0);
 
        self.visit_statement(h, h[block].statements[len - 1])
 
    }
 
    fn visit_skip_statement(&mut self, h: &mut Heap, stmt: SkipStatementId) -> VisitorResult {
 
        self.function_error(h[stmt].position)
 
    }
 
    fn visit_break_statement(&mut self, h: &mut Heap, stmt: BreakStatementId) -> VisitorResult {
 
        self.function_error(h[stmt].position)
 
    }
 
    fn visit_continue_statement(
 
        &mut self,
 
        h: &mut Heap,
 
        stmt: ContinueStatementId,
 
    ) -> VisitorResult {
 
        self.function_error(h[stmt].position)
 
    }
 
    fn visit_assert_statement(&mut self, h: &mut Heap, stmt: AssertStatementId) -> VisitorResult {
 
        self.function_error(h[stmt].position)
 
    }
 
    fn visit_new_statement(&mut self, h: &mut Heap, stmt: NewStatementId) -> VisitorResult {
 
        self.function_error(h[stmt].position)
 
    }
 
    fn visit_expression_statement(
 
        &mut self,
 
        h: &mut Heap,
 
        stmt: ExpressionStatementId,
 
    ) -> VisitorResult {
 
        self.function_error(h[stmt].position)
 
    }
 
    fn visit_expression(&mut self, _h: &mut Heap, _expr: ExpressionId) -> VisitorResult {
 
        Ok(())
 
    }
 
}
 

	
 
struct ComponentStatementReturnNew {
 
    illegal_new: bool,
 
    illegal_return: bool,
 
}
 

	
 
impl ComponentStatementReturnNew {
 
    fn new() -> Self {
 
        ComponentStatementReturnNew { illegal_new: false, illegal_return: false }
 
    }
 
}
 

	
 
impl Visitor for ComponentStatementReturnNew {
 
    fn visit_component_definition(&mut self, h: &mut Heap, def: ComponentId) -> VisitorResult {
 
        assert!(!(self.illegal_new || self.illegal_return));
 
        self.illegal_return = true;
 
        recursive_component_definition(self, h, def)?;
 
        self.illegal_return = false;
 
        Ok(())
 
    }
 
    fn visit_primitive_definition(&mut self, h: &mut Heap, def: PrimitiveId) -> VisitorResult {
 
        assert!(!self.illegal_new);
 
        self.illegal_new = true;
 
        recursive_primitive_definition(self, h, def)?;
 
        self.illegal_new = false;
 
        Ok(())
 
    }
 
    fn visit_function_definition(&mut self, h: &mut Heap, def: FunctionId) -> VisitorResult {
 
        assert!(!(self.illegal_new || self.illegal_return));
 
        self.illegal_new = true;
 
        recursive_function_definition(self, h, def)?;
 
        self.illegal_new = false;
 
        Ok(())
 
    }
 
    fn visit_variable_declaration(&mut self, _h: &mut Heap, _decl: VariableId) -> VisitorResult {
 
        Ok(())
 
    }
 
    fn visit_return_statement(&mut self, h: &mut Heap, stmt: ReturnStatementId) -> VisitorResult {
 
        if self.illegal_return {
 
            Err(ParseError::new(h[stmt].position, "Component definition must not return"))
 
        } else {
 
            recursive_return_statement(self, h, stmt)
 
        }
 
    }
 
    fn visit_new_statement(&mut self, h: &mut Heap, stmt: NewStatementId) -> VisitorResult {
 
        if self.illegal_new {
 
            Err(ParseError::new(
 
                h[stmt].position,
 
                "Symbol definition contains illegal new statement",
 
            ))
 
        } else {
 
            recursive_new_statement(self, h, stmt)
 
        }
 
    }
 
    fn visit_expression(&mut self, _h: &mut Heap, _expr: ExpressionId) -> VisitorResult {
 
        Ok(())
 
    }
 
}
 

	
 
struct CheckBuiltinOccurrences {
 
    legal: bool,
 
}
 

	
 
impl CheckBuiltinOccurrences {
 
    fn new() -> Self {
 
        CheckBuiltinOccurrences { legal: false }
 
    }
 
}
 

	
 
impl Visitor for CheckBuiltinOccurrences {
 
    fn visit_synchronous_statement(
 
        &mut self,
 
        h: &mut Heap,
 
        stmt: SynchronousStatementId,
 
    ) -> VisitorResult {
 
        assert!(!self.legal);
 
        self.legal = true;
 
        recursive_synchronous_statement(self, h, stmt)?;
 
        self.legal = false;
 
        Ok(())
 
    }
 
    fn visit_call_expression(&mut self, h: &mut Heap, expr: CallExpressionId) -> VisitorResult {
 
        match h[expr].method {
 
            Method::Get | Method::Fires => {
 
                if !self.legal {
 
                    return Err(ParseError::new(h[expr].position, "Illegal built-in occurrence"));
 
                }
 
            }
 
            _ => {}
 
        }
 
        recursive_call_expression(self, h, expr)
 
    }
 
}
 

	
 
struct BuildSymbolDeclarations {
 
    declarations: Vec<DeclarationId>,
 
}
 

	
 
impl BuildSymbolDeclarations {
 
    fn new() -> Self {
 
        BuildSymbolDeclarations { declarations: Vec::new() }
 
    }
 
    fn checked_add(&mut self, h: &mut Heap, decl: DeclarationId) -> VisitorResult {
 
        for &old in self.declarations.iter() {
 
            let id = h[decl].identifier();
 
            if h[id] == h[h[old].identifier()] {
 
                return match h[decl].clone() {
 
                    Declaration::Defined(defined) => Err(ParseError::new(
 
                        h[defined.definition].position(),
 
                        format!("Defined symbol clash: {}", h[id]),
 
                    )),
 
                    Declaration::Imported(imported) => Err(ParseError::new(
 
                        h[imported.import].position(),
 
                        format!("Imported symbol clash: {}", h[id]),
 
                    )),
 
                };
 
            }
 
        }
 
        self.declarations.push(decl);
 
        Ok(())
 
    }
 
}
 

	
 
impl Visitor for BuildSymbolDeclarations {
 
    fn visit_protocol_description(&mut self, h: &mut Heap, pd: RootId) -> VisitorResult {
 
        recursive_protocol_description(self, h, pd)?;
 
        // Move all collected declarations to the protocol description
 
        h[pd].declarations.append(&mut self.declarations);
 
        Ok(())
 
    }
 
    fn visit_import(&mut self, _h: &mut Heap, _import: ImportId) -> VisitorResult {
 
        todo!()
 
        // let vec = library::get_declarations(h, import)?;
 
        // // Destructively iterate over the vector
 
        // for decl in vec {
 
        //     self.checked_add(h, decl)?;
 
        // }
 
        // Ok(())
 
    fn visit_import(&mut self, h: &mut Heap, import: ImportId) -> VisitorResult {
 
        println!("DEBUG: Warning (at {}:{}), import actually not yet implemented", file!(), line!());
 
        let vec = library::get_declarations(h, import)?;
 
        // Destructively iterate over the vector
 
        for decl in vec {
 
            self.checked_add(h, decl)?;
 
        }
 
        Ok(())
 
    }
 
    fn visit_symbol_definition(&mut self, h: &mut Heap, definition: DefinitionId) -> VisitorResult {
 
        let signature = Signature::from_definition(h, definition);
 
        let decl = h
 
            .alloc_defined_declaration(|this| DefinedDeclaration { this, definition, signature })
 
            .upcast();
 
        self.checked_add(h, decl)?;
 
        Ok(())
 
    }
 
}
 

	
 
struct LinkCallExpressions {
 
    pd: Option<RootId>,
 
    composite: bool,
 
    new_statement: bool,
 
}
 

	
 
impl LinkCallExpressions {
 
    fn new() -> Self {
 
        LinkCallExpressions { pd: None, composite: false, new_statement: false }
 
    }
 
    fn get_declaration(
 
        &self,
 
        h: &Heap,
 
        id: SourceIdentifierId,
 
    ) -> Result<DeclarationId, ParseError> {
 
        match h[self.pd.unwrap()].get_declaration(h, id.upcast()) {
 
            Some(id) => Ok(id),
 
            None => Err(ParseError::new(h[id].position, "Unresolved method")),
 
        }
 
    }
 
}
 

	
 
impl Visitor for LinkCallExpressions {
 
    fn visit_protocol_description(&mut self, h: &mut Heap, pd: RootId) -> VisitorResult {
 
        self.pd = Some(pd);
 
        recursive_protocol_description(self, h, pd)?;
 
        self.pd = None;
 
        Ok(())
 
    }
 
    fn visit_composite_definition(&mut self, h: &mut Heap, def: CompositeId) -> VisitorResult {
 
        assert!(!self.composite);
 
        self.composite = true;
 
        recursive_composite_definition(self, h, def)?;
 
        self.composite = false;
 
        Ok(())
 
    }
 
    fn visit_new_statement(&mut self, h: &mut Heap, stmt: NewStatementId) -> VisitorResult {
 
        assert!(self.composite);
 
        assert!(!self.new_statement);
 
        self.new_statement = true;
 
        recursive_new_statement(self, h, stmt)?;
 
        self.new_statement = false;
 
        Ok(())
 
    }
 
    fn visit_call_expression(&mut self, h: &mut Heap, expr: CallExpressionId) -> VisitorResult {
 
        if let Method::Symbolic(id) = h[expr].method {
 
            let decl = self.get_declaration(h, id)?;
 
            if self.new_statement && h[decl].is_function() {
 
                return Err(ParseError::new(h[id].position, "Illegal call expression"));
 
            }
 
            if !self.new_statement && h[decl].is_component() {
 
                return Err(ParseError::new(h[id].position, "Illegal call expression"));
 
            }
 
            // Set the corresponding declaration of the call
 
            h[expr].declaration = Some(decl);
 
        }
 
        // A new statement's call expression may have as arguments function calls
 
        let old = self.new_statement;
 
        self.new_statement = false;
 
        recursive_call_expression(self, h, expr)?;
 
        self.new_statement = old;
 
        Ok(())
 
    }
 
}
 

	
 
struct BuildScope {
 
    scope: Option<Scope>,
 
}
 

	
 
impl BuildScope {
 
    fn new() -> Self {
 
        BuildScope { scope: None }
 
    }
 
}
 

	
 
impl Visitor for BuildScope {
 
    fn visit_symbol_definition(&mut self, h: &mut Heap, def: DefinitionId) -> VisitorResult {
 
        assert!(self.scope.is_none());
 
        self.scope = Some(Scope::Definition(def));
 
        recursive_symbol_definition(self, h, def)?;
 
        self.scope = None;
 
        Ok(())
 
    }
 
    fn visit_block_statement(&mut self, h: &mut Heap, stmt: BlockStatementId) -> VisitorResult {
 
        assert!(!self.scope.is_none());
 
        let old = self.scope;
 
        // First store the current scope
 
        h[stmt].parent_scope = self.scope;
 
        // Then move scope down to current block
 
        self.scope = Some(Scope::Block(stmt));
 
        recursive_block_statement(self, h, stmt)?;
 
        // Move scope back up
 
        self.scope = old;
 
        Ok(())
 
    }
 
    fn visit_synchronous_statement(
 
        &mut self,
 
        h: &mut Heap,
 
        stmt: SynchronousStatementId,
 
    ) -> VisitorResult {
 
        assert!(!self.scope.is_none());
 
        let old = self.scope;
 
        // First store the current scope
 
        h[stmt].parent_scope = self.scope;
 
        // Then move scope down to current sync
 
        self.scope = Some(Scope::Synchronous(stmt));
 
        recursive_synchronous_statement(self, h, stmt)?;
 
        // Move scope back up
 
        self.scope = old;
 
        Ok(())
 
    }
 
    fn visit_expression(&mut self, _h: &mut Heap, _expr: ExpressionId) -> VisitorResult {
 
        Ok(())
 
    }
 
}
 

	
 
struct ResolveVariables {
 
    scope: Option<Scope>,
 
}
 

	
 
impl ResolveVariables {
 
    fn new() -> Self {
 
        ResolveVariables { scope: None }
 
    }
 
    fn get_variable(&self, h: &Heap, id: SourceIdentifierId) -> Result<VariableId, ParseError> {
 
        if let Some(var) = self.find_variable(h, id) {
 
            Ok(var)
 
        } else {
 
            Err(ParseError::new(h[id].position, "Unresolved variable"))
 
        }
 
    }
 
    fn find_variable(&self, h: &Heap, id: SourceIdentifierId) -> Option<VariableId> {
 
        ResolveVariables::find_variable_impl(h, self.scope, id)
 
    }
 
    fn find_variable_impl(
 
        h: &Heap,
 
        scope: Option<Scope>,
 
        id: SourceIdentifierId,
 
    ) -> Option<VariableId> {
 
        if let Some(scope) = scope {
 
            // The order in which we check for variables is important:
 
            // otherwise, two variables with the same name are shadowed.
 
            if let Some(var) = ResolveVariables::find_variable_impl(h, scope.parent_scope(h), id) {
 
                Some(var)
 
            } else {
 
                scope.get_variable(h, id)
 
            }
 
        } else {
 
            None
 
        }
 
    }
 
}
 

	
 
impl Visitor for ResolveVariables {
 
    fn visit_symbol_definition(&mut self, h: &mut Heap, def: DefinitionId) -> VisitorResult {
 
        assert!(self.scope.is_none());
 
        self.scope = Some(Scope::Definition(def));
 
        recursive_symbol_definition(self, h, def)?;
 
        self.scope = None;
 
        Ok(())
 
    }
 
    fn visit_variable_declaration(&mut self, h: &mut Heap, decl: VariableId) -> VisitorResult {
 
        // This is only called for parameters of definitions and synchronous statements,
 
        // since the local variables of block statements are still empty
 
        // the moment it is traversed. After resolving variables, this
 
        // function is also called for every local variable declaration.
 

	
 
        // We want to make sure that the resolved variable is the variable declared itself;
 
        // otherwise, there is some variable defined in the parent scope. This check
 
        // imposes that the order in which find_variable looks is significant!
 
        let id = h[decl].identifier();
 
        let check_same = self.find_variable(h, id);
 
        if let Some(check_same) = check_same {
 
            if check_same != decl {
 
                return Err(ParseError::new(h[id].position, "Declared variable clash"));
 
            }
 
        }
 
        recursive_variable_declaration(self, h, decl)
 
    }
 
    fn visit_memory_statement(&mut self, h: &mut Heap, stmt: MemoryStatementId) -> VisitorResult {
 
        assert!(!self.scope.is_none());
 
        let var = h[stmt].variable;
 
        let id = h[var].identifier;
 
        // First check whether variable with same identifier is in scope
 
        let check_duplicate = self.find_variable(h, id);
 
        if check_duplicate.is_some() {
 
            return Err(ParseError::new(h[id].position, "Declared variable clash"));
 
        }
 
        // Then check the expression's variables (this should not refer to own variable)
 
        recursive_memory_statement(self, h, stmt)?;
 
        // Finally, we may add the variable to the scope, which is guaranteed to be a block
 
        {
 
            let block = &mut h[self.scope.unwrap().to_block()];
 
            block.locals.push(var);
 
        }
 
        Ok(())
 
    }
 
    fn visit_channel_statement(&mut self, h: &mut Heap, stmt: ChannelStatementId) -> VisitorResult {
 
        assert!(!self.scope.is_none());
 
        // First handle the from variable
 
        {
 
            let var = h[stmt].from;
 
            let id = h[var].identifier;
 
            let check_duplicate = self.find_variable(h, id);
 
            if check_duplicate.is_some() {
 
                return Err(ParseError::new(h[id].position, "Declared variable clash"));
 
            }
 
            let block = &mut h[self.scope.unwrap().to_block()];
 
            block.locals.push(var);
 
        }
 
        // Then handle the to variable (which may not be the same as the from)
 
        {
 
            let var = h[stmt].to;
 
            let id = h[var].identifier;
 
            let check_duplicate = self.find_variable(h, id);
 
            if check_duplicate.is_some() {
 
                return Err(ParseError::new(h[id].position, "Declared variable clash"));
 
            }
 
            let block = &mut h[self.scope.unwrap().to_block()];
 
            block.locals.push(var);
 
        }
 
        Ok(())
 
    }
 
    fn visit_block_statement(&mut self, h: &mut Heap, stmt: BlockStatementId) -> VisitorResult {
 
        assert!(!self.scope.is_none());
 
        let old = self.scope;
 
        self.scope = Some(Scope::Block(stmt));
 
        recursive_block_statement(self, h, stmt)?;
 
        self.scope = old;
 
        Ok(())
 
    }
 
    fn visit_synchronous_statement(
 
        &mut self,
 
        h: &mut Heap,
 
        stmt: SynchronousStatementId,
 
    ) -> VisitorResult {
 
        assert!(!self.scope.is_none());
 
        let old = self.scope;
 
        self.scope = Some(Scope::Synchronous(stmt));
 
        recursive_synchronous_statement(self, h, stmt)?;
 
        self.scope = old;
 
        Ok(())
 
    }
 
    fn visit_variable_expression(
 
        &mut self,
 
        h: &mut Heap,
 
        expr: VariableExpressionId,
 
    ) -> VisitorResult {
 
        let var = self.get_variable(h, h[expr].identifier)?;
 
        h[expr].declaration = Some(var);
 
        Ok(())
 
    }
 
}
 

	
 
struct UniqueStatementId(StatementId);
 

	
 
struct LinkStatements {
 
    prev: Option<UniqueStatementId>,
 
}
 

	
 
impl LinkStatements {
 
    fn new() -> Self {
 
        LinkStatements { prev: None }
 
    }
 
}
 

	
 
impl Visitor for LinkStatements {
 
    fn visit_symbol_definition(&mut self, h: &mut Heap, def: DefinitionId) -> VisitorResult {
 
        assert!(self.prev.is_none());
 
        recursive_symbol_definition(self, h, def)?;
 
        // Clear out last statement
 
        self.prev = None;
 
        Ok(())
 
    }
 
    fn visit_statement(&mut self, h: &mut Heap, stmt: StatementId) -> VisitorResult {
 
        if let Some(UniqueStatementId(prev)) = self.prev.take() {
 
            h[prev].link_next(stmt);
 
        }
 
        recursive_statement(self, h, stmt)
 
    }
 
    fn visit_local_statement(&mut self, _h: &mut Heap, stmt: LocalStatementId) -> VisitorResult {
 
        self.prev = Some(UniqueStatementId(stmt.upcast()));
 
        Ok(())
 
    }
 
    fn visit_labeled_statement(&mut self, h: &mut Heap, stmt: LabeledStatementId) -> VisitorResult {
 
        recursive_labeled_statement(self, h, stmt)
 
    }
 
    fn visit_skip_statement(&mut self, _h: &mut Heap, stmt: SkipStatementId) -> VisitorResult {
 
        self.prev = Some(UniqueStatementId(stmt.upcast()));
 
        Ok(())
 
    }
 
    fn visit_if_statement(&mut self, h: &mut Heap, stmt: IfStatementId) -> VisitorResult {
 
        // We allocate a pseudo-statement, which combines both branches into one next statement
 
        let position = h[stmt].position;
 
        let pseudo =
 
            h.alloc_end_if_statement(|this| EndIfStatement { this, position, next: None }).upcast();
 
        assert!(self.prev.is_none());
 
        self.visit_statement(h, h[stmt].true_body)?;
 
        if let Some(UniqueStatementId(prev)) = self.prev.take() {
 
            h[prev].link_next(pseudo);
 
        }
 
        assert!(self.prev.is_none());
 
        self.visit_statement(h, h[stmt].false_body)?;
 
        if let Some(UniqueStatementId(prev)) = self.prev.take() {
 
            h[prev].link_next(pseudo);
 
        }
 
        // Use the pseudo-statement as the statement where to update the next pointer
 
        self.prev = Some(UniqueStatementId(pseudo));
 
        Ok(())
 
    }
 
    fn visit_while_statement(&mut self, h: &mut Heap, stmt: WhileStatementId) -> VisitorResult {
 
        // We allocate a pseudo-statement, to which the break statement finds its target
 
        let position = h[stmt].position;
 
        let pseudo =
 
            h.alloc_end_while_statement(|this| EndWhileStatement { this, position, next: None });
 
        // Update the while's next statement to point to the pseudo-statement
 
        h[stmt].next = Some(pseudo);
 
        assert!(self.prev.is_none());
 
        self.visit_statement(h, h[stmt].body)?;
 
        // The body's next statement loops back to the while statement itself
 
        // Note: continue statements also loop back to the while statement itself
 
        if let Some(UniqueStatementId(prev)) = std::mem::replace(&mut self.prev, None) {
 
            h[prev].link_next(stmt.upcast());
 
        }
 
        // Use the while statement as the statement where the next pointer is updated
 
        self.prev = Some(UniqueStatementId(pseudo.upcast()));
 
        Ok(())
 
    }
 
    fn visit_break_statement(&mut self, _h: &mut Heap, _stmt: BreakStatementId) -> VisitorResult {
 
        Ok(())
 
    }
 
    fn visit_continue_statement(
 
        &mut self,
 
        _h: &mut Heap,
 
        _stmt: ContinueStatementId,
 
    ) -> VisitorResult {
 
        Ok(())
 
    }
 
    fn visit_synchronous_statement(
 
        &mut self,
 
        h: &mut Heap,
 
        stmt: SynchronousStatementId,
 
    ) -> VisitorResult {
 
        // Allocate a pseudo-statement, that is added for helping the evaluator to issue a command
 
        // that marks the end of the synchronous block. Every evaluation has to pause at this
 
        // point, only to resume later when the thread is selected as unique thread to continue.
 
        let position = h[stmt].position;
 
        let pseudo = h
 
            .alloc_end_synchronous_statement(|this| EndSynchronousStatement {
 
                this,
 
                position,
 
                next: None,
 
            })
 
            .upcast();
 
        assert!(self.prev.is_none());
 
        self.visit_statement(h, h[stmt].body)?;
 
        // The body's next statement points to the pseudo element
 
        if let Some(UniqueStatementId(prev)) = std::mem::replace(&mut self.prev, None) {
 
            h[prev].link_next(pseudo);
 
        }
 
        // Use the pseudo-statement as the statement where the next pointer is updated
 
        self.prev = Some(UniqueStatementId(pseudo));
 
        Ok(())
 
    }
 
    fn visit_return_statement(&mut self, _h: &mut Heap, _stmt: ReturnStatementId) -> VisitorResult {
 
        Ok(())
 
    }
 
    fn visit_assert_statement(&mut self, _h: &mut Heap, stmt: AssertStatementId) -> VisitorResult {
 
        self.prev = Some(UniqueStatementId(stmt.upcast()));
 
        Ok(())
 
    }
 
    fn visit_goto_statement(&mut self, _h: &mut Heap, _stmt: GotoStatementId) -> VisitorResult {
 
        Ok(())
 
@@ -1440,447 +1440,533 @@ impl Visitor for ResolveLabels {
 
        Ok(())
 
    }
 
}
 

	
 
struct AssignableExpressions {
 
    assignable: bool,
 
}
 

	
 
impl AssignableExpressions {
 
    fn new() -> Self {
 
        AssignableExpressions { assignable: false }
 
    }
 
    fn error(&self, position: InputPosition) -> VisitorResult {
 
        Err(ParseError::new(position, "Unassignable expression"))
 
    }
 
}
 

	
 
impl Visitor for AssignableExpressions {
 
    fn visit_assignment_expression(
 
        &mut self,
 
        h: &mut Heap,
 
        expr: AssignmentExpressionId,
 
    ) -> VisitorResult {
 
        if self.assignable {
 
            self.error(h[expr].position)
 
        } else {
 
            self.assignable = true;
 
            self.visit_expression(h, h[expr].left)?;
 
            self.assignable = false;
 
            self.visit_expression(h, h[expr].right)
 
        }
 
    }
 
    fn visit_conditional_expression(
 
        &mut self,
 
        h: &mut Heap,
 
        expr: ConditionalExpressionId,
 
    ) -> VisitorResult {
 
        if self.assignable {
 
            self.error(h[expr].position)
 
        } else {
 
            recursive_conditional_expression(self, h, expr)
 
        }
 
    }
 
    fn visit_binary_expression(&mut self, h: &mut Heap, expr: BinaryExpressionId) -> VisitorResult {
 
        if self.assignable {
 
            self.error(h[expr].position)
 
        } else {
 
            recursive_binary_expression(self, h, expr)
 
        }
 
    }
 
    fn visit_unary_expression(&mut self, h: &mut Heap, expr: UnaryExpressionId) -> VisitorResult {
 
        if self.assignable {
 
            self.error(h[expr].position)
 
        } else {
 
            match h[expr].operation {
 
                UnaryOperation::PostDecrement
 
                | UnaryOperation::PreDecrement
 
                | UnaryOperation::PostIncrement
 
                | UnaryOperation::PreIncrement => {
 
                    self.assignable = true;
 
                    recursive_unary_expression(self, h, expr)?;
 
                    self.assignable = false;
 
                    Ok(())
 
                }
 
                _ => recursive_unary_expression(self, h, expr),
 
            }
 
        }
 
    }
 
    fn visit_indexing_expression(
 
        &mut self,
 
        h: &mut Heap,
 
        expr: IndexingExpressionId,
 
    ) -> VisitorResult {
 
        let old = self.assignable;
 
        self.assignable = false;
 
        recursive_indexing_expression(self, h, expr)?;
 
        self.assignable = old;
 
        Ok(())
 
    }
 
    fn visit_slicing_expression(
 
        &mut self,
 
        h: &mut Heap,
 
        expr: SlicingExpressionId,
 
    ) -> VisitorResult {
 
        let old = self.assignable;
 
        self.assignable = false;
 
        recursive_slicing_expression(self, h, expr)?;
 
        self.assignable = old;
 
        Ok(())
 
    }
 
    fn visit_select_expression(&mut self, h: &mut Heap, expr: SelectExpressionId) -> VisitorResult {
 
        if h[expr].field.is_length() && self.assignable {
 
            return self.error(h[expr].position);
 
        }
 
        let old = self.assignable;
 
        self.assignable = false;
 
        recursive_select_expression(self, h, expr)?;
 
        self.assignable = old;
 
        Ok(())
 
    }
 
    fn visit_array_expression(&mut self, h: &mut Heap, expr: ArrayExpressionId) -> VisitorResult {
 
        if self.assignable {
 
            self.error(h[expr].position)
 
        } else {
 
            recursive_array_expression(self, h, expr)
 
        }
 
    }
 
    fn visit_call_expression(&mut self, h: &mut Heap, expr: CallExpressionId) -> VisitorResult {
 
        if self.assignable {
 
            self.error(h[expr].position)
 
        } else {
 
            recursive_call_expression(self, h, expr)
 
        }
 
    }
 
    fn visit_constant_expression(
 
        &mut self,
 
        h: &mut Heap,
 
        expr: ConstantExpressionId,
 
    ) -> VisitorResult {
 
        if self.assignable {
 
            self.error(h[expr].position)
 
        } else {
 
            Ok(())
 
        }
 
    }
 
    fn visit_variable_expression(
 
        &mut self,
 
        _h: &mut Heap,
 
        _expr: VariableExpressionId,
 
    ) -> VisitorResult {
 
        Ok(())
 
    }
 
}
 

	
 
struct IndexableExpressions {
 
    indexable: bool,
 
}
 

	
 
impl IndexableExpressions {
 
    fn new() -> Self {
 
        IndexableExpressions { indexable: false }
 
    }
 
    fn error(&self, position: InputPosition) -> VisitorResult {
 
        Err(ParseError::new(position, "Unindexable expression"))
 
    }
 
}
 

	
 
impl Visitor for IndexableExpressions {
 
    fn visit_assignment_expression(
 
        &mut self,
 
        h: &mut Heap,
 
        expr: AssignmentExpressionId,
 
    ) -> VisitorResult {
 
        if self.indexable {
 
            self.error(h[expr].position)
 
        } else {
 
            recursive_assignment_expression(self, h, expr)
 
        }
 
    }
 
    fn visit_conditional_expression(
 
        &mut self,
 
        h: &mut Heap,
 
        expr: ConditionalExpressionId,
 
    ) -> VisitorResult {
 
        let old = self.indexable;
 
        self.indexable = false;
 
        self.visit_expression(h, h[expr].test)?;
 
        self.indexable = old;
 
        self.visit_expression(h, h[expr].true_expression)?;
 
        self.visit_expression(h, h[expr].false_expression)
 
    }
 
    fn visit_binary_expression(&mut self, h: &mut Heap, expr: BinaryExpressionId) -> VisitorResult {
 
        if self.indexable && h[expr].operation != BinaryOperator::Concatenate {
 
            self.error(h[expr].position)
 
        } else {
 
            recursive_binary_expression(self, h, expr)
 
        }
 
    }
 
    fn visit_unary_expression(&mut self, h: &mut Heap, expr: UnaryExpressionId) -> VisitorResult {
 
        if self.indexable {
 
            self.error(h[expr].position)
 
        } else {
 
            recursive_unary_expression(self, h, expr)
 
        }
 
    }
 
    fn visit_indexing_expression(
 
        &mut self,
 
        h: &mut Heap,
 
        expr: IndexingExpressionId,
 
    ) -> VisitorResult {
 
        let old = self.indexable;
 
        self.indexable = true;
 
        self.visit_expression(h, h[expr].subject)?;
 
        self.indexable = false;
 
        self.visit_expression(h, h[expr].index)?;
 
        self.indexable = old;
 
        Ok(())
 
    }
 
    fn visit_slicing_expression(
 
        &mut self,
 
        h: &mut Heap,
 
        expr: SlicingExpressionId,
 
    ) -> VisitorResult {
 
        let old = self.indexable;
 
        self.indexable = true;
 
        self.visit_expression(h, h[expr].subject)?;
 
        self.indexable = false;
 
        self.visit_expression(h, h[expr].from_index)?;
 
        self.visit_expression(h, h[expr].to_index)?;
 
        self.indexable = old;
 
        Ok(())
 
    }
 
    fn visit_select_expression(&mut self, h: &mut Heap, expr: SelectExpressionId) -> VisitorResult {
 
        let old = self.indexable;
 
        self.indexable = false;
 
        recursive_select_expression(self, h, expr)?;
 
        self.indexable = old;
 
        Ok(())
 
    }
 
    fn visit_array_expression(&mut self, h: &mut Heap, expr: ArrayExpressionId) -> VisitorResult {
 
        let old = self.indexable;
 
        self.indexable = false;
 
        recursive_array_expression(self, h, expr)?;
 
        self.indexable = old;
 
        Ok(())
 
    }
 
    fn visit_call_expression(&mut self, h: &mut Heap, expr: CallExpressionId) -> VisitorResult {
 
        let old = self.indexable;
 
        self.indexable = false;
 
        recursive_call_expression(self, h, expr)?;
 
        self.indexable = old;
 
        Ok(())
 
    }
 
    fn visit_constant_expression(
 
        &mut self,
 
        h: &mut Heap,
 
        expr: ConstantExpressionId,
 
    ) -> VisitorResult {
 
        if self.indexable {
 
            self.error(h[expr].position)
 
        } else {
 
            Ok(())
 
        }
 
    }
 
}
 

	
 
struct SelectableExpressions {
 
    selectable: bool,
 
}
 

	
 
impl SelectableExpressions {
 
    fn new() -> Self {
 
        SelectableExpressions { selectable: false }
 
    }
 
    fn error(&self, position: InputPosition) -> VisitorResult {
 
        Err(ParseError::new(position, "Unselectable expression"))
 
    }
 
}
 

	
 
impl Visitor for SelectableExpressions {
 
    fn visit_assignment_expression(
 
        &mut self,
 
        h: &mut Heap,
 
        expr: AssignmentExpressionId,
 
    ) -> VisitorResult {
 
        // left-hand side of assignment can be skipped
 
        let old = self.selectable;
 
        self.selectable = false;
 
        self.visit_expression(h, h[expr].right)?;
 
        self.selectable = old;
 
        Ok(())
 
    }
 
    fn visit_conditional_expression(
 
        &mut self,
 
        h: &mut Heap,
 
        expr: ConditionalExpressionId,
 
    ) -> VisitorResult {
 
        let old = self.selectable;
 
        self.selectable = false;
 
        self.visit_expression(h, h[expr].test)?;
 
        self.selectable = old;
 
        self.visit_expression(h, h[expr].true_expression)?;
 
        self.visit_expression(h, h[expr].false_expression)
 
    }
 
    fn visit_binary_expression(&mut self, h: &mut Heap, expr: BinaryExpressionId) -> VisitorResult {
 
        if self.selectable && h[expr].operation != BinaryOperator::Concatenate {
 
            self.error(h[expr].position)
 
        } else {
 
            recursive_binary_expression(self, h, expr)
 
        }
 
    }
 
    fn visit_unary_expression(&mut self, h: &mut Heap, expr: UnaryExpressionId) -> VisitorResult {
 
        if self.selectable {
 
            self.error(h[expr].position)
 
        } else {
 
            recursive_unary_expression(self, h, expr)
 
        }
 
    }
 
    fn visit_indexing_expression(
 
        &mut self,
 
        h: &mut Heap,
 
        expr: IndexingExpressionId,
 
    ) -> VisitorResult {
 
        let old = self.selectable;
 
        self.selectable = false;
 
        recursive_indexing_expression(self, h, expr)?;
 
        self.selectable = old;
 
        Ok(())
 
    }
 
    fn visit_slicing_expression(
 
        &mut self,
 
        h: &mut Heap,
 
        expr: SlicingExpressionId,
 
    ) -> VisitorResult {
 
        let old = self.selectable;
 
        self.selectable = false;
 
        recursive_slicing_expression(self, h, expr)?;
 
        self.selectable = old;
 
        Ok(())
 
    }
 
    fn visit_select_expression(&mut self, h: &mut Heap, expr: SelectExpressionId) -> VisitorResult {
 
        let old = self.selectable;
 
        self.selectable = false;
 
        recursive_select_expression(self, h, expr)?;
 
        self.selectable = old;
 
        Ok(())
 
    }
 
    fn visit_array_expression(&mut self, h: &mut Heap, expr: ArrayExpressionId) -> VisitorResult {
 
        let old = self.selectable;
 
        self.selectable = false;
 
        recursive_array_expression(self, h, expr)?;
 
        self.selectable = old;
 
        Ok(())
 
    }
 
    fn visit_call_expression(&mut self, h: &mut Heap, expr: CallExpressionId) -> VisitorResult {
 
        let old = self.selectable;
 
        self.selectable = false;
 
        recursive_call_expression(self, h, expr)?;
 
        self.selectable = old;
 
        Ok(())
 
    }
 
    fn visit_constant_expression(
 
        &mut self,
 
        h: &mut Heap,
 
        expr: ConstantExpressionId,
 
    ) -> VisitorResult {
 
        if self.selectable {
 
            self.error(h[expr].position)
 
        } else {
 
            Ok(())
 
        }
 
    }
 
}
 

	
 
pub struct Parser<'a> {
 
    source: &'a mut InputSource,
 
}
 

	
 
impl<'a> Parser<'a> {
 
    pub fn new(source: &'a mut InputSource) -> Self {
 
        Parser { source }
 
    }
 
    pub fn parse(&mut self, h: &mut Heap) -> Result<RootId, ParseError> {
 
        let mut lex = Lexer::new(self.source);
 
        let pd = lex.consume_protocol_description(h)?;
 
        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(pd)
 
    }
 
}
 

	
 
// #[cfg(test)]
 
// mod tests {
 
//     extern crate test_generator;
 

	
 
//     use std::fs::File;
 
//     use std::io::Read;
 
//     use std::path::Path;
 

	
 
//     use test_generator::test_resources;
 

	
 
//     use super::*;
 

	
 
//     #[test_resources("testdata/parser/positive/*.pdl")]
 
//     fn batch1(resource: &str) {
 
//         let path = Path::new(resource);
 
//         let mut heap = Heap::new();
 
//         let mut source = InputSource::from_file(&path).unwrap();
 
//         let mut parser = Parser::new(&mut source);
 
//         match parser.parse(&mut heap) {
 
//             Ok(_) => {}
 
//             Err(err) => {
 
//                 println!("{}", err.display(&source));
 
//                 println!("{:?}", err);
 
//                 assert!(false);
 
//             }
 
//         }
 
//     }
 

	
 
//     #[test_resources("testdata/parser/negative/*.pdl")]
 
//     fn batch2(resource: &str) {
 
//         let path = Path::new(resource);
 
//         let expect = path.with_extension("txt");
 
//         let mut heap = Heap::new();
 
//         let mut source = InputSource::from_file(&path).unwrap();
 
//         let mut parser = Parser::new(&mut source);
 
//         match parser.parse(&mut heap) {
 
//             Ok(pd) => {
 
//                 println!("{:?}", heap[pd]);
 
//                 println!("Expected parse error:");
 

	
 
//                 let mut cev: Vec<u8> = Vec::new();
 
//                 let mut f = File::open(expect).unwrap();
 
//                 f.read_to_end(&mut cev).unwrap();
 
//                 println!("{}", String::from_utf8_lossy(&cev));
 
//                 assert!(false);
 
//             }
 
//             Err(err) => {
 
//                 println!("{:?}", err);
 

	
 
//                 let mut vec: Vec<u8> = Vec::new();
 
//                 err.write(&source, &mut vec).unwrap();
 
//                 println!("{}", String::from_utf8_lossy(&vec));
 

	
 
//                 let mut cev: Vec<u8> = Vec::new();
 
//                 let mut f = File::open(expect).unwrap();
 
//                 f.read_to_end(&mut cev).unwrap();
 
//                 println!("{}", String::from_utf8_lossy(&cev));
 

	
 
//                 assert_eq!(vec, cev);
 
//             }
 
//         }
 
//     }
 
// }
 
#[cfg(test)]
 
mod tests {
 
    use std::fs::File;
 
    use std::io::Read;
 
    use std::path::Path;
 

	
 
    use super::*;
 

	
 
    #[test]
 
    fn positive_tests() {
 
        for resource in TestFileIter::new("testdata/parser/positive", "pdl") {
 
            let resource = resource.expect("read testdata filepath");
 
            // println!(" * running: {}", &resource);
 
            let path = Path::new(&resource);
 
            let mut heap = Heap::new();
 
            let mut source = InputSource::from_file(&path).unwrap();
 
            // println!("DEBUG -- input:\n{}", String::from_utf8_lossy(&source.input));
 
            let mut parser = Parser::new(&mut source);
 
            match parser.parse(&mut heap) {
 
                Ok(_) => {}
 
                Err(err) => {
 
                    println!(" > file: {}", &resource);
 
                    println!("{}", err.display(&source));
 
                    println!("{:?}", err);
 
                    assert!(false);
 
                }
 
            }
 
        }
 
    }
 

	
 
    #[test]
 
    fn negative_tests() {
 
        for resource in TestFileIter::new("testdata/parser/negative", "pdl") {
 
            let resource = resource.expect("read testdata filepath");
 
            let path = Path::new(&resource);
 
            let expect = path.with_extension("txt");
 
            let mut heap = Heap::new();
 
            let mut source = InputSource::from_file(&path).unwrap();
 
            let mut parser = Parser::new(&mut source);
 
            match parser.parse(&mut heap) {
 
                Ok(pd) => {
 
                    println!("{:?}", heap[pd]);
 
                    println!("Expected parse error:");
 

	
 
                    let mut cev: Vec<u8> = Vec::new();
 
                    let mut f = File::open(expect).unwrap();
 
                    f.read_to_end(&mut cev).unwrap();
 
                    println!("{}", String::from_utf8_lossy(&cev));
 
                    assert!(false);
 
                }
 
                Err(err) => {
 
                    println!("{:?}", err);
 

	
 
                    let mut vec: Vec<u8> = Vec::new();
 
                    err.write(&source, &mut vec).unwrap();
 
                    println!("{}", String::from_utf8_lossy(&vec));
 

	
 
                    let mut cev: Vec<u8> = Vec::new();
 
                    let mut f = File::open(expect).unwrap();
 
                    f.read_to_end(&mut cev).unwrap();
 
                    println!("{}", String::from_utf8_lossy(&cev));
 

	
 
                    assert_eq!(vec, cev);
 
                }
 
            }
 
        }
 
    }
 

	
 
    #[test]
 
    fn counterexample_tests() {
 
        for resource in TestFileIter::new("testdata/parser/counterexamples", "pdl") {
 
            let resource = resource.expect("read testdata filepath");
 
            let path = Path::new(&resource);
 
            let mut heap = Heap::new();
 
            let mut source = InputSource::from_file(&path).unwrap();
 
            let mut parser = Parser::new(&mut source);
 

	
 
            fn print_header(s: &str) {
 
                println!("{}", "=".repeat(80));
 
                println!(" > File: {}", s);
 
                println!("{}", "=".repeat(80));
 
            }
 

	
 
            match parser.parse(&mut heap) {
 
                Ok(parsed) => {
 
                    print_header(&resource);
 
                    println!("\n  SUCCESS\n\n --- source:\n{}", String::from_utf8_lossy(&source.input));
 
                },
 
                Err(err) => {
 
                    print_header(&resource);
 

	
 
                    let mut err_buf = Vec::new();
 
                    err.write(&source, &mut err_buf);
 
                    println!(
 
                        "\n  FAILURE\n\n --- error:\n{}\n --- source:\n{}",
 
                        String::from_utf8_lossy(&err_buf),
 
                        String::from_utf8_lossy(&source.input)
 
                    )
 
                }
 
            }
 
        }
 
    }
 

	
 
    struct TestFileIter {
 
        iter: std::fs::ReadDir,
 
        root: String,
 
        extension: String
 
    }
 

	
 
    impl TestFileIter {
 
        fn new(root_dir: &str, extension: &str) -> Self {
 
            let path = Path::new(root_dir);
 
            assert!(path.is_dir(), "root '{}' is not a directory", root_dir);
 

	
 
            let iter = std::fs::read_dir(path).expect("list dir contents");
 

	
 
            Self {
 
                iter,
 
                root: root_dir.to_string(),
 
                extension: extension.to_string(),
 
            }
 
        }
 
    }
 

	
 
    impl Iterator for TestFileIter {
 
        type Item = Result<String, String>;
 

	
 
        fn next(&mut self) -> Option<Self::Item> {
 
            while let Some(entry) = self.iter.next() {
 
                if let Err(e) = entry {
 
                    return Some(Err(format!("failed to read dir entry, because: {}", e)));
 
                }
 
                let entry = entry.unwrap();
 

	
 
                let path = entry.path();
 
                if !path.is_file() { continue; }
 

	
 
                let extension = path.extension();
 
                if extension.is_none() { continue; }
 
                let extension = extension.unwrap().to_string_lossy();
 
                if extension != self.extension { continue; }
 

	
 
                return Some(Ok(path.to_string_lossy().to_string()));
 
            }
 

	
 
            None
 
        }
 
    }
 
}
testdata/parser/counterexamples/arity_checking.pdl
Show inline comments
 
new file 100644
 

	
 
int funcy() {
 
    return 5;
 
}
 

	
 
int funcadelic(int a) {
 
    return  a;
 
}
 

	
 
int caller() {
 
    funcy();
 
    funcy(1);
 
    funcy(1, 2, 3);
 
    funcadelic();
 
    funcadelic(5);
 
    return funcadelic(1, 2, 3);
 
}
testdata/parser/counterexamples/declaration_after_function_call.pdl
Show inline comments
 
new file 100644
 
#version 1
 
// My bad: C-ism of declarations on top
 

	
 
int func_b() {
 
    return 5;
 
}
 

	
 
int func_a() {
 
    int a = 2; int b = 3;
 
    int c = 5; func_b(c);
 
    int e = 3;
 

	
 
    return b;
 
}
testdata/parser/counterexamples/definition_order.pdl
Show inline comments
 
new file 100644
 
#version 1
 
// My bad: C-ism of declarations on top
 

	
 
int call_me(int later) {
 
    return later;
 
}
 

	
 
int function() {
 
    int a = 2;
 
    int b = 3;
 

	
 
    int d = call_me(b); // succeeds, because of assignment
 
    call_me(b); // bare function call seems to work, unless we perform assignment afterwards
 

	
 
    int d = 5;
 

	
 
    return 2;
 
}
 
\ No newline at end of file
testdata/parser/counterexamples/empty_file_reporting.pdl
Show inline comments
 
new file 100644
 
// This seems silly, but should be more neatly reported
 
#version 1
 
\ No newline at end of file
testdata/parser/counterexamples/function_type_checks.pdl
Show inline comments
 
new file 100644
 
// Note sure if this is allowed. It seems silly, but could be useful to
 
// select ports to return from. In any case, we are returning an out port from
 
// a function returning an in port
 

	
 
#version 1
 

	
 
in do_something(in a, out b) {
 
    return b;
 
}
 

	
 
float another_something(in a) {
 
    return a;
 
}
 

	
 
whatami yet_another_one(andwhatismypurpose a) {
 
    return a;
 
}
 

	
 
composite main() {}
testdata/parser/counterexamples/import_bad_reporting.pdl
Show inline comments
 
new file 100644
 
// Bad reporting of EOF. Also main parser loop would be fine if pragmas, imports
 
// and declarations are mixed. Maybe force pragmas at top for readability...
 

	
 
#version 1
 

	
 
composite main() {}
 

	
 
#version 2
 

	
 
composite another() {}
 
\ No newline at end of file
testdata/parser/counterexamples/import_stmt.pdl
Show inline comments
 
new file 100644
 
// Import succeeds due to bad parsing (checking for characters, not numbers,
 
// should expect whitespace, then a single number
 

	
 
#version123 456
 

	
 
composite main() {}
testdata/parser/counterexamples/integer_specification.pdl
Show inline comments
 
new file 100644
 
#version 1
 

	
 
int check_integer_specs() {
 
    int a = 0xFF;
 
    // no octal support, but thats fine
 
    int b = 0xxxxFF;
 
    int c = 0x1x2X3x4X5x6X7x8X; // Wut
 
    int d = 1FF;
 
    return a;
 
}
 
\ No newline at end of file
testdata/parser/counterexamples/multiple_versions.pdl
Show inline comments
 
new file 100644
 
#version 1
 
#version 2
 

	
 
composite main() {}
testdata/parser/counterexamples/out_of_order_assignment.pdl
Show inline comments
 
new file 100644
 
// It fails, so that is nice, but it fails due to the wrong reasons
 
// My bad: C-ism of declarations on top
 
bool some_function() {
 
    result_c = false;
 
    bool result_c = true;
 
    return result_c;
 
}
 
\ No newline at end of file
0 comments (0 inline, 0 general)