use crate::protocol::ast::*; use super::symbol_table2::*; use super::{Module, ModuleCompilationPhase, PassCtx}; use super::tokens::*; use super::token_parsing::*; use crate::protocol::input_source2::{InputSource2 as InputSource, InputPosition2 as InputPosition, InputSpan, ParseError}; use crate::collections::*; /// Parses all the tokenized definitions into actual AST nodes. pub(crate) struct PassDefinitions { buffer: String, identifiers: Vec, struct_fields: Vec, enum_variants: Vec, union_variants: Vec, parameters: Vec, expressions: ScopedBuffer, parser_types: Vec, } impl PassDefinitions { pub(crate) fn parse(&mut self, modules: &mut [Module], module_idx: usize, ctx: &mut PassCtx) -> Result<(), ParseError> { let module = &modules[module_idx]; let module_range = &module.tokens.ranges[0]; debug_assert_eq!(module.phase, ModuleCompilationPhase::ImportsResolved); debug_assert_eq!(module_range.range_kind, TokenRangeKind::Module); // TODO: Very important to go through ALL ranges of the module so that we parse the entire // input source. Only skip the ones we're certain we've handled before. let mut range_idx = module_range.first_child_idx; loop { let range_idx_usize = range_idx as usize; let cur_range = &module.tokens.ranges[range_idx_usize]; if cur_range.range_kind == TokenRangeKind::Definition { self.visit_definition_range(modules, module_idx, ctx, range_idx_usize)?; } match cur_range.next_sibling_idx { Some(idx) => { range_idx = idx; }, None => { break; }, } } Ok(()) } fn visit_definition_range( &mut self, modules: &[Module], module_idx: usize, ctx: &mut PassCtx, range_idx: usize ) -> Result<(), ParseError> { let module = &modules[module_idx]; let cur_range = &module.tokens.ranges[range_idx]; debug_assert_eq!(cur_range.range_kind, TokenRangeKind::Definition); // Detect which definition we're parsing let mut iter = module.tokens.iter_range(cur_range); let keyword = peek_ident(&module.source, &mut iter).unwrap(); match keyword { KW_STRUCT => { }, KW_ENUM => { }, KW_UNION => { }, KW_FUNCTION => { }, KW_PRIMITIVE => { }, KW_COMPOSITE => { }, _ => unreachable!("encountered keyword '{}' in definition range", String::from_utf8_lossy(keyword)), }; Ok(()) } // TODO: @Cleanup, still not sure about polymorphic variable parsing. Pre-parsing the variables // allows us to directly construct proper ParserType trees. But this does require two lookups // of the corresponding definition. fn visit_struct_definition( &mut self, module: &Module, iter: &mut TokenIter, ctx: &mut PassCtx ) -> Result<(), ParseError> { consume_exact_ident(&module.source, iter, KW_STRUCT)?; let (ident_text, _) = consume_ident(&module.source, iter)?; // Retrieve preallocated DefinitionId let module_scope = SymbolScope::Module(module.root_id); let definition_id = ctx.symbols.get_symbol_by_name_defined_in_scope(module_scope, ident_text) .unwrap().variant.as_definition().definition_id; let poly_vars = ctx.heap[definition_id].poly_vars(); // Parse struct definition consume_polymorphic_vars_spilled(source, iter)?; debug_assert!(self.struct_fields.is_empty()); consume_comma_separated( TokenKind::OpenCurly, TokenKind::CloseCurly, source, iter, |source, iter| { let parser_type = consume_parser_type( source, iter, &ctx.symbols, &ctx.heap, poly_vars, module_scope, definition_id, false )?; let field = consume_ident_interned(source, iter, ctx)?; Ok(StructFieldDefinition{ field, parser_type }) }, &mut self.struct_fields, "a struct field", "a list of struct fields" )?; // Transfer to preallocated definition let struct_def = ctx.heap[definition_id].as_struct_mut(); struct_def.fields.clone_from(&self.struct_fields); self.struct_fields.clear(); Ok(()) } fn visit_enum_definition( &mut self, module: &Module, iter: &mut TokenIter, ctx: &mut PassCtx ) -> Result<(), ParseError> { consume_exact_ident(&module.source, iter, KW_ENUM)?; let (ident_text, _) = consume_ident(&module.source, iter)?; // Retrieve preallocated DefinitionId let module_scope = SymbolScope::Module(module.root_id); let definition_id = ctx.symbols.get_symbol_by_name_defined_in_scope(module_scope, ident_text) .unwrap().variant.as_definition().definition_id; let poly_vars = ctx.heap[definition_id].poly_vars(); // Parse enum definition consume_polymorphic_vars_spilled(source, iter)?; debug_assert!(self.enum_variants.is_empty()); consume_comma_separated( TokenKind::OpenCurly, TokenKind::CloseCurly, source, iter, |source, iter| { let identifier = consume_ident_interned(source, iter, ctx)?; let value = if iter.next() == Some(TokenKind::Equal) { iter.consume(); let (variant_number, _) = consume_integer_literal(source, iter, &mut self.buffer)?; EnumVariantValue::Integer(variant_number as i64) // TODO: @int } else { EnumVariantValue::None }; Ok(EnumVariantDefinition{ identifier, value }) }, &mut self.enum_variants, "an enum variant", "a list of enum variants" )?; // Transfer to definition let enum_def = ctx.heap[definition_id].as_enum_mut(); enum_def.variants.clone_from(&self.enum_variants); self.enum_variants.clear(); Ok(()) } fn visit_union_definition( &mut self, module: &Module, iter: &mut TokenIter, ctx: &mut PassCtx ) -> Result<(), ParseError> { consume_exact_ident(&module.source, iter, KW_UNION)?; let (ident_text, _) = consume_ident(&module.source, iter)?; // Retrieve preallocated DefinitionId let module_scope = SymbolScope::Module(module.root_id); let definition_id = ctx.symbols.get_symbol_by_name_defined_in_scope(module_scope, ident_text) .unwrap().variant.as_definition().definition_id; let poly_vars = ctx.heap[definition_id].poly_vars(); // Parse union definition consume_polymorphic_vars_spilled(source, iter)?; debug_assert!(self.union_variants.is_empty()); consume_comma_separated( TokenKind::OpenCurly, TokenKind::CloseCurly, source, iter, |source, iter| { let identifier = consume_ident_interned(source, iter, ctx)?; let close_pos = identifier.span.end; let has_embedded = maybe_consume_comma_separated( TokenKind::OpenParen, TokenKind::CloseParen, source, iter, |source, iter| { consume_parser_type( source, iter, &ctx.symbols, &ctx.heap, poly_vars, module_scope, definition_id, false ) }, &mut self.parser_types, "an embedded type", Some(&mut close_pos) )?; let value = if has_embedded { UnionVariantValue::Embedded(self.parser_types.clone()) } else { UnionVariantValue::None }; self.parser_types.clear(); Ok(UnionVariantDefinition{ span: InputSpan::from_positions(identifier.span.begin, close_pos), identifier, value }) }, &mut self.union_variants, "a union variant", "a list of union variants", None )?; // Transfer to AST let union_def = ctx.heap[definition_id].as_union_mut(); union_def.variants.clone_from(&self.union_variants); self.union_variants.clear(); Ok(()) } fn visit_function_definition( &mut self, module: &Module, iter: &mut TokenIter, ctx: &mut PassCtx ) -> Result<(), ParseError> { consume_exact_ident(&module.source, iter, KW_FUNCTION)?; let (ident_text, _) = consume_ident(&module.source, iter)?; // Retrieve preallocated DefinitionId let module_scope = SymbolScope::Module(module.root_id); let definition_id = ctx.symbols.get_symbol_by_name_defined_in_scope(module_scope, ident_text) .unwrap().variant.as_definition().definition_id; let poly_vars = ctx.heap[definition_id].poly_vars(); // Parse function's argument list consume_parameter_list( source, iter, ctx, &mut self.parameters, poly_vars, module_scope, definition_id )?; let parameters = self.parameters.clone(); self.parameters.clear(); // Consume return types consume_comma_separated( TokenKind::ArrowRight, TokenKind::OpenCurly, &module.source, iter, |source, iter| { consume_parser_type(source, iter, &ctx.symbols, &ctx.heap, poly_vars, module_scope, definition_id, false) }, &mut self.parser_types, "a return type", "the return types", None )?; let return_types = self.parser_types.clone(); self.parser_types.clear(); // Consume block } fn consume_statement( &mut self, module: &Module, iter: &mut TokenIter, ctx: &mut PassCtx ) -> Result { let next = iter.next().expect("consume_statement has a next token"); if next == TokenKind::OpenCurly { return self.consume_block_statement(module, iter, ctx)?.upcast(); } else if next == TokenKind::Ident { let (ident, _) = consume_any_ident(source, iter)?; if ident == KW_STMT_IF { return self.consume_if_statement(module, iter, ctx)?; } else if ident == KW_STMT_WHILE { return self.consume_while_statement(module, iter, ctx)?; } else if ident == KW_STMT_BREAK { return self.consume_break_statement(module, iter, ctx)?; } else if ident == KW_STMT_CONTINUE { return self.consume_continue_statement(module, iter, ctx)?; } else if ident == KW_STMT_SYNC { return self.consume_synchronous_statement(module, iter, ctx)?; } else if ident == KW_STMT_RETURN { return self.consume_return_statement(module, iter, ctx)?; } else if ident == KW_STMT_ASSERT { // TODO: Unify all builtin function calls as expressions return self.consume_assert_statement(module, iter, ctx)?; } else if ident == KW_STMT_GOTO { return self.consume_goto_statement(module, iter, ctx)?; } else if ident == KW_STMT_NEW { return self.consume_new_statement(module, iter, ctx)?; } else if iter.peek() == Some(TokenKind::Colon) { return self.consume_labeled_statement(module, iter, ctx)?; } } // If here then attempt to parse as expression return self.consume_expr_statement(module, iter, ctx)?; } fn consume_block_statement( &mut self, module: &Module, iter: &mut TokenIter, ctx: &mut PassCtx ) -> Result { let open_span = consume_token(source, iter, TokenKind::OpenCurly)?; self.consume_block_statement_without_leading_curly(module, iter, ctx, open_span.begin) } fn consume_block_statement_without_leading_curly( &mut self, module: &Module, iter: &mut TokenIter, ctx: &mut PassCtx, open_curly_pos: InputPosition ) -> Result { let mut statements = Vec::new(); let mut next = iter.next(); while next.is_some() && next != Some(TokenKind::CloseCurly) { } let mut block_span = consume_token(&module.source, iter, TokenKind::CloseCurly)?; block_span.begin = open_curly_pos; Ok(ctx.heap.alloc_block_statement(|this| BlockStatement{ this, span: block_span, statements, parent_scope: None, relative_pos_in_parent: 0, locals: Vec::new(), labels: Vec::new(), })) } fn consume_if_statement( &mut self, module: &Module, iter: &mut TokenIter, ctx: &mut PassCtx ) -> Result { consume_exact_ident(&module.source, iter, KW_STMT_IF)?; let test = consume_parenthesized_expression() } //-------------------------------------------------------------------------- // Expression Parsing //-------------------------------------------------------------------------- fn consume_expression( &mut self, module: &Module, iter: &mut TokenIter, ctx: &mut PassCtx ) -> Result { self.consume_assignment_expression(module, iter, ctx) } fn consume_assignment_expression( &mut self, module: &Module, iter: &mut TokenIter, ctx: &mut PassCtx ) -> Result { // Utility to convert token into assignment operator fn parse_assignment_operator(token: Option) -> Option { use TokenKind as TK; use AssignmentOperator as AO; if token.is_none() { return None } let matched = match token.unwrap() { TK::Equal => Some(AO::Set), TK::StarEquals => Some(AO::Multiplied), TK::SlashEquals => Some(AO::Divided), TK::PercentEquals => Some(AO::Remained), TK::PlusEquals => Some(AO::Added), TK::MinusEquals => Some(AO::Subtracted), TK::ShiftLeftEquals => Some(AO::ShiftedLeft), TK::ShiftRightEquals => Some(AO::ShiftedRight), TK::AndEquals => Some(AO::BitwiseAnded), TK::CaretEquals => Some(AO::BitwiseXored), TK::OrEquals => Some(AO::BitwiseOred), _ => None }; } let expr = self.consume_conditional_expression(module, iter, ctx)?; if let Some(operation) = parse_assignment_operator(iter.next()) { let span = iter.next_span(); iter.consume(); let left = expr; let right = self.consume_expression(module, iter, ctx)?; Ok(ctx.heap.alloc_assignment_expression(|this| AssignmentExpression{ this, span, left, operation, right, parent: ExpressionParent::None, concrete_type: ConcreteType::default(), }).upcast()) } else { Ok(expr) } } fn consume_conditional_expression( &mut self, module: &Module, iter: &mut TokenIter, ctx: &mut PassCtx ) -> Result { let result = self.consume_concat_expression(module, iter, ctx)?; if let Some(TokenKind::Question) = iter.next() { let span = iter.next_span(); iter.consume(); let test = result; let true_expression = self.consume_expression(module, iter, ctx)?; consume_token(source, iter, TokenKind::Colon)?; let false_expression = self.consume_expression(module, iter, ctx)?; Ok(ctx.heap.alloc_conditional_expression(|this| ConditionalExpression{ this, span, test, true_expression, false_expression, parent: ExpressionParent::None, concrete_type: ConcreteType::default(), }).upcast()) } else { Ok(result) } } fn consume_concat_expression( &mut self, module: &Module, iter: &mut TokenIter, ctx: &mut PassCtx ) -> Result { self.consume_generic_binary_expression( module, iter, ctx, |token| match token { Some(TokenKind::At) => Some(BinaryOperator::Concatenate), _ => None }, Self::consume_logical_or_expression ) } fn consume_logical_or_expression( &mut self, module: &Module, iter: &mut TokenIter, ctx: &mut PassCtx ) -> Result { self.consume_generic_binary_expression( module, iter, ctx, |token| match token { Some(TokenKind::OrOr) => Some(BinaryOperator::LogicalOr), _ => None }, Self::consume_logical_and_expression ) } fn consume_logical_and_expression( &mut self, module: &Module, iter: &mut TokenIter, ctx: &mut PassCtx ) -> Result { self.consume_generic_binary_expression( module, iter, ctx, |token| match token { Some(TokenKind::AndAnd) => Some(BinaryOperator::LogicalAnd), _ => None }, Self::consume_bitwise_or_expression ) } fn consume_bitwise_or_expression( &mut self, module: &Module, iter: &mut TokenIter, ctx: &mut PassCtx ) -> Result { self.consume_generic_binary_expression( module, iter, ctx, |token| match token { Some(TokenKind::Or) => Some(BinaryOperator::BitwiseOr), _ => None }, Self::consume_bitwise_xor_expression ) } fn consume_bitwise_xor_expression( &mut self, module: &Module, iter: &mut TokenIter, ctx: &mut PassCtx ) -> Result { self.consume_generic_binary_expression( module, iter, ctx, |token| match token { Some(TokenKind::Caret) => Some(BinaryOperator::BitwiseXor), _ => None }, Self::consume_bitwise_and_expression ) } fn consume_bitwise_and_expression( &mut self, module: &Module, iter: &mut TokenIter, ctx: &mut PassCtx ) -> Result { self.consume_generic_binary_expression( module, iter, ctx, |token| match token { Some(TokenKind::And) => Some(BinaryOperator::BitwiseAnd), _ => None }, Self::consume_equality_expression ) } fn consume_equality_expression( &mut self, module: &Module, iter: &mut TokenIter, ctx: &mut PassCtx ) -> Result { self.consume_generic_binary_expression( module, iter, ctx, |token| match token { Some(TokenKind::EqualEqual) => Some(BinaryOperator::Equality), Some(TokenKind::NotEqual) => Some(BinaryOperator::Inequality), _ => None }, Self::consume_relational_expression ) } fn consume_relational_expression( &mut self, module: &Module, iter: &mut TokenIter, ctx: &mut PassCtx ) -> Result { self.consume_generic_binary_expression( module, iter, ctx, |token| match token { Some(TokenKind::OpenAngle) => Some(BinaryOperator::LessThan), Some(TokenKind::CloseAngle) => Some(BinaryOperator::GreaterThan), Some(TokenKind::LessEquals) => Some(BinaryOperator::LessThanEqual), Some(TokenKind::GreaterEquals) => Some(BinaryOperator::GreaterThanEqual), _ => None }, Self::consume_shift_expression ) } fn consume_shift_expression( &mut self, module: &Module, iter: &mut TokenIter, ctx: &mut PassCtx ) -> Result { self.consume_generic_binary_expression( module, iter, ctx, |token| match token { Some(TokenKind::ShiftLeft) => Some(BinaryOperator::ShiftLeft), Some(TokenKind::ShiftRight) => Some(BinaryOperator::ShiftRight), _ => None }, Self::consume_add_or_subtract_expression ) } fn consume_add_or_subtract_expression( &mut self, module: &Module, iter: &mut TokenIter, ctx: &mut PassCtx ) -> Result { self.consume_generic_binary_expression( module, iter, ctx, |token| match token { Some(TokenKind::Plus) => Some(BinaryOperator::Add), Some(TokenKind::Minus) => Some(BinaryOperator::Subtract), _ => None, }, Self::consume_multiply_divide_or_modulus_expression ) } fn consume_multiply_divide_or_modulus_expression( &mut self, module: &Module, iter: &mut Tokeniter, ctx: &mut PassCtx ) -> Result { self.consume_generic_binary_expression( module, iter, ctx, |token| match token { Some(TokenKind::Star) => Some(BinaryOperator::Multiply), Some(TokenKind::Slash) => Some(BinaryOperator::Divide), Some(TokenKind::Percent) => Some(BinaryOperator::Remainder), _ => None }, Self::consume_prefix_expression ) } fn consume_prefix_expression( &mut self, module: &Module, iter: &mut TokenIter, ctx: &mut PassCtx ) -> Result { fn parse_prefix_token(token: Option) -> Some(UnaryOperation) { use TokenKind as TK; use UnaryOperation as UO; match token { Some(TK::Plus) => Some(UO::Positive), Some(TK::Minus) => Some(UO::Negative), Some(TK::PlusPlus) => Some(UO::PreIncrement), Some(TK::MinusMinus) => Some(UO::PreDecrement), Some(TK::Tilde) => Some(UO::BitwiseNot), Some(TK::Exclamation) => Some(UO::LogicalNot), _ => None } } if let Some(operation) = parse_prefix_token(iter.next()) { let span = iter.next_span(); iter.consume(); let expression = self.consume_prefix_expression(module, iter, ctx)?; Ok(ctx.heap.alloc_unary_expression(|this| UnaryExpression { this, span, operation, expression, parent: ExpressionParent::None, concrete_type: ConcreteType::default() }).upcast()) } else { self.consume_postfix_expression(module, iter, ctx) } } fn consume_postfix_expression( &mut self, module: &Module, iter: &mut TokenIter, ctx: &mut PassCtx ) -> Result { fn has_matching_postfix_token(token: Option) -> bool { use TokenKind as TK; if token.is_none() { return false; } match token.unwrap() { TK::PlusPlus | TK::MinusMinus | TK::OpenSquare | TK::Dot => true, _ => false } } let mut result = self.consume_primary_expression(module, iter, ctx)?; let mut next = iter.next(); while has_matching_postfix_token(next) { let token = next.unwrap(); let mut span = iter.next_span(); iter.consume(); if token == TokenKind::PlusPlus { result = ctx.heap.alloc_unary_expression(|this| UnaryExpression{ this, span, operation: UnaryOperation::PostIncrement, expression: result, parent: ExpressionParent::None, concrete_type: ConcreteType::default() }).upcast(); } else if token == TokenKind::MinusMinus { result = ctx.heap.alloc_unary_expression(|this| UnaryExpression{ this, span, operation: UnaryOperation::PostDecrement, expression: result, parent: ExpressionParent::None, concrete_type: ConcreteType::default() }).upcast(); } else if token == TokenKind::OpenSquare { let subject = result; let from_index = self.consume_expression(module, iter, ctx)?; // Check if we have an indexing or slicing operation next = iter.next(); if Some(TokenKind::DotDot) = next { iter.consume(); let to_index = self.consume_expression(module, iter, ctx)?; let end_span = consume_token(&module.source, iter, TokenKind::CloseSquare)?; span.end = end_span.end; result = ctx.heap.alloc_slicing_expression(|this| SlicingExpression{ this, span, subject, from_index, to_index, parent: ExpressionParent::None, concrete_type: ConcreteType::default() }).upcast(); } else if Some(TokenKind::CloseSquare) { let end_span = consume_token(&module.source, iter, TokenKind::CloseSquare)?; span.end = end_span.end; result = ctx.heap.alloc_indexing_expression(|this| IndexingExpression{ this, span, subject, index: from_index, parent: ExpressionParent::None, concrete_type: ConcreteType::default() }).upcast(); } else { return Err(ParseError::new_error_str_at_pos( &module.source, iter.last_valid_pos(), "unexpected token: expected ']' or '..'" )); } } else { debug_assert_eq!(token, TokenKind::Dot); let subject = result; let (field_text, field_span) = consume_ident(&module.source, iter)?; let field = if field_text == b"length" { Field::Length } else { let value = ctx.pool.intern(field_text); let identifier = Identifier{ value, span: field_span }; Field::Symbolic(FieldSymbolic{ identifier, definition: None, field_idx: 0 }); }; result = ctx.heap.alloc_select_expression(|this| SelectExpression{ this, span, subject, field, parent: ExpressionParent::None, concrete_type: ConcreteType::default() }).upcast(); } next = iter.next(); } Ok(result) } fn consume_primary_expression( &mut self, module: &Module, iter: &mut TokenIter, ctx: &mut PassCtx ) -> Result { let next = iter.next(); let result; if next == Some(TokenKind::OpenParen) { // Expression between parentheses iter.consume(); result = self.consume_expression(module, iter, ctx)?; consume_token(&module.source, iter, TokenKind::CloseParen)?; } else if next == Some(TokenKind::OpenCurly) { // Array literal let (start_pos, mut end_pos) = iter.next_positions(); let mut expressions = Vec::new(); consume_comma_separated( TokenKind::OpenCurly, TokenKind::CloseCurly, &module.source, iter, |source, iter| self.consume_expression(module, iter, ctx), &mut expressions, "an expression", "a list of expressions", Some(&mut end_pos) )?; // TODO: Turn into literal result = ctx.heap.alloc_array_expression(|this| ArrayExpression{ this, span: InputSpan::from_positions(start_pos, end_pos), elements: expressions, parent: ExpressionParent::None, concrete_type: ConcreteType::default(), }).upcast(); } else if next == Some(TokenKind::Integer) { let (literal, span) = consume_integer_literal(&module.source, iter, &mut self.buffer)?; result = ctx.heap.alloc_literal_expression(|this| LiteralExpression{ this, span, value: Literal::Integer(LiteralInteger{ unsigned_value: literal, negated: false }), parent: ExpressionParent::None, concrete_type: ConcreteType::default(), }).upcast(); } else if next == Some(TokenKind::String) { let (text, span) = consume_string_literal(&module.source, iter, &mut self.buffer)?; } else if next == Some(TokenKind::Character) { } Ok(result) } //-------------------------------------------------------------------------- // Expression Utilities //-------------------------------------------------------------------------- #[inline] fn consume_generic_binary_expression< M: Fn(Option) -> Option, F: Fn(&mut PassDefinitions, &Module, &mut TokenIter, &mut PassCtx) -> Result >( &mut self, module: &Module, iter: &mut TokenIter, ctx: &mut PassCtx, match_fn: M, higher_precedence_fn: F ) -> Result { let mut result = higher_precedence_fn(self, module, iter, ctx)?; while let Some(operation) = match_fn(iter.next()) { let span = iter.next_span(); iter.consume(); let left = result; let right = higher_precedence_fn(self, module, iter, ctx)?; result = ctx.heap.alloc_binary_expression(|this| BinaryExpression{ this, span, left, operation, right, parent: ExpressionParent::None, concrete_type: ConcreteType::default() }).upcast(); } Ok(result) } } /// Consumes a type. A type always starts with an identifier which may indicate /// a builtin type or a user-defined type. The fact that it may contain /// polymorphic arguments makes it a tree-like structure. Because we cannot rely /// on knowing the exact number of polymorphic arguments we do not check for /// these. // TODO: @Optimize, and fix spans if needed fn consume_parser_type( source: &InputSource, iter: &mut TokenIter, symbols: &SymbolTable, heap: &Heap, poly_vars: &[Identifier], cur_scope: SymbolScope, wrapping_definition: DefinitionId, allow_inference: bool ) -> Result { struct Entry{ element: ParserTypeElement, depth: i32, } fn insert_array_before(elements: &mut Vec, depth: i32, span: InputSpan) { let index = elements.iter().rposition(|e| e.depth == depth).unwrap(); elements.insert(index, Entry{ element: ParserTypeElement{ full_span: span, variant: ParserTypeVariant::Array }, depth, }); } // Most common case we just have one type, perhaps with some array // annotations. let element = consume_parser_type_ident(source, iter, symbols, heap, poly_vars, cur_scope, wrapping_definition, allow_inference)?; if iter.next() != Some(TokenKind::OpenAngle) { let mut num_array = 0; while iter.next() == Some(TokenKind::OpenSquare) { iter.consume(); consume_token(source, iter, TokenKind::CloseSquare)?; num_array += 1; } let array_span = element.full_span; let mut elements = Vec::with_capacity(num_array + 1); for _ in 0..num_array { elements.push(ParserTypeElement{ full_span: array_span, variant: ParserTypeVariant::Array }); } elements.push(element); return Ok(ParserType{ elements }); }; // We have a polymorphic specification. So we start by pushing the item onto // our stack, then start adding entries together with the angle-brace depth // at which they're found. let mut elements = Vec::new(); elements.push(Entry{ element, depth: 0 }); // Start out with the first '<' consumed. iter.consume(); enum State { Ident, Open, Close, Comma }; let mut state = State::Open; let mut angle_depth = 1; loop { let next = iter.next(); match state { State::Ident => { // Just parsed an identifier, may expect comma, angled braces, // or the tokens indicating an array if Some(TokenKind::OpenAngle) == next { angle_depth += 1; state = State::Open; } else if Some(TokenKind::CloseAngle) == next { angle_depth -= 1; state = State::Close; } else if Some(TokenKind::ShiftRight) == next { angle_depth -= 2; state = State::Close; } else if Some(TokenKind::Comma) == next { state = State::Comma; } else if Some(TokenKind::OpenSquare) == next { let (start_pos, _) = iter.next_positions(); iter.consume(); // consume opening square if iter.next() != Some(TokenKind::CloseSquare) { return Err(ParseError::new_error_str_at_pos( source, iter.last_valid_pos(), "unexpected token: expected ']'" )); } let (_, end_pos) = iter.next_positions(); let array_span = InputSpan::from_positions(start_pos, end_pos); insert_array_before(&mut elements, angle_depth, array_span); } else { return Err(ParseError::new_error_str_at_pos( source, iter.last_valid_pos(), "unexpected token: expected '<', '>', ',' or '['") ); } iter.consume(); }, State::Open => { // Just parsed an opening angle bracket, expecting an identifier let element = consume_parser_type_ident(source, iter, symbols, heap, poly_vars, cur_scope, wrapping_definition, allow_inference)?; elements.push(Entry{ element, depth: angle_depth }); state = State::Ident; }, State::Close => { // Just parsed 1 or 2 closing angle brackets, expecting comma, // more closing brackets or the tokens indicating an array if Some(TokenKind::Comma) == next { state = State::Comma; } else if Some(TokenKind::CloseAngle) == next { angle_depth -= 1; state = State::Close; } else if Some(TokenKind::ShiftRight) == next { angle_depth -= 2; state = State::Close; } else if Some(TokenKind::OpenSquare) == next { let (start_pos, _) = iter.next_positions(); iter.consume(); if iter.next() != Some(TokenKind::CloseSquare) { return Err(ParseError::new_error_str_at_pos( source, iter.last_valid_pos(), "unexpected token: expected ']'" )); } let (_, end_pos) = iter.next_positions(); let array_span = InputSpan::from_positions(start_pos, end_pos); insert_array_before(&mut elements, angle_depth, array_span); } else { return Err(ParseError::new_error_str_at_pos( source, iter.last_valid_pos(), "unexpected token: expected ',', '>', or '['") ); } iter.consume(); }, State::Comma => { // Just parsed a comma, expecting an identifier or more closing // braces if Some(TokenKind::Ident) == next { let element = consume_parser_type_ident(source, iter, symbols, heap, poly_vars, cur_scope, wrapping_definition, allow_inference)?; elements.push(Entry{ element, depth: angle_depth }); state = State::Ident; } else if Some(TokenKind::CloseAngle) == next { iter.consume(); angle_depth -= 1; state = State::Close; } else if Some(TokenKind::ShiftRight) == next { iter.consume(); angle_depth -= 2; state = State::Close; } else { return Err(ParseError::new_error_str_at_pos( source, iter.last_valid_pos(), "unexpected token: expected '>' or a type name" )); } } } if angle_depth < 0 { return Err(ParseError::new_error_str_at_pos(source, iter.last_valid_pos(), "unmatched '>'")); } else if angle_depth == 0 { break; } } // If here then we found the correct number of angle braces. But we still // need to make sure that each encountered type has the correct number of // embedded types. let mut idx = 0; while idx < elements.len() { let cur_element = &elements[idx]; let expected_subtypes = cur_element.element.variant.num_embedded(); let mut encountered_subtypes = 0; for peek_idx in idx + 1..elements.len() { let peek_element = &elements[peek_idx]; if peek_element.depth == cur_element.depth + 1 { encountered_subtypes += 1; } else if peek_element.depth <= cur_element.depth { break; } } if expected_subtypes != encountered_subtypes { if encountered_subtypes == 0 { // Case where we have elided the embedded types, all of them // should be inferred. if !allow_inference { return Err(ParseError::new_error_str_at_span( source, cur_element.element.full_span, "type inference is not allowed here" )); } // Insert the missing types let inserted_span = cur_element.element.full_span; let inserted_depth = cur_element.depth + 1; elements.reserve(expected_subtypes); for _ in 0..expected_subtypes { elements.insert(idx + 1, Entry{ element: ParserTypeElement{ full_span: inserted_span, variant: ParserTypeVariant::Inferred }, depth: inserted_depth, }); } } else { // Mismatch in number of embedded types let expected_args_text = if expected_subtypes == 1 { "polymorphic argument" } else { "polymorphic arguments" }; let maybe_infer_text = if allow_inference { " (or none, to perform implicit type inference)" } else { "" }; return Err(ParseError::new_error_at_span( source, cur_element.element.full_span, format!( "expected {} {}{}, but {} were provided", expected_subtypes, expected_args_text, maybe_infer_text, encountered_subtypes ) )); } } idx += 1; } let mut constructed_elements = Vec::with_capacity(elements.len()); for element in elements.into_iter() { constructed_elements.push(element.element); } Ok(ParserType{ elements: constructed_elements }) } fn consume_parser_type_ident( source: &InputSource, iter: &mut TokenIter, symbols: &SymbolTable, heap: &Heap, poly_vars: &[Identifier], mut scope: SymbolScope, wrapping_definition: DefinitionId, allow_inference: bool, ) -> Result { use ParserTypeVariant as PTV; let (mut type_text, mut type_span) = consume_any_ident(source, iter)?; let variant = match type_text { KW_TYPE_MESSAGE => PTV::Message, KW_TYPE_BOOL => PTV::Bool, KW_TYPE_UINT8 => PTV::UInt8, KW_TYPE_UINT16 => PTV::UInt16, KW_TYPE_UINT32 => PTV::UInt32, KW_TYPE_UINT64 => PTV::UInt64, KW_TYPE_SINT8 => PTV::SInt8, KW_TYPE_SINT16 => PTV::SInt16, KW_TYPE_SINT32 => PTV::SInt32, KW_TYPE_SINT64 => PTV::SInt64, KW_TYPE_IN_PORT => PTV::Input, KW_TYPE_OUT_PORT => PTV::Output, KW_TYPE_CHAR => PTV::Character, KW_TYPE_STRING => PTV::String, KW_TYPE_INFERRED => { if !allow_inference { return Err(ParseError::new_error_str_at_span(source, type_span, "type inference is not allowed here")); } PTV::Inferred }, _ => { // Must be some kind of symbolic type let mut type_kind = None; for (poly_idx, poly_var) in poly_vars.iter().enumerate() { if poly_var.value.as_bytes() == type_text { type_kind = Some(PTV::PolymorphicArgument(wrapping_definition, poly_idx)); } } if type_kind.is_none() { // Check symbol table for definition. To be fair, the language // only allows a single namespace for now. That said: let last_symbol = symbols.get_symbol_by_name(scope, type_text); if last_symbol.is_none() { return Err(ParseError::new_error_str_at_span(source, type_span, "unknown type")); } let mut last_symbol = last_symbol.unwrap(); loop { match &last_symbol.variant { SymbolVariant::Module(symbol_module) => { // Expecting more identifiers if Some(TokenKind::ColonColon) != iter.next() { return Err(ParseError::new_error_str_at_span(source, type_span, "expected type but got module")); } consume_token(source, iter, TokenKind::ColonColon)?; // Consume next part of type and prepare for next // lookup loop let (next_text, next_span) = consume_any_ident(source, iter)?; let old_text = type_text; type_text = next_text; type_span.end = next_span.end; scope = SymbolScope::Module(symbol_module.root_id); let new_symbol = symbols.get_symbol_by_name_defined_in_scope(scope, type_text); if new_symbol.is_none() { return Err(ParseError::new_error_at_span( source, next_span, format!( "unknown type '{}' in module '{}'", String::from_utf8_lossy(type_text), String::from_utf8_lossy(old_text) ) )); } last_symbol = new_symbol.unwrap(); }, SymbolVariant::Definition(symbol_definition) => { let num_poly_vars = heap[symbol_definition.definition_id].poly_vars().len(); type_kind = Some(PTV::Definition(symbol_definition.definition_id, num_poly_vars)); break; } } } } debug_assert!(type_kind.is_some()); type_kind.unwrap() }, }; Ok(ParserTypeElement{ full_span: type_span, variant }) } /// Consumes polymorphic variables and throws them on the floor. fn consume_polymorphic_vars_spilled(source: &InputSource, iter: &mut TokenIter) -> Result<(), ParseError> { maybe_consume_comma_separated_spilled( TokenKind::OpenAngle, TokenKind::CloseAngle, source, iter, |source, iter| { consume_ident(source, iter)?; Ok(()) }, "a polymorphic variable" )?; Ok(()) } /// Consumes the parameter list to functions/components fn consume_parameter_list( source: &InputSource, iter: &mut TokenIter, ctx: &mut PassCtx, target: &mut Vec, poly_vars: &[Identifier], scope: SymbolScope, definition_id: DefinitionId ) -> Result<(), ParseError> { consume_comma_separated( TokenKind::OpenParen, TokenKind::CloseParen, source, iter, |source, iter| { let (start_pos, _) = iter.next_positions(); let parser_type = consume_parser_type( source, iter, &ctx.symbols, &ctx.heap, poly_vars, scope, definition_id, false )?; let identifier = consume_ident_interned(source, iter, ctx)?; let parameter_id = ctx.heap.alloc_parameter(|this| Parameter{ this, span: InputSpan::from_positions(start_pos, identifier.span.end), parser_type, identifier }); Ok(parameter_id) }, target, "a parameter", "a parameter list", None ) }