Lightweight token stream facade for recursive-descent parsers. More...

#include <Compiler_Parser_Utils.H>

Collaboration diagram for Aleph::Compiler_Parser_Stream:

Public Member Functions
	Compiler_Parser_Stream (Compiler_Lexer &token_source, Diagnostic_Engine *dx=nullptr) noexcept
	Builds one parser stream over an existing lexer.

Compiler_Token	peek ()
	Returns the next token without consuming it.

Compiler_Token	next ()
	Consumes and returns the next token.

bool	check (const Compiler_Token_Kind kind)
	Returns whether the next token has the requested kind.

bool	match (const Compiler_Token_Kind kind)
	Consumes the next token if it matches `kind`.

Compiler_Token	expect (const Compiler_Token_Kind kind, const std::string &message, const std::string &code, const std::string &note="", const std::string &help="")
	Consumes a token of kind `kind` or emits one diagnostic error.

Compiler_Token	expect_identifier (const std::string_view context, const std::string &code="PAR002")
	Consumes one identifier token or emits one diagnostic error.

template<typename Parse_Item >
bool	parse_separated_list (const Compiler_Token_Kind separator, const Compiler_Token_Kind terminator, Parse_Item &&parse_item, const bool allow_trailing_separator=false)
	Parses one separated list until a terminator token is reached.

void	synchronize_statement ()
	Skips tokens until a statement boundary suitable for recovery.

Private Member Functions
void	emit_error (const Source_Span &span, const std::string &message, const std::string &code, const std::string &note="", const std::string &help="") const

Private Attributes
Compiler_Lexer *	lexer = nullptr

Diagnostic_Engine *	diagnostics = nullptr

Detailed Description

Lightweight token stream facade for recursive-descent parsers.

The stream wraps one Compiler_Lexer and exposes parser-oriented helpers: lookahead, match, expect, identifier expectations, separated-list parsing, and statement-oriented recovery.

Definition at line 128 of file Compiler_Parser_Utils.H.

Constructor & Destructor Documentation

◆ Compiler_Parser_Stream()

Aleph::Compiler_Parser_Stream::Compiler_Parser_Stream	(	Compiler_Lexer &	token_source,
		Diagnostic_Engine *	dx = `nullptr`
	)

inlinenoexcept

Builds one parser stream over an existing lexer.

Definition at line 152 of file Compiler_Parser_Utils.H.

Member Function Documentation

◆ check()

bool Aleph::Compiler_Parser_Stream::check ( const Compiler_Token_Kind kind )

inline

Returns whether the next token has the requested kind.

Definition at line 169 of file Compiler_Parser_Utils.H.

References Aleph::Compiler_Token::kind, and peek().

Referenced by match(), and parse_separated_list().

◆ emit_error()

void Aleph::Compiler_Parser_Stream::emit_error	(	const Source_Span &	span,
		const std::string &	message,
		const std::string &	code,
		const std::string &	note = `""`,
		const std::string &	help = `""`
	)		const

inlineprivate

Definition at line 133 of file Compiler_Parser_Utils.H.

References Aleph::blossom_maximum_cardinality_matching(), Aleph::Diagnostic_Builder::code(), Aleph::code(), diagnostics, Aleph::Diagnostic_Builder::emit(), Aleph::Diagnostic_Engine::error(), Aleph::Diagnostic_Builder::help(), Aleph::message(), and Aleph::Diagnostic_Builder::note().

Referenced by expect(), and expect_identifier().

◆ expect()

Compiler_Token Aleph::Compiler_Parser_Stream::expect	(	const Compiler_Token_Kind	kind,
		const std::string &	message,
		const std::string &	code,
		const std::string &	note = `""`,
		const std::string &	help = `""`
	)

inline

Consumes a token of kind kind or emits one diagnostic error.

Definition at line 184 of file Compiler_Parser_Utils.H.

References Aleph::blossom_maximum_cardinality_matching(), Aleph::code(), emit_error(), Aleph::message(), next(), and peek().

Referenced by Aleph::Compiler_Parser::expect().

◆ expect_identifier()

Compiler_Token Aleph::Compiler_Parser_Stream::expect_identifier	(	const std::string_view	context,
		const std::string &	code = `"PAR002"`
	)

inline

Consumes one identifier token or emits one diagnostic error.

Definition at line 199 of file Compiler_Parser_Utils.H.

References Aleph::blossom_maximum_cardinality_matching(), Aleph::code(), emit_error(), Aleph::Identifier, next(), and peek().

Referenced by Aleph::Compiler_Parser::expect_identifier().

◆ match()

bool Aleph::Compiler_Parser_Stream::match ( const Compiler_Token_Kind kind )

inline

Consumes the next token if it matches kind.

Definition at line 175 of file Compiler_Parser_Utils.H.

References Aleph::blossom_maximum_cardinality_matching(), check(), and next().

Referenced by Aleph::Compiler_Parser::match(), and parse_separated_list().

◆ next()

Compiler_Token Aleph::Compiler_Parser_Stream::next ( )

inline

Consumes and returns the next token.

Definition at line 163 of file Compiler_Parser_Utils.H.

References lexer, and Aleph::Compiler_Lexer::next().

Referenced by expect(), expect_identifier(), match(), Aleph::Compiler_Parser::next(), and synchronize_statement().

◆ parse_separated_list()

template<typename Parse_Item >

bool Aleph::Compiler_Parser_Stream::parse_separated_list	(	const Compiler_Token_Kind	separator,
		const Compiler_Token_Kind	terminator,
		Parse_Item &&	parse_item,
		const bool	allow_trailing_separator = `false`
	)

inline

Parses one separated list until a terminator token is reached.

Parameters

separator	Separator token between items, such as `Comma`.
terminator	Closing token that ends the list.
parse_item	Callback that parses and records one item.
allow_trailing_separator	If `true`, `a, b, )` is accepted.

Returns: false if parse_item() reports failure; true otherwise.

Definition at line 219 of file Compiler_Parser_Utils.H.

References Aleph::and, Aleph::blossom_maximum_cardinality_matching(), check(), match(), and separator().

Referenced by Aleph::Compiler_Parser::parse_call_suffix(), Aleph::Compiler_Parser::parse_enum_declaration(), Aleph::Compiler_Parser::parse_function(), Aleph::Compiler_Parser::parse_function_type(), and Aleph::Compiler_Parser::parse_parenthesized_type().

◆ peek()

Compiler_Token Aleph::Compiler_Parser_Stream::peek ( )

inline

Returns the next token without consuming it.

Definition at line 157 of file Compiler_Parser_Utils.H.

References lexer, and Aleph::Compiler_Lexer::peek().

Referenced by check(), expect(), expect_identifier(), Aleph::Compiler_Parser::peek(), and synchronize_statement().

◆ synchronize_statement()

void Aleph::Compiler_Parser_Stream::synchronize_statement ( )

inline

Skips tokens until a statement boundary suitable for recovery.

The method stops at EOF, }, the next top-level declaration keyword, or the next structural statement starter ({, let, return, if, while, break, continue). If a semicolon is encountered, it is consumed before returning so that callers can resume after the failed statement.

Definition at line 248 of file Compiler_Parser_Utils.H.

References Aleph::blossom_maximum_cardinality_matching(), Aleph::compiler_is_top_level_declaration_start(), Aleph::Kw_Break, Aleph::Kw_Continue, Aleph::Kw_If, Aleph::Kw_Let, Aleph::Kw_Return, Aleph::Kw_While, Aleph::LBrace, next(), peek(), Aleph::RBrace, and Aleph::Semicolon.

Referenced by Aleph::Compiler_Parser::synchronize_statement().

Member Data Documentation

◆ diagnostics

Diagnostic_Engine* Aleph::Compiler_Parser_Stream::diagnostics = nullptr

private

Definition at line 131 of file Compiler_Parser_Utils.H.

Referenced by emit_error().

◆ lexer

Compiler_Lexer* Aleph::Compiler_Parser_Stream::lexer = nullptr

private

Definition at line 130 of file Compiler_Parser_Utils.H.

Referenced by next(), and peek().

The documentation for this class was generated from the following file:

Compiler_Parser_Utils.H

Public Member Functions

Private Member Functions

Private Attributes

Detailed Description

Constructor & Destructor Documentation

◆ Compiler_Parser_Stream()

Member Function Documentation

◆ check()

◆ emit_error()

◆ expect()

◆ expect_identifier()

◆ match()

◆ next()

◆ parse_separated_list()

◆ peek()

◆ synchronize_statement()

Member Data Documentation

◆ diagnostics

◆ lexer