Loyc.Syntax.IParsingService Interface Reference

An interface that encapsulates the lexer and parser of a programming language, or a non-programming language that can be represented by Loyc trees. More...

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Source file:

• /Core/Loyc.Syntax/IParsingService.cs

Inheritance diagram for Loyc.Syntax.IParsingService:

Remarks

An interface that encapsulates the lexer and parser of a programming language, or a non-programming language that can be represented by Loyc trees.

The simplest way to parse code is with the extension method Parse(string, IMessageSink msgs = null, Symbol inputType = null). The simplest way to print is with Print(LNode, IMessageSink)

The ToString() method should return a string that indicates the programming language represented by this object, e.g. "Enhanced C#".

See also

ParsingService, ILNodePrinter

Properties
IEnumerable< string >	FileExtensions [get]
	Standard file extensions for this language, without leading dots, with the first one being the most common. More...
bool	HasTokenizer [get]
	Returns true if the Tokenize method is available. More...
bool	CanPreserveComments [get]
	Returns true if the parser supports preserving comments. More...

Public Member Functions
ILexer< Token >	Tokenize (ICharSource text, string fileName, IMessageSink msgs, IParsingOptions options)
	Returns a lexer that is configured to begin reading the specified file. More...
IListSource< LNode >	Parse (ICharSource text, string fileName, IMessageSink?msgs, IParsingOptions options)
	Parses a source file into one or more Loyc trees. More...
IListSource< LNode >	Parse (ILexer< Token > input, IMessageSink?msgs, IParsingOptions options)
	If HasTokenizer is true, this method accepts a lexer returned by Tokenize() and begins parsing. More...
IListSource< LNode >	Parse (IListSource< Token > tokens, ISourceFile file, IMessageSink?msgs, IParsingOptions options)
	Parses a token tree, such as one that came from a token literal. More...

Member Function Documentation

IListSource<LNode> Loyc.Syntax.IParsingService.Parse	(	ICharSource	text,
		string	fileName,
		IMessageSink?	msgs,
		IParsingOptions	options
	)

Parses a source file into one or more Loyc trees.

Parameters

text	input file or string.
fileName	A file name to associate with errors, warnings, and output nodes.
msgs	Error and warning messages are sent to this object. If this parameter is null, messages should be sent to MessageSink.Default.
options	Parsing options.

Implemented in Loyc.Syntax.Les.Les2LanguageService, and Loyc.Syntax.Les.Les3LanguageService.

IListSource<LNode> Loyc.Syntax.IParsingService.Parse	(	ILexer< Token >	input,
		IMessageSink?	msgs,
		IParsingOptions	options
	)

If HasTokenizer is true, this method accepts a lexer returned by Tokenize() and begins parsing.

Parameters

input	A source of tokens.
msgs	Error and warning messages are sent to this object. If this parameter is null, messages should be sent to MessageSink.Default.

Exceptions

NotSupportedException

HasTokenizer is false.

This method adds any preprocessing steps to the lexer (tree-ification or token preprocessing) that are required by this language before it sends the results to the parser. If possible, the output is computed lazily.

Implemented in Loyc.Syntax.Les.Les2LanguageService, and Loyc.Syntax.Les.Les3LanguageService.

IListSource<LNode> Loyc.Syntax.IParsingService.Parse	(	IListSource< Token >	tokens,
		ISourceFile	file,
		IMessageSink?	msgs,
		IParsingOptions	options
	)

Parses a token tree, such as one that came from a token literal.

Parameters

tokens	List of tokens
file	A source file to associate with errors, warnings, and output nodes.
msgs	Error and warning messages are sent to this object. If this parameter is null, messages should be sent to MessageSink.Default.
options	Indicates how the input should be parsed.

Some languages may offer token literals, which are stored as token trees that can be processed by "macros" or compiler plugins. A macro may wish to parse some of the token literal using the host language's parser (e.g. LLLPG needs to do this), so this method is provided for that purpose.

Exceptions

NotSupportedException

This feature is not supported by this parsing service.

Implemented in Loyc.Syntax.Les.Les2LanguageService, and Loyc.Syntax.Les.Les3LanguageService.

ILexer<Token> Loyc.Syntax.IParsingService.Tokenize	(	ICharSource	text,
		string	fileName,
		IMessageSink	msgs,
		IParsingOptions	options
	)

Returns a lexer that is configured to begin reading the specified file.

Parameters

text	Text to be tokenized (e.g. UString)
fileName	File name to be associated with any errors that occur.
msgs	Error messages are sent to this object.

The returned lexer should be a "simple" tokenizer. If the language uses tree lexing (in which tokens are grouped by parentheses and braces), the returned lexer should NOT include the grouping process.

It is recommended that the implementation of this method filter out spaces (for best performance) but not comments or newlines. If there is a preprocessor, it should not run. If ParsingOptions.PreserveComments is false, it is not this method's responsibility to filter them out.

Implemented in Loyc.Ecs.EcsLanguageService, Loyc.Syntax.Les.Les3LanguageService, and Loyc.Syntax.Les.Les2LanguageService.

Property Documentation

bool Loyc.Syntax.IParsingService.CanPreserveComments

get

Returns true if the parser supports preserving comments.

IEnumerable<string> Loyc.Syntax.IParsingService.FileExtensions

get

Standard file extensions for this language, without leading dots, with the first one being the most common.

bool Loyc.Syntax.IParsingService.HasTokenizer

get

Returns true if the Tokenize method is available.