Loyc.Syntax.IParsingService Interface Reference

An interface that encapsulates the lexer, parser, and printer 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, parser, and printer 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. "LES 1.0 parser".

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...
LNodePrinter	Printer [get]
	Gets a printer delegate that you can use with LNode.Printer and LNode.PushPrinter, or null if there is no corresponding printer available for the parser reresented by this object. More...

Public Member Functions
ILexer< Token >	Tokenize (ICharSource file, string fileName, IMessageSink msgs)
	Returns a lexer that is configured to begin reading the specified file. More...
IListSource< LNode >	Parse (ICharSource file, string fileName, IMessageSink msgs, Symbol inputType=null)
	Parses a source file into one or more Loyc trees. More...
IListSource< LNode >	Parse (ILexer< Token > input, IMessageSink msgs, Symbol inputType=null)
	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, Symbol inputType)
	Parses a token tree, such as one that came from a token literal. More...
string	Print (LNode node, IMessageSink msgs=null, object mode=null, string indentString="\t", string lineSeparator="\n")
	Converts the specified syntax tree to a string. More...

Member Function Documentation

IListSource<LNode> Loyc.Syntax.IParsingService.Parse	(	ICharSource	file,
		string	fileName,
		IMessageSink	msgs,
		Symbol	inputType = null
	)

Parses a source file into one or more Loyc trees.

Parameters

file	input file or string.
msgs	output sink for error and warning messages.
inputType	Indicates the kind of input: Exprs (one or more expressions, typically seprated by commas but this is language- defined), Stmts (a series of statements), or File (an entire source file). null is a synonym for File.

Implemented in Loyc.Ecs.EcsLanguageService, and Loyc.Syntax.Les.LesLanguageService.

IListSource<LNode> Loyc.Syntax.IParsingService.Parse	(	ILexer< Token >	input,
		IMessageSink	msgs,
		Symbol	inputType = null
	)

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

Parameters

msgs	output sink for error and warning messages.
inputType	Indicates how the input should be interpreted: ParsingService.File, ParsingService.Exprs or ParsingService.Stmts. The default input type should be File.

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.Ecs.EcsLanguageService, and Loyc.Syntax.Les.LesLanguageService.

IListSource<LNode> Loyc.Syntax.IParsingService.Parse	(	IListSource< Token >	tokens,
		ISourceFile	file,
		IMessageSink	msgs,
		Symbol	inputType
	)

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

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.Ecs.EcsLanguageService, and Loyc.Syntax.Les.LesLanguageService.

string Loyc.Syntax.IParsingService.Print	(	LNode	node,
		IMessageSink	msgs = null,
		object	mode = null,
		string	indentString = "\t",
		string	lineSeparator = "\n"
	)

Converts the specified syntax tree to a string.

Parameters

node	A syntax tree to print.
msgs	If errors or warnings occur during printing, they are sent here. If this is null, messages shall be sent to MessageSink.Current.
mode	Language-defined configuration. It is suggested that the printing service should accept ParsingService.Exprs, ParsingService.Stmts and ParsingService.File as possible printing modes.
indentString	Indent character for multi-line nodes
lineSeparator	Newline string for multi-line nodes

Implemented in Loyc.Ecs.EcsLanguageService, and Loyc.Syntax.Les.LesLanguageService.

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

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

Parameters

file	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, and it should not remove comments, although it may skip spaces and perhaps newlines. If there is a preprocessor, it should not run.

Implemented in Loyc.Ecs.EcsLanguageService, and Loyc.Syntax.Les.LesLanguageService.

Property Documentation

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.

LNodePrinter Loyc.Syntax.IParsingService.Printer

get

Gets a printer delegate that you can use with LNode.Printer and LNode.PushPrinter, or null if there is no corresponding printer available for the parser reresented by this object.