Loyc.Ecs.Parser.EcsPreprocessor Class Reference

Handles EC# processor directives. More...

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Source file:

• /Main/Ecs/Parser/EcsPreprocessor.cs

Inheritance diagram for Loyc.Ecs.Parser.EcsPreprocessor:

Remarks

Handles EC# processor directives.

This class not only preprocesses C# source code, it saves preprocessor directives and comments so that any code excluded by the preprocessor can be added back in later, if and when the parsed code is printed out. For example, given input like this:

void foo // see below
#if false
invalid code!
#endif
() { Console.WriteLine("foo()!"); }

EcsPreprocessor removes the #if...#endif region of tokens, creates a single Token of type TokenType.PPFalseBlock to represent that region, and saves it, after the "see below" comment token, in a list.

C# has the following preprocessor directives:

#define Id
#undef Id
#if expr
#elif expr
#else
#endif
#warning {arbitrary text}
#error {arbitrary text}
#region {arbitrary text}
#endregion
#line 123 "filename"
#pragma warning ...
#pragma ... // ignored

Public fields
HashSet< Symbol >	DefinedSymbols = new HashSet<Symbol>()

Properties
IList< Token >	CommentList [get]
Properties inherited from Loyc.Syntax.Lexing.LexerWrapper< Token >
ILexer< Token >	Lexer [get, set]
ISourceFile	SourceFile [get]
virtual IMessageSink	ErrorSink [get, set]
int	IndentLevel [get]
UString	IndentString [get]
int	LineNumber [get]
int	InputPosition [get]
Properties inherited from Loyc.Syntax.Lexing.ILexer< Token >
ISourceFile	SourceFile [get]
	The file being lexed. More...
IMessageSink	ErrorSink [get, set]
	Event handler for errors. More...
int	IndentLevel [get]
	Indentation level of the current line. This is updated after scanning the first whitespaces on a new line, and may be reset to zero when NextToken() returns a newline. More...
UString	IndentString [get]
	Gets a string slice that holds the spaces or tabs that were used to indent the current line. More...
int	LineNumber [get]
	Current line number (1 for the first line). More...
int	InputPosition [get]
	Current input position (an index into SourceFile.Text). More...

Public Member Functions
	EcsPreprocessor (ILexer< Token > source, Action< Token > onComment=null)
override Maybe< Token >	NextToken ()
	Returns the next (postprocessed) token. This method should set the _current field to the returned value. More...
Public Member Functions inherited from Loyc.Syntax.Lexing.LexerWrapper< Token >
	LexerWrapper (ILexer< Token > sourceLexer)
SourcePos	IndexToLine (int index)
	Returns the position in a source file of the specified index. More...
virtual void	Reset ()

Additional Inherited Members
Protected Member Functions inherited from Loyc.Syntax.Lexing.LexerWrapper< Token >
void	WriteError (int index, string msg, params object[] args)
Protected fields inherited from Loyc.Syntax.Lexing.LexerWrapper< Token >
Maybe< Token >	_current

Member Function Documentation

override Maybe<Token> Loyc.Ecs.Parser.EcsPreprocessor.NextToken ( )

inlinevirtual

Returns the next (postprocessed) token. This method should set the _current field to the returned value.

Implements Loyc.Syntax.Lexing.LexerWrapper< Token >.