Archon::Utilities::LexerBase Struct Reference

An abstract base class for lexers. More...

#include <archon/util/lexer.H>

Inheritance diagram for Archon::Utilities::LexerBase:

[legend]List of all members.

Public Member Functions
virtual	~LexerBase ()
virtual void	getNext (Lexeme &l)=0
	Extract the next lexeme from the input.
virtual ustring	getText () const =0
virtual int	getType () const =0
Classes
struct	InputException
struct	Lexeme

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Detailed Description

An abstract base class for lexers.

An abstract base class for lexers defining a lexeme object and a virtual method to fetch the next lexeme.

A lexer derived from LexerBase is required by LrParserBase for example.

See also:

LrParserBase::parse(LexerBase &, Logger *)

Definition at line 50 of file lexer.H.

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Member Function Documentation

virtual void Archon::Utilities::LexerBase::getNext (  Lexeme &  l  )  [pure virtual]

Extract the next lexeme from the input. Parameters: l  The extracted lexeme is stored herein. If l.type is -1 upon return this idicates EOI (end of input). Implemented in Archon::Utilities::Regex::Lexer.

virtual ustring Archon::Utilities::LexerBase::getText (   )  const [pure virtual]

Returns: The text corresponding the the last lexeme extracted by getNext(). This method may also be used within Context::lexerError to fetch the faulty character. Implemented in Archon::Utilities::Lexer, and Archon::Utilities::Regex::Lexer.

virtual int Archon::Utilities::LexerBase::getType (   )  const [pure virtual]

Returns: The type of the last lexeme extracted by getNext(). -1 indicates EOI. Implemented in Archon::Utilities::Lexer, and Archon::Utilities::Regex::Lexer.

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

• archon/util/lexer.H

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