[antlr-interest] multilexer

[craigmain001 <craig at palantir.co.za>]

Hi,

I am using antlr 2.7.2

I have created two lexers, one that merely copies the input to output 
using a filter, and another that reads language statements that are 
contained in delimited sections of the input.

It almost works. I have shown the output below. I have two questions.

Why does the parser recognise if before it recognises foreach?
Why does the selector->pop not work. Why does it stop parsing at that 
point? How do I get the lexer to continue reading????

Please help.
Regards
Craig.

The test input looks as follows.
==========================
this is a test
int i = 0;
procedure pop;
[foreach]
[if]
end
==========================
The output produces is as follows.
==========================
this is a test
int i = 0;
procedure pop;
{ifstatement encountered}
==========================

Here are the files.
xgen.g
==========================================================
header {
#include "antlr/TokenStreamSelector.hpp"
#include <iostream>
}

options
{ language="Cpp"; }

class XGenParser extends Parser;

statement : (forstatement | ifstatement);

             
ifstatement : IF
               { std::cout << "{ifstatement encountered}"; }
            ;
             
forstatement : FOREACH
               { std::cout << "{foreach encountered}"; }
             ;

class XGenLexer extends Lexer;
options {
     k=2;
}


tokens {
        FOREACH="foreach";
        IF="if";
}


{
private:
 ANTLR_USE_NAMESPACE(antlr)TokenStreamSelector* selector;
public:
 void setSelector(ANTLR_USE_NAMESPACE(antlr)TokenStreamSelector* 
selector_) {
  selector=selector_;
 }
}

CODE_END
 : "]" {selector->pop(); }
 ;


WS_ : (' '
 | '\t'
 | '\n'
 | '\r')
  { _ttype = ANTLR_USE_NAMESPACE(antlr)Token::SKIP; }
 ;

==========================================================
code.g
header {
#include "antlr/TokenStreamSelector.hpp"
#include <iostream>
}

options {
        language="Cpp";
}

class CodeLexer extends Lexer;
options {
     k=2;
     filter=IGNORE;
     charVocabulary='\u0000'..'\u007F'; // ASCII
}
{
private:
 ANTLR_USE_NAMESPACE(antlr)TokenStreamSelector* selector;
public:
 void setSelector(ANTLR_USE_NAMESPACE(antlr)TokenStreamSelector* 
selector_) {
  selector=selector_;
 }
}

CODE_BEGIN : "[" {selector->push("xgen"); }
           ;

protected
IGNORE
     :  ( "\r\n" /*| '\r' | '\n'*/ )
         {newline(); std::cout << std::endl;}
     | c:. {std::cout << c;}
     ;
header {
#include "antlr/TokenStreamSelector.hpp"
#include <iostream>
}

options {
        language="Cpp";
}

class CodeLexer extends Lexer;
options {
     k=2;
     filter=IGNORE;
     charVocabulary='\u0000'..'\u007F'; // ASCII
}
{
private:
 ANTLR_USE_NAMESPACE(antlr)TokenStreamSelector* selector;
public:
 void setSelector(ANTLR_USE_NAMESPACE(antlr)TokenStreamSelector* 
selector_) {
  selector=selector_;
 }
}

CODE_BEGIN : "[" {selector->push("xgen"); }
           ;

protected
IGNORE
     :  ( "\r\n" /*| '\r' | '\n'*/ )
         {newline(); std::cout << std::endl;}
     | c:. {std::cout << c;}
     ;

==========================================================



 

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