[antlr-interest] help regrading actions in antlr grammer

[Bjoern Doebel]

Hi,

> Hello Dear
> I am a student .And I am trying to add actions to this grammer as below.

So assuming input like

add foo, bar ;

you want to print

add foo bar

in your terminal? Just add some print statements to your parser rules.

> I want to get a list of OPCODES and then operands on the terminal.
> Can any one plz help me how can I do it without using the string
> Template and will be useful if also using the string template.
> i will be greatful.
> 
> 
> Here is the grammer
> 
> grammar assemb;
> options {output=template; rewrite=true;}

You don't need these options.

> program
>    :   (stat)+
> 
>    ;
> 
> stat:    OPCODE operands

rewrite to:

stat : OPCODE operands {print $OPCODE.text} ;

> 
>    ;
> operands
>    :REGISTER SEMI
>     | REGISTER  COMMA REGISTER  SEMI
>    ;

operands:
	REGISTER SEMI	{ print $REGISTER.text }
      | r1=REGISTER COMMA r2=REGISTER SEMI { print r1.text, r2.text }

> OPCODE :
>     'add'
>     |'store'
>     |'load'
>     |'call'
>     |'ret'
>     |'print' ;
> 
> REGISTER :
>        'r1'
>           |'r2'
>        |'r3'
>           |'r4'   ;
> 
> NUM  :    '[0-9]+' ;
> ID   :    '[a-zA-Z]+' ;
> 
> EOL
>    : (('\r')? '\n') ;
> 
> WS
>    : (
>    | (' ' | '\t')
>    ) { $channel=HIDDEN; }
>    ;

Do you really want to catch EOL? Otherwise you could include it into the
ignored whitespace rule.

Regards,
Bjoern