[antlr-interest] parsing rules

[Jim Idle]

> -----Original Message-----
> From: antlr-interest-bounces at antlr.org [mailto:antlr-interest-
> bounces at antlr.org] On Behalf Of George Soom
> Sent: Thursday, May 27, 2010 3:52 AM
> To: antlr-interest at antlr.org
> Subject: Re: [antlr-interest] parsing rules
> 
> Thank You,
> 
> now I understand my mistake. However, can You give me a bit bigger
> example?

OK. I use this (all the time ;-):

statements
    :   s+=statement*

        // The list of statements just needs to go on up the chain, but we
        // still use a template in our template group in case we ever
        // wish to adorn statements with something or the target changes
        //
        -> statements(stats={$s})
    ;

Then a template of:

statements(stats) ::= <<
<stats: {<it>}; separator="\n">
>>

(Sometimes you will need to iterate, sometimes not, depending on what you did lower down the chain. 

Other constructs are:

    |   COMMENT                 
            {
                // Get rid of leading spaces and the ' character, generate the comment line
                //
                $st = %lineComment(comment={$COMMENT.text.trim().substring(1)});
            }

To use a template within an action.

And:

        {
            // Ask the code generator to deal with the assignment
            //
            $st = codeGen.assign($v.st, $v.symbol, $expression.st, $expression.symbol, $expression.type);
        }

To call a method that returns a template (or List).

And:

	:	^(CALL

            id=IDENTIFIER
            {
                $st = %({$id.text})();

                f = (Function)localSymbols.lookup($id.text);
                %{$st}.instr=f.getInstruction();

                argNum = 0;
            }

...


To instantiate a template, the name of which is held in some String.


Jim