[antlr-interest] newbi question : operator + any

Jim Idle jimi at temporal-wave.com
Wed Feb 8 10:54:09 PST 2012


Did you see my explanation of why you must use:

ANYTHING : . ;

And not use + or * with the . ?

Jim

> -----Original Message-----
> From: antlr-interest-bounces at antlr.org [mailto:antlr-interest-
> bounces at antlr.org] On Behalf Of Marco Laponder
> Sent: Tuesday, February 07, 2012 10:58 PM
> To: antlr-interest at antlr.org
> Subject: Re: [antlr-interest] newbi question : operator + any
>
> Lets explain what I am trying to accomplish, maybe you can provide me
> the most impressive grammars :-)
>
>
>
> I am trying to parse a filter string which filter on a column of a
> table, so I need to know the operator. In my example I stated the '>'
> but of course I would like to expand it to '<','>=' etc and alter on
> even add parenthesis, 'and' and 'or' etc. But I would like to start
> simple as I am new at ANTLR.
>
>
>
> Your sample does the trick, however looks hard to maintain, e.g., when
> I add the '<' to COMPARE I also need to add it to ANYTHING. (Well it
> seems still more maintainable than a single regular expression no one
> understands to do the trick ;-) )
>
>
>
> Kind regards,
> Marco
>
>
>
> ________________________________
>
> Van: Marco Laponder
> Verzonden: dinsdag 7 februari 2012 8:45
> Aan: 'Gokulakannan Somasundaram'
> CC: antlr-interest at antlr.org
> Onderwerp: RE: [antlr-interest] newbi question : operator + any
>
>
>
> This still gives me the same error, any other ideas ? Of is antlr just
> not appropriate for this ?
>
>
>
> Kind regards,
>
> Marco
>
>
>
> ________________________________
>
> Van: Gokulakannan Somasundaram [mailto:gokul007 at gmail.com]
> Verzonden: maandag 6 februari 2012 16:56
> Aan: Marco Laponder
> CC: antlr-interest at antlr.org
> Onderwerp: Re: [antlr-interest] newbi question : operator + any
>
>
>
> COMPARE : '>';
>
> ANYTHING : (~'>')(.)*;
>
> testExpression : COMPARE ANYTHING;
>
>
>
>
>
> Try this.
>
>
>
> Gokul.
>
> On Mon, Feb 6, 2012 at 8:30 PM, Marco Laponder
> <marco.laponder at kewill.com> wrote:
>
> Hi All,
>
>
>
> I am trying to setup a very simple grammar, ik should be able to handle
>
>
>
> "> thiscouldbeanything"
>
>
>
> So I tried:
>
>
>
> COMPARE : '>';
>
> ANYTHING : (.)+;
>
> testExpression : COMPARE ANYTHING;
>
>
>
> but when generating java resources it gave me the error:
>
>
>
> "The following alternatives can never be matched: 1"
>
>
>
> The problems seems to be the ANYTHING, so how should I define a grammar
> to be able to handle this ?
>
>
>
> Kind regards,
>
> Marco
>
>
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