[antlr-interest] COBOL

Balvinder Singh bals1978 at hotmail.com
Wed May 29 11:04:10 PDT 2002


Hi Sinan,

But If I will use your scheme, getting warning

warning:Syntactic predicate ignored for single alternative

what should I refactor?

balvinder



>From: Sinan <sinan.karasu at boeing.com>
>Reply-To: antlr-interest at yahoogroups.com
>To: antlr-interest at yahoogroups.com
>Subject: Re: [antlr-interest] COBOL
>Date: Wed, 29 May 2002 08:55:03 -0700
>
>Balvinder Singh wrote:
> >
> > Hi all,
> >
> >    I'm writing cobol parser only for WORKING STORAGE AREA of data 
>division.
> > I'm using grammar rule and lexical rule for WORKING STORAGE AREA from VS
> > COBOL II (http://adam.wins.uva.nl/~x/grammars/vs-cobol-ii/)
> >
> > I have converted lexical rule to ANTLR format, but I'm getting conflicts 
>for
> > some of the rules, rules are as follows :
> >
> > Literal : NonNumeric | Numeric
> >         ;
> >
> > protected
> > NonNumeric : '"' ( (~'"') | '"' '"' )* '"'
> >            | '\'' ( (~'\'') | '\'' '\'')* '\''
> >            | ('X' 'x') '"' HexDigits '"'
> >            | ('X' 'x') '\'' HexDigits '\''
> >            ;
>Factor this:
>
>NonNumeric : '"' ( (~'"') | '"' '"' )* '"'
>             | '\'' ( (~'\'') | '\'' '\'')* '\''
>             | ('X' 'x')( '"' HexDigits '"' | '\'' HexDigits '\'')
>             ;
>
>
>
>
> > AphabeticUserDefinedWord : (('0'.. '9')+ ('-')*)* ('0' .. '9')* ('A' 
>..
> > 'Z' 'a' .. 'z') ('A' .. 'Z' 'a' .. 'z' '0' .. '9')* (('-')+ ('A' .. 'Z' 
>'a'
> > .. 'z' '0' .. '9')+)*
> >                           ;
>
>This is infinite lookahead. since you can have 9- , 99- etc...
>
>Fix it by saying
>  AphabeticUserDefinedWord : ((('0'.. '9')+ ('-')*)=> ('0'.. '9')+
>('-')*)* ('0' .. '9')* ('A' ..
>  'Z' 'a' .. 'z') ('A' .. 'Z' 'a' .. 'z' '0' .. '9')* (('-')+ ('A' .. 'Z'
>'a'
>  .. 'z' '0' .. '9')+)*
>                            ;
>
>
>
>
>Sinan
>
>
>
>Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
>
>




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