From: hemant <gethemant@...>
Date: 2006-12-05T13:56:21+09:00
Subject: Re: doubt with positive lookaround

On 12/5/06, Martin DeMello <martindemello@gmail.com> wrote:
> On 12/5/06, hemant <gethemant@gmail.com> wrote:
> > I do not understand behavior of positive look arounds in Ruby:
> >
> > chunked_data = "DIVex>##ECHO=b698fd4cc1ea4c7a4b5c4e1d1c402911##"
> > p $& if chunked_data =~ /(?=DIVex)DI/            # =>  DI
> >
> > However,
> >
> > chunked_data = "<DIVex>##ECHO=b698fd4cc1ea4c7a4b5c4e1d1c402911##"
> > p $& if chunked_data =~ /(?=<DIVex)DI/            # =>  nil
> >
> >
> > does < gets treated as special character inside (?= ..) ?
>
> No, but lookahead assertions are zero-width, so if your assertion
> matches <DIV, your cursor is still before the <, and thus won't match
> DI.  p $& if chunked_data =~ /(?=<DIVex)<DI/  works fine.

Holy cat...thanks



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