From: Simon Strandgaard <neoneye@...>
Date: 2004-05-14T06:13:16+09:00
Subject: Re: nasty regexp problem

David Alan Black wrote:
> Simon Strandgaard <neoneye@adslhome.dk> writes:
> 
> > Francis Hwang wrote:
> > > I discovered a strange bug in Lafcadio which I'm trying to work out,
> > > but the regexp is getting really nasty. Basically, to commit text
> > > values to the database I need to double any apostrophe, except those
> > > that are preceded by a backslash. This has to account for apostrophes
> > > at the beginning of the string, and multiline strings where the
> > > apostrophe is at the start of a new line. Examples would be:
> >  
> > 
> > irb(main):001:0> "''\\\\'z\\'\\z''".gsub(/ ( (?: [^\\] | \\ . )*? ) ' /x, '\1\'\'')
> > => "''''\\\\''z\\'\\z''''"
> 
> The ' before the first z isn't supposed to get doubled though, is it?
> 

The behavier is correct.. because its an escaped slash right before it.
yes it can easily be confused with an ordinary slash.

-- 
Simon Strandgaard