From: Robert Klemme <bob.news@...>
Date: 2004-03-11T21:09:35+09:00
Subject: Re: Regular Expression for D(elimiter) Separated Values  File


"Iki" <npoly_iki@yahoo.com> schrieb im Newsbeitrag
news:ad334b15.0403110224.4d3d5b2@posting.google.com...
> Hi all,
>
> I thought I could parse a dsv file with say a ';' delimiter
> (escaped with a backslash where appropriate) just by using
> a regexp such as /(?=[^\\]);/x  and String#split
>
>
> "eggs\\;bread;butter".split(/(?=[^\\]);/x)'
> => ["eggs\\", "bread", "butter"]
>
>
> but ..
>
> "eggs;\\bread;butter".split(/;(?=[^\\])/x)'
> => ["eggs;\\bread", "butter"]
>
> Am I missing something?

Yes, Ruby regular expressions can't do lookbehind, which is what you need
for the escaping.  But you can use scan:

irb(main):005:0> "eggs\\;bread;butter".scan /(?:[^\\;]+|\\.)+/
=> ["eggs\\;bread", "butter"]
irb(main):006:0> "eggs\\;bread;butter".scan /(?:[^\\;]|\\.)+/
=> ["eggs\\;bread", "butter"]

Regards

    robert