From: Martin DeMello <martindemello@...>
Date: 2003-07-22T17:11:11+09:00
Subject: Re: Should String#strip take a parameter?

Yukihiro Matsumoto <matz@ruby-lang.org> wrote:
> Hi,
> 
> In message "Should String#strip take a parameter?"
>    on 03/07/22, "Warren Brown" <wkb@airmail.net> writes:
> 
> |    If there is an interest in this, I can provide patches for 1.6.8 and/or
> |the latest 1.8 snapshot.
> 
> We need to define the behavior first.  Python 2.3's strip takes a
> parameter, but it strips off all characters in the string, i.e.
> 
>  a = "<><<>>>><abc>><><>"
>  a.strip("<>")                # => "abc"

That's unintuitive, IMO. I think if strip takes a parameter, it should
be a regex (a string can be autoconverted to its Regex.quoted form), and
implicitly wrap the regex in a (...)*. e.g.

s.strip(/[<>]/) -> 
  s.gsub!(/^([<>])*/,'')
  s.gsub!(/([<>])*$/,'')

whereas
s.strip('<>') ->
  s.gsub!(/^(<>)*/,'')
  s.gsub!(/(<>)*$/,'')

Treating a string as a character class is not convenient enough to
justify its limitingness.

(Do ruby regexes support a noncapturing, nonbacktracking form of ()*?)

martin