From: Robert Klemme <shortcutter@...>
Date: 2010-10-28T17:47:23+09:00
Subject: Re: ctype functionality without a gem?

On Thu, Oct 28, 2010 at 9:50 AM, Ammar Ali <ammarabuali@gmail.com> wrote:
> Is there a built-in method for identifying character types a la
> ctype() in C? I would like to avoid requiring a gem dependency.

No other than regexp as far as I know.

> I'm considering the following approach, if nothing exists, but it
> seems like overkill to me.
>
> def ctype(c)
>  case c
>  when /[[:alnum:]]/; :alnum
>  when /[[:alpha:]]/; :alpha
>  # etc...
>  end
> end
>
> def alnum?(c); ctype(c) == :alnum end
> def alpha?(c); ctype(c) == :alpha end
> # etc...

What do you need that for?  Why not directly use a regexp to match a
string?  Often you can use capturing groups in a single regexp, e.g.

irb(main):009:0> %w{foo bar 123}.each do |s|
irb(main):010:1* if /(\d+)|(\w+)/ =~ s
irb(main):011:2> puts "number" if $1
irb(main):012:2> puts "chars" if $2
irb(main):013:2> end
irb(main):014:1> end
chars
chars
number
=> ["foo", "bar", "123"]

Kind regards

robert

-- 
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