From: Christian Neukirchen <chneukirchen@...>
Date: 2005-11-22T02:48:08+09:00
Subject: Re: Regular Expressions and Ruby

Jeff Wood <jeff.darklight@gmail.com> writes:

> well, not that it's perfect, but I would do something like:
>
> elements = %w( He LI Be C O Ne Na Mg Al Si S Cl Ar Ca Sc Ti Cr Mn Fe Co Ni
> Cu Zn Ga Ge As Se Br Kr Rb Sr Zr Nb Mo Tc Ru Rh Pd Ag Cd In Sn Sb Te Xe Cs
> Ba Hf Ta Re Os Ir Pt Au Hg Tl Pb Bi Po At Rn Fr Ra Rf Db Sg Bh Hs Mt Uun Uuu
> Uub Uuq Uuh Uuo Ds La Ce Pr Nd Pm Sm Eu Gd Tb Dy Ho Er Tm Yb Lu Ac Th Pa Np
> Pu Am Cm Bk Cf Es Fm Md No Lr H B N F P V Y I W Uaal )
>
> class Array
> def to_re( regex_modifier )
> eval "/#{ self.join "|" }/#{ regex_modifier }"
> end
> end
>
> "present".scan elements.to_re( "i" ) # the "i" means case insensitive
> #=> [ "pr", "es", "n" ]
>
> ... hope that helps. I'm sure there are more efficient regex patterns for
> this, but I couldn't imagine anything that was easier to write.

Regexp.union exists.

> Jeff Wood
-- 
Christian Neukirchen  <chneukirchen@gmail.com>  http://chneukirchen.org