From: martindemello@... (Martin DeMello)
Date: 2002-09-24T18:40:16+09:00
Subject: Re: select and select

GOTO Kentaro <gotoken@notwork.org> wrote in message news:<200209231328.g8NDSsND040379@miso.k.notwork.org>...
> At Mon, 23 Sep 2002 21:33:05 +0900,
> Martin DeMello wrote:
> > Has anyone suggested 'values'? array.values(1,2,3) sounds reasonably
> > natural, as does hash.values(key1, key2, key3).
> 
> See http://ruby-talk.org/50932

oops - yes, anything with a plural noun would fail requirement 2,
since you'd expect the entire list when no argument was given.

How about getval (and, for symmetry, setval)? A bonus would be that
there might be cases where

  a.each_index {|i| a.setval(i,f(i))} 

looks nicer than 

  a.each_index {|i| a[i]=f(i)}

The drawback is that using 'getval' rather than 'getvals' doesn't
suggest that multiple arguments are accepted.

The problem I have with 'pick' (and friends like 'sift' and 'glean')
is that it seems to call for a criterion rather than an index list,
and therefore be more a synonym of 'select' than of 'indices'

Another option I like is 'extract', especially since it seems to fit
the four cited common cases (array, hash, matchdata and struct).
Though perhaps that suggest something more along the lines of
{k1 => v1, k2 => v2, k3 => v3}.extract(k1,k3) = {k1 => v1, k3 => v3}

martin