From: matz@... (Yukihiro Matsumoto)
Date: 2002-09-20T09:14:10+09:00
Subject: Re: select and select

Hi,

In message "Re: select and select"
    on 02/09/20, Joel VanderWerf <vjoel@PATH.Berkeley.EDU> writes:

|Would it be less confusing to extend the behavior of #entries, instead, 
|like this:
|
|   [0,1,2,3,4].entries(1,3)    #==> [1,3]
|
|or would this lead to the same problems as with overloading #select?

To avoid repeating same disuccsion again, let me summarize:

We want to have a new method to replace "indices", because of
inconsistency between "indices" (or "indexes") and "index". "index"
returns index of a value, "indices" returns values corresponding to
indices.

A new method (say "quux" for example) should satisfy

  * obj.quux(a,b,c) returns [obj[a],obj[b],obj[c]] for all indexable
    collections (i.e. Array, Hash, MatchData and Struct), perhaps
    except for String, which is mere string of characters rather than
    indexable collection.  So preferably it should sound natural both
    for arrays, hashes and others.

  * obj.quux() either returns an empty array or causes exception, due
    to the case like obj.quux(*ary) where ary is an empty array.

							matz.