From: murphy <murphy@...>
Date: 2007-11-15T08:10:42+09:00
Subject: Re: Proposal: Array#walker

Hugh Sasse wrote:
>> Actually, can anyone recommend a better name than #crack? --or a way
>> to already do this?
> 
> ...split (taken)...
no, it's not. however, String.split works in a different way, so maybe
this isn't the best name.

Array#split_at seems a logical option. I would expect it to behave like
an anti-slice:

/*
 *  call-seq:
 *     array.split_at(index)          -> [left_array, right_array]
 *     array.split_at(start, length)  -> [left_array, right_array]
 *     array.split_at(range)          -> [left_array, right_array]
 *
 *  Splits an array into two parts, with the first one containing
 *  all elements before the given range, and the second one containing
 *  all elements after it. See Array#slice for information about the
 *  range expressions.
 *
 *     a = [ "a", "b", "c", "d", "e" ]
 *     a.split_at(0)          #=> [[], ["b", "c", "d", "e"]]
 *     a.split_at(2)          #=> [["a", "b"], ["d", "e"]]
 *     a.split_at(-1)         #=> [["a", "b", "c", "d"], []]
 *     a.split_at(1, 2)       #=> [["a"], ["d", "e"]]
 *     a.split_at(1, 0)       #=> [["a"], ["b", "c", "d", "e"]]
 *     a.split_at(1..3)       #=> [["a"], ["e"]]
 *     a.split_at(0..-1)      #=> [[], []]
 *
 *     range = 1..3
 *     slice = a.slice(range)
 *     pre, post = a.split_at(range)
 *     a == pre + slice + post  #=> true
 *
 */

[murphy]