From: matz@... (Yukihiro Matsumoto)
Date: 2001-03-10T14:41:50+09:00
Subject: [ruby-talk:12374] Re: Haskell goodies, RCR and challenge

Hi,

In message "[ruby-talk:12330] Haskell goodies, RCR and challenge"
    on 01/03/10, Robert Feldt <feldt@ce.chalmers.se> writes:

|        [0,2,4,6,8].all? {|e| e>=0}           # => true
|        [10,14,18].any? {|e| e%2 == 1}        # => false

I think it's good to add them to Enumerable.

|        (0..4).to_a.partition {|e| e%2 == 0}  # => [[0,2,4], [1,3]]

I like this function.  Although it's mere combination of "select" and
"reject".  But I don't prefer the word "partition" for the
functionality.

|        [1,2,3,4].foldl(:+)                   # => 10

I like something like

         [1,2,3,4].foldl{|a,b|a+b}             # => 10

There might be better name.

|        [1,2,3].scanl(0) {|a,b| a+b})         # => [0,1,3,6]

Will Enumerable#inject do this job?

|        [1,2,3,4].zip([10,20,30])             # => [[1,10],[2,20],[3,30]]
|        [1,2,3].tail                          # => [2,3]
|        [1,2,3,4].init                        # => [1,2,3]

Behavior of these functions are not really apparent.  I think we need
to discuss more about these.

							matz.