From: Benoit Daloze <eregontp@...>
Date: 2011-01-07T23:58:54+09:00
Subject: [ruby-core:34225] Re: [Ruby 1.9-Feature#4247][Open] New features for Array#sample, Array#choice

On 7 January 2011 14:14, Yusuke ENDOH <mame@tsg.ne.jp> wrote:
> 2011/1/7 Benoit Daloze <eregontp@gmail.com>:
>> Did you consider having another option to {each_,}sample to allow replacement ?
>> Such as:
>> ary.sample 3, replace: true
>
> The word "replace" gives impression of modification, for those who
> are familiar with programming and not familiar with statistics.
> Especially, Ruby provides Array#replace. �For example, I imagine the
> following behavior:
>
> �ary = [1, 2, 3]
> �p ary.sample(replace: true) #=> 1
> �p ary #=> [2, 3]

You are right, it is misleading.
Maybe, (I thought originally to that, but I changed seeing your answer
in [ruby-dev:42811])
  ary.sample(n, replacement: true)
is clearer?

Or, to be concise and explicit:
  ary.sample(n, repeat: true)

I like this one, what do you think?

Boolean flags in a Hash are not so cool though.
But just a Symbol flag (sample(n, :repeat, opts)) would complicate too
much the method signature.
And I think it is still better than having 2 methods.

>> Or to follow combinations/permutations:
>> ary.repeated_sample 3
>
> Hmm. �Is each_repeated_sample OK?

I think it is not too bad, but 'repeated_sample' give me the
impression there are a few samples, while it is a single one with
replacement.

>> Off-topic:
>> I think it would be nice if some ruby-dev/ruby-core discussions could be merged.
>> Even if I cannot currently understand Japanese, I can at least read
>> their "coded" ideas.
>> I would see that as using the same topic, with both languages.
>
> Interesting :-)

Sure, any concrete idea how that could be made possible?