From: Ryan Davis <ryand-ruby@...>
Date: 2010-10-11T07:23:51+09:00
Subject: Re: More readable array querying


On Oct 10, 2010, at 13:59 , Andrew Wagner wrote:

> All,
> I've been playing with some code to make querying an array more readable.
> Basically, it lets you write one of the following:
> 
> puts [1,2,3].first that {|x| x.even? }
> puts [1,2,3].first that is :even
> 
> instead of this:
> 
> puts [1,2,3].find {|x| x.even? }
> 
> The code is below. I'm curious whether you'd find it useful, interesting,
> worthwhile, etc., and if there are improvements you can think of. Either
> way, it was a fun little exercise. I love the flexibility I get from writing
> in ruby!

I doubt I would ever want to use this. The amount of readability it adds is completely offset by how much slower it is:

# of iterations = 1000000
                          user     system      total        real
null_time             0.090000   0.000000   0.090000 (  0.095464)
ary.find              1.680000   0.010000   1.690000 (  1.717772)
ary.first that       18.580000   1.140000  19.720000 ( 23.080667)
ary.first that is    21.770000   0.260000  22.030000 ( 30.326090)

>  def that proc=nil, &block
>    p = proc.nil? ? block : proc

p = proc || block

>  def is message
>    lambda { |x| x.send "#{message}?".to_sym }

no need for to_sym at all.

>  def first func=nil
>    return old_first if func.nil?
>    each do |x|
>      return x if func.call x
>    end

Any reason why you're not using find? 

Also, if you don't match, you're going to return self, which would be wrong imo.