From: Logan Capaldo <logancapaldo@...>
Date: 2005-05-07T05:49:21+09:00
Subject: Re: Array#squeeze

On 5/6/05, Mark Hubbart <discordantus@gmail.com> wrote:
> On 5/6/05, Logan Capaldo <logancapaldo@gmail.com> wrote:
> > On 5/6/05, Martin DeMello <martindemello@yahoo.com> wrote:
> > > The recent mention of String#squeeze made me wonder if it would not be a
> > > good idea to add a #squeeze method to Array (or possibly even to
> > > Enumerable) as well. Certainly I've needed it at least as often as I've
> > > needed #uniq
> > >
> > > martin
> > >
> > >
> >
> > Well here's a possible implementation:
> >
> > module Enumerable
> >         def squeeze(*args)
> >                 raise ArgumentError.new("Provide 0 or 1 arguments") if
> > args.length > 1
> >                 inject([]) do |a, b|
> >                         if args.length == 0
> >                                 if b == a.last
> >                                         a
> >                                 else
> >                                         a << b
> >                                 end
> >                         else
> >                                 if b == a.last && a.last == args[0]
> >                                         a
> >                                 else
> >                                         a << b
> >                                 end
> >                         end
> >                 end
> >         end
> > end
> 
> String's squeeze allows arbitrary numbers of character arguments. II
> would think Enumerable#squeeze should do the same:
> 
> module Enumerable
>   def squeeze(*args)
>     ary = []
>     check = proc{|item| args.empty?? true : args.include?(item) }
>     each{|elem| ary << elem unless ary.last == elem and check[elem] }
>     ary
>   end
> end
> 
> cheers,
> Mark
> 
> 

String's squeeze does, but their are problems with duplicating the
exact semantics of String#squeeze because according to the
documentation it uses the intersection of the strings passed as an
argument and has support for ranges of strings (ie "m-z"). Ranges
would be pretty easy just use x..y.include? but if we are following
the same semantics as String#squeeze your implementation is incorrect.
I will admit yours is more succint then my silly nested ifs. ;)