From: Mike Barton <barton.michael@...>
Date: 2008-06-19T23:08:58+09:00
Subject: Re: I don't really understand inject

I see, I see, I see.
That solved the problem. Thanks for that help injection!
Ha Ha Ha!

On Jun 19, 2:36 pm, Jesús Gabriel y Galán <jgabrielyga...@gmail.com>
wrote:
> On Thu, Jun 19, 2008 at 3:13 PM, Mike Barton <barton.mich...@gmail.com> wrote:
> > I think these methods should both do the same thing. The second works,
> > however in the first I get errors that string is not matched, where
> > hash is an instance of String not hash
>
> > def sequences
> >    self.alignment.split(/\n/).inject(Hash.new) do |hash, line|
> >      id, sequence = line.split(/\s+/,2)
> >      # hash.class == String
> >      hash[id] = sequence
> >    end
> > end
>
> How inject works is that it passes the block two values:
> an accumulator and one of the elements in the enumerable
> (one at a time). In each iteration, the accumulator will be the
> return value of the block in the previous iteration.
>
> So in your example, if you want the accumulator to be a hash,
> your block should return a hash. Try this (untested):
>
> def sequences
>     self.alignment.split(/\n/).inject(Hash.new) do |hash, line|
>       id, sequence = line.split(/\s+/,2)
>       # hash.class == String
>       hash[id] = sequence
>       hash    # <<< the change
>     end
>  end
>
> Hope this helps,
>
> Jesus.