From: Martin DeMello <martindemello@...>
Date: 2005-09-16T04:06:33+09:00
Subject: Re: Appropriate use of "inject()" ?

itsme213 <itsme213@hotmail.com> wrote:
> I have a hash table HASH containing strings, and want to generate a string
> for an equivalent Javascript variable JS from it e.g.
> 
> HASH = {'a' => 'A', 'b' => 'B'}
> 
> "var JS = { 'a' : 'A', 'b' : 'B' }"
> 
> I thought inject was just the ticket:
> 
> 'var JS = {' +
>   HASH.inject("") { |str, kv| str << "\n\t'#{kv[0]}' : #{kv[1]}, " } +
>   "};"
> 
> But this puts a "," after the last item. Is there a simple alternative?

The simplest is the two-pass 

'var JS = {' + HASH.map {|k,v| "'#{k}' : '#{v}'"}.join(",\n\t") +  "};"

#join has extra logic to specialcase the last element, which is painful
with #inject.

martin