From: "Jesús Gabriel y Galán" <jgabrielygalan@...>
Date: 2008-12-15T23:03:20+09:00
Subject: Re: string to hash

On Tue, Dec 9, 2008 at 8:33 PM, Brian Adkins <lojicdotcom@gmail.com> wrote:
> Jens -- <jens@carroll.de> writes:
>
>> Hi All,
>>
>> I am in the need of a method that does the following:
>>
>> get 2 arguments a string and an integer (int_val).
>> The string has the following form "a.b.c.d"
>>
>> the method should return a nested hash like that:
>>
>> { :a => { :b => { :c => { :d => int_val } } } }
>>
>> Hmmmm I am not rubyist enough to solve that elegant (or not at all :-/).
>
> Dave's solution is a good one & "idiomatic Ruby", and it should be
> efficient since it spends much time in C code.

Sorry to answer after so long, but I wanted to give another version:

irb(main):059:0> def nested_hash s, i
irb(main):060:1> hash = Hash.new {|h,k| h[k] = Hash.new(&h.default_proc)}
irb(main):061:1> terms = s.split(".")
irb(main):062:1> temp = terms[0..-2].inject(hash) {|acc,val| acc[val.to_sym]}
irb(main):063:1> temp[terms[-1].to_sym] = i
irb(main):064:1> hash
irb(main):065:1> end
=> nil
irb(main):066:0> nested_hash "a.b.c.d", 55
=> {:a=>{:b=>{:c=>{:d=>55}}}}

I am so fond of the arbitrarily nested hash construct :-).

Jesus.