From: Lionel Bouton <lionel-subscription@...>
Date: 2007-09-11T19:57:34+09:00
Subject: Re: Substitution with Hash

Lionel Bouton wrote the following on 11.09.2007 12:48 :
> Lee Jarvis wrote the following on 11.09.2007 12:41 :
>   
>> Ok i'll try to explain what i mean as well as i can
>>
>> Lets say i have a hash like this
>>
>> hash { 'a' => '1' } #just as example, its actually far bigger
>>
>> and if a user inputs abcdabcd i was it to sub all of the a's with 1's..
>>
>> As i said, the hash is far larger which is why i can't just do it with
>> gsub..
>>
>> Any ideas?
>>
>> Thanks in advance..
>>
>> Lee
>>   
>>     
>
> yourstring.split(//).map{|c| hash[c] || c}.join
>
>   
Note that if your hash is only used to convert single characters to
single characters, you can use String#tr (or tr!). If you are after
performance, as you must prepare the strings used by String#tr from your
hash, you'll have to bench it to see if it's worth it in your use case
even if String#tr is faster in itself.
If you are processing UTF-8 content, String#tr is probably not safe
(there are libraries out there for fixing this though IIRC), but my
first answer probably is (assuming $KCODE='u'; require 'jcode'...) as
the regexp processing is utf-8 aware, so the String#split should be safe.

Lionel