From: James Edward Gray II <james@...>
Date: 2007-10-12T21:38:12+09:00
Subject: Re: How to delete specific characters from a string?

On Oct 11, 2007, at 11:00 PM, mortee wrote:

> Wayne E. Seguin wrote:
>> On 10/11/07, Giles Bowkett <gilesb@gmail.com> wrote:
>>> I think the OP was looking for a method on String itself, but the
>>> whole point of Ruby is that if the language doesn't have the  
>>> features
>>> you want, you just add the features to the language.
>>>
>>> class String
>>>   def delete_n_from_p(n, p)
>>>     n.times do
>>>       self[p] = ''
>>>     end
>>>     self
>>>   end
>>> end
>>>
>>>>> "muppet".delete_n_from_p(2,3)
>>> => "mupt"
>>>
>>> That makes it easy to reuse the functionality.
>>>
>>> --
>>> Giles Bowkett
>>>
>>
>>
>> This little problem is quite enjoyable:
>>
>> class String
>>   def delete_indices(*indices)
>>     indices.each do |index|
>>       self[index] = ''
>>     end
>>     self
>>   end
>> end
>>
>>>> a = "Testing String"
>> => "Testing String"
>>>> a.delete_indices(0,3,6,8)
>> => "estng trng"
>
> What's your point? Your code probably won't do what it seems to intend
> to, because the characters shift to the left during the process.

You can fix the ordering issue above by changing the line:

   indices.each do |index|

to:

   indices.sort { b <=> a }.each do |index|

Fixing for range usage is more complicated though.

James Edward Gray II