From: Jani Monoses <jani@...>
Date: 2004-09-20T22:12:54+09:00
Subject: Re: methods with and without !

Robert Klemme wrote:

>"Jani Monoses" <jani@iv.ro> schrieb im Newsbeitrag
>news:414EC550.2040700@iv.ro...
>  
>
>>Hello
>>
>>what is the criterion for methods to have a ! terminated variant in the
>>standard ruby APIs?
>>For instance in String strip has a receiver-modifying counterpart but
>>ljust does not.
>>Is it that the result fits in the same memory? (strip returns a string
>>at most as long as the original while just can return a much longer one)
>>    
>>
>
>Normally the rule is that the method modifies the current instance as
>opposed to the creation of a new instance (e.g. String#gsub! and
>String#gsub).  But that convention is not followed consistently in the std
>lib.   I guess the explanatory text contains "historic reasons" somewhere.
>:-}
>
>  
>
maybe it was my bad wording ;) I know that ! versions modify in place 
(scheme heritage?)
I was asking which methods should have a ! variant along the regular one.
We have sub and sub!, strip and strip! but no String#just! only String#just
Does in-place imply then that  no memory allocation will be done and the 
result must fit in the calling object?

Jani



Jani