From: Robert Klemme <shortcutter@...>
Date: 2009-01-22T16:28:25+09:00
Subject: Re: String doesnt auto dup on modification

On 21.01.2009 22:57, Brian Candler wrote:
> RK Sentinel wrote:
>> Anyway, through trial and error, I start dup()'ing strings myself. I am
>> aware of freeze().
>>
>> But would like to know how others handle this generally in large apps.
>>
>> - Do you keep freezing Strings you make in your classes to avoid
>> accidental change
>>
>> - Do you habitually dup() your string ?
> 
> Generally, no.

Same here.

> Of course there is no contract to enforce this, but in many cases it 
> would be considered bad manners to modify an object which is passed in 
> as an argument.

Depends: for example, if you have a method that is supposed to dump 
something to a stream (IO and friends) which only uses << you can as 
well use String there.

> If you only read the object, then it doesn't matter.

That may be true for methods but if you need to store a String as 
instance variable then I tend to dup it if the application is larger. 
You can even automate conditional dup'ing by doing something like this

class Object
   def dupf
     frozen? ? self : dup
   end
end

and then

class MyClass
   def initialize(name)
     @name = name.dupf
   end
end

Kind regards

	robert

-- 
remember.guy do |as, often| as.you_can - without end