Yes i understand that, behaviour is in a single method, all others are 
wrappers.

But:
- all others do hold a copy of the default values.
- they are 2**N
So imagine you want to change a default value, or you want to add 
another argument...

Unless wrappers pass nil, and core method implements
'var = var || default' nonsense:
   realValue := argValue ifNil: [defaultValue].

Nicolas

J J a écrit :
>> From: nicolas cellier <ncellier at ifrance.com>
>> Reply-To: The general-purpose Squeak developers 
>> list<squeak-dev at lists.squeakfoundation.org>
>> To: squeak-dev at lists.squeakfoundation.org
>> Subject: Re: Any reason for assigning block parameter in inject:into:
>> Date: Sun, 29 Apr 2007 15:00:02 +0200
>>
>> However, this pattern should be limited to very few optional args, 
>> because N optional args make (2 raisedTo: N) different messages.
>> That's a lot of code to maintain.
>>
>> Nicolas
> 
> You're over-stating this.  It's simple.  You provide the base method 
> that takes all options and one method for each different interface to 
> that method you provide.  And this approach certainly scales better then 
> setting the defaults by hand, although Python style defaulting would be 
> less typing.
> 
> Languages like Smalltalk can use keyword arguments for default arguments 
> [1], languages like Python use special default argument syntax [2] and 
> languages that were not designed as well (at least in this area) have to 
> rely on 'var = var || default' nonsense.
> 
> [1] IMO, this is the superior method for a dynamic language because the 
> others require runtime checks to be done every time the function is 
> entered, while this way it is only a compile time check.
> 
> [2] This is certainly better then having to manually type out every 
> default case, but (afaik) it is still a runtime check for a dynamic 
> language.
> 
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