From: Dave Howell <groups@...>
Date: 2006-02-06T09:09:44+09:00
Subject: Re: Quiz #65, Principle of Great Surprise, and Array.delete sledgehammer


On Feb 5, 2006, at 8:50, ara.t.howard@noaa.gov wrote:

> On Sun, 5 Feb 2006, [ISO-8859-1] Simon Kr�ger wrote:
>
>> ara.t.howard@noaa.gov wrote:
>>
>>> [...]
>>> not raising an error when the element is not found is an
>>> amazingly bad idea that would mask many bugs
>>> [...]
>>
>
> in general i think methods basically fail into two categories
>
>   - those that always succeed, Array#clear for example.  these can 
> simply
>     return self.
>
>   - those that might fail and need to either return nil or raise an 
> exception
>     to indicate this.  raising is nice because you can chain.
>
> it's not clear to me why 'delete_first' would be in the first category 
> but i
> think this is largely religious.

I think you're confusing "failure" with something else. If I ask a 
method to delete a "22" from an array that contains none of them, then, 
as I see it, deleting nothing from the array is a correct, successful 
response. If I *care* if there are any such elements in the array in 
the first place I can easily (and succinctly)
	if myArray.index(element)