> IMHO, that would be the _insane_ definitions :-) Firstly, nothing
> suggests to me that rationale of such behaviour.
The rationale is:
1. these are useful functions
2. if this is insane, so is python. The corresponding python is:
def take list n: return list[:n]
def drop list n: return list[n:]
Python interpreter example:
>>> list="abcdef"
>>> list[:-2]
'abcd'
>>> list[-2:]
'ef'
>>>
3. think of n as being calculated 'mod' length of the list
take n list | n<0 = take (n `mod` (length list)) list
drop n list | n<0 = drop (n `mod` (length list)) list
--(equivalent definitions)
> Secondly, it would mean loosing an important set of laws:
> drop n . drop m === drop (n + m)
> take n . take m === take (n + m)
> (which, I note in passing, is broken also by suggestion A)
All the proposals break this law as well, so I this argument is weak (if
not insane :-))
-Alex-
___________________________________________________________________
S. Alexander Jacobson Shop.Com
1-212-697-0184 voice The Easiest Way To Shop
On Mon, 24 Jan 2000, Tommy Thorn wrote:
> S. Alexander Jacobson writes:
> > The correct definitions would be:
> >
> > take -2 -- drops the last 2 elements from the list
> > (takes everything except the last 2 elements)
> > drop -2 -- grabs the last 2 elements from the list
> > (drops everything except the last 2 elements)
> ....
> > These are also sane definitions..
>
>
>
> Regards,
>
> Tommy
>
