questions, questions; always questions :)
this last round of optimizing simplistic functions (ABS for one)
has left me with this real nagging question...
*ponder*... how to explain this... hrmmmmmm
take Carl's code to do abs for example:
return x * (x>0) - (x<0)
it's the part where (x>0) is actually looking at the
==whole== sequence. but you cannot do that here:
if (x>0) then blah end if
because at that point, x must be an atom or the resultant
expression must be an atom to be more precise...
so why can you make a comparison that involves an entire
sequence or an operation that involves an entire
sequence in a return line but cannot do the same thing
in a ==real== comparison statement???
another example is supposing again x and y are a sequence
you cannot do:
if (x*3) > y then blah
but you can do:
return x*3 > y
some would say that you should use compare!
you can... sometimes...
but not for Carl's example, for example--heh.
if (compare(x,0)=1) - (compare(x,0)=-1 )
well that doesn't work for sequences cuz 0 is an atom...
but compare(x*3,y)=1 would work for the other example...
so why the disparity between return statements and
any of the conditionals as to how they relate to sequences???
seems to me that if you were to have me choose which
commands had more priority, ie: which ones were to get
more beefed up interpretations, I woulda picked having
the conditionals (if.then,while.do etc) being able to
operate on entire sequences before I woulda picked having
'return' operate as it does... seems to me the conditionals
are a "higher priority" type of situation as they are
used more and and in fact are the ones that should be
doing comparisions in the first place...
return returns values, and conditionals check conditions.
having return check conditions on that magnitude and
the conditionals not being able to do that...
but i'm not complaining :)
--Hawke'
(side note: jiri?? was it?? mentioned the counter-intuitive
nature of compare... i figured out a way to think about
compare that makes sense... if you don't think of it like:
is x and y the same?
but instead think:
is x lessthan, equalto, or greaterthan y?
which corresponds to compare equaling -1, 0 or 1...
helps me... and i don't wind up forgetting that damned =0
and lest we forget the good ol'fashioned IsSame() command :)
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