OpenEuphoria

Re: Short Circuiting

• Posted by Hawke <mdeland at NWINFO.NET> Jun 24, 1998
• 585 views

Ralf Nieuwenhuijsen wrote:
> if this then
>     if that () then
>         ..
>     end if
> end if
>
> In other words, short-circuiting is a very clumbsy things and results in
> very weird errors and it is very inconsistent.
> The that () function should always be called.
> Please, don't implent short-circuiting.


ummmm...no.
up till now i agreed with all of your arguments and examples ralf.
short-circuiting(SC) is a necessary tool in programming. often
implemented
by a programmer without them realizing it.
SC is a often a major optimization to coding... classes in boolean logic
teach 'tricks' to determining what cases occur most often and what cases
can be completely, utterly avoided from conditional checking.
this is the case here. the that() function should NOT always be called.
if this is false, there is no need for calling that(),
ergo:optimization.
on this issue, however, there is no need for Rob to implement SC in
Euph.
IMHO:if it can be done already, in a manner that exacts no performance
penalty and can also be made _clear_ to another coder, there is
absolutely NO reason for modification to the interpreter.
i see this as the case here.  SC as it stands with
if a and b then dothis end if
becomes:
if a then -->will SC if a and b...ergo:test case a needs to be
          -->the case that profile says occurs most often, with
          -->b not even being looked at if a is false
if b then
dothis
end if
end if
is a very viable, clear, and non-performance compromising solution to
the
topic of SC.
in closing, SC is indeed a needed tool, and an extremely powerful
optimizer.
however, nothing needs done by Rob for euphorians to implement this
tool.
we don't need &&, we don't need ||, we don't need ?:, and we don't need
with SC on/off. we either have mechanisms that accomplish it elegantly,
succinctly and efficiently, or sign the 'grammar' or 'syntax' issues off
to a PreProcessor or subroutine...if u don't like the syntax, change
it...
why? because you _can_. please do not change the euphoria core, it
actually
has _more_ than it realllllllyyyyyyyyyyyy needs right now anyway.

Hawke'