for/next fundamental flaw

[Charles Pegge]

To handle all contingencies, I can redesign the basic for loop, decomposing it first to a do loop

There is a slight performance hit, because the stepper value is iteratively tested for +/-.

Code: [Select]

for i=b to e step s
  ...
next

----->

i=b
._for
  if s>0
    if i>e
      jmp fwd ._end_for
    end if
  else 's<=0
    if i<e
      jmp fwd _end_for
    endif
  endif
  '
  ...
  '
  ._next
  i+=s
  jmp _for
._end_for


[Brian Alvarez]

Hello Charles,

  That is kind of how i fixed it here. No problems here anymore.
 Yes, there is a performance hit, but it is barely noticeable.

 Besides, you still have the control and it can be optimized by still
supporting the explicit - operator at compilation time, or ommitting the
generation of this code for the for/next blocks that do not have a STEP
parameter.

Thoughts: I personally think it is better to define the STEP at runtime
because if a - operator is provided with a variable, and the variable is
a negative value... the conditions for the end of the loop will never be met.

[JRS]

To handle all contingencies, I can redesign the basic for loop, decomposing it first to a do loop.

That's how I see FOR. DO with more options. (range and step)

[Charles Pegge]

Released 0.2.4 in OxygenBasicProgress.zip, with unscoped blocks, and new for block with runtime step testing as disscussed.

[Brian Alvarez]

Thanks Charles, i just downloaded, everything seems great.