[fpc-pascal] Metaware

[Mark Wood]

It strikes me that whilst it may not be the best programming form, the 
same thing could be done readily with a global variable?

M.

Tom Walsh wrote:
> Mark Wood wrote:
>>
>>>> I have found that there are some functional differences that 
>>>> Metaware has over
>>>> fpc, one example is the yield() function which returns the 
>>>> intermediate result
>>>> of a function call.
>>>>     
>>> ?
>>>   
>> '?' indeed! I am fascinated! What does yield do exactly... presumably 
>> it returns a result from the function without closing down that 
>> instance of the function? Amazing concept. I am still trying to work 
>> out how that could be useful or even how it could be used (without 
>> breaking stuff upstream).
>>
>
> This would be one example, a function which returns a value each time 
> it is called.  There are some scoping rules which dictate whether the 
> yield'ed function will init or continue from the last yield point:
>
> ============== begin ====================
> iterator LoopStep(Start, Stop, StepSize   : StdInt) : StdInt;
>  var
>    i, Answer, NumLoops : StdInt;
>  begin
>    if StepSize = 0 then return;
>    Answer := Start;
>    NumLoops := ((Stop - Start) DIV StepSize) + 1;
>    for i := 1 to NumLoops do begin
>      Yield(Answer);
>      Answer := Answer + StepSize;
>    end;
>  end;
> ============== snip =====================
>
>
> Not sure why they found this terribly useful, but I don't write 
> financial code...
>
> TomW
>
>