Ralf Hemmecke wrote:
>
> > import Character
> > zero := ord(char("0")) pretend SI
> >
> > parseInt(str : String) : I ==
> > b := zero
> > l := # str pretend SI
> > s := 0 :: I
> > ten := 10 :: I
> > for i in (1 .. l) repeat
> > dNum := (ord(qelt(str, i)) pretend SI) - b
> > s := (ten*s) + dNum
> > s
>
> Waldek, I don't understand, why you have put "pretend SI" there. I
> assume by SI you mean SingleInteger.
>
> From what I know, SingleInteger (or MachineInteger in libaldor) need
> not (does not) have the same representation as Integer.
>
Abstractly need not (and AFAIK does not in Aldor -> C compiler), but
currently in Lisp backend SingleInteger is a subset of Integer.
> That you code does what you expect, might have (at least) 3 reasons.
> 1) In the underlying lisp SingleInteger and Integer have the same
> representation
Yes.
> 2) In SPAD SingleInteger and Integer have the same representation.
> 3) "pretend SI" is not simply a "pretend" but is actually doing some
> casting operation, i.e. a runtime operation. (It's not in Aldor as far
> as I know.)
>
> I would have expected something like "::SingleInteger", since there is a
> function "coerce: Integer->%" in SingleInteger.
I do not want 'coerce' because 'coerce' doing bound checking and
due to this currently can not be inlined. I was thinking about
adding someting called 'qcoerce' which would be 'pretend' for
Lisp backend, but could be changed to something else with
different backend. OTOH I am not sure if I want to support
backends where SingleInteger has different representation than
Integer -- at least currently I am thinking about keeping
common representation of Integer and SingleInteger in future
C backend.
--
Waldek Hebisch
[email protected]
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