On 01 Dec 2008, at 22:33, Martin Friebe wrote:
I suggested to have a rtl, that has overloaded functions for each
string type.
of course that sounds easier than in fact it will be.
Florian pointed out a few issues, like overloading by result is not
possible (yet?).
No, it is fundamentally impossible. First of all, because a Pascal
compiler does not look at how the result of an expression is used
while parsing the expression (so while evaluating a function call, the
compiler has no idea what the "expected" result type is). That's
simply how Pascal works.
And how could the compiler decide what to call here:
function f: longint;
begin
result:=1;
end;
function f: string;
begin
result:='s';
end;
begin
writeln(f);
end.
There are an immense amount of similar examples possible (and if you
add operator overloading in the mix, it increases exponentially), and
you'd get a huge amount of "can't decide which overloaded function to
call" errors even if the compiler were hacked to take the use of the
function results into account.
Jonas
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