[fpc-pascal] For .. in .. loops with sets and valued enums

[Michael Van Canneyt]

On Fri, 19 Jun 2015, Torsten Bonde Christiansen wrote:

> Consider the following program:
> 
> program Project1;
> 
> type
>   TMyEnum = (
>     a = 1,
>     b = 3,
>     c = 5
>   );
>   TMySet = set of TMyEnum;
> var
>   Item: TMyEnum;
> 
> begin
>   for Item in TMySet do
>     Writeln('Value = ', Integer(Item));
> end.
>         
> 
> I would expect the output of the program to contain the values 1, 3 and 5 only. But the actual output is:
> Value = 1
> Value = 2
> Value = 3
> Value = 4
> Value = 5
> 
> Is this a bug or a know limitation of the "for ... In ... do" loop?

This is a known limitation: you cannot use for..in..  with enums that have assigned values.

The compiler gives an error if you do:

home: >cat tef.pp
type
   TMyEnum = (a = 1,b = 3,c = 5);
    var
    Item: TMyEnum;
    begin
    for Item in TMyEnum do
    Writeln('Value = ', Integer(Item));
    end.
home: >fpc tef.pp
tef.pp(6,16) Error: For in loop cannot be used for the type "TMyEnum"
tef.pp(8,7) Fatal: There were 1 errors compiling module, stopping

But it is a bug that the compiler does not give an error for the set type. Please report it.

If you use a variable as indicated by Peter, it will work.

Michael.