🚀 go-pugleaf

gstark@ifs.org.uk wrote:
>.. one of two "ISO Compliant" compilers we've tested (XDS), this is legal:
> VAR
>   s : StrArr;
> BEGIN
>   s := StrArr{"Hello" , "Mum" };
> 
> ... but this is *illegal*:
> 
> TYPE
>   Str = ARRAY[1 .. 10] OF CHAR;
>   StrArr = ARRAY[1 .. 2] OF Str;
> CONST
>   s = StrArr{"Hello" , "Mum"};
> 
> However this structured constant *is* allowed under GPM2,

I've got Fourth Draft of the ISO standard, which I believe was quite close to
the final.  It clearly states that the value given for a named constant in a 
constant declaration must be a constant expression.  It is also states that an
array constructor is a constant expression if its contents are constant expressions.
My understanding of that is that one could construct arbitrarily nested array/record
structures, so long as "leaf" items were constant values.

-- 
person: Graham Perkins         paper: School of Computing
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