RES: [fpc-pascal] dot within unit file name

[Vinzent Höfler]

Daniël Mantione wrote:

> Op Fri, 18 Jan 2008, schreef Vinzent Höfler:
> 
>> Maybe my view is skewed too much by the use of Ada where even a 
>> function declares a "record identifier". In Ada it is even possible to 
>> do:
>>
>> ---
>> procedure Test is
>>
>>   X : Integer;
>>
>>   procedure B is
>>      X : Integer;
>>   begin
>>      X      := 1;
>>      Test.X := 2; -- references X of "Test" procedure
>>   end B;
>>
>> begin
>>   X := 3;
>> end Test;
>> ---
> 
> There is fundamental problem which such a construct even using normal 
> Pascal scoping rules. The identifier "test" in this case, is in the 
> symtable of procedure B, which is a deeper lexical level, thus can hide 
> global identifiers.

Yes. That's precisely why in Ada you have to write "Test.X" to go up 
that "lexical level". The hiding happens here, too - but you have the 
possibility to explicitely override it.

(Let's put aside the fact, that such constructs are usually bad coding 
style.)

> On the other hand:
> 
> uses a;
> 
> var a:byte;
> 
> ... both unit a as variable a would go into the global symtable, which 
> is the same lexical level, thus causing duplicate identifier conflicts.

In Ada the fully qualified name of the variable would be "A.A" here.

I certainly see the problems for the (Pascal) compiler write here, but 
from a user's point of view this identifier is in no way different than 
"SysUtils.Sleep".


Vinzent.