[fpc-pascal] a proposal about "with" syntax

[Paul Ishenin]

18.03.13, 9:27, Xiangrong Fang пишет:
> I am sorry I didn't follow this thread although I am the "OP" :-).   If
> I understand correct, I would suggest NOT introduce the "absolute"
> keyword, instead, make it ALWAYS absolute. i.e.:
>
> with a = SomeObject, b = SomeRecord do begin
>    ... ...
> end;
>
> Both a and b are "reference" to the object or record, IMO there seems no
> need to do assignment in the with syntax. Thus, I suggest use = instead
> of :=

'=' can't be used because it can be a part of expression. There is no 
big difference between
with (a = SomeObject) do
and
with a = SomeObject do

After more thinking I see that ':=' as well as absolute keyword are also 
bad because they will complicate the parser (although it is possible to 
use them). Parser will need to read the first token and check if it is 
an identifier, read second token and compare with ':=' (or 'absolute') 
and if it is not ':=' (or 'absolute') return to expression parse.

At the same time we will not complicate the parser if we place alias 
identifier after the with expression like:

with expression1, expression2 => alias2, expression3, expression4 => 
alias4 do

begin

end;

Where '=>' is some token which can't be used in expressions.

Best regards,
Paul Ishenin