Olin Lathrop wrote:

> Walter Banks wrote:
> > I wish that pascal had braces and statement locals and C had
> > pascal's local functions.
>
> Pascal has BEGIN/END, which is pretty much the same as C braces.  A
> BEGIN/END block is a compound statement that is viewed as a single statem=
ent
> outside the block.

The major difference is pascal uses a ";" as a statement separator in a
a compound statement.

begin
  statement
end;

begin
  statement ;
  statement1
end

In C ";" terminates a statement



> temporary
> variables only within the scope of a specific block of code, as apposed t=
o a
> whole routine, then I don't know of anything similar in Pascal.  That is =
a
> reasonable idea that is embodied in C (Wow, who'd have thought!).

This is a very good idea, I agree

> In my source to source translator, there is a significant section of code=
 in
> the C back end to deal with local functions.  I emulate them by using glo=
bal
> functions and explicitly passing any accessed local state down to the
> function.
>
> This can get messy with nesting.  Let's say routine A calls local routine=
 B,
> which calls its own local routine C.  C may access a local variable of A,=
 so
> that variable has to be passed to B just so B can pass it to C when these
> local routines are emulated with global routines.  My translator does
> multiple passes of pushing call arguments up the chain until no changes a=
re
> made in a pass.  The result is not pretty, but it works for the C output
> language.

This has always been the argument used in WG14 meetings that scope
resolution is complex for nested functions. The problem has several solutio=
ns
including the one you describe. It is actually no more complex than resolvi=
ng
temporary variables in nested brace blocks. Pascal local functions have the
same implementation issues. Nested functions are one feature that I wish C
had.


All the best of the season,

Walter..
--
Walter Banks
Byte Craft Limited
http://www.bytecraft.com







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