Re: S-expression I/O in Ada

[Natacha Kerensikova <lithiumcat@gmail.com>]

On Aug 11, 2:58 pm, Robert A Duff <bobd...@shell01.TheWorld.com>
wrote:
> If your brain can understand the complexities of C (when do
> arrays "decay" into pointers?

Always, except when they're an argument of sizeof, unary &, or a
string literal used to initialize an array (C99 §6.3.2.1.3). Though I
have to admit from the top of my head I only remember sizeof and that
there are three of them, after think a bit I remembered unary &, and I
had to look up the Standard to find out the thrid one (even though I
use fluently this feature when I needed it).

> how do you typedef an array
> of pointers to functions returning pointers to functions
> returning void?

typedef void (*voidfn)(arguments unspecified above);
typedef voidfn (*returning_voidfn)(other arguments unspecified above);
typedef returning_voidfn wanted_type[SIZE_UNSPECIFIED];

Now of course this is probably less impressive than the much-less-
readable version doing everything in one statement:

typedef void (*(*wanted_type[SIZE])(void))(void);

> what's a "sequence point"?

Basically, points in the program flow between which whatever should
happen happens in an undefined order. They happen roughly at commas
(expression separator), semicolons (statement separators) and lazy
logical operators.

> ), then I assure you it can deal with Ada.

But what's the point of knowing all this when one can't design a three-
digit LOC program properly?
It's just like knowing the dictionary contents by heart without
knowing anything about grammar.



Thanks for your time,
Natacha