Re: local variables

[Simon Wright <simon@pogner.demon.co.uk>]

"B.Voh" <voh@young.epc.lmms.lmco.com> writes:

> Does new ADA support a retention of local variables similar to Fortran's
> "save" or C's "static" declaration?
> In my last encounter with ADA, some years back, I found that to be a
> rather crippling ommission and often working against the very principles
> (encapsulation) it was supposed to champion.

Current Ada is exactly like Ada83 in this respect; you get the effect
you want by using *package* variables.

-------- foo.h ---------

int f(void);

-------- foo.c ---------

static int fi = 0;

int f(void)
{
  fi++;
  return fi;
}

-------- foo.ads ---------

package foo is
  function f return integer;
end foo;

-------- foo.adb ---------

package body foo is
  fi : integer := 0;
  function f return integer is
  begin
    fi := fi + 1;
    return fi;
  end f;
end foo;

-------------------------

OK, within foo.c the scope of fi is a bit wider than it would have
been if it'd been declared inside f(), but I don't see this as being
that big a deal.

Remember that if you use tasking (or, in C, threads) you will have to
protect accesses to fi; putting it inside f() won't help.