Re: more to ada paper critic

["Gautier direct_replies_not_read" <gautier_niouzes@hotmail.com>]

Immanuel Scholz:

>Oh come. Arent there race conditions when initializing more than these
>"before the main"s. This solution seems quite similar to C++'s problem
>of initializing global statics. Example: (forgive any syntax-errors I
>havent got GNAT to run until now ;-)

>function Prob1 return integer is
>begin
>   return Var2;
>end Prob1;
>
>function Prob2 return integer is
>begin
>   return Var1;
>end Prob2;
>
>Var1 : constant integer := Prob1;
>Var2 : constant integer := Prob2;

This obviously don't pass the compilation,
since Var1 and Var2 are undefined: this is the
one-pass design of Ada (like Pascal, unlike C or Fortran)

Anyway it is interesting to try.

-- -- -- -- -- -- -- -- --
procedure kiki1 is

  function Prob1 return integer is
  begin
    return Var2;
  end Prob1;

  function Prob2 return integer is
  begin
    return Var1;
  end Prob2;

  Var1 : constant integer := Prob1;
  Var2 : constant integer := Prob2;

begin
  null;
end;
-- -- -- -- -- -- -- -- --
GNAT says:
kiki1.adb:5:12: "Var2" is undefined
kiki1.adb:10:12: "Var1" is undefined

If I push a bit more and "forward" the definition of Prob1, Prob2:
-- -- -- -- -- -- -- -- --
procedure kiki2 is

  function Prob1 return integer;
  function Prob2 return integer;

  Var1 : constant integer := Prob1;
  Var2 : constant integer := Prob2;

  function Prob1 return integer is
  begin
    return Var2;
  end Prob1;

  function Prob2 return integer is
  begin
    return Var1;
  end Prob2;

begin
  null;
end;
-- -- -- -- -- -- -- -- --
GNAT compiles, but says:
kiki2.adb:6:30: warning: cannot call "Prob1" before body seen
kiki2.adb:6:30: warning: Program_Error will be raised at run time
kiki2.adb:7:30: warning: cannot call "Prob2" before body seen
kiki2.adb:7:30: warning: Program_Error will be raised at run time

Running kiki2 produces:
raised PROGRAM_ERROR : kiki2.adb:6

____________________________________________________________
Gautier  --  http://www.mysunrise.ch/users/gdm/index.htm#Ada

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