Re: Procedures and Functions

Re: Procedures and Functions

[W. Wesley Groleau (Wes)]

:> "with Text_Io; use Text_Io;
:> procedure one is
:> function one (...)return stuff is separate;
:> procedure two(...) is separatoe;
:> begin
:> ...
:> end one
:> begin
:> ...
:> end two"
:>
:> This bears no relation to correct Ada syntax. I suspect you should not
:> be using subunits at all at this stage of understanding.

If you saw half of the silliness R. Dewar has to put up with (including
at least one class-A screw-up from me) you'd be impressed with how nice
he is on the net.

I'll try to help a little, but what you really need is gnatinfo.txt AND
a good beginner's book on Ada.  If you've done a lot of programming in
other languages, I suggest "Ada as a Second Language"

Also, since this is an Ada question and not a gnat question, I'm
transplanting the thread to the comp.lang.ada newsgroup.  If you don't
have Usenet news, I'll tell you (by e-mail) how you can still participate
(also by e-mail).

So here's lesson one:

A procedure, function, package, or task can be defined in three ways.
Two of these ways only identify the item (and its parameters, for
subprograms).  For functions, these are like this:

-- function specification:

function One ( Parameter : Parameter_Type ) return Result_Type;

-- function stub:

function One ( Parameter : Parameter_Type )
               return      Result_Type      is separate;


-- function body:

function One ( Parameter : Parameter_Type )
               return      Result_Type      is

begin
  ......

Note that all three are identical up to the "is" or ";"

GNAT wants only one compilation unit per file.  A spec or a body can be
a compilation unit, or a spec, a stub, or a body can be BETWEEN the
"is" and "begin" of another body.  A stub and a body for the same routine
can NOT be in the same area.  A stub can not be a compilation unit, but
it indicates that the body IS a _separate_ compilation unit.

You'll have to check your book or one of the on-line tutorials for
other details.

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