🚀 go-pugleaf

Subject: Modula-2 and other languages (under UNIX on VAX)

Both Powells compiler and one I've been working on locally use the same
trick.  You write the DEFINITION module in M2 but the IMPLEMENTATION of
that module in some other language.  I can't remember what the conventions
are in Powells but I have all identifier names qualified with the module
name at the begining followed by an '_'.  There is also an initialisation
function for each module with the name module-name__init.

For example:

DEFINITION MODULE x;

	EXPORT QUALIFIED 
	PROCEDURE f ( a : INTEGER ) : INTEGER;
END x;

/* implementation of x in C */
x_f( a )
int a;
{
	blah blah blah
	return( 0 );
}

x__init()
{
	function to initialise x
	call to this automatically generated by modules that import x.
}


Although this has the IMPLEMENTATION in C so long as the name
conventions (and of course the call/return conventions) are adhered to
any language can be used.

Using a M2 module from C is just as easy so long as you remember to
call module-name__init() before using it.
--
UKUUCP SUPPORT  Lee McLoughlin
	"What you once thought was only a nightmare is now a reality!"

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