Re: Ada expression resolvers

[gvcormack@watdaisy.UUCP (Gordon V. Cormack)]

> Does anyone have any information on strategies that might be used to 
> resolve an assignment statement in Ada?
> 
> I'm not sure if the term "resolve" is universally used, so let me explain
> 	procedure P is
> 	    x : int;
> 	    y : int;
> 	    x : float;
> 	begin
> 	    x := y;
> 	end P;

This requires a reasonably straightforward extension to any Ada
overloading algorithm to allow variables as well as functions etc.
to be overloaded.  One has to treat := as an overloaded operator
that is applicable to all non-limited types.

An good entry into the literature on overload resolution is the introduction to

  T.P. Baker, "A one-pass algorithm for overload resolution in Ada",
               ACM TOPLAS 4:4 , 601-614.

I should note that the above program is not legal in Ada; variables
may not be overloaded.
-- 
Gordon V. Cormack      CS Department, University of Waterloo
   gvcormack@watdaisy.uucp     gvcormack%watdaisy@waterloo.csnet