Re: Q: access to subprogram

[rogoff@sccm.Stanford.EDU (Brian Rogoff)]

ok@goanna.cs.rmit.edu.au (Richard A. O'Keefe) writes:
   dewar@cs.nyu.edu (Robert Dewar) writes:
   <... about the decision to omit "downward closures"...>

   >As to whether the decision is right in retrospect? hard to say. So far
   >I have not seen any really convincing examples.

   Self-fulfilling prophecy.  It's a better use of my time to figure out
   how I _can_ accomplish something in Ada 95 (my favourite imperative
   language) than to construct examples showing what I'd like to do and can't.
   If I _were_ going to spend time on that, I'd explain why I would like to
   be able to pass a generic procedure as a generic parameter (not an
   *instance* of a generic procedure, the generic itself).

I guess I would ask Pascal programmers how useful they found this, and whether 
any interesting idioms emerged which used this feature. The same for similar 
languages (does Borland's Delphi have Pascal-like downward closures?). The 
iterator example is a good one I think, but apparently not good enough. 
Maybe a few more useful examples, and a consensus on the implementation 
issues would enable this issue to be reopened in the future.

While I (as a user) think that downward closures and some other language 
tidying would have been good, the ability to write OCXes easily in GNAT 
would be far more useful :-). 

-- Brian