From mboxrd@z Thu Jan 1 00:00:00 1970 X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on polar.synack.me X-Spam-Level: X-Spam-Status: No, score=0.2 required=5.0 tests=BAYES_00,INVALID_MSGID, REPLYTO_WITHOUT_TO_CC autolearn=no autolearn_force=no version=3.4.4 X-Google-Language: ENGLISH,ASCII-7-bit X-Google-Thread: 103376,99ab4bb580fc34cd X-Google-Attributes: gid103376,public From: rogoff@sccm.Stanford.EDU (Brian Rogoff) Subject: Re: Q: access to subprogram Date: 1996/07/19 Message-ID: #1/1 X-Deja-AN: 169701386 references: <4rb9dp$qe6@news1.delphi.com> organization: /u/rogoff/.organization reply-to: rogoff@sccm.stanford.edu newsgroups: comp.lang.ada Date: 1996-07-19T00:00:00+00:00 List-Id: 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