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=-1.3 required=5.0 tests=BAYES_00,INVALID_MSGID 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: mab@dst17.wdl.loral.com (Mark A Biggar) Subject: Re: Q: access to subprogram Date: 1996/07/03 Message-ID: <4re2ng$t7u@wdl1.wdl.loral.com>#1/1 X-Deja-AN: 163493678 references: <4rb9dp$qe6@news1.delphi.com> organization: Loral Western Development Labs newsgroups: comp.lang.ada Date: 1996-07-03T00:00:00+00:00 List-Id: In article jsa@organon.com (Jon S Anthony) writes: >In article bobduff@world.std.com (Robert A Duff) writes: >> During the design of Ada 9X, we proposed a SAFE way of taking 'Access of >> more-deeply-nesting subprograms. To this day, I remain astonished and >> sad that this particular feature didn't make it into Ada 95. After >> all, even Pascal has that feature! And GNU C, which allows nested >> functions (unlike standard C) allows this feature. >Is there an "elevator version" of why people didn't want this in? Tucker, >if you are reading this, what swayed you to not let this in???? It's >not one of those things that bothers me all that much (well, it hasn't) >but it is indeed curious... If I remember right, it was felt that implementing "closures" (which is the solution to this problem) placed an unacceptable distributed overhead on programs that didn't use the feature. Also I think that half the then current Ada implementations were using "static links" and the other half were using "displays" and implementing "clousers" would have been real difficult for one of those groups (the "display" bunch I think). -- Mark Biggar mab@wdl.lmco.com