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=-1.9 required=5.0 tests=BAYES_00
	autolearn=unavailable autolearn_force=no version=3.4.4
Path: 
 eternal-september.org!reader01.eternal-september.org!reader02.eternal-september.org!feeder.eternal-september.org!nntp-feed.chiark.greenend.org.uk!ewrotcd!newsfeed.xs3.de!io.xs3.de!news.jacob-sparre.dk!franka.jacob-sparre.dk!pnx.dk!.POSTED.rrsoftware.com!not-for-mail
From: "Randy Brukardt" <randy@rrsoftware.com>
Newsgroups: comp.lang.ada
Subject: Re: Trouble translating a C++ data-structure.
Date: Mon, 12 Mar 2018 18:46:29 -0500
Organization: JSA Research & Innovation
Message-ID: <p873gl$clv$1@franka.jacob-sparre.dk>
References: <1aac45bf-2baf-4ca5-9cb5-07e1748ff6b4@googlegroups.com>
 <06ffd998-f5b4-4ffd-a23e-cf922df2681b@googlegroups.com>
 <7a285484-20b5-475e-b252-113b8a803785@googlegroups.com>
Injection-Date: Mon, 12 Mar 2018 23:46:29 -0000 (UTC)
Injection-Info: franka.jacob-sparre.dk;
 posting-host="rrsoftware.com:24.196.82.226";
	logging-data="12991"; mail-complaints-to="news@jacob-sparre.dk"
X-Priority: 3
X-MSMail-Priority: Normal
X-Newsreader: Microsoft Outlook Express 6.00.2900.5931
X-RFC2646: Format=Flowed; Original
X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.7246
Xref: reader02.eternal-september.org comp.lang.ada:50948
Date: 2018-03-12T18:46:29-05:00
List-Id: <comp.lang.ada>

"Shark8" <onewingedshark@gmail.com> wrote in message 
news:7a285484-20b5-475e-b252-113b8a803785@googlegroups.com...
...
> Yeah, it's a very simple decomposition, but things like semantic-analysis
> could be done as a collection of simple transformation-functions and 
> validators,
> perhaps exactly mirroring the LRM. (I haven't gotten into the semantic 
> analysis,
> but this idea appeals to me in that it can allow things do be decomposed 
> and
> maintained easily.)

Sounds reasonable, but I have to think every compiler starts out with a 
grand vision of some sort. And then the real world intrudes and some part of 
that has to be given up in order for the result to be practical (for 
instance, Ada requires lengthy lookahead in some cases, so you'll probably 
find that you will want to cheat a bit and gather some information early to 
feed into later transformations). In our case, we also had to fit the result 
on very small machines, so keeping the program completely in memory was 
impractical (and thus we don't use trees for most of the compilation outside 
of expressions). Etc.

                                      Randy.