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!.POSTED!not-for-mail From: Paul Rubin Newsgroups: comp.lang.ada Subject: Re: How to get Ada to ?cross the chasm?? Date: Sun, 29 Apr 2018 11:52:37 -0700 Organization: A noiseless patient Spider Message-ID: <87k1sponey.fsf@nightsong.com> References: <1c73f159-eae4-4ae7-a348-03964b007197@googlegroups.com> <87k1su7nag.fsf@nightsong.com> <87po2la2qt.fsf@nightsong.com> <87in8buttb.fsf@jacob-sparre.dk> <87wowqpowu.fsf@nightsong.com> <87efiyuh10.fsf@jacob-sparre.dk> <87vacanebz.fsf@nightsong.com> <87a7tlvppi.fsf@jacob-sparre.dk> Mime-Version: 1.0 Content-Type: text/plain Injection-Info: reader02.eternal-september.org; posting-host="2973c66b8467d5e5c38d149f2cdfa94b"; logging-data="12424"; mail-complaints-to="abuse@eternal-september.org"; posting-account="U2FsdGVkX19IHp6NBMjivbZhgyHepVJO" User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/25.3 (gnu/linux) Cancel-Lock: sha1:qqdtFjcfKwaGB0fLqkGyjFUppiE= sha1:stPetsUaTJYLPEUbTevj+jKi85Q= Xref: reader02.eternal-september.org comp.lang.ada:51805 Date: 2018-04-29T11:52:37-07:00 List-Id: Jacob Sparre Andersen writes: >> Why not use arbitrary precision integers > Among other reasons because a fixed-length bar-code can't handle it. Worry about that when it's time to print the bar code, not when doing the calculations. > Well. We got OOP in an ISO standard for the first time in January 1995, > but what other major advances in the state of the art have we seen in > since 1988? Type inference, and languages built around the idea that types can specify complex properties of the program, so that program behaviour can be verified with typecheckers that are much simpler to use than SPARK. Functional programming as something past being a research subject. This book is good: http://www.cs.cmu.edu/~rwh/pfpl.html So is this: https://softwarefoundations.cis.upenn.edu/ (Hmm, ok, it does look like ML goes back to the 1970s. I thought it was much newer. The Definition of Standard ML was published in 1990. Haskell is from the 1990s.) >> Even Java wasn't invented til the 1990s, and Perl was from 1987. > What new did Java bring to the world of programming languages? Nothing new, but it's a widely used HLL in long-lived applications, that has multiple implementations. So it seemed like a good place to look for 30yo HLL programs. But on checking, I saw that it didn't exist 30 years ago. > What is your definition of a HLL? Except that it apparently isn't C > or Ada? Is it any language you can't write an operating system in? It may be idiosyncratic but I'm going with something like this: HLL's can handle large and potentially complicated data objects as easily as low-level languages handle machine integers. That means you can write them as literals (e.g. Lisp S-expressions), create them as intermediate values and pass them as arguments, include them in other data, etc. and not have to manually manage their storage. That in practice means that the language is garbage collected. >> Sure, that's fine, but it sounds like a fairly thin wrapper. > Then I gave the wrong impression. Checking that the results make sense > is a different operation than calculating the results, but that doesn't > make it trivial. Hmm ok, but what advantage does Ada bring in checking the results? Do you have some SPARK verification of the checker?