66 lines
3.1 KiB
Markdown
66 lines
3.1 KiB
Markdown
# Scryer Prolog
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```
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?- append("Hello, ", X, "Hello, Scryer Prolog!").
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X = "Scryer Prolog!".
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```
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{width=128 style=float:right;} Scryer Prolog is a free software ISO Prolog system intended to be an industrial
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strength production environment *and* a testbed for bleeding edge research in
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logic and constraint programming.
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Some of the Scryer Prolog features are:
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* ISO standard compliant
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* Integrated constraint progamming libraries: clp(B), clp(Z).
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* Definite Clause Grammars
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* Coroutining support (`dif/2`, `freeze/2`, ...)
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* Tabling and SLG resolution
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* Compact string representation
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* Network libraries (TCP sockets, HTTP server, HTTP client, ...)
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* Cryptographical predicates
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* WAM based engine, cross-platform made in Rust
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* _and more..._
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## What is Prolog?
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Prolog is a logic programming language created by [Alain Colmerauer](https://en.wikipedia.org/wiki/Alain_Colmerauer) and [Robert Kowalski](https://en.wikipedia.org/wiki/Robert_Kowalski) in 1972.
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The idea behind Prolog is try to express a task in language similar to First Order Logic.
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Prolog systems include _unification_ and _non-determinism_ as key concepts upon which we build programs.
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A Prolog program is made up of predicates which define a relation between its arguments. A predicate
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is made from clauses. A clause can be either a fact or a rule. There's also a toplevel, which we
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can use to ask and reason about our task.
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It's still to this day one of the best examples and one of the most popular languages in the field
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of logic programming. That's because Prolog allows us to elegantly solve many tasks with short and
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general programs.
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If you want to learn more about Prolog history, [check this video](https://www.youtube.com/watch?v=74Ig_QKndvE).
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## Where can I learn Prolog?
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There are a lot of classical Prolog books. Those books can teach you the basics of Prolog. Some
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examples are: _The Art of Prolog (Shapiro)_, _Programming in Prolog (Cloksin, Mellish)_ and _The Craft
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of Prolog (O'Keefe)_. However, most of them are not updated to _modern_ Prolog.
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We recommend _[The Power of Prolog (Markus Triska)](https://www.metalevel.at/prolog)_ for modern Prolog. For reference about
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the builtin Prolog modules and libraries in Scryer, check the documentation site. It's this!
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## Downloads
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The latest version of Scryer Prolog is *0.9.1*. And it's already useful for lots of tasks.
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Scryer Prolog can be compiled from source, instructions are on the [GitHub README](https://github.com/mthom/scryer-prolog). It runs on Linux, macOS and Windows. Other operating systems may work but they're not regularly tested.
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If you're in Linux, maybe your distribution already has an Scryer Prolog package.
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There's also a [Docker image](https://github.com/mthom/scryer-prolog#docker-install) available.
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## Support and discussions
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If Scryer Prolog crashes or yields unexpected errors, consider filing
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an [issue](https://github.com/mthom/scryer-prolog/issues).
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To get in touch with the Scryer Prolog community, participate in
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[discussions](https://github.com/mthom/scryer-prolog/discussions)
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or visit our #scryer IRC channel on [Libera](https://libera.chat)! |