5 ms·

Web Programming in SWI Prolog (2019)

85 points by luu 7y ago

carapace 7y ago
Also check out Anne Ogborn's tutorial "Creating Web Applications in SWI-Prolog" http://www.pathwayslms.com/swipltuts/html/ http://www.pathwayslms.com/swipltuts/html/ Following that I made a very simple ("hello world" simple) server that serves Tau Prolog ( http://tau-prolog.org/ http://tau-prolog.org/ ) to the client and establishes a websocket connection between them. It's here FWIW: https://git.sr.ht/~sforman/yrad-nettles https://git.sr.ht/~sforman/yrad-nettles (WARNING: it's not meant for public consumption, I think it might be broken at the moment because I was experimenting with serving prolog scripts like js scripts when I stopped working on it... I'm putting it out here in case you want to try to glean some insight from it. I was looking over it myself just now and I forget a lot about how it's supposed to work, so read it alongside Anne's tutorial, if at all. Cheers! Also, I should mention it depends on a whole different project, an implementation of Joy programming language, to actually do anything, because it's meant to act as a remote shell/UI for that language hosted in a Prolog server. So, yeah... you're gonna want to comment that out.)
jakearmitage 7y ago
What could be good uses of a prolog-based web service? Calendar availability? Scheduling appointments? Issue diagnosis?
- momofarm 7y ago
  Maybe we should ask what's the real world use of prolog nowadays ? We already have countless database at dispodispose. Too many shiny tech which can do recommendations.
- bawolff 7y ago
  It's a turing complete language... so anything you want!
ipnon 7y ago
While web programming in Prolog has been insightful, I think there are more expedient areas of application for the language. Prolog is especially underutilized in databases.
- segmondy 7y ago
  Prolog is already a database, why bring in the mess of an external DB. I have used Prolog and ODBC to access a postgres DB. I found it better to just export the data and turn it into a Prolog DB then process my rules than have it run all those logic across the wire.
  - The_rationalist 7y ago
    What about performance?
- chekovcodes 7y ago
  This is a database written in Prolog: https://github.com/terminusdb/terminus-server https://github.com/terminusdb/terminus-server - albeit with a RUST storage engine - prolog's lack of types means there are better storage solutions, but for constraint logic, it's unbeatable.
  - ipnon 7y ago
    A statically typed logic language would be ideal for both
    - Avshalom 7y ago
      https://mercurylang.org/ https://mercurylang.org/
      - lliamander 7y ago
        Mercury is cool. I translated a simple Prolog program to it once, and it was a head trip. Hard to get my mind around, but also helped me see the connection between functions and relations.
simplify 7y ago
Learning web Prolog is my current programming side project. My ultimate goal is to create an online board gaming platform, as writing board game rules in Prolog has turned out to be a smooth and pleasant experience :) Not to mention, SWI Prolog already has http, websockets, rpcs, and pubsub built in, so there isn't really a need to download any external libraries.

85 points by luu 7y ago

Also check out Anne Ogborn's tutorial "Creating Web Applications in SWI-Prolog" http://www.pathwayslms.com/swipltuts/html/ http://www.pathwayslms.com/swipltuts/html/ Following that I made a very simple ("hello world" simple) server that serves Tau Prolog ( http://tau-prolog.org/ http://tau-prolog.org/ ) to the client and establishes a websocket connection between them. It's here FWIW: https://git.sr.ht/~sforman/yrad-nettles https://git.sr.ht/~sforman/yrad-nettles (WARNING: it's not meant for public consumption, I think it might be broken at the moment because I was experimenting with serving prolog scripts like js scripts when I stopped working on it... I'm putting it out here in case you want to try to glean some insight from it. I was looking over it myself just now and I forget a lot about how it's supposed to work, so read it alongside Anne's tutorial, if at all. Cheers! Also, I should mention it depends on a whole different project, an implementation of Joy programming language, to actually do anything, because it's meant to act as a remote shell/UI for that language hosted in a Prolog server. So, yeah... you're gonna want to comment that out.)

jakearmitage 7y ago

What could be good uses of a prolog-based web service? Calendar availability? Scheduling appointments? Issue diagnosis?

momofarm 7y ago
Maybe we should ask what's the real world use of prolog nowadays ? We already have countless database at dispodispose. Too many shiny tech which can do recommendations.
bawolff 7y ago
It's a turing complete language... so anything you want!

ipnon 7y ago

While web programming in Prolog has been insightful, I think there are more expedient areas of application for the language. Prolog is especially underutilized in databases.

segmondy 7y ago
Prolog is already a database, why bring in the mess of an external DB. I have used Prolog and ODBC to access a postgres DB. I found it better to just export the data and turn it into a Prolog DB then process my rules than have it run all those logic across the wire.
- The_rationalist 7y ago
  What about performance?
chekovcodes 7y ago
This is a database written in Prolog: https://github.com/terminusdb/terminus-server https://github.com/terminusdb/terminus-server - albeit with a RUST storage engine - prolog's lack of types means there are better storage solutions, but for constraint logic, it's unbeatable.
- ipnon 7y ago
  A statically typed logic language would be ideal for both
  - Avshalom 7y ago
    https://mercurylang.org/ https://mercurylang.org/
    - lliamander 7y ago
      Mercury is cool. I translated a simple Prolog program to it once, and it was a head trip. Hard to get my mind around, but also helped me see the connection between functions and relations.

simplify 7y ago

Learning web Prolog is my current programming side project. My ultimate goal is to create an online board gaming platform, as writing board game rules in Prolog has turned out to be a smooth and pleasant experience :) Not to mention, SWI Prolog already has http, websockets, rpcs, and pubsub built in, so there isn't really a need to download any external libraries.