https://github.com/nathsou/picolog

Minimal Prolog interpreter
https://github.com/nathsou/picolog

Last synced: 25 days ago
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Minimal Prolog interpreter

• Host: GitHub
• URL: https://github.com/nathsou/picolog
• Owner: nathsou
• License: mit
• Created: 2020-09-30T04:27:55.000Z (about 4 years ago)
• Default Branch: master
• Last Pushed: 2021-04-11T15:00:51.000Z (over 3 years ago)
• Last Synced: 2023-10-20T21:59:18.205Z (about 1 year ago)
• Language: TypeScript
• Size: 48.8 KB
• Stars: 0
• Watchers: 1
• Forks: 0
• Open Issues: 0
• Metadata Files:
  • Readme: README.md
  • License: LICENSE

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README

        
# Picolog

## Minimalistic prolog interpreter

Picolog provides a minimal prolog

interpreter implementation that can be embedded in other js/ts/node/deno projects to perform logical computations.

### Installation

Picolog is available on [deno.land](https://deno.land/x/pico)

### Usage

See the [documentation](https://doc.deno.land/https/deno.land/x/pico/mod.ts)

To launch the REPL:

```bash

deno run -A --unstable https://deno.land/x/pico/repl/Repl.ts src.pl

```

the --unstable flag is needed since Deno.setRaw (used by the REPL) is a new API.

To embed in a project :

```typescript

import {

    resolve, parse, program, query,

    isOk, formatAnswer

} from 'https://deno.land/x/pico/mod.ts';

const prog = parse(`

    append([], Bs, Bs).

    append([A|As], Bs, [A|ABs]) :- append(As, Bs, ABs).

`, program);

const goals = parse('append(A, B, [1, 2, 3]).', query);

if (isOk(prog) && isOk(goals)) {

    // iterator of all solutions

    const solutions = resolve(prog.value, goals.value);

    for (const answer of solutions) {

        // answer maps free variables from the query

        // to values satisfying the rules

        console.log(formatAnswer(answer));

    }

}

// output:

// A = []

// B = [1, 2, 3]

// A = [1]

// B = [2, 3]

// A = [1, 2]

// B = [3]

// A = [1, 2, 3]

// B = []

```

### Todo

- [x] support the cut operator

- [ ] support arithmetic expressions

- [ ] add modules

- [ ] add a trace mode

- [ ] compile to [WAM](https://www.wikiwand.com/fr/Warren%27s_Abstract_Machine) for better performance?