Swish Bish Prolog

The project consists of an interpreter and an accompanying editor built with tkinter.

How to run

• Install dependencies

pip install -r requirements.txt

• To start the editor

python editor.py

• To run the tests

pytest tests

Project Overview

Intepreter

The programming language is a subset of pure prolog.

• The prolog interpreter implements an SLD resolution scheme(unification + backtracking).

• Negation as failure is also supported.

Sample programs can be found in the sample folder.

Examples

Given the clauses in the family_relations.pl program in the sample folder, here are some sample queries:

ancestor(X, Y).

ancestor(hamish, anne).

ancestor(hamish, 'anne').

ancestor(hamish, 'rosie').

sibling(X, Y).

not(ancestor(hamish, jack)).

Editor features

File menu

Includes the standard operations new,open, save, save as, exit.

Preferences menu

• Font
  The user can set the font family and size

• Mode
  There are 3 modes to choose from:

  • Dark
  • Light
  • Swish Bish

Other features

• Line-number bar
• Key-bindings
  • for saving <Control-s>
  • for running the current program, with respect to the current query <Control-Return>

Future improvements

• list support
• more informative error messages
• arithmetics
• unification over infinite trees