README.md

slogic: Simple Logic Parser

slogic is a simple logic parser written in JavaScript (ES2015).

Its current implementation rests on an Earley-style chart parser and an unambiguous grammar for propositional logic.

Installation

The library can be installed with npm from github:

npm install synsem/slogic#build

Usage

The library exports a single function parse that takes a string representation of a formula as input and returns a list of parse tree objects.

Each node in the tree has the following properties:

• name: A normalized string representation of this subformula.
• type: The node type (one of "iff", "imp", "or", "and", "not", "IDENT").
• children: A list of child nodes.

For example:

import parse from 'slogic';
parse('ab&cd|ef')[0];

will return the object:

{
  'name': '((ab ∧ cd) ∨ ef)',
  'type': 'or',
  'children': [
    {
      'name': '(ab ∧ cd)',
      'type': 'and',
      'children': [
        {
          'name': 'ab',
          'type': 'IDENT',
          'children': []
        },
        {
          'name': 'cd',
          'type': 'IDENT',
          'children': []
        }
      ]
    },
    {
      'name': 'ef',
      'type': 'IDENT',
      'children': []
    }
  ]
}

Demo

• syntree: A browser-based visualization of the syntactic structure of logical formulas, built on top of D3 and slogic.

License

Copyright 2016 Mathias Schenner

This software is distributed under the ISC License.