compromise/src/term/verb/conjugate/toAdjective.js

natural language processing in the browser

'use strict';
//turn a infinitiveVerb, like "walk" into an adjective like "walkable"

const rules = [
  [/[^aeiou]y$/, 'i'], //relay - reliable
  [/([aeiou][n])$/, '$1n'], //win - winnable
];

//convert - 'convertible'
//http://grammarist.com/usage/able-ible/
//http://blog.oxforddictionaries.com/2012/10/ibles-and-ables/
const ible_suffixes = {
  collect: true,
  exhaust: true,
  convert: true,
  digest: true,
  discern: true,
  dismiss: true,
  reverse: true,
  access: true,
  collapse: true,
  express: true
};

const irregulars = {
  eat: 'edible',
  hear: 'audible',
  see: 'visible',
  defend: 'defensible',
  write: 'legible',
  move: 'movable',
  divide: 'divisible',
  perceive: 'perceptible'
};

//takes an infitive verb, and returns an adjective form
const toAdjective = function(str) {
  if (irregulars[str]) {
    return irregulars[str];
  }
  for(let i = 0; i < rules.length; i++) {
    if (str.match(rules[i][0])) {
      str = str.replace(rules[i][0], rules[i][1]);
    }
  }
  let adj = str + 'able';
  if (ible_suffixes[str]) {
    adj = str + 'ible';
  }
  return adj;
};

module.exports = toAdjective;
// console.log(toAdjective('buy'));