compromise/src/term/verb/toInfinitive/index.js

natural language processing in the browser

'use strict';
//turn any verb into its infinitive form
const rules = require('./rules');
let irregulars = require('../paths').data.irregular_verbs;

//map the irregulars for easy infinitive lookup
// {bought: 'buy'}
const verb_mapping = () => {
  return Object.keys(irregulars).reduce((h, k) => {
    Object.keys(irregulars[k]).forEach((pos) => {
      h[irregulars[k][pos]] = k;
    });
    return h;
  }, {});
};

irregulars = verb_mapping();

const toInfinitive = function(t, verbose) {
  if (t.tag.Infinitive) {
    return t.normal;
  }
  //check the irregular verb conjugations
  if (irregulars[t.normal]) {
    return irregulars[t.normal];
  }
  //check the suffix rules
  let form = t.verb.conjugation();
  if (rules[form]) {
    for (let i = 0; i < rules[form].length; i++) {
      let rule = rules[form][i];
      if (t.normal.match(rule.reg)) {
        return t.normal.replace(rule.reg, rule.to);
      }
    }
  }
  return t.normal;
};

module.exports = toInfinitive;