compromise/src/2-two/preTagger/methods/looksPlural.js

modest natural language processing

//similar to plural/singularize rules, but not the same
const isPlural = {
  e: ['mice', 'louse', 'antennae', 'formulae', 'nebulae', 'vertebrae', 'vitae'],
  i: ['tia', 'octopi', 'viri', 'radii', 'nuclei', 'fungi', 'cacti', 'stimuli'],
  n: ['men'],
  t: ['feet'],
}
// plural words as exceptions to suffix-rules
const exceptions = new Set([
  // 'formulas',
  // 'umbrellas',
  // 'gorillas',
  // 'koalas',
  'israelis',
  'menus',
  'logos',
])

const notPlural = [
  'bus',
  'mas', //christmas
  'was',
  // 'las',
  'ias', //alias
  'xas',
  'vas',
  'cis', //probocis
  'lis',
  'nis', //tennis
  'ois',
  'ris',
  'sis', //thesis
  'tis', //mantis, testis
  'xis',
  'aus',
  'cus',
  'eus', //nucleus
  'fus', //doofus
  'gus', //fungus
  'ius', //radius
  'lus', //stimulus
  'nus',
  'das',
  'ous',
  'pus', //octopus
  'rus', //virus
  'sus', //census
  'tus', //status,cactus
  'xus',
  'aos', //chaos
  'igos',
  'ados', //barbados
  'ogos',
  "'s",
  'ss',
]

const looksPlural = function (str) {
  // not long enough to be plural
  if (!str || str.length <= 3) {
    return false
  }
  // 'menus' etc
  if (exceptions.has(str)) {
    return true
  }
  let end = str[str.length - 1]
  // look at 'firemen'
  if (isPlural.hasOwnProperty(end)) {
    return isPlural[end].find(suff => str.endsWith(suff))
  }
  if (end !== 's') {
    return false
  }
  // look for 'virus'
  if (notPlural.find(suff => str.endsWith(suff))) {
    return false
  }
  // ends with an s, seems plural i guess.
  return true
}
export default looksPlural