compromise/src/1-one/tokenize/methods/01-sentences/is-sentence.js

modest natural language processing

const isAcronym = /[ .][A-Z]\.? *$/i //asci - 'n.s.a.'
const hasEllipse = /(?:\u2026|\.{2,}) *$/ // '...'
const hasLetter = /\p{L}/u
const hasPeriod = /\. *$/
const leadInit = /^[A-Z]\. $/ // "W. Kensington"

/** does this look like a sentence? */
const isSentence = function (str, abbrevs) {
  // must have a letter
  if (hasLetter.test(str) === false) {
    return false
  }
  // check for 'F.B.I.'
  if (isAcronym.test(str) === true) {
    return false
  }
  // check for leading initial - "W. Kensington"
  if (str.length === 3 && leadInit.test(str)) {
    return false
  }
  //check for '...'
  if (hasEllipse.test(str) === true) {
    return false
  }
  let txt = str.replace(/[.!?\u203D\u2E18\u203C\u2047-\u2049] *$/, '')
  let words = txt.split(' ')
  let lastWord = words[words.length - 1].toLowerCase()
  // check for 'Mr.' (and not mr?)
  if (abbrevs.hasOwnProperty(lastWord) === true && hasPeriod.test(str) === true) {
    return false
  }
  // //check for jeopardy!
  // if (blacklist.hasOwnProperty(lastWord)) {
  //   return false
  // }
  return true
}
export default isSentence