Function takeFlag

src/index.js:113–117

(rest, flag)

  return input
}

function escapeRegExp(value) {
  return String(value).replace(/[-/\\^$*+?.()|[\]{}]/g, "\\$&")
}

function takeFlag(rest, flag) {
  const pattern = new RegExp(`(^|\\s)${escapeRegExp(flag)}(?=\\s|$)`, "i")
  const found = pattern.test(rest)