i did a bad

words.scala

/**
  * Intersperses words with spaces and trims ends, accounts for basic smilies.
  */
def wordsToSentence(words: Vector[String]): String = {
  val punctuation = Set(":", ";", ".", ",", "!", "?")
  val smilies = Set(":)", ":(", ":<", ":}", ":|", ":o")

  // @TODO really bad implementation probably, clean this up later
  words.zipWithIndex.foldLeft("") { case (acc, (word, i)) =>
    val isLastWordPairSmilie = if (words.isDefinedAt(i - 1)) {
      smilies(words(i - 1) + word)
    } else {
      false
    }

    if (words.isDefinedAt(i + 1) && !isLastWordPairSmilie) {
      val nextWord = words(i + 1)

      if (punctuation(word) && !smilies(word + nextWord)) {
        acc + word
      } else if (smilies(word + nextWord)) {
        acc + " " + (word + nextWord)
      } else {
        acc + " " + word
      }
    } else if (!isLastWordPairSmilie) {
      acc + " " + word
    } else {
      acc
    }
  }.trim
}

val words = Vector("i", "am", ";", "a", ":", "simple", "sentence", ":", "(", ",", "a", "simple", "one", ".", ":", ")")

val sentence = wordsToSentence(words)

println(sentence)
// i am; a: simple sentence :(, a simple one. :)

needs emoji support.