word_freq.scala en Scala

Un reporte completo: normalizar un pasaje, contar sus palabras, ordenarlas e imprimirlas.

// A word-frequency report over an inline passage.

val passage: String =
  """Sailors watch the sky, because the sky warns the sailors.
    |A red sky at night can delight a sailor; a red sky in the
    |morning will warn the same sailor. Watch the sky, watch the
    |wind, and the sea will rarely surprise you.""".stripMargin

// Lowercasing first means Sky and sky land in the same bucket.
// Splitting on runs of non-letters drops punctuation and newlines.
def words(text: String): List[String] =
  text.toLowerCase.split("[^a-z]+").filter(_.nonEmpty).toList

// Two words carry no signal, so they are dropped from the report.
val stopWords: Set[String] = Set("the", "a", "and", "is", "in", "at", "you")

// groupBy(identity) buckets equal words; the size of a bucket is
// that word's count.
def tally(items: List[String]): Map[String, Int] =
  items.groupBy(identity).view.mapValues(_.size).toMap

@main def wordFreq(): Unit =
  val counted = tally(words(passage).filterNot(stopWords.contains))
  // Sorting by the negated count puts the most frequent first, and
  // the word itself breaks ties alphabetically.
  val ranked = counted.toList.sortBy((word, count) => (-count, word))
  val distinct = counted.size
  val total = counted.values.sum

  println(f"${"word"}%-12s${"count"}%6s${"share"}%8s")
  println("-" * 26)
  for (word, count) <- ranked.take(8) do
    val share = 100.0 * count / total
    println(f"$word%-12s$count%6d$share%7.1f%%")
  println("-" * 26)
  println(f"${"total"}%-12s$total%6d")
  println(f"$distinct distinct words kept out of ${words(passage).size}")

Cómo funciona

text.toLowerCase.split("[^a-z]+") borra mayúsculas y puntuación en una sola pasada.
items.groupBy(identity).view.mapValues(_.size).toMap vuelve conteos la lista de palabras.
sortBy((word, count) => (-count, word)) ordena por conteo y luego alfabético; $word%-12s$count%6d alinea columnas.

Palabras clave y builtins usados aquí

def
do
for
val

El intento, en números

Líneas: 37
Caracteres a escribir: 1538
Tokens: 262
Ritmo de tres estrellas: 75 tpm

Al ritmo de tres estrellas de 75 tokens por minuto, este intento toma unos 210 segundos.

Escribe este fragmento

Paso 1 de 3 en Bis; paso 25 de 27 en Fundamentos del lenguaje.

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