Function step1b

packages/text-search/src/stemmer.ts:96–136

* Step 1b: Handle -eed, -ed, -ing endings

(word: string)

 * Step 1b: Handle -eed, -ed, -ing endings
 */
function step1b(word: string): string {
  if (word.endsWith("eed")) {
    const stem = word.slice(0, -3);
    if (hasMeasureGreaterThan0(stem)) {
      return word.slice(0, -1);
    }
    return word;
  }

  let stem = "";
  let suffix = "";

  if (word.endsWith("ed")) {
    stem = word.slice(0, -2);
    suffix = "ed";
  } else if (word.endsWith("ing")) {
    stem = word.slice(0, -3);
    suffix = "ing";
  }

  if (suffix && containsVowel(stem)) {
    word = stem;

    if (word.endsWith("at") || word.endsWith("bl") || word.endsWith("iz")) {
      return word + "e";
    }

    if (endsWithDoubleConsonant(word)) {
      const last = word[word.length - 1]!;
      if (last !== "l" && last !== "s" && last !== "z") {
        return word.slice(0, -1);
      }
    }

    if (hasMeasureEqual1(word) && endsWithCVC(word)) {
      return word + "e";
    }
  }

  return word;
}

/**
 * Step 1c: Handle -y endings