latynkatar/src/latynkatar.js

Маленькая і простая бібліятэка для канвертацыі кірыліцы ў сучасную, 'чэшскую' (з ž, č, š і v) .

/*
This file is part of Łatynkatar.js.

Łatynkatar.js is free software: you can redistribute it and/or modify it under the
terms of the GNU Lesser General Public License v3 (LGPLv3) as published by the 
Free Software Foundation, either version 3 of the License, or (at your option) 
any later version.

Łatynkatar is distributed in the hope that it will be useful, but WITHOUT ANY 
WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A
PARTICULAR PURPOSE. See the GNU Lesser General Public License v3 (LGPLv3) for 
more details. In file LICENSE which should came with a package, or look at it
in the repo, see <https://github.com/measles/latynkatar.js/blob/main/LICENSE>.

You should have received a copy of the GNU Lesser General Public License v3 
(LGPLv3) along with Łatynkatar. If not, see <https://www.gnu.org/licenses/>. 

:copyright: (c) 2025 by Łatynkatar.
*/

const pravilyKanvertacyi = {
  а: "a",
  э: "e",
  ы: "y",
  у: "u",
  ў: "ŭ",
  б: "b",
  в: "v",
  г: "h",
  ґ: "g",
  д: "d",
  ж: "ž",
  й: "j",
  к: "k",
  м: "m",
  о: "o",
  п: "p",
  р: "r",
  т: "t",
  ф: "f",
  ч: "č",
  ш: "š",
  х: "ch",
};

const jotavanyjaLitary = {
  е: "e",
  ё: "o",
  і: "",
  ю: "u",
  я: "a",
};

const zycznyjaZTranzitam = [
  "б",
  "в",
  "д",
  "ж",
  "з",
  "й",
  "л",
  "м",
  "н",
  "п",
  "р",
  "с",
  "т",
  "ў",
  "ф",
  "ц",
  "ч",
  "ш",
];

const halosnyja = ["а", "е", "ё", "і", "у", "ы", "э", "ю", "я"];

const mohućŹmiakčacca = {
  н: {
    ćviordy: "n",
    miakki: "ń",
  },
  с: {
    ćviordy: "s",
    miakki: "ś",
  },
  ц: {
    ćviordy: "c",
    miakki: "ć",
  },
  з: {
    ćviordy: "z",
    miakki: "ź",
  },
  л: {
    ćviordy: "ł",
    miakki: "l",
  },
};

class CurrentLetter {
  constructor(current) {
    this.letter = current;
    this.lower = this.letter.toLowerCase();
    this.isUpper = true;

    if (this.lower == this.letter) {
      this.isUpper = false;
    }
  }
}

function capitalize(text) {
  return text.charAt(0).toUpperCase() + text.slice(1);
}

function convertJotavanyja(currentLetter, previousLetter) {
  previousLetter = previousLetter
    ? previousLetter.toLowerCase()
    : previousLetter;
  let baseLetter = "";
  let secondLetter = "";

  if (
    (!previousLetter ||
      halosnyja.find((letter) => letter == previousLetter) ||
      !previousLetter.match(/[а-я]/i) ||
      previousLetter == "'" ||
      previousLetter == "ь") &&
    currentLetter != "і"
  ) {
    baseLetter = "j";
  } else {
    baseLetter = "i";
  }

  secondLetter = jotavanyjaLitary[currentLetter];

  if (previousLetter && previousLetter == "л" && currentLetter != "і") {
    baseLetter = "";
  }

  return baseLetter + secondLetter;
}

export function convertCyrToLat(inputText) {
  if (typeof inputText != "string") {
    throw new TypeError(
      `Struing expected, but instead got ${toString(inputText)} with type ${typeof inputText}`,
    );
  }
  let convertedText = "";

  for (let i = 0; i < inputText.length; i++) {
    let convertedLetter;
    const currentLetter = new CurrentLetter(inputText[i]);

    let previousLetter;
    if (i > 0) {
      previousLetter = inputText[i - 1];
    }

    let nextLetter, nextNextLetter;
    if (i < inputText.length - 1) {
      nextLetter = inputText[i + 1];
    }

    if (i < inputText.length - 2) {
      nextNextLetter = inputText[i + 2];
    }

    switch (true) {
      // маюць просты і безальтэрнатыўны адпаведнік
      case currentLetter.lower in pravilyKanvertacyi:
        convertedLetter = pravilyKanvertacyi[currentLetter.lower];
        break;
      case currentLetter.lower == "ь" || currentLetter.letter == "'":
        convertedLetter = "";
        break;
      // літары з i/j: і, й, е, ё, ю, я
      case currentLetter.lower in jotavanyjaLitary:
        convertedLetter = convertJotavanyja(
          currentLetter.lower,
          previousLetter,
        );
        break;
      // Могуць пазначацца як мяккія
      case currentLetter.lower in mohućŹmiakčacca:
        if (
          // змякчаюцца калі стаяць перад мяккім знакам
          (nextLetter && nextLetter.toLowerCase() == "ь") ||
          // а Л яшчэ і перад ётаванымі літарамі
          (currentLetter.lower == "л" &&
            nextLetter &&
            nextLetter.toLowerCase() in jotavanyjaLitary) ||
          // Калі наступная зычная літара мяккая і не г, к, х
          (nextLetter &&
            nextNextLetter &&
            zycznyjaZTranzitam.find(
              (litara) => litara == nextLetter.toLowerCase(),
            ) &&
            (nextNextLetter in jotavanyjaLitary ||
              nextNextLetter.toLowerCase() == "ь"))
        ) {
          convertedLetter = mohućŹmiakčacca[currentLetter.lower].miakki;
        } else {
          convertedLetter = mohućŹmiakčacca[currentLetter.lower].ćviordy;
        }
        break;
      default:
        convertedLetter = currentLetter.letter;
    }

    if (currentLetter.isUpper) {
      convertedLetter = capitalize(convertedLetter);
    }
    convertedText = convertedText + convertedLetter;
  }
  return convertedText;
}

export default convertCyrToLat;