sugar-language/language/var/widthConversionTable.js

Language module for the Sugar Javascript utility library.

'use strict';

var ZENKAKU_KATAKANA = require('./ZENKAKU_KATAKANA'),
    HANKAKU_KATAKANA = require('./HANKAKU_KATAKANA'),
    FULL_WIDTH_OFFSET = require('./FULL_WIDTH_OFFSET'),
    ZENKAKU_PUNCTUATION = require('./ZENKAKU_PUNCTUATION'),
    VOICED_KATAKANA_REG = require('./VOICED_KATAKANA_REG'),
    HANKAKU_PUNCTUATION = require('./HANKAKU_PUNCTUATION'),
    WIDTH_CONVERSION_RANGES = require('./WIDTH_CONVERSION_RANGES'),
    SEMI_VOICED_KATAKANA_REG = require('./SEMI_VOICED_KATAKANA_REG'),
    chr = require('../../common/var/chr'),
    forEach = require('../../common/internal/forEach'),
    shiftChar = require('../internal/shiftChar'),
    simpleRepeat = require('../../common/internal/simpleRepeat');

var widthConversionTable;

function buildWidthConversion() {
  var hankaku;

  widthConversionTable = {
    'zenkaku': {},
    'hankaku': {}
  };

  function setWidthConversion(type, half, full) {
    setConversionTableEntry('zenkaku', type, half, full);
    setConversionTableEntry('hankaku', type, full, half);
  }

  function setConversionTableEntry(width, type, from, to, all) {
    var obj = widthConversionTable[width][from] || {};
    if (all !== false) {
      obj.all = to;
    }
    obj[type]  = to;
    widthConversionTable[width][from] = obj;
  }

  function setKatakanaConversion() {
    for (var i = 0; i < ZENKAKU_KATAKANA.length; i++) {
      var c = ZENKAKU_KATAKANA.charAt(i);
      hankaku = HANKAKU_KATAKANA.charAt(i);
      setWidthConversion('k', hankaku, c);
      if (c.match(VOICED_KATAKANA_REG)) {
        setWidthConversion('k', hankaku + 'ﾞ', shiftChar(c, 1));
      }
      if (c.match(SEMI_VOICED_KATAKANA_REG)) {
        setWidthConversion('k', hankaku + 'ﾟ', shiftChar(c, 2));
      }
    }
  }

  function setPunctuationConversion() {
    for (var i = 0; i < ZENKAKU_PUNCTUATION.length; i++) {
      setWidthConversion('p', HANKAKU_PUNCTUATION.charAt(i), ZENKAKU_PUNCTUATION.charAt(i));
    }
  }

  forEach(WIDTH_CONVERSION_RANGES, function(r) {
    simpleRepeat(r.end - r.start + 1, function(n) {
      n += r.start;
      setWidthConversion(r.type, chr(n), chr(n + FULL_WIDTH_OFFSET));
    });
  });

  setKatakanaConversion();
  setPunctuationConversion();

  setWidthConversion('s', ' ', '　');
  setWidthConversion('k', 'ｳﾞ', 'ヴ');
  setWidthConversion('k', 'ｦﾞ', 'ヺ');
  setConversionTableEntry('hankaku', 'n', '−', '-');
  setConversionTableEntry('hankaku', 'n', 'ー', '-', false);
  setConversionTableEntry('zenkaku', 'n', '-', '－', false);
}

buildWidthConversion();

module.exports = widthConversionTable;