@zxing/text-encoding
Version:
Polyfill for the Encoding Living Standard's API.
154 lines • 6.05 kB
JavaScript
;
Object.defineProperty(exports, "__esModule", { value: true });
var getArrayVal_1 = require("../helper/getArrayVal");
var utilities_1 = require("./utilities");
var encoding_indexes_provider_1 = require("./encoding-indexes-provider");
/**
* @param {number} pointer The |pointer| to search for.
* @param {(!Array.<?number>|undefined)} index The |index| to search within.
* @return {?number} The code point corresponding to |pointer| in |index|,
* or null if |code point| is not in |index|.
*/
function indexCodePointFor(pointer, index) {
if (!index)
return null;
return index[pointer] || null;
}
exports.indexCodePointFor = indexCodePointFor;
/**
* @param {number} code_point The |code point| to search for.
* @param {!Array.<?number>} index The |index| to search within.
* @return {?number} The first pointer corresponding to |code point| in
* |index|, or null if |code point| is not in |index|.
*/
function indexPointerFor(code_point, index) {
var pointer = index.indexOf(code_point);
return pointer === -1 ? null : pointer;
}
exports.indexPointerFor = indexPointerFor;
/**
* @param {string} name Name of the index.
* @return {(!Array.<number>|!Array.<Array.<number>>)}
* */
function index(name) {
var encodingIndexes = encoding_indexes_provider_1.getEncodingIndexes();
if (!encodingIndexes) {
throw Error("Indexes missing." +
" Did you forget to include encoding-indexes.js first?");
}
return encodingIndexes[name];
}
exports.index = index;
/**
* @param {number} pointer The |pointer| to search for in the gb18030 index.
* @return {?number} The code point corresponding to |pointer| in |index|,
* or null if |code point| is not in the gb18030 index.
*/
function indexGB18030RangesCodePointFor(pointer) {
// 1. If pointer is greater than 39419 and less than 189000, or
// pointer is greater than 1237575, return null.
if ((pointer > 39419 && pointer < 189000) || (pointer > 1237575))
return null;
// 2. If pointer is 7457, return code point U+E7C7.
if (pointer === 7457)
return 0xE7C7;
// 3. Let offset be the last pointer in index gb18030 ranges that
// is equal to or less than pointer and let code point offset be
// its corresponding code point.
var offset = 0;
var code_point_offset = 0;
var idx = index('gb18030-ranges');
for (var i = 0; i < idx.length; ++i) {
/** @type {!Array.<number>} */
var entry = getArrayVal_1.getArrayVal(idx[i]);
if (entry[0] <= pointer) {
offset = entry[0];
code_point_offset = entry[1];
}
else {
break;
}
}
// 4. Return a code point whose value is code point offset +
// pointer − offset.
return code_point_offset + pointer - offset;
}
exports.indexGB18030RangesCodePointFor = indexGB18030RangesCodePointFor;
/**
* @param {number} code_point The |code point| to locate in the gb18030 index.
* @return {number} The first pointer corresponding to |code point| in the
* gb18030 index.
*/
function indexGB18030RangesPointerFor(code_point) {
// 1. If code point is U+E7C7, return pointer 7457.
if (code_point === 0xE7C7)
return 7457;
// 2. Let offset be the last code point in index gb18030 ranges
// that is equal to or less than code point and let pointer offset
// be its corresponding pointer.
var offset = 0;
var pointer_offset = 0;
var idx = index('gb18030-ranges');
for (var i = 0; i < idx.length; ++i) {
var idxVal = idx[i];
/** @type {!Array.<number>} */
var entry = getArrayVal_1.getArrayVal(idxVal);
if (entry[1] <= code_point) {
offset = entry[1];
pointer_offset = entry[0];
}
else {
break;
}
}
// 3. Return a pointer whose value is pointer offset + code point
// − offset.
return pointer_offset + code_point - offset;
}
exports.indexGB18030RangesPointerFor = indexGB18030RangesPointerFor;
/**
* @param {number} code_point The |code_point| to search for in the Shift_JIS
* index.
* @return {?number} The code point corresponding to |pointer| in |index|,
* or null if |code point| is not in the Shift_JIS index.
*/
function indexShiftJISPointerFor(code_point) {
// 1. Let index be index jis0208 excluding all entries whose
// pointer is in the range 8272 to 8835, inclusive.
shift_jis_index = shift_jis_index ||
index('jis0208').map(function (code_point, pointer) {
return utilities_1.inRange(pointer, 8272, 8835) ? null : code_point;
});
var index_ = shift_jis_index;
// 2. Return the index pointer for code point in index.
return index_.indexOf(code_point);
}
exports.indexShiftJISPointerFor = indexShiftJISPointerFor;
var shift_jis_index;
/**
* @param {number} code_point The |code_point| to search for in the big5
* index.
* @return {?number} The code point corresponding to |pointer| in |index|,
* or null if |code point| is not in the big5 index.
*/
function indexBig5PointerFor(code_point) {
// 1. Let index be index Big5 excluding all entries whose pointer
big5_index_no_hkscs = big5_index_no_hkscs ||
index('big5').map(function (code_point, pointer) {
return (pointer < (0xA1 - 0x81) * 157) ? null : code_point;
});
var index_ = big5_index_no_hkscs;
// 2. If code point is U+2550, U+255E, U+2561, U+256A, U+5341, or
// U+5345, return the last pointer corresponding to code point in
// index.
if (code_point === 0x2550 || code_point === 0x255E ||
code_point === 0x2561 || code_point === 0x256A ||
code_point === 0x5341 || code_point === 0x5345) {
return index_.lastIndexOf(code_point);
}
// 3. Return the index pointer for code point in index.
return indexPointerFor(code_point, index_);
}
exports.indexBig5PointerFor = indexBig5PointerFor;
var big5_index_no_hkscs;
//# sourceMappingURL=indexes.js.map