encoder.js
1.19 KB
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"use strict";
Object.defineProperty(exports, "__esModule", {
value: true
});
exports.encode = encode;
function _toConsumableArray(arr) { if (Array.isArray(arr)) { for (var i = 0, arr2 = new Array(arr.length); i < arr.length; i++) { arr2[i] = arr[i]; } return arr2; } else { return Array.from(arr); } }
function _toArray(arr) { return Array.isArray(arr) ? arr : Array.from(arr); }
function con(n) {
return 0x80 | n & 0x3f;
}
function encode(str) {
var arr = str.split("").map(function (x) {
return x.charCodeAt(0);
});
return _encode(arr);
}
function _encode(arr) {
if (arr.length === 0) {
return [];
}
var _arr = _toArray(arr),
n = _arr[0],
ns = _arr.slice(1);
if (n < 0) {
throw new Error("utf8");
}
if (n < 0x80) {
return [n].concat(_toConsumableArray(_encode(ns)));
}
if (n < 0x800) {
return [0xc0 | n >>> 6, con(n)].concat(_toConsumableArray(_encode(ns)));
}
if (n < 0x10000) {
return [0xe0 | n >>> 12, con(n >>> 6), con(n)].concat(_toConsumableArray(_encode(ns)));
}
if (n < 0x110000) {
return [0xf0 | n >>> 18, con(n >>> 12), con(n >>> 6), con(n)].concat(_toConsumableArray(_encode(ns)));
}
throw new Error("utf8");
}