46 lines
1.1 KiB
JavaScript
46 lines
1.1 KiB
JavaScript
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;
|
|
}
|
|
|
|
export 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");
|
|
} |