74 lines
1.4 KiB
JavaScript
74 lines
1.4 KiB
JavaScript
"use strict";
|
|
|
|
Object.defineProperty(exports, "__esModule", {
|
|
value: true
|
|
});
|
|
exports.decode = decode;
|
|
|
|
function con(b) {
|
|
if ((b & 0xc0) === 0x80) {
|
|
return b & 0x3f;
|
|
} else {
|
|
throw new Error("invalid UTF-8 encoding");
|
|
}
|
|
}
|
|
|
|
function code(min, n) {
|
|
if (n < min || 0xd800 <= n && n < 0xe000 || n >= 0x10000) {
|
|
throw new Error("invalid UTF-8 encoding");
|
|
} else {
|
|
return n;
|
|
}
|
|
}
|
|
|
|
function decode(bytes) {
|
|
return _decode(bytes).map(function (x) {
|
|
return String.fromCharCode(x);
|
|
}).join("");
|
|
}
|
|
|
|
function _decode(bytes) {
|
|
var result = [];
|
|
|
|
while (bytes.length > 0) {
|
|
var b1 = bytes[0];
|
|
|
|
if (b1 < 0x80) {
|
|
result.push(code(0x0, b1));
|
|
bytes = bytes.slice(1);
|
|
continue;
|
|
}
|
|
|
|
if (b1 < 0xc0) {
|
|
throw new Error("invalid UTF-8 encoding");
|
|
}
|
|
|
|
var b2 = bytes[1];
|
|
|
|
if (b1 < 0xe0) {
|
|
result.push(code(0x80, ((b1 & 0x1f) << 6) + con(b2)));
|
|
bytes = bytes.slice(2);
|
|
continue;
|
|
}
|
|
|
|
var b3 = bytes[2];
|
|
|
|
if (b1 < 0xf0) {
|
|
result.push(code(0x800, ((b1 & 0x0f) << 12) + (con(b2) << 6) + con(b3)));
|
|
bytes = bytes.slice(3);
|
|
continue;
|
|
}
|
|
|
|
var b4 = bytes[3];
|
|
|
|
if (b1 < 0xf8) {
|
|
result.push(code(0x10000, (((b1 & 0x07) << 18) + con(b2) << 12) + (con(b3) << 6) + con(b4)));
|
|
bytes = bytes.slice(4);
|
|
continue;
|
|
}
|
|
|
|
throw new Error("invalid UTF-8 encoding");
|
|
}
|
|
|
|
return result;
|
|
} |