Spaces:
Sleeping
Sleeping
File size: 1,357 Bytes
cc651f6 |
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 |
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;
}
}
export function decode(bytes) {
return _decode(bytes)
.map((x) => String.fromCharCode(x))
.join("");
}
function _decode(bytes) {
const result = [];
while (bytes.length > 0) {
const 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");
}
const b2 = bytes[1];
if (b1 < 0xe0) {
result.push(code(0x80, ((b1 & 0x1f) << 6) + con(b2)));
bytes = bytes.slice(2);
continue;
}
const b3 = bytes[2];
if (b1 < 0xf0) {
result.push(code(0x800, ((b1 & 0x0f) << 12) + (con(b2) << 6) + con(b3)));
bytes = bytes.slice(3);
continue;
}
const 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;
}
|