diff options
Diffstat (limited to 'node_modules/@webassemblyjs/utf8/lib/decoder.js')
| -rw-r--r-- | node_modules/@webassemblyjs/utf8/lib/decoder.js | 74 |
1 files changed, 74 insertions, 0 deletions
diff --git a/node_modules/@webassemblyjs/utf8/lib/decoder.js b/node_modules/@webassemblyjs/utf8/lib/decoder.js new file mode 100644 index 00000000..305a2b6e --- /dev/null +++ b/node_modules/@webassemblyjs/utf8/lib/decoder.js @@ -0,0 +1,74 @@ +"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; +}
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