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authorBenoit Giannangeli <benoit.giannangeli@boursorama.fr>2017-03-06 15:58:11 +0100
committerBenoit Giannangeli <giann@users.noreply.github.com>2017-03-13 11:03:24 +0100
commite96d75a87d879f7f455e4b9c6457bf6580743fa5 (patch)
treea468f1c71ef765b0fc6acbfb32a49dc8ad9a0d65 /src/lua.js
parent342a7db19607446720770cd2cfc5d275ce3f2ca9 (diff)
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String are represented by Array of 8-bit numbers
Diffstat (limited to 'src/lua.js')
-rw-r--r--src/lua.js58
1 files changed, 57 insertions, 1 deletions
diff --git a/src/lua.js b/src/lua.js
index 95d0ef8..971593d 100644
--- a/src/lua.js
+++ b/src/lua.js
@@ -132,6 +132,61 @@ class lua_Debug {
}
+const to_luastring = function(str, maxBytesToWrite) {
+ let outU8Array = new Array(maxBytesToWrite);
+
+ if (!(maxBytesToWrite > 0)) // Parameter maxBytesToWrite is not optional. Negative values, 0, null, undefined and false each don't write out any bytes.
+ return 0;
+
+ let outIdx = 0;
+ let startIdx = 0;
+ let endIdx = maxBytesToWrite - 1; // -1 for string null terminator.
+ for (let i = 0; i < str.length; ++i) {
+ // Gotcha: charCodeAt returns a 16-bit word that is a UTF-16 encoded code unit, not a Unicode code point of the character! So decode UTF16->UTF32->UTF8.
+ // See http://unicode.org/faq/utf_bom.html#utf16-3
+ // For UTF8 byte structure, see http://en.wikipedia.org/wiki/UTF-8#Description and https://www.ietf.org/rfc/rfc2279.txt and https://tools.ietf.org/html/rfc3629
+ let u = str.charCodeAt(i); // possibly a lead surrogate
+ if (u >= 0xD800 && u <= 0xDFFF) u = 0x10000 + ((u & 0x3FF) << 10) | (str.charCodeAt(++i) & 0x3FF);
+ if (u <= 0x7F) {
+ if (outIdx >= endIdx) break;
+ outU8Array[outIdx++] = u;
+ } else if (u <= 0x7FF) {
+ if (outIdx + 1 >= endIdx) break;
+ outU8Array[outIdx++] = 0xC0 | (u >> 6);
+ outU8Array[outIdx++] = 0x80 | (u & 63);
+ } else if (u <= 0xFFFF) {
+ if (outIdx + 2 >= endIdx) break;
+ outU8Array[outIdx++] = 0xE0 | (u >> 12);
+ outU8Array[outIdx++] = 0x80 | ((u >> 6) & 63);
+ outU8Array[outIdx++] = 0x80 | (u & 63);
+ } else if (u <= 0x1FFFFF) {
+ if (outIdx + 3 >= endIdx) break;
+ outU8Array[outIdx++] = 0xF0 | (u >> 18);
+ outU8Array[outIdx++] = 0x80 | ((u >> 12) & 63);
+ outU8Array[outIdx++] = 0x80 | ((u >> 6) & 63);
+ outU8Array[outIdx++] = 0x80 | (u & 63);
+ } else if (u <= 0x3FFFFFF) {
+ if (outIdx + 4 >= endIdx) break;
+ outU8Array[outIdx++] = 0xF8 | (u >> 24);
+ outU8Array[outIdx++] = 0x80 | ((u >> 18) & 63);
+ outU8Array[outIdx++] = 0x80 | ((u >> 12) & 63);
+ outU8Array[outIdx++] = 0x80 | ((u >> 6) & 63);
+ outU8Array[outIdx++] = 0x80 | (u & 63);
+ } else {
+ if (outIdx + 5 >= endIdx) break;
+ outU8Array[outIdx++] = 0xFC | (u >> 30);
+ outU8Array[outIdx++] = 0x80 | ((u >> 24) & 63);
+ outU8Array[outIdx++] = 0x80 | ((u >> 18) & 63);
+ outU8Array[outIdx++] = 0x80 | ((u >> 12) & 63);
+ outU8Array[outIdx++] = 0x80 | ((u >> 6) & 63);
+ outU8Array[outIdx++] = 0x80 | (u & 63);
+ }
+ }
+ // Null-terminate the pointer to the buffer.
+ outU8Array[outIdx] = 0;
+ return outU8Array;
+};
+
module.exports.CT = CT;
module.exports.FENGARI_AUTHORS = FENGARI_AUTHORS;
module.exports.FENGARI_COPYRIGHT = FENGARI_COPYRIGHT;
@@ -181,4 +236,5 @@ module.exports.constant_types = constant_types;
module.exports.lua_Debug = lua_Debug;
module.exports.lua_upvalueindex = lua_upvalueindex;
module.exports.print_version = print_version;
-module.exports.thread_status = thread_status; \ No newline at end of file
+module.exports.thread_status = thread_status;
+module.exports.to_luastring = to_luastring; \ No newline at end of file