string.format operate on byte array instead of js strings

1 files changed, 40 insertions, 35 deletions

diff --git a/src/lobject.js b/src/lobject.js
index bdbccb9..32a7573 100644
--- a/src/lobject.js
+++ b/src/lobject.js
@@ -122,48 +122,52 @@ class TValue {
     }
 
     jsstring(from, to) {
-        let u0, u1, u2, u3, u4, u5;
-        let idx = 0;
-        let value = this.value.slice(from ? from : 0, to);
-
-        var str = '';
-        while (1) {
-            // 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
-            u0 = value[idx++];
-            if (u0 === 0) { str += "\0"; continue; } // Lua string embed '\0'
-            if (!u0) return str;
-            if (!(u0 & 0x80)) { str += String.fromCharCode(u0); continue; }
-            u1 = value[idx++] & 63;
-            if ((u0 & 0xE0) == 0xC0) { str += String.fromCharCode(((u0 & 31) << 6) | u1); continue; }
-            u2 = value[idx++] & 63;
-            if ((u0 & 0xF0) == 0xE0) {
-                u0 = ((u0 & 15) << 12) | (u1 << 6) | u2;
+        return jsstring(this.value, from, to);
+    }
+
+}
+
+const jsstring = function(value, from, to) {
+    let u0, u1, u2, u3, u4, u5;
+    let idx = 0;
+    value = value.slice(from ? from : 0, to);
+
+    var str = '';
+    while (1) {
+        // 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
+        u0 = value[idx++];
+        if (u0 === 0) { str += "\0"; continue; } // Lua string embed '\0'
+        if (!u0) return str;
+        if (!(u0 & 0x80)) { str += String.fromCharCode(u0); continue; }
+        u1 = value[idx++] & 63;
+        if ((u0 & 0xE0) == 0xC0) { str += String.fromCharCode(((u0 & 31) << 6) | u1); continue; }
+        u2 = value[idx++] & 63;
+        if ((u0 & 0xF0) == 0xE0) {
+            u0 = ((u0 & 15) << 12) | (u1 << 6) | u2;
+        } else {
+            u3 = value[idx++] & 63;
+            if ((u0 & 0xF8) == 0xF0) {
+                u0 = ((u0 & 7) << 18) | (u1 << 12) | (u2 << 6) | u3;
             } else {
-                u3 = value[idx++] & 63;
-                if ((u0 & 0xF8) == 0xF0) {
-                    u0 = ((u0 & 7) << 18) | (u1 << 12) | (u2 << 6) | u3;
+                u4 = value[idx++] & 63;
+                if ((u0 & 0xFC) == 0xF8) {
+                    u0 = ((u0 & 3) << 24) | (u1 << 18) | (u2 << 12) | (u3 << 6) | u4;
                 } else {
-                    u4 = value[idx++] & 63;
-                    if ((u0 & 0xFC) == 0xF8) {
-                        u0 = ((u0 & 3) << 24) | (u1 << 18) | (u2 << 12) | (u3 << 6) | u4;
-                    } else {
-                        u5 = value[idx++] & 63;
-                        u0 = ((u0 & 1) << 30) | (u1 << 24) | (u2 << 18) | (u3 << 12) | (u4 << 6) | u5;
-                    }
+                    u5 = value[idx++] & 63;
+                    u0 = ((u0 & 1) << 30) | (u1 << 24) | (u2 << 18) | (u3 << 12) | (u4 << 6) | u5;
                 }
             }
-            if (u0 < 0x10000) {
-                str += String.fromCharCode(u0);
-            } else {
-                var ch = u0 - 0x10000;
-                str += String.fromCharCode(0xD800 | (ch >> 10), 0xDC00 | (ch & 0x3FF));
-            }
         }
-
-        return str;
+        if (u0 < 0x10000) {
+            str += String.fromCharCode(u0);
+        } else {
+            var ch = u0 - 0x10000;
+            str += String.fromCharCode(0xD800 | (ch >> 10), 0xDC00 | (ch & 0x3FF));
+        }
     }
 
-}
+    return str;
+};
 
 const nil   = new TValue(CT.LUA_TNIL, null);
 
@@ -466,6 +470,7 @@ module.exports.TValue         = TValue;
 module.exports.Table          = Table;
 module.exports.UTF8BUFFSZ     = UTF8BUFFSZ;
 module.exports.intarith       = intarith;
+module.exports.jsstring       = jsstring;
 module.exports.luaO_chunkid   = luaO_chunkid;
 module.exports.luaO_hexavalue = luaO_hexavalue;
 module.exports.luaO_int2fb    = luaO_int2fb;