3 files changed, 6 insertions, 6 deletions
diff --git a/src/lauxlib.js b/src/lauxlib.js
index 84b625e..2f86720 100644
--- a/src/lauxlib.js
+++ b/src/lauxlib.js
@@ -110,7 +110,7 @@ const luaL_traceback = function(L, L1, msg, level) {
     let last = lastlevel(L1);
     let n1 = last - level > LEVELS1 + LEVELS2 ? LEVELS1 : -1;
     if (msg)
-        lua.lua_pushstring(L, msg.concat('\n'.charCodeAt(0)));
+        lua.lua_pushfstring(L, lua.to_luastring("%s\n"), msg);
     luaL_checkstack(L, 10, null);
     lua.lua_pushliteral(L, "stack traceback:");
     while (lua.lua_getstack(L1, level++, ar)) {
@@ -119,7 +119,7 @@ const luaL_traceback = function(L, L1, msg, level) {
             level = last - LEVELS2 + 1;  /* and skip to last ones */
         } else {
             lua.lua_getinfo(L1, lua.to_luastring("Slnt", true), ar);
-            lua.lua_pushstring(L, ['\n'.charCodeAt(0), '\t'.charCodeAt(0)].concat(ar.short_src).concat([':'.charCodeAt(0)]));
+            lua.lua_pushfstring(L, lua.to_luastring("\n\t%s:"), ar.short_src);
             if (ar.currentline > 0)
                 lua.lua_pushliteral(L, `${ar.currentline}:`);
             lua.lua_pushliteral(L, " in ");
diff --git a/src/ldblib.js b/src/ldblib.js
index ac3a2a4..441dec0 100644
--- a/src/ldblib.js
+++ b/src/ldblib.js
@@ -123,7 +123,7 @@ const db_getinfo = function(L) {
     let options = lauxlib.luaL_optstring(L, arg + 2, lua.to_luastring("flnStu", true));
     checkstack(L, L1, 3);
     if (lua.lua_isfunction(L, arg + 1)) {  /* info about a function? */
-        options = ['>'.charCodeAt(0)].concat(options);  /* add '>' to 'options' */
+        options = lua.lua_pushfstring(L, lua.to_luastring(">%s"), options);  /* add '>' to 'options' */
         lua.lua_pushvalue(L, arg + 1);  /* move function to 'L1' stack */
         lua.lua_xmove(L, L1, 1);
     } else {  /* stack level */
diff --git a/src/lstrlib.js b/src/lstrlib.js
index 0fb8631..4b83ac1 100644
--- a/src/lstrlib.js
+++ b/src/lstrlib.js
@@ -103,10 +103,10 @@ const num2straux = function(x) {
         return lua.to_luastring('nan', true).slice(0);
     else if (x === 0) {  /* can be -0... */
         /* create "0" or "-0" followed by exponent */
-        let zero = sprintf(luaconf.LUA_NUMBER_FMT + "x0p+0", x).split('').map(e => e.charCodeAt(0));
+        let zero = sprintf(luaconf.LUA_NUMBER_FMT + "x0p+0", x);
         if (Object.is(x, -0))
-            return ['-'.charCodeAt(0)].concat(zero);
-        return zero;
+            zero = "-" + zero;
+        return lua.to_luastring(zero);
     } else {
         let buff = [];
         let fe = luaconf.frexp(x);  /* 'x' fraction and exponent */