Proper use of luaO_nilobject

8 files changed, 34 insertions, 47 deletions

diff --git a/src/lapi.js b/src/lapi.js
index d1ca02f..8cabf12 100644
--- a/src/lapi.js
+++ b/src/lapi.js
@@ -20,6 +20,10 @@ const TS        = lua.thread_status;
 const TValue    = lobject.TValue;
 const CClosure  = lobject.CClosure;
 
+const isvalid = function(o) {
+    return o !== lobject.luaO_nilobject;
+};
+
 const lua_version = function(L) {
     if (L === null) return lua.LUA_VERSION_NUM;
     else return L.l_G.version;
@@ -37,7 +41,7 @@ const index2addr = function(L, idx) {
     if (idx > 0) {
         let o = ci.funcOff + idx;
         assert(idx <= ci.top - (ci.funcOff + 1), "unacceptable index");
-        if (o >= L.top) return ldo.nil;
+        if (o >= L.top) return lobject.luaO_nilobject;
         else return L.stack[o];
     } else if (idx > lua.LUA_REGISTRYINDEX) {
         assert(idx !== 0 && -idx <= L.top, "invalid index");
@@ -48,9 +52,9 @@ const index2addr = function(L, idx) {
         idx = lua.LUA_REGISTRYINDEX - idx;
         assert(idx <= MAXUPVAL + 1, "upvalue index too large");
         if (ci.func.ttislcf()) /* light C function? */
-            return ldo.nil; /* it has no upvalues */
+            return lobject.luaO_nilobject; /* it has no upvalues */
         else {
-            return idx <= ci.func.nupvalues ? ci.func.upvalue[idx - 1] : ldo.nil;
+            return idx <= ci.func.nupvalues ? ci.func.upvalue[idx - 1] : lobject.luaO_nilobject;
         }
     }
 };
@@ -129,7 +133,7 @@ const lua_settop = function(L, idx) {
     let func = L.ci.funcOff;
     if (idx >= 0) {
         while (L.top < func + 1 + idx)
-            L.stack[L.top++] = ldo.nil;
+            L.stack[L.top++] = new TValue(CT.LUA_TNIL, null);
         L.top = func + 1 + idx;
     } else {
         assert(-(idx + 1) <= L.top - (func + 1), "invalid new top");
@@ -158,7 +162,7 @@ const lua_rotate = function(L, idx, n) {
     let p = index2addr(L, idx);
     let pIdx = index2addr_(L, idx);
 
-    assert(/*!p.ttisnil() && */idx > lua.LUA_REGISTRYINDEX, "index not in the stack");
+    assert(p !== lobject.luaO_nilobject && idx > lua.LUA_REGISTRYINDEX, "index not in the stack");
     assert((n >= 0 ? n : -n) <= (L.top - idx), "invalid 'n'");
 
     let m = n >= 0 ? L.top - 1 - n : pIdx - n - 1;  /* end of prefix */
@@ -193,7 +197,7 @@ const lua_replace = function(L, idx) {
 */
 
 const lua_pushnil = function(L) {
-    L.stack[L.top++] = ldo.nil;
+    L.stack[L.top++] = new TValue(CT.LUA_TNIL, null);
 
     assert(L.top <= L.ci.top, "stack overflow");
 };
@@ -228,7 +232,7 @@ const lua_pushlstring = function(L, s, len) { // TODO: embedded \0
 
 const lua_pushstring = function (L, s) {
     if (typeof s !== "string")
-        L.stack[L.top] = ldo.nil;
+        L.stack[L.top] = new TValue(CT.LUA_TNIL, null);
     else {
         let ts = L.l_G.intern(lua.to_luastring(s));
         L.stack[L.top] = ts;
@@ -631,7 +635,7 @@ const lua_compare = function(L, index1, index2, op) {
 const lua_compare_ = function(L, o1, o2, op) {
     let i = 0;
 
-    if (!o1.ttisnil() && !o2.ttisnil()) {
+    if (isvalid(o1) && isvalid(o2)) {
         switch (op) {
             case lua.LUA_OPEQ: i = lvm.luaV_equalobj(L, o1, o2); break;
             case lua.LUA_OPLT: i = lvm.luaV_lessthan(L, o1, o2); break;
@@ -661,7 +665,7 @@ const f_call = function(L, ud) {
 
 const lua_type = function(L, idx) {
     let o = index2addr(L, idx);
-    return o.ttnov(); // TODO: isvalid ? luaO_nilobject !== nil tvalue ?
+    return isvalid(o) ?  o.ttnov() : CT.LUA_TNONE;
 };
 
 const lua_typename = function(L, t) {
@@ -706,7 +710,7 @@ const lua_isuserdata = function(L, idx) {
 const lua_rawequal = function(L, index1, index2) {
     let o1 = index2addr(L, index1);
     let o2 = index2addr(L, index2);
-    return lvm.luaV_equalobj(null, o1, o2); // TODO: isvalid ?
+    return isvalid(o1) && isvalid(o2) ? lvm.luaV_equalobj(null, o1, o2) : 0; // TODO: isvalid ?
 };
 
 /*
diff --git a/src/lbaselib.js b/src/lbaselib.js
index 762838c..11906db 100644
--- a/src/lbaselib.js
+++ b/src/lbaselib.js
@@ -341,21 +341,6 @@ if (typeof require === "function") {
     } catch (e) {}
 
     if (fs) {
-        const load_aux = function(L, status, envidx) {
-            if (status === TS.LUA_OK) {
-                if (envidx !== 0) {  /* 'env' parameter? */
-                    lapi.lua_pushvalue(L, envidx);  /* environment for loaded function */
-                    if (!lapi.lua_setupvalue(L, -2, 1))  /* set it as 1st upvalue */
-                        lapi.lua_pop(L, 1);  /* remove 'env' if not used by previous call */
-                }
-                return 1;
-            } else {  /* error (message is on top of the stack) */
-                lapi.lua_pushnil(L);
-                lapi.lua_insert(L, -2);  /* put before error message */
-                return 2;  /* return nil plus error message */
-            }
-        };
-
         const luaB_loadfile = function(L) {
             let fname = lauxlib.luaL_optstring(L, 1, null);
             let mode = lauxlib.luaL_optstring(L, 2, null);
diff --git a/src/ldebug.js b/src/ldebug.js
index aa57aef..7c892a5 100644
--- a/src/ldebug.js
+++ b/src/ldebug.js
@@ -78,7 +78,7 @@ const funcinfo = function(ar, cl) {
 
 const collectvalidlines = function(L, f) {
     if (f === null || f.c.type === CT.LUA_TCCL) {
-        L.stack[L.top++] = ldo.nil;
+        L.stack[L.top++] = new TValue(CT.LUA_TNIL, null);
         assert(L.top <= L.ci.top, "stack overflow");
     } else {
         let lineinfo = f.l.p.lineinfo;
diff --git a/src/ldo.js b/src/ldo.js
index a9f442a..50d455e 100644
--- a/src/ldo.js
+++ b/src/ldo.js
@@ -20,8 +20,6 @@ const TS             = lua.thread_status;
 const LUA_MULTRET    = lua.LUA_MULTRET;
 const TValue         = lobject.TValue;
 
-const nil            = new TValue(CT.LUA_TNIL, null);
-
 const seterrorobj = function(L, errcode, oldtop) {
     switch (errcode) {
         case TS.LUA_ERRMEM: {
@@ -94,7 +92,7 @@ const luaD_precall = function(L, off, nresults) {
                 base = adjust_varargs(L, p, n);
             } else {
                 for (; n < p.numparams; n++)
-                    L.stack[L.top++] = nil; // complete missing arguments
+                    L.stack[L.top++] = new TValue(CT.LUA_TNIL, null); // complete missing arguments
                 base = off + 1;
             }
 
@@ -143,7 +141,7 @@ const moveresults = function(L, firstResult, res, nres, wanted) {
             break;
         case 1: {
             if (nres === 0)
-                L.stack[firstResult] = nil;
+                L.stack[firstResult] = lobject.luaO_nilobject;
             L.stack[res] = L.stack[firstResult];
             break;
         }
@@ -163,7 +161,7 @@ const moveresults = function(L, firstResult, res, nres, wanted) {
                 for (i = 0; i < nres; i++)
                     L.stack[res + i] = L.stack[firstResult + i];
                 for (; i < wanted; i++)
-                    L.stack[res + i] = nil;
+                    L.stack[res + i] = new TValue(CT.LUA_TNIL, null);
             }
             break;
         }
@@ -182,11 +180,11 @@ const adjust_varargs = function(L, p, actual) {
     let i;
     for (i = 0; i < nfixargs && i < actual; i++) {
         L.stack[L.top++] = L.stack[fixed + i];
-        L.stack[fixed + i] = nil;
+        L.stack[fixed + i] = new TValue(CT.LUA_TNIL, null);
     }
 
     for (; i < nfixargs; i++)
-        L.stack[L.top++] = nil;
+        L.stack[L.top++] = new TValue(CT.LUA_TNIL, null);
 
     return base;
 };
@@ -579,6 +577,5 @@ module.exports.lua_resume           = lua_resume;
 module.exports.lua_yield            = lua_yield;
 module.exports.lua_yieldk           = lua_yieldk;
 module.exports.moveresults          = moveresults;
-module.exports.nil                  = nil;
 module.exports.stackerror           = stackerror;
-module.exports.tryfuncTM            = tryfuncTM;
\ No newline at end of file
+module.exports.tryfuncTM            = tryfuncTM;
diff --git a/src/lobject.js b/src/lobject.js
index 32a7573..58e2d21 100644
--- a/src/lobject.js
+++ b/src/lobject.js
@@ -127,6 +127,9 @@ class TValue {
 
 }
 
+const luaO_nilobject = new TValue(CT.LUA_TNIL, null);
+module.exports.luaO_nilobject = luaO_nilobject;
+
 const jsstring = function(value, from, to) {
     let u0, u1, u2, u3, u4, u5;
     let idx = 0;
@@ -169,8 +172,6 @@ const jsstring = function(value, from, to) {
     return str;
 };
 
-const nil   = new TValue(CT.LUA_TNIL, null);
-
 class Table extends TValue {
 
     constructor(array, hash) {
@@ -210,14 +211,14 @@ class Table extends TValue {
     __index(table, key) {
         key = Table.keyValue(key);
 
-        let v = nil;
+        let v = luaO_nilobject;
         if (typeof key === 'number' && key > 0) {
             v = table.value.get(key - 1); // Lua array starts at 1
         } else {
             v = table.value.get(key);
         }
 
-        return v ? v : nil;
+        return v ? v : luaO_nilobject;
     }
 
     __len(table) {
diff --git a/src/lstate.js b/src/lstate.js
index 80dcc21..74c908d 100644
--- a/src/lstate.js
+++ b/src/lstate.js
@@ -68,7 +68,7 @@ class global_State {
     constructor(L) {
         this.mainthread = L;
         this.strt = new Map();
-        this.l_registry = ldo.nil;
+        this.l_registry = new lobject.TValue(CT.LUA_TNIL, null);
         this.panic = null;
         this.version = null;
         this.twups = [];
@@ -98,7 +98,7 @@ const stack_init = function(L1, L) {
     ci.callstatus = 0;
     ci.func = L1.stack[L1.top];
     ci.funcOff = L1.top;
-    L1.stack[L1.top++] = ldo.nil;
+    L1.stack[L1.top++] = new lobject.TValue(CT.LUA_TNIL, null);
     ci.top = L1.top + lua.LUA_MINSTACK;
     L1.ci = ci;
 };
@@ -183,4 +183,4 @@ module.exports.CIST_HOOKYIELD = (1<<6);  /* last hook called yielded */
 module.exports.CIST_LEQ       = (1<<7);  /* using __lt for __le */
 module.exports.CIST_FIN       = (1<<8);   /* call is running a finalizer */
 module.exports.lua_newstate   = lua_newstate;
-module.exports.lua_newthread  = lua_newthread;
\ No newline at end of file
+module.exports.lua_newthread  = lua_newthread;
diff --git a/src/ltm.js b/src/ltm.js
index e48ff23..7ef772f 100644
--- a/src/ltm.js
+++ b/src/ltm.js
@@ -179,7 +179,7 @@ const luaT_gettmbyobj = function(L, o, event) {
             mt = L.l_G.mt[o.ttnov()];
     }
 
-    return mt ? mt.__index(mt, event) : ldo.nil;
+    return mt ? mt.__index(mt, event) : lobject.luaO_nilobject;
 };
 
 module.exports.TMS              = TMS;
@@ -190,4 +190,4 @@ module.exports.luaT_callorderTM = luaT_callorderTM;
 module.exports.luaT_gettmbyobj  = luaT_gettmbyobj;
 module.exports.luaT_init        = luaT_init;
 module.exports.luaT_objtypename = luaT_objtypename;
-module.exports.ttypename        = ttypename;
\ No newline at end of file
+module.exports.ttypename        = ttypename;
diff --git a/src/lvm.js b/src/lvm.js
index c5628cf..53e1584 100644
--- a/src/lvm.js
+++ b/src/lvm.js
@@ -154,7 +154,7 @@ const luaV_execute = function(L) {
             }
             case "OP_LOADNIL": {
                 for (let j = 0; j <= i.B; j++)
-                    L.stack[ra + j] = ldo.nil;
+                    L.stack[ra + j] = new TValue(CT.LUA_TNIL, null);
                 break;
             }
             case "OP_GETUPVAL": {
@@ -694,7 +694,7 @@ const luaV_execute = function(L) {
                     L.stack[ra + j] = L.stack[base - n + j];
 
                 for (; j < b; j++) /* complete required results with nil */
-                    L.stack[ra + j] = ldo.nil;
+                    L.stack[ra + j] = new TValue(CT.LUA_TNIL, null);
                 break;
             }
             case "OP_EXTRAARG": {
@@ -1068,7 +1068,7 @@ const luaV_finishget = function(L, t, key, val, slot, recur) {
         assert(slot.ttisnil());
         tm = ltm.luaT_gettmbyobj(L, t, ltm.TMS.TM_INDEX); // TODO: fasttm
         if (tm.ttisnil()) {
-            L.stack[val] = ldo.nil;
+            L.stack[val] = new TValue(CT.LUA_TNIL, null);
             return;
         }
     }