select

3 files changed, 33 insertions, 1 deletions

diff --git a/src/lapi.js b/src/lapi.js
index e149619..bc4dd54 100644
--- a/src/lapi.js
+++ b/src/lapi.js
@@ -472,6 +472,22 @@ const lua_tonumber = function(L, idx) {
     return lvm.tonumber(index2addr(L, idx))
 };
 
+const lua_topointer = function(L, idx) {
+    let o = index2addr(L, idx);
+    switch (o.ttype()) {
+        case CT.LUA_TTABLE:
+        case CT.LUA_TLCL:
+        case CT.LUA_TCCL:
+        case CT.LUA_TLCF:
+        case CT.LUA_TTHREAD:
+        case CT.LUA_TUSERDATA:
+        case CT.LUA_TLIGHTUSERDATA:
+            return o.value;
+        default:
+            return null;
+    }
+};
+
 const f_call = function(L, ud) {
     ldo.luaD_callnoyield(L, ud.funcOff, ud.nresults);
 };
@@ -653,6 +669,7 @@ module.exports.lua_tointeger       = lua_tointeger;
 module.exports.lua_toboolean       = lua_toboolean;
 module.exports.lua_tolstring       = lua_tolstring;
 module.exports.lua_tostring        = lua_tostring;
+module.exports.lua_topointer       = lua_topointer;
 module.exports.lua_load            = lua_load;
 module.exports.lua_callk           = lua_callk;
 module.exports.lua_call            = lua_call;
diff --git a/src/lauxlib.js b/src/lauxlib.js
index 3ebcc7d..c44780e 100644
--- a/src/lauxlib.js
+++ b/src/lauxlib.js
@@ -92,7 +92,7 @@ const luaL_typename = function(L, i) {
 };
 
 const luaL_argcheck = function(L, cond, arg, extramsg) {
-    if (!cond) throw new Error("bad argument"); // TODO: luaL_argerror
+    if (!cond) throw new Error(extramsg); // TODO: luaL_argerror
 };
 
 const luaL_checkany = function(L, arg) {
diff --git a/src/lbaselib.js b/src/lbaselib.js
index d0e094f..19a990e 100644
--- a/src/lbaselib.js
+++ b/src/lbaselib.js
@@ -138,6 +138,20 @@ const luaB_error = function(L) {
     return lapi.lua_error(L);
 };
 
+const luaB_select = function(L) {
+    let n = lapi.lua_gettop(L);
+    if (lapi.lua_type(L, 1) === CT.LUA_TSTRING && lapi.lua_tostring(L, 1) === "#") {
+        lapi.lua_pushinteger(L, n - 1);
+        return 1;
+    } else {
+        let i = lauxlib.luaL_checkinteger(L, 1);
+        if (i < 0) i = n + i;
+        else if (i > n) i = n;
+        lauxlib.luaL_argcheck(L, 1 <= i, 1, "index out of range");
+        return n - i;
+    }
+};
+
 /*
 ** Continuation function for 'pcall' and 'xpcall'. Both functions
 ** already pushed a 'true' before doing the call, so in case of success
@@ -183,6 +197,7 @@ const base_funcs = {
     "tostring":       luaB_tostring,
     "getmetatable":   luaB_getmetatable,
     "ipairs":         luaB_ipairs,
+    "select":         luaB_select,
     "setmetatable":   luaB_setmetatable,
     "rawequal":       luaB_rawequal,
     "rawset":         luaB_rawset,