table.pack

2 files changed, 21 insertions, 1 deletions

diff --git a/src/lapi.js b/src/lapi.js
index 6316326..f34216b 100644
--- a/src/lapi.js
+++ b/src/lapi.js
@@ -355,6 +355,13 @@ const lua_setfield = function(L, idx, k) {
     auxsetstr(L, index2addr(L, idx), k)
 };
 
+const lua_seti = function(L, idx, n) {
+    assert(1 < L.top - L.ci.funcOff, "not enough elements in the stack");
+    let t = index2addr(L, idx);
+    lvm.settable(L, t, n, L.stack[L.top - 1]);
+    L.top--;  /* pop value */
+};
+
 const lua_rawset = function(L, idx) {
     assert(2 < L.top - L.ci.funcOff, "not enough elements in the stack");
     let o = index2addr(L, idx);
@@ -780,6 +787,7 @@ module.exports.lua_remove          = lua_remove;
 module.exports.lua_rotate          = lua_rotate;
 module.exports.lua_setfield        = lua_setfield;
 module.exports.lua_setglobal       = lua_setglobal;
+module.exports.lua_seti            = lua_seti;
 module.exports.lua_setmetatable    = lua_setmetatable;
 module.exports.lua_settable        = lua_settable;
 module.exports.lua_settop          = lua_settop;
diff --git a/src/ltablib.js b/src/ltablib.js
index 8e1f758..ec7c578 100644
--- a/src/ltablib.js
+++ b/src/ltablib.js
@@ -80,8 +80,20 @@ const tconcat = function(L) {
     return 1;
 };
 
+const pack = function(L) {
+    let n = lapi.lua_gettop(L);  /* number of elements to pack */
+    lapi.lua_createtable(L, n, 1);  /* create result table */
+    lapi.lua_insert(L, 1);  /* put it at index 1 */
+    for (let i = n; i >= 1; i--)  /* assign elements */
+        lapi.lua_seti(L, 1, i);
+    lapi.lua_pushinteger(L, n);
+    lapi.lua_setfield(L, 1, "n");  /* t.n = number of elements */
+    return 1;  /* return table */
+};
+
 const tab_funcs = {
-    "concat": tconcat
+    "concat": tconcat,
+    "pack":   pack
 };
 
 const luaopen_table = function(L) {