4 files changed, 29 insertions, 3 deletions
diff --git a/src/lua.h b/src/lua.h
index 834ed85..af6e8ab 100644
--- a/src/lua.h
+++ b/src/lua.h
@@ -115,6 +115,13 @@ extern int _print_errors;
     sprintf(err, "(%s:%i) %s assertion failed", file, line, #eq);\
     luaI_error(L, -1, err);}}
 
+#define luaI_assert2(L, eq){_helperluaI_assert2(L, eq, __FILE__, __LINE__);}
+#define _helperluaI_assert2(L, eq, file, line){\
+  if(!(eq)){\
+    char err[1024] = {0};\
+    sprintf(err, "(%s:%i) %s assertion failed", file, line, #eq);\
+    luaL_error(L, err);}}
+
 int writer(lua_State*, const void*, size_t, void*);
 
 #if LUA_VERSION_NUM != 501
diff --git a/src/math.c b/src/math.c
index e7cd1bb..47e8391 100644
--- a/src/math.c
+++ b/src/math.c
@@ -65,10 +65,10 @@ int l_random(lua_State* L){
   size_t min = 1;
   switch(lua_gettop(L)){
     case 2:
-      min = lua_tointeger(L, 1);
+      min = luaL_checkinteger(L, 1);
       lua_remove(L, 1);
     case 1:
-      lua_pushinteger(L, (erand48(seedv) * (lua_tointeger(L, 1) - min + 1)) + min);
+      lua_pushinteger(L, (erand48(seedv) * (luaL_checkinteger(L, 1) - min + 1)) + min);
       break;
     case 0:
     default:
diff --git a/src/table.c b/src/table.c
index f5bdd5d..e2130dc 100644
--- a/src/table.c
+++ b/src/table.c
@@ -3,6 +3,23 @@
 #include <string.h>
 #include <stdint.h>
 
+int l_contains(lua_State* L){
+  luaI_assert2(L, lua_gettop(L) >= 2);
+  luaL_checktype(L, 1, LUA_TTABLE);
+
+  lua_pushnil(L);
+  for(;lua_next(L, 1);){
+    if(lua_rawequal(L, -1, 2)){
+      lua_pushvalue(L, -2);
+      return 1;
+    }
+    lua_pop(L, 1);
+  }
+
+  lua_pushnil(L);
+  return 1;
+}
+
 void value_clone_req(lua_State* L){
   int idx = lua_gettop(L);
 
@@ -32,7 +49,7 @@ void value_clone_req(lua_State* L){
 }
 
 int l_dup(lua_State* L){
-  if(lua_gettop(L) != 1) return 0;
+  luaI_assert2(L, lua_gettop(L) == 1);
 
   value_clone_req(L);
   lua_pushvalue(L, 2);
diff --git a/src/table.h b/src/table.h
index b114cd2..27cbaf7 100644
--- a/src/table.h
+++ b/src/table.h
@@ -7,6 +7,7 @@
 void i_shuffle(double*, size_t);
 uint64_t i_len(lua_State*,int);
 
+int l_contains(lua_State*);
 int l_len(lua_State*);          //[double+int] -> i
 int l_reverse(lua_State*);      //[double+int] -> arr[N]
 int l_max(lua_State*);     //[double+int] -> i
@@ -28,6 +29,7 @@ int l_dup(lua_State*);
 
 #warning "docs needed here"
 static const luaL_Reg table_function_list [] = {
+  {"contains",l_contains},
   {"len",l_len},
   {"reverse",l_reverse}, //no docs
   {"max",l_max}, //no docs