hehehehehe what if I forgot to git add?

src/lua_taglib.c

@@ -0,0 +1,186 @@
+// SONIC ROBO BLAST 2
+//-----------------------------------------------------------------------------
+// Copyright (C) 2020 by James R.
+// Copyright (C) 2020 by Sonic Team Junior.
+//
+// This program is free software distributed under the
+// terms of the GNU General Public License, version 2.
+// See the 'LICENSE' file for more details.
+//-----------------------------------------------------------------------------
+/// \file  lua_taglib.c
+/// \brief tag list iterator for Lua scripting
+
+#include "doomdef.h"
+#include "taglist.h"
+#include "r_state.h"
+
+#include "lua_script.h"
+#include "lua_libs.h"
+
+static int tag_iterator(lua_State *L)
+{
+	INT32 tag = lua_isnil(L, 2) ? -1 : lua_tonumber(L, 2);
+	do
+	{
+		if (++tag >= MAXTAGS)
+			return 0;
+	}
+	while (! in_bit_array(tags_available, tag)) ;
+	lua_pushnumber(L, tag);
+	return 1;
+}
+
+enum {
+#define UPVALUE lua_upvalueindex
+	up_garray         = UPVALUE(1),
+	up_max_elements   = UPVALUE(2),
+	up_element_array  = UPVALUE(3),
+	up_sizeof_element = UPVALUE(4),
+	up_meta           = UPVALUE(5),
+#undef UPVALUE
+};
+
+static INT32 next_element(lua_State *L, const mtag_t tag, const size_t p)
+{
+	taggroup_t ** garray = lua_touserdata(L, up_garray);
+	const size_t * max_elements = lua_touserdata(L, up_max_elements);
+	return Taggroup_Iterate(garray, *max_elements, tag, p);
+}
+
+static void push_element(lua_State *L, void *element)
+{
+	if (LUA_RawPushUserdata(L, element) == LPUSHED_NEW)
+	{
+		lua_pushvalue(L, up_meta);
+		lua_setmetatable(L, -2);
+	}
+}
+
+static void push_next_element(lua_State *L, const INT32 element)
+{
+	char * element_array = *(char **)lua_touserdata(L, up_element_array);
+	const size_t sizeof_element = lua_tonumber(L, up_sizeof_element);
+	push_element(L, &element_array[element * sizeof_element]);
+}
+
+struct element_iterator_state {
+	mtag_t tag;
+	size_t p;
+};
+
+static int element_iterator(lua_State *L)
+{
+	struct element_iterator_state * state = lua_touserdata(L, 1);
+	const INT32 element = next_element(L, state->tag, state->p);
+
+	if (element == -1)
+		return 0;
+	else
+	{
+		push_next_element(L, element);
+		state->p++;
+		return 1;
+	}
+}
+
+static int lib_iterateTags(lua_State *L)
+{
+	if (lua_gettop(L) < 2)
+	{
+		lua_pushcfunction(L, tag_iterator);
+		return 1;
+	}
+	else
+		return tag_iterator(L);
+}
+
+static int lib_numTags(lua_State *L)
+{
+	lua_pushnumber(L, num_tags);
+	return 1;
+}
+
+static int lib_getTaggroup(lua_State *L)
+{
+	struct element_iterator_state *state;
+
+	mtag_t tag;
+
+	if (lua_gettop(L) > 1)
+		return luaL_error(L, "too many arguments");
+
+	if (lua_isnoneornil(L, 1))
+	{
+		tag = MTAG_GLOBAL;
+	}
+	else
+	{
+		tag = lua_tonumber(L, 1);
+		luaL_argcheck(L, tag >= -1, 1, "tag out of range");
+	}
+
+	state = lua_newuserdata(L, sizeof *state);
+	state->tag = tag;
+	state->p = 0;
+
+	lua_pushvalue(L, lua_upvalueindex(1));
+	lua_setmetatable(L, -2);
+
+	return 1;
+}
+
+static int lib_numTaggroupElements(lua_State *L)
+{
+	const mtag_t tag = *(mtag_t *)lua_touserdata(L, 1);
+	if (tag == MTAG_GLOBAL)
+		lua_pushnumber(L, *(size_t *)lua_touserdata(L, up_max_elements));
+	else
+	{
+		const taggroup_t ** garray = lua_touserdata(L, up_garray);
+		lua_pushnumber(L, garray[tag] ? garray[tag]->count : 0);
+	}
+	return 1;
+}
+
+void LUA_InsertTaggroupIterator
+(		lua_State *L,
+		taggroup_t *garray[],
+		size_t * max_elements,
+		void * element_array,
+		size_t sizeof_element,
+		const char * meta)
+{
+	lua_createtable(L, 0, 2);
+		lua_pushlightuserdata(L, garray);
+		lua_pushlightuserdata(L, max_elements);
+
+		lua_pushvalue(L, -2);
+		lua_pushvalue(L, -2);
+		lua_pushlightuserdata(L, element_array);
+		lua_pushnumber(L, sizeof_element);
+		luaL_getmetatable(L, meta);
+		lua_pushcclosure(L, element_iterator, 5);
+		lua_setfield(L, -4, "__call");
+
+		lua_pushcclosure(L, lib_numTaggroupElements, 2);
+		lua_setfield(L, -2, "__len");
+	lua_pushcclosure(L, lib_getTaggroup, 1);
+	lua_setfield(L, -2, "tagged");
+}
+
+int LUA_TagLib(lua_State *L)
+{
+	lua_newuserdata(L, 0);
+		lua_createtable(L, 0, 2);
+			lua_createtable(L, 0, 1);
+				lua_pushcfunction(L, lib_iterateTags);
+				lua_setfield(L, -2, "iterate");
+			lua_setfield(L, -2, "__index");
+
+			lua_pushcfunction(L, lib_numTags);
+			lua_setfield(L, -2, "__len");
+		lua_setmetatable(L, -2);
+	lua_setglobal(L, "tags");
+
+	return 0;
+}