Add lua_isvector, luaL_checkvector and luaL_optvector (#261)

Co-authored-by: Petri Häkkinen <petrih@rmd.remedy.fi>
Co-authored-by: Arseny Kapoulkine <arseny.kapoulkine@gmail.com>

VM/include/lua.h

@@ -296,6 +296,7 @@ LUA_API void lua_unref(lua_State* L, int ref);
 #define lua_islightuserdata(L, n) (lua_type(L, (n)) == LUA_TLIGHTUSERDATA)
 #define lua_isnil(L, n) (lua_type(L, (n)) == LUA_TNIL)
 #define lua_isboolean(L, n) (lua_type(L, (n)) == LUA_TBOOLEAN)
+#define lua_isvector(L, n) (lua_type(L, (n)) == LUA_TVECTOR)
 #define lua_isthread(L, n) (lua_type(L, (n)) == LUA_TTHREAD)
 #define lua_isnone(L, n) (lua_type(L, (n)) == LUA_TNONE)
 #define lua_isnoneornil(L, n) (lua_type(L, (n)) <= LUA_TNIL)

VM/include/lualib.h

@@ -33,6 +33,9 @@ LUALIB_API int luaL_optinteger(lua_State* L, int nArg, int def);
 LUALIB_API unsigned luaL_checkunsigned(lua_State* L, int numArg);
 LUALIB_API unsigned luaL_optunsigned(lua_State* L, int numArg, unsigned def);
 
+LUALIB_API const float* luaL_checkvector(lua_State* L, int narg);
+LUALIB_API const float* luaL_optvector(lua_State* L, int narg, const float* def);
+
 LUALIB_API void luaL_checkstack(lua_State* L, int sz, const char* msg);
 LUALIB_API void luaL_checktype(lua_State* L, int narg, int t);
 LUALIB_API void luaL_checkany(lua_State* L, int narg);

VM/src/laux.cpp

@@ -227,6 +227,19 @@ unsigned luaL_optunsigned(lua_State* L, int narg, unsigned def)
     return luaL_opt(L, luaL_checkunsigned, narg, def);
 }
 
+const float* luaL_checkvector(lua_State* L, int narg)
+{
+    const float* v = lua_tovector(L, narg);
+    if (!v)
+        tag_error(L, narg, LUA_TVECTOR);
+    return v;
+}
+
+const float* luaL_optvector(lua_State* L, int narg, const float* def)
+{
+    return luaL_opt(L, luaL_checkvector, narg, def);
+}
+
 int luaL_getmetafield(lua_State* L, int obj, const char* event)
 {
     if (!lua_getmetatable(L, obj)) /* no metatable? */

tests/Conformance.test.cpp

@@ -78,38 +78,31 @@ static int lua_vector(lua_State* L)
 
 static int lua_vector_dot(lua_State* L)
 {
-    const float* a = lua_tovector(L, 1);
-    const float* b = lua_tovector(L, 2);
+    const float* a = luaL_checkvector(L, 1);
+    const float* b = luaL_checkvector(L, 2);
 
-    if (a && b)
-    {
-        lua_pushnumber(L, a[0] * b[0] + a[1] * b[1] + a[2] * b[2]);
-        return 1;
-    }
-
-    throw std::runtime_error("invalid arguments to vector:Dot");
+    lua_pushnumber(L, a[0] * b[0] + a[1] * b[1] + a[2] * b[2]);
+    return 1;
 }
 
 static int lua_vector_index(lua_State* L)
 {
+    const float* v = luaL_checkvector(L, 1);
     const char* name = luaL_checkstring(L, 2);
 
-    if (const float* v = lua_tovector(L, 1))
+    if (strcmp(name, "Magnitude") == 0)
     {
-        if (strcmp(name, "Magnitude") == 0)
-        {
-            lua_pushnumber(L, sqrtf(v[0] * v[0] + v[1] * v[1] + v[2] * v[2]));
-            return 1;
-        }
+        lua_pushnumber(L, sqrtf(v[0] * v[0] + v[1] * v[1] + v[2] * v[2]));
+        return 1;
+    }
 
-        if (strcmp(name, "Dot") == 0)
-        {
-            lua_pushcfunction(L, lua_vector_dot, "Dot");
-            return 1;
-        }
+    if (strcmp(name, "Dot") == 0)
+    {
+        lua_pushcfunction(L, lua_vector_dot, "Dot");
+        return 1;
     }
 
-    throw std::runtime_error(Luau::format("%s is not a valid member of vector", name));
+    luaL_error(L, "%s is not a valid member of vector", name);
 }
 
 static int lua_vector_namecall(lua_State* L)
@@ -120,7 +113,7 @@ static int lua_vector_namecall(lua_State* L)
             return lua_vector_dot(L);
     }
 
-    throw std::runtime_error(Luau::format("%s is not a valid method of vector", luaL_checkstring(L, 1)));
+    luaL_error(L, "%s is not a valid method of vector", luaL_checkstring(L, 1));
 }
 
 int lua_silence(lua_State* L)