initial

src/luainterp.cpp

@@ -0,0 +1,68 @@
+
+// Handle errors with a Lua function, defined in lua-env.lua
+int bll_error_handler(lua_State *L) {
+	lua_getfield(L, LUA_GLOBALSINDEX, "_bllua_on_error");
+	if (!lua_isfunction(L, -1)) {
+		BlPrintf("  Lua error handler: _bllua_on_error not defined.");
+		lua_pop(L, 1);
+		return 1;
+	}
+	
+	// move function to before arg
+	int hpos = lua_gettop(L) - 1;
+	lua_insert(L, hpos);
+	
+	lua_pcall(L, 1, 1, 0);
+	return 1;
+}
+int bll_pcall(lua_State* L, int nargs, int nret) {
+	// calculate stack position for message handler
+	int hpos = lua_gettop(L) - nargs;
+	// push custom error message handler
+	lua_pushcfunction(L, bll_error_handler);
+	// move it before function and arguments
+	lua_insert(L, hpos);
+	// call lua_pcall function with custom handler
+	int ret = lua_pcall(L, nargs, nret, hpos);
+	// remove custom error message handler from stack
+	lua_remove(L, hpos);
+	return ret;
+}
+
+// Display the last Lua error in the BL console
+void bll_printError(lua_State* L, const char* operation, const char* item) {
+	//error_handler(L);
+	BlPrintf("\x03Lua error: %s", lua_tostring(L, -1));
+	BlPrintf("\x03  (%s: %s)", operation, item);
+	lua_pop(L, 1);
+}
+
+// Eval a string of Lua code
+bool bll_LuaEval(lua_State* L, const char* str) {
+	if(luaL_loadbuffer(L, str, strlen(str), "input") || bll_pcall(L, 0, 1)) {
+		bll_printError(L, "eval", str);
+		return false;
+	}
+	return true;
+}
+
+// Convert a Lua stack entry into a string for providing to TS
+// Use static buffer to avoid excessive malloc
+#define BLL_ARG_COUNT 20
+#define BLL_ARG_MAX 8192
+char bll_arg_buffer[BLL_ARG_COUNT][BLL_ARG_MAX];
+bool bll_toarg(lua_State* L, char* buf, int i, bool err) {
+	if(lua_isstring(L, i)) {
+		const char* str = lua_tostring(L, i);
+		if(strlen(str) >= BLL_ARG_MAX) {
+			if(err) luaL_error(L, "argument to TS is too long - max length is 8192");
+			return true;
+		} else {
+			strcpy(buf, str);
+			return false;
+		}
+	} else {
+		if(err) luaL_error(L, "argument to TS must be a string");
+		return true;
+	}
+}