Add eval command, add/remove variables for eval command

builtin_commands.gd

@@ -10,6 +10,7 @@ static func register_commands() -> void:
 	LimboConsole.register_command(LimboConsole.clear_console, "clear", "clear console screen")
 	LimboConsole.register_command(cmd_commands, "commands", "list all commands")
 	LimboConsole.register_command(LimboConsole.info, "echo", "display a line of text")
+	LimboConsole.register_command(cmd_eval, "eval", "evaluate an expression")
 	LimboConsole.register_command(cmd_fps_max, "fps_max", "limit framerate")
 	LimboConsole.register_command(cmd_fullscreen, "fullscreen", "toggle fullscreen mode")
 	LimboConsole.register_command(cmd_help, "help", "show command info")
@@ -42,6 +43,22 @@ static func cmd_commands() -> void:
 		LimboConsole.info(name if desc.is_empty() else "%s -- %s" % [name, desc])
 
 
+static func cmd_eval(p_expression: String) -> Error:
+	var exp := Expression.new()
+	var err: int = exp.parse(p_expression, LimboConsole.get_eval_input_names())
+	if err != OK:
+		LimboConsole.error(exp.get_error_text())
+		return err
+	var result = exp.execute(LimboConsole.get_eval_inputs())
+	if not exp.has_execute_failed():
+		if result != null:
+			LimboConsole.info(str(result))
+		return OK
+	else:
+		LimboConsole.error(exp.get_error_text())
+		return ERR_SCRIPT_FAILED
+
+
 static func cmd_fps_max(p_limit: int = -1) -> void:
 	if p_limit < 0:
 		if Engine.max_fps == 0:

limbo_console.gd

@@ -45,6 +45,7 @@ var _argument_autocomplete_sources: Dictionary # [command_name, arg_idx] => Call
 var _history: PackedStringArray
 var _hist_idx: int = -1
 var _autocomplete_matches: PackedStringArray
+var _eval_inputs: Dictionary
 var _silent: bool = false
 
 
@@ -375,6 +376,26 @@ func usage(p_command_name: String) -> Error:
 	return OK
 
 
+## Define an input variable for "eval" command.
+func add_eval_input(p_name: String, p_value) -> void:
+	_eval_inputs[p_name] = p_value
+
+
+## Remove specified input variable from "eval" command.
+func remove_eval_input(p_name) -> void:
+	_eval_inputs.erase(p_name)
+
+
+## List the defined input variables used in "eval" command.
+func get_eval_input_names() -> PackedStringArray:
+	return _eval_inputs.keys()
+
+
+## Get input variable values used in "eval" command, listed in the same order as names.
+func get_eval_inputs() -> Array:
+	return _eval_inputs.values()
+
+
 # *** PRIVATE
 
 # *** INITIALIZATION