A WIP GDScript port of the an XNA InputSequence: https://github.com/SimonDarksideJ/XNAGameStudio/wiki/Input-Sequence

InputManager.gd

# InputManager.gd
extends Node

export var wait_time := 0.5
export var merge_time := 0.1

var player_index := 0
var buffer := []
var _buf_timer: Timer = null

func _init(p_player_index: int, p_buf_size: int) -> void:
	player_index = p_player_index
	buffer.resize(p_buf_size)

	_buf_timer = Timer.new()
	add_child(_buf_timer)
	_buf_timer.connect("timeout", self, "_on_buf_timer_timeout")

func _on_buf_timer_timeout() -> void:
	buffer.clear()

func _unhandled_input(p_event: InputEvent) -> void:
	if p_event.is_action("non_directional_button"):
		var merge_input := true
		if buffer.empty():
			_buf_timer.start(wait_time)
			merge_input = false
		else:
			merge_input |= _buf_timer.time_left > merge_time

Move.gd

# Move.gd
class_name Move

var name := ""
var sequence := []
var is_sub_move := false

func _init(p_name: String, p_sequence: Array) -> void:
	name = p_name
	sequence = p_sequence

MoveList.gd

# MoveList.gd
class_name MoveList

var _moves := []

func _init(p_moves: Array) -> void:
	_moves = p_moves
	_moves.sort_custom(self, "_sort")

static func _sort(a, b):
	return a.sequence.size() > b.sequence.size()

func detect_move(p_input: InputEvent) -> Move:
	for a_move in _moves:
		if p_input.is_action(""):
		return a_move
	return null

func get_longest_move_length -> int:
	return _moves[0].sequence.size() if _moves.size() else 0