recursive parsec

#! /usr/bin/env python3
import parsec as psc
digit = psc.regex("[0-9]")


def number():
  @psc.Parser
  def number_parser(text, index):
    res = (digit + number())(text, index)
    return res if res.status else digit(text, index)
  return number_parser

try:
  _ = number().parse("42423")
  print(_)
except RecursionError as _:
  print("Recursion!")

@psc.Parser
def number(text, index):
  return ((digit + number) ^ digit)(text, index)

try:
  print(number.parse("42423"))
except RecursionError as _:
  print("Recursion!")

@psc.generate
def number():
  r = yield (digit + number) ^ digit
  return r

try:
  print(number.parse("42423"))
except RecursionError as _:
  print("Recursion!")