import re

from typing import Iterable

def findcommands(mailtext:str) -> Iterable[re.Match]:
	return re.finditer(r'\n(' # match any of:
		r'STATUS (OPEN|CLOSED|UNCONF|REJECT|UPSTRM)|' # a status change, STATUS <state>
		r'TYPE (BUG|DISCUS|PATCH)|' # a type change, TYPE <type>
		r'SUBJECT .*|' # a subject change, SUBJECT <any valid text without newlines>
		r'DESCRIPTION( @[0-9]*(:[0-9]*)?)?\r?\n(.*|\r?\n)*\r?\nDESCRIPTION END|' # DESCRIPTION [@<startingline[:<endingline]]\n<any valid text including newlines>\nEND DESCRIPTION
		r'(UN)?PERMIT .*)' # change command permission for an emailaddress, (UN)PERMIT <email>
		,mailtext)