diff --git a/info4/kapitel-8/Interpreter/test_while_interpreter.py b/info4/kapitel-8/Interpreter/test_while_interpreter.py
index cae730e4a89927db053ab063711ef7309d834362..f326993b202191e4a6fd9c5915f6bb8bf440258f 100644
--- a/info4/kapitel-8/Interpreter/test_while_interpreter.py
+++ b/info4/kapitel-8/Interpreter/test_while_interpreter.py
@@ -1,5 +1,10 @@
from whileinterpreter import interpret
from test_loop_interpreter import LOOPInterpreterTest
+from unittest import mock
+
+
+def str_yes(a):
+ return "J"
class WHILEInterpreterTest(LOOPInterpreterTest):
@@ -109,3 +114,7 @@ class WHILEInterpreterTest(LOOPInterpreterTest):
interpret('x1:=2;; x0:=3')
with self.assertRaises(SyntaxError):
interpret('WHILE x1 != 0 DO x0:=2;;x2:=1 END')
+
+ @mock.patch('whileinterpreter.input', side_effect=str_yes)
+ def test_infinite_loop(self, input):
+ self.assertEqual(interpret('x1:=100000; WHILE x1 != 0 DO x0:=1; x1:=x1-1 END', 1), -1)
diff --git a/info4/kapitel-8/Interpreter/whileinterpreter.py b/info4/kapitel-8/Interpreter/whileinterpreter.py
index cbddb54d9df5470fe74a068d2e0ca923cd1a1ca7..1c401de6f784c06324911c72ff00bb68f05b27ee 100644
--- a/info4/kapitel-8/Interpreter/whileinterpreter.py
+++ b/info4/kapitel-8/Interpreter/whileinterpreter.py
@@ -1,9 +1,35 @@
-from loopinterpreter import LOOPInterpreter
+import lexer
+from loopinterpreter import LOOPInterpreter, ErrorHandler
import re
+import signal
+
+
+class Timeout:
+ def __init__(self, time):
+ self.time = time
+
+ def __enter__(self):
+ if self.time > 0:
+ signal.signal(signal.SIGALRM, self.interrupt)
+ signal.alarm(self.time)
+
+ def __exit__(self, exc_type, exc_value, exc_traceback):
+ signal.alarm(0)
+
+ def interrupt(self, sig_num, stack_frame):
+ try:
+ abort = input('''Die Funktion rechnet relativ lange.
+Vielleicht liegt eine Endlosschleife vor.
+Möchten sie abbrechen? [J,n]:''')
+ if abort.upper() in ['J', 'JA', 'Y', 'YES', '']:
+ raise KeyboardInterrupt
+ signal.alarm(self.time)
+ except EOFError:
+ pass
class WHILEInterpreter(LOOPInterpreter):
- def __init__(self):
+ def __init__(self, timeout=60):
super().__init__()
self.regex_to_token = [(re.compile(r'\d+'), 'NUMBER'),
(re.compile(r'x\d+'), 'IDENTIFIER'),
@@ -19,11 +45,12 @@ class WHILEInterpreter(LOOPInterpreter):
(re.compile(r'BREAK'), 'BREAK'),
(re.compile(r'\s+', re.MULTILINE), 'WHITESPACE'),
(re.compile(r'[^\n]*'), 'UNKNOWN')]
+ self.timeout = timeout
def process_program(self, forbidden_identifiers, current_token):
if current_token is None or current_token.k not in ['IDENTIFIER', 'LOOP', 'WHILE']:
- self.error_handler.handle_error("Keine passende Anweisung gefunden\n" +
- "Erwartet: IDENTIFIER (x0, x1, ...), LOOP oder WHILE")
+ self.error_handler.handle_error('Keine passende Anweisung gefunden\n' +
+ 'Erwartet: IDENTIFIER (x0, x1, ...), LOOP oder WHILE')
elif current_token.k == 'IDENTIFIER':
current_token = self.process_assignment(forbidden_identifiers, current_token)
elif current_token.k == 'LOOP':
@@ -34,8 +61,8 @@ class WHILEInterpreter(LOOPInterpreter):
def verify_program(self, forbidden_identifiers, current_token):
if current_token is None or current_token.k not in ['IDENTIFIER', 'LOOP', 'WHILE']:
- self.error_handler.handle_error("Keine passende Anweisung gefunden\n" +
- "Erwartet: IDENTIFIER (x0, x1, ...), LOOP oder WHILE")
+ self.error_handler.handle_error('Keine passende Anweisung gefunden\n' +
+ 'Erwartet: IDENTIFIER (x0, x1, ...), LOOP oder WHILE')
elif current_token.k == 'IDENTIFIER':
current_token = self.verify_assignment(forbidden_identifiers, current_token)
elif current_token.k == 'LOOP':
@@ -51,16 +78,16 @@ class WHILEInterpreter(LOOPInterpreter):
if identifier_token.v in forbidden_identifiers:
self.error_handler.handle_error('Identifier ' + identifier_token.v +
' ist bereits in Loop vorhanden und darf nicht verwendet werden.')
- if not self.next_nonempty_token("WHILE", "UNGLEICH").k == 'NOTEQUALS':
+ if not self.next_nonempty_token('WHILE', 'UNGLEICH').k == 'NOTEQUALS':
self.error_handler.handle_error('UNGLEICH in WHILE erwartet.')
- zero_token = self.next_nonempty_token("WHILE", "0")
+ zero_token = self.next_nonempty_token('WHILE', '0')
if not zero_token.k == 'NUMBER':
self.error_handler.handle_error('0 in WHILE erwartet.')
if not int(zero_token.v) == 0:
self.error_handler.handle_error('0 in WHILE erwartet.')
- if not self.next_nonempty_token("WHILE", "DO").k == 'DO':
+ if not self.next_nonempty_token('WHILE', 'DO').k == 'DO':
self.error_handler.handle_error('DO in WHILE erwartet.')
if identifier_token.v in self.values:
@@ -76,7 +103,7 @@ class WHILEInterpreter(LOOPInterpreter):
while not end_found:
token = self.verify_program(forbidden_identifiers, self.next_token())
if token is None or token.k not in ['SEMICOLON', 'END']:
- self.error_handler.handle_error("SEMICOLON oder END in WHILE erwartet.")
+ self.error_handler.handle_error('SEMICOLON oder END in WHILE erwartet.')
elif token.k == 'SEMICOLON':
continue
elif token.k == 'END':
@@ -89,7 +116,7 @@ class WHILEInterpreter(LOOPInterpreter):
while not end_found:
token = self.process_program(forbidden_identifiers, self.next_token())
if token is None or token.k not in ['SEMICOLON', 'END']:
- self.error_handler.handle_error("SEMICOLON oder END in WHILE erwartet.")
+ self.error_handler.handle_error('SEMICOLON oder END in WHILE erwartet.')
elif token.k == 'SEMICOLON':
continue
elif token.k == 'END':
@@ -102,29 +129,29 @@ class WHILEInterpreter(LOOPInterpreter):
return self.next_token()
def verify_while(self, forbidden_identifiers, current_token):
- identifier_token = self.next_nonempty_token("WHILE", "IDENTIFIER")
+ identifier_token = self.next_nonempty_token('WHILE', 'IDENTIFIER')
if not identifier_token.k == 'IDENTIFIER':
self.error_handler.handle_error('IDENTIFIER in WHILE erwartet.')
if identifier_token.v in forbidden_identifiers:
- self.error_handler.handle_error("Identifier " + identifier_token.v +
- " ist bereits in Loop vorhanden und darf nicht verwendet werden.")
- if not self.next_nonempty_token("WHILE", "UNGLEICH").k == 'NOTEQUALS':
+ self.error_handler.handle_error('Identifier ' + identifier_token.v +
+ ' ist bereits in Loop vorhanden und darf nicht verwendet werden.')
+ if not self.next_nonempty_token('WHILE', 'UNGLEICH').k == 'NOTEQUALS':
self.error_handler.handle_error('UNGLEICH in WHILE erwartet.')
- zero_token = self.next_nonempty_token("WHILE", "0")
+ zero_token = self.next_nonempty_token('WHILE', '0')
if not zero_token.k == 'NUMBER':
self.error_handler.handle_error('0 in WHILE erwartet.')
if not int(zero_token.v) == 0:
self.error_handler.handle_error('0 in WHILE erwartet.')
- if not self.next_nonempty_token("WHILE", "DO").k == 'DO':
+ if not self.next_nonempty_token('WHILE', 'DO').k == 'DO':
self.error_handler.handle_error('DO in WHILE erwartet.')
end_found = False
while not end_found:
token = self.verify_program(forbidden_identifiers, self.next_token())
if token is None or token.k not in ['SEMICOLON', 'END']:
- self.error_handler.handle_error("SEMICOLON oder END in WHILE erwartet.")
+ self.error_handler.handle_error('SEMICOLON oder END in WHILE erwartet.')
elif token.k == 'SEMICOLON':
continue
elif token.k == 'END':
@@ -132,7 +159,30 @@ class WHILEInterpreter(LOOPInterpreter):
return self.next_token()
-
-def interpret(program):
- interpreter = WHILEInterpreter()
+ def interpret(self, program):
+ try:
+ with Timeout(self.timeout):
+ self.lex = lexer.Lexer(self.regex_to_token, program)
+ self.error_handler = ErrorHandler(program, self)
+ self.values = {}
+ forbidden_identifiers = []
+ current_token = self.next_token()
+ while current_token is not None:
+ current_token = self.process_program(forbidden_identifiers, current_token)
+ if current_token is not None:
+ if not current_token.k == 'SEMICOLON':
+ self.error_handler.handle_error('Semicolon erwartet')
+ current_token = self.next_token()
+ if current_token is None:
+ self.error_handler.handle_error('Semikolons werden nur zur Trennung und nicht zum ' +
+ 'Abschluss von Programmen verwendet')
+ if 'x0' in self.values:
+ return self.values.get('x0')
+ return 0
+ except KeyboardInterrupt:
+ return -1
+
+
+def interpret(program, timeout=60):
+ interpreter = WHILEInterpreter(timeout)
return interpreter.interpret(program)