diff options
| -rw-r--r-- | pyparsing/core.py | 5 | ||||
| -rw-r--r-- | tests/test_unit.py | 31 |
2 files changed, 35 insertions, 1 deletions
diff --git a/pyparsing/core.py b/pyparsing/core.py index f24369c..dec64c7 100644 --- a/pyparsing/core.py +++ b/pyparsing/core.py @@ -4543,9 +4543,12 @@ class OnlyOnce: results = self.callable(s, l, t) self.called = True return results - raise ParseException(s, l, "") + raise ParseException(s, l, "OnlyOnce obj called multiple times w/out reset") def reset(self): + """Allow the associated parse action to be called once more. + """ + self.called = False diff --git a/tests/test_unit.py b/tests/test_unit.py index d7bb77d..a2a5580 100644 --- a/tests/test_unit.py +++ b/tests/test_unit.py @@ -7087,6 +7087,37 @@ class Test2_WithoutPackrat(ppt.TestParseResultsAsserts, TestCase): exprWithInt, "rucksack 49", {"item": "rucksack", "qty": 49} ) + def testOnlyOnce(self): + """test class OnlyOnce and its reset method""" + + # use a parse action to compute the sum of the parsed integers, + # and add it to the end + def append_sum(tokens): + tokens.append(sum(map(int, tokens))) + + pa = pp.OnlyOnce(append_sum) + expr = pp.OneOrMore(pp.Word(pp.nums)).addParseAction(pa) + + result = expr.parseString("0 123 321") + print(result.dump()) + expected = ["0", "123", "321", 444] + self.assertParseResultsEquals( + result, expected, msg="issue with OnlyOnce first call" + ) + + with self.assertRaisesParseException( + msg="failed to raise exception calling OnlyOnce more than once" + ): + result2 = expr.parseString("1 2 3 4 5") + + pa.reset() + result = expr.parseString("100 200 300") + print(result.dump()) + expected = ["100", "200", "300", 600] + self.assertParseResultsEquals( + result, expected, msg="issue with OnlyOnce after reset" + ) + class Test3_EnablePackratParsing(TestCase): def runTest(self): |