diff options
| -rw-r--r-- | pyparsing/core.py | 12 | ||||
| -rw-r--r-- | pyparsing/helpers.py | 11 | ||||
| -rw-r--r-- | tests/test_unit.py | 18 |
3 files changed, 25 insertions, 16 deletions
diff --git a/pyparsing/core.py b/pyparsing/core.py index a8d1f32..17428bf 100644 --- a/pyparsing/core.py +++ b/pyparsing/core.py @@ -1386,7 +1386,7 @@ class ParserElement(ABC): "second tuple value must be greater or equal to first tuple value" ) if minElements == optElements == 0: - raise ValueError("cannot multiply ParserElement by 0 or (0, 0)") + return And([]) if optElements: @@ -3629,10 +3629,12 @@ class And(ParseExpression): exprs[:] = tmp super().__init__(exprs, savelist) self.mayReturnEmpty = all(e.mayReturnEmpty for e in self.exprs) - self.set_whitespace_chars( - self.exprs[0].whiteChars, copy_defaults=self.exprs[0].copyDefaultWhiteChars - ) - self.skipWhitespace = self.exprs[0].skipWhitespace + if self.exprs: + self.set_whitespace_chars( + self.exprs[0].whiteChars, + copy_defaults=self.exprs[0].copyDefaultWhiteChars, + ) + self.skipWhitespace = self.exprs[0].skipWhitespace self.callPreparse = True def streamline(self): diff --git a/pyparsing/helpers.py b/pyparsing/helpers.py index 42510b8..251092a 100644 --- a/pyparsing/helpers.py +++ b/pyparsing/helpers.py @@ -92,11 +92,12 @@ def counted_array( # - type: 'bool' """ intExpr = intExpr or int_expr - arrayExpr = Forward() + array_expr = Forward() - def countFieldParseAction(s, l, t): + def count_field_parse_action(s, l, t): + nonlocal array_expr n = t[0] - arrayExpr << (And([expr] * n) if n else empty) + array_expr <<= (expr * n) if n else Empty() # clear list contents, but keep any named results del t[:] @@ -105,8 +106,8 @@ def counted_array( else: intExpr = intExpr.copy() intExpr.set_name("arrayLen") - intExpr.add_parse_action(countFieldParseAction, callDuringTry=True) - return (intExpr + arrayExpr).set_name("(len) " + str(expr) + "...") + intExpr.add_parse_action(count_field_parse_action, call_during_try=True) + return (intExpr + array_expr).set_name("(len) " + str(expr) + "...") def match_previous_literal(expr: ParserElement) -> ParserElement: diff --git a/tests/test_unit.py b/tests/test_unit.py index 6df6002..1ad8f82 100644 --- a/tests/test_unit.py +++ b/tests/test_unit.py @@ -2477,12 +2477,6 @@ class Test02_WithoutPackrat(ppt.TestParseResultsAsserts, TestCase): def testParserElementMulOperatorWithTuples(self): """test ParserElement "*" with various tuples""" - # ParserElement * (0, 0) - with self.assertRaises( - ValueError, msg="ParserElement * (0,0) should raise error" - ): - expr = pp.Word(pp.alphas)("first") + pp.Word(pp.nums)("second*") * (0, 0) - # ParserElement * (None, n) expr = pp.Word(pp.alphas)("first") + pp.Word(pp.nums)("second*") * (None, 3) @@ -2556,6 +2550,18 @@ class Test02_WithoutPackrat(ppt.TestParseResultsAsserts, TestCase): ): expr = pp.Word(pp.alphas)("first") + pp.Word(pp.nums)("second") * ("2", "3") + def testParserElementMulByZero(self): + alpwd = pp.Word(pp.alphas) + numwd = pp.Word(pp.nums) + + test_string = "abd def ghi jkl" + + parser = alpwd * 2 + numwd * 0 + alpwd * 2 + self.assertParseAndCheckList(parser, test_string, expected_list=test_string.split()) + + parser = alpwd * 2 + numwd * (0, 0) + alpwd * 2 + self.assertParseAndCheckList(parser, test_string, expected_list=test_string.split()) + def testParserElementMulOperatorWithOtherTypes(self): """test the overridden "*" operator with other data types""" |