def test_bad_rule_reference(self):
""" Refer to a rule that doesn't exist. """
p = ParserBase()
p.new_rule('bad', 'notarule')
with self.assertRaises(KeyError,
msg='non-existent rule did not raise error'):
p.parse('any text')
def test_flatten(self):
""" Test the flatten method. """
p = ParserBase()
string = 'aaaaaa'
p.new_rule('as', '"a" as | "a"', main=True)
token = p.parse(string)
token.flatten()
self.assertEqual(string,
''.join(c.value() for c in token.children),
msg='flatten failed for simple example')
def test_ignore(self):
""" Test the 'ignore' whitespace handling technique. """
# set up parser with new grammar and the digit_run function
p = ParserBase(ws_handler=ignore)
p.from_function(digit_run, ws_handling=True)
p.grammar(GRAMMAR, main='programme')
# trial various combinations of whitespace
# single spacing
p.parse('if 34 > 33 then 44 + 3')
# no spacing
p.parse('if34>33then44+3')
# random spacing, including a tab
p.parse('if34 > 33 then 44+\t3')
def test_require_with_ignore(self):
""" Test the 'require' whitespace handling technique, using
the 'ignore' option. """
# set up parser with new grammar and the digit_run function
p = ParserBase(ws_handler=require(' ', ignore=True))
p.from_function(digit_run, ws_handling=True)
p.grammar(GRAMMAR, main='programme')
# trial various combinations of whitespace
# single spacing - should work
p.parse('if 34 > 33 then 44 + 3')
# double spacing - should now work
p.parse('if 34 > 33 then 44 + 3')
# no spacing - should fail
with self.assertRaises(DelimiterError):
p.parse('if34>33then44+3')
def test_ignore_specific(self):
""" Test the 'ignore_specific' whitespace handling
technique.
"""
# set up parser with new grammar and the digit_run function
p = ParserBase(ws_handler=ignore_specific(' '))
p.from_function(digit_run, ws_handling=True)
p.grammar(GRAMMAR, main='programme')
# trial various combinations of whitespace
# single spacing
p.parse('if 34 > 33 then 44 + 3')
# no spacing
p.parse('if34>33then44+3')
# random spacing, including a tab - should fail
with self.assertRaises(NotFoundError, msg='should ignore tab'):
p.parse('if34 > 33 then 44+\t3')
def test_backslash_escaping(self):
""" Try escaping a backslash in a rule. """
p = ParserBase()
p.new_rule('escape', '"\\\\"')
p.parse('\\')
def test_quote_escaping(self):
""" Try using an escaped double-quote in a rule. """
p = ParserBase()
p.new_rule('quote', r'"\""')
p.parse('"')
def test_pipe_escaping(self):
""" Try using an escaped pipe in a rule. """
p = ParserBase()
p.new_rule(r'escaped', '"pipe: " "\|"')
p.parse('pipe: |')
def test_grammar(self):
""" Use the grammar method, also providing an opportunity to
check a more complex multi-rule example.
"""
p = ParserBase()
p.grammar(GRAMMAR)
# these should all succeed
p.parse('https://www.abcabc.com')
p.parse('https://www.bcaabc.co.uk')
p.parse('http://www.a.fr')
# these should all fail
with self.assertRaises(NotFoundError):
p.parse('www.abc.com')
with self.assertRaises(NotFoundError):
p.parse('https:/www.abcabc.com')
with self.assertRaises(NotFoundError):
p.parse('https://www.abcd.co.uk')
with self.assertRaises(NotFoundError):
p.parse('http://www..com')
with self.assertRaises(IncompleteParseError):
p.parse('https://www.a.fra')