def test_optional(self):
parser = ~Char('A')
self.assertEqual(parser('X').result, [])
self.assertEqual(parser('A').result, ['A'])
parser = ~Char('A') + Char('B')
self.assertEqual(parser('B').result, [['B']])
self.assertEqual(parser('AB').result, [['A'], ['B']])
def test_seq(self):
parser = Seq([Char('A'), Char('B'), Char('C')])
result = parser('ABC').result
self.assertEqual(result, [['A'], ['B'], ['C']])
parser = Seq('ABC')
result = parser('ABC').result
self.assertEqual(result, [['A'], ['B'], ['C']])
def test_any(self):
parser = Any([Char('A'), Char('B'), Char('C')])
result = parser('BC').result
self.assertEqual(result, ['B'])
parser = Any('ABC')
result = parser('BC').result
self.assertEqual(result, ['B'])
def test_ZeroOrMore(self):
parser = ZeroOrMore(Char('A'))
self.assertEqual(parser('X').result, [])
self.assertEqual(parser('A').result, [['A']])
self.assertEqual(parser('AAAA').result, [['A'], ['A'], ['A'], ['A']])
parser = ZeroOrMore(Any('12345'))
self.assertEqual(parser('X').result, [])
self.assertEqual(parser('1').result, [['1']])
self.assertEqual(parser('1234').result, [['1'], ['2'], ['3'], ['4']])
def test_OneOrMore(self):
parser = OneOrMore(Char('A'))
self.assertEqual(parser('X').success, False)
self.assertEqual(parser('A').result, [['A']])
self.assertEqual(parser('AAAA').result, [['A'], ['A'], ['A'], ['A']])
parser = OneOrMore(Any('12345'))
self.assertEqual(parser('X').success, False)
self.assertEqual(parser('1').result, [['1']])
self.assertEqual(parser('1234').result, [['1'], ['2'], ['3'], ['4']])
def exp_parser():
number = number_parser()
# exponent -> ( exp ) | NUMBER
exponent = Between(Char('('), Ref('exp'), Char(')')) | number
# a reference to 'exp' parser is used since its not defined yet
# factor -> exponent factor'
# factor' -> ^ exponent factor' | NULL
factor = (exponent + ZeroOrMore(Char('^') + exponent)).map(eval_exp)
# term -> factor term'
# term' -> * factor term' | / factor term' | NULL
term = (factor + ZeroOrMore(Any('*/') + factor)).map(eval_exp)
# exp -> term exp'
# exp' -> + term exp' | - term exp' | NULL
exp = (term + ZeroOrMore(Any('+-') + term)).map(eval_exp)
# linking reference to actual parser
Ref.link({'exp': exp})
return StripWhitespace() + exp + End()
def number_parser():
# based on JSON's specs for number
# digit: any char from 0 - 9
digit = Any('0123456789')
# non zero numbers: digits without a leading 0
non_zero = Any('123456789') + ZeroOrMore(digit)
# int: optional minus sign, followed by a 0 OR non zero numbers
integer = ~Char('-') + (Char('0') | non_zero)
# decimal: point followed by digits
decimal = Char('.') + OneOrMore(digit)
# exponent: e or E with a optional sign followed by digits
exp = Seq([Any('eE'), ~Any('+-'), OneOrMore(digit)])
# all combinations of integer, decimal and exponent
number = ((integer + decimal + exp) | (integer + decimal) | (integer + exp)
|
integer).map(lambda result: float(''.join(x[0] for x in result)))
# ^ map the result list to float
return number
def json_parser():
# NULL, TRUE, FALSE parser
null = Seq('null').map(lambda r: None)
true = Seq('true').map(lambda r: True)
false = Seq('false').map(lambda r: False)
# NUMBER and STRING parser
number = number_parser()
# json string: QUOTE string QUOTE
string = Between(Char('"'), string_parser(), Char('"'))
# value -> STRING | NUMBER | TRUE | FALSE | NULL | list | object
value = Any([string, number, null, true, false, Ref('lst'), Ref('obj')])
# references to 'lst' and 'obj' are use since they are not defined yet
# pair -> STRING COLON value
to_dict = lambda result: {result[0][0]: result[2][0]}
pair = (string + Char(':') + value).map(to_dict)
# pairs_list -> pair COMMA pairs_list | pair
pairs_list = (pair + ZeroOrMore(Char(',') + pair)).map(concat_dicts)
# object -> OPEN_CURLYBRACE pairs_list CLOSE_CURLYBRACE
obj = Between(Char('{'), pairs_list, Char('}'))
# values_list -> value COMMA values_list | value
values_list = (value + ZeroOrMore(Char(',') + value)).map(concat_lists)
# list -> OPEN_SQBRACE values_list CLOSE_BRACE
lst = Between(Char('['), values_list, Char(']'))
# linking references to actual parsers
Ref.link({'lst': lst, 'obj': obj})
# json -> value
parser = StripWhitespace() + value + End()
parser.map(lambda result: result[0][0])
return parser
def test_between(self):
parser = Between(Char('A'), Char('B'), Char('C'))
self.assertEqual(parser('ABC').result, ['B'])
parser = Between(Char('A'), (Char('B') + Char('C')), Char('D'))
self.assertEqual(parser('ABCD').result, [['B'], ['C']])
def test_ref(self):
parser = Ref('A_and_B') + Char('C')
A_and_B = Char('A') + Char('B')
Ref.link({'A_and_B': A_and_B})
self.assertEqual(parser('ABC').result, [['A'], ['B'], ['C']])
def test_and_multiple(self):
parser = Char('A') + Char('B') + Char('C') + Char('D') + Char('E')
result = parser('ABCDE').result
self.assertEqual(result, [['A'], ['B'], ['C'], ['D'], ['E']])
def test_and(self):
parser = Char('A') + Char('B')
result = parser('ABC').result
self.assertEqual(result, [['A'], ['B']])
def test_single_char(self):
parse_A = Char('A')
self.assertEqual(parse_A('ABC').result, ['A'])
self.assertEqual(parse_A('DBC').success, False)
def test_and_complex(self):
parser_AB = Char('A') + Char('B')
parser_CD = Char('C') + Char('D')
parser = parser_AB + parser_CD
result = parser('ABCDE').result
self.assertEqual(result, [['A'], ['B'], ['C'], ['D']])
def test_or(self):
parser = Char('A') | Char('B')
result = parser('ABC').result
self.assertEqual(result, ['A'])
def test_end(self):
parser = Char('A') + End()
self.assertEqual(parser('A').result, [['A']])
self.assertEqual(parser('ABCD').success, False)
def test_or_multiple(self):
parser = Char('A') | Char('B') | Char('C') | Char('D') | Char('E')
result = parser('CDE').result
self.assertEqual(result, ['C'])