def test_CorrectlyHandlesDifferentNumberOfArguments(self):
# Arrange
txt = 'lorem ipsum'
parser_l = bpr.LParser('l')
parser_o = bpr.LParser('o')
parser_r = bpr.LParser('r')
parser_e = bpr.LParser('e')
parser1 = cmb.and_then(parser_l)
parser2 = cmb.and_then(parser_l, parser_o)
parser3 = cmb.and_then(parser_l, parser_o, parser_r)
parser4 = cmb.and_then(parser_l, parser_o, parser_r, parser_e)
# Act
result1 = parser1(txt)
result2 = parser2(txt)
result3 = parser3(txt)
result4 = parser4(txt)
expected1 = res.Success(('l', 'orem ipsum'))
expected2 = res.Success(('lo', 'rem ipsum'))
expected3 = res.Success(('lor', 'em ipsum'))
expected4 = res.Success(('lore', 'm ipsum'))
# Assert
self.assertEqual(result1, expected1)
self.assertEqual(result2, expected2)
self.assertEqual(result3, expected3)
self.assertEqual(result4, expected4)
def parse_float(label='FLOAT'):
"""
returns parser for floating point number
"""
sign = cmb.opt(bp.LParser('-'))
coma = bp.LParser('.')
e = cmb.or_else(bp.LParser('e'), bp.LParser('E'))
exponent = cmb.opt(cmb.and_then(e, parse_integer()))
integer = parse_integer()
return cmb.and_then(sign, cmb.opt(integer), coma, parse_digits(), exponent, label=label)
def test_AddingLabel(self):
# Arrange
parser1 = bpr.LParser('l')
parser2 = bpr.LParser('o')
parser3 = bpr.LParser('r')
parser = cmb.and_then(parser1, parser2, parser3, label='Parser: lor')
parser_default_label = cmb.and_then(parser1, parser2, parser3)
# Assert
self.assertEqual(parser.label, 'Parser: lor')
self.assertEqual(parser_default_label.label, 'lor')
def parse_string(string, label=None):
"""
returns parser of a given string
"""
if not isinstance(string, str):
raise Exception('Expected string')
return cmb.and_then(*[bp.LParser(char) for char in string], label=label)
def test_WhenFirstLettersAreIncorrect_ReturnFailure(self):
# Arrange
txt = 'lorem ipsum'
parser1 = bpr.LParser('l')
parser2 = bpr.LParser('x')
parser3 = bpr.LParser('r')
parser = cmb.and_then(parser1, parser2, parser3)
# Act
result = parser(txt)
expected = res.Failure('error')
# Assert
self.assertEqual(result, expected)
def test_WhenFirstLettersAreCorrect_ReturnSuccess(self):
# Arrange
txt = 'lorem ipsum'
parser1 = bpr.LParser('l')
parser2 = bpr.LParser('o')
parser3 = bpr.LParser('r')
parser = cmb.and_then(parser1, parser2, parser3)
# Act
result = parser(txt)
expected = res.Success(('lor', 'em ipsum'))
# Assert
self.assertEqual(result, expected)
def parse_unsignedinteger(label='UINTEGER'):
"""
returns parser for unsigned integer
"""
digits_09 = parse_digit('0123456789')
digits_19 = parse_character('123456789')
nonzero = cmb.and_then(digits_19, cmb.many(digits_09))
zero = bp.LParser('0')
def internal(txt):
fst_digit = zero(txt)
if fst_digit.isSuccess:
snd = digits_09(fst_digit.value[1])
if snd.isSuccess:
return res.Failure('error')
else:
return fst_digit
return nonzero(txt)
return bp.LParser(internal, label)
def parse_integer(label='INTEGER'):
"""
returns parser for integer
"""
sign = cmb.opt(bp.LParser('-'))
return cmb.and_then(sign, parse_unsignedinteger(), label=label)
