def test_fizzbuzz_with_Writer():
pairs = ((3, 'fizz'), (5, 'buzz'))
def fizzer(n, pairs):
fizzed = ''.join([b for f, b in pairs if n and not n % f]) or n
return Writer(n + 1, {n: fizzed})
fizzers = [lambda n: fizzer(n, pairs)] * 15
fizzbuzzed = multibind(Writer.unit(1), *fizzers)
assert fizzbuzzed.v == (16, {
1: 1,
2: 2,
3: 'fizz',
4: 4,
5: 'buzz',
6: 'fizz',
7: 7,
8: 8,
9: 'fizz',
10: 'buzz',
11: 11,
12: 'fizz',
13: 13,
14: 14,
15: 'fizzbuzz'
})
def fizzer(n, pairs):
fizzed = ''.join([b for f, b in pairs if n and not n % f]) or n
return Writer(n + 1, {n: fizzed})
def test_writer_bind():
w = Writer.unit(2) >> m_add_two
assert w.v == (4, List.unit('added two'))
def test_writer_dict_updates_multiple_times():
w = Writer.unit(4) >> dict_add_two >> dict_div_two
assert w.v == (3, {'added': 2, 'divided': 2})
def test_writer_apply():
w = (Writer.unit(add_two)) * (Writer.unit(2))
assert w.v == (4, Mempty)
def test_writer_fmap():
w = Writer.unit(2).fmap(add_two)
assert w.v == (4, Mempty)
def test_fmap_id():
w = Writer.unit(2).fmap(identity)
assert w.v == (2, Mempty)
def test_writer_unit():
w = Writer.unit(2)
assert w.v == (2, Mempty)
from pynads import Writer, Mempty, List
from pynads.funcs import identity, multibind
import pytest
add_two = lambda x: x + 2
m_add_two = lambda x: Writer(x + 2, List.unit('added two'))
str_add_two = lambda x: Writer(add_two(x), ' added two')
int_add_two = lambda x: Writer(add_two(x), 4)
dict_add_two = lambda x: Writer(add_two(x), {'added': 2})
dict_div_two = lambda x: Writer(x // 2, {'divided': 2})
def test_writer_unit():
w = Writer.unit(2)
assert w.v == (2, Mempty)
def test_fmap_id():
w = Writer.unit(2).fmap(identity)
assert w.v == (2, Mempty)
def test_writer_fmap():
w = Writer.unit(2).fmap(add_two)
assert w.v == (4, Mempty)
def test_writer_apply():
w = (Writer.unit(add_two)) * (Writer.unit(2))
assert w.v == (4, Mempty)