def zip_(a_it, b_it):
return match(a_it,
("[]", lambda: []),
("a,*b", lambda a, b: \
match(b_it,
("[]", lambda: []),
("c,*d", lambda c, d: [(a,c)] + zip_(b,d)))))
def test_match():
assert match("1", ("'1'", lambda: "one")) == "one"
assert match("whaever", ("_", lambda: "anything")) == "anything"
def sum(*values):
return match(values, ("[]", lambda: 0),
("a, *b", lambda a, b: a + sum(*b)))
def fact(n):
return match(n, ("0", lambda: 1), ("n", lambda n: n * fact(n - 1)))
def map_(cb, it):
return match(it, ("[]", lambda: []),
("a, *b", lambda a, b: [cb(a)] + map_(cb, b)))
def zip_(a_it, b_it):
return match(a_it,
("[]", lambda: []),
("a,*b", lambda a, b: \
match(b_it,
("[]", lambda: []),
("c,*d", lambda c, d: [(a,c)] + zip_(b,d)))))
print(zip_([1, 2, 3], ["a", "b", "c"])) # => [(1, 'a'), (2, 'b'), ...]
class Bar:
bar = 1
class Foo:
bar = Bar()
zar = "hello"
match(
Foo(),
# object destruction
("Foo(zar, bar=Bar(bar=1))", lambda zar: print(f"{zar} pattern match")
),
("_", lambda: print("whaever")))
print(
match((False, False), ("True,_", lambda: f"True ?"),
("False,_", lambda: f"False ?")))
print(sum(1, 2, 3, 4))
print(fact(5))
print(map_(str.upper, ["foo", "bar"]))
from enum import Enum
class E(Enum):
A = 1
B = 2
C = 3
match(
E.B,
("E.A", lambda: print("A")),
("E.B", lambda: print("B")),
("E.C", lambda: print("C")),
)
try:
match(
E.B,
("E.A", lambda: print("A")),
("E.B", lambda: print("B")),
)
except TypeError as e: # because match is not exaustive
print(e)
def fact(n):
return match(n, ("0", lambda: 1), ("n", lambda n: n * fact(n - 1)))
def map_(cb, it):
return match(it, ("[]", lambda: []),
("a, *b", lambda a, b: [cb(a)] + map_(cb, b)))
def sum(*values):
return match(values, ("[]", lambda: 0),
("a, *b", lambda a, b: a + sum(*b)))