match1.py

# This sample tests basic parsing of match statements as
# described in PEP 634.

from typing import Any

value_obj: Any = 4

class Foo:
    x: int


match (1, ):
    case a1, b1 if True:
        pass

    case (a2, b2):
        pass

    case [a3, b3]:
        pass

    case () | []:
        pass

    # This should generate an error because of a missing pattern.
    case :
        pass

    # This should generate an error because it is an irrefutable pattern
    # and is not at the end.
    case (a4):
        pass

    case (a5,):
        pass

    case [a6,]:
        pass

    case a7 as b7, c7 as d7 if True:
        pass

    case (a8, b8, ) as c8 if 1 == 3:
        pass

    case a9, *b8:
        pass

    # This should generate an error because multiple star
    # patterns in a sequence are not allowed.
    case *a10, *b10:
        pass

    # This should generate an error because star
    # patterns cannot be used with "as".
    case *a11 as b11, b12:
        pass

    case value_obj.a, value_obj.b:
        pass

    # This should generate an error because star
    # patterns can't be used with |.
    case (3 as b13) | (4 as b13) | *b13:
        pass

    case *a14, b14:
        pass

    case (a20, (b20,), [c20, *d20]) as e20:
        pass

    case 3 | -3:
        pass

    case 3.2 - 2.1j | -3.2 + 2.1j | 3j:
        pass

    # This should generate an error because the grammar
    # indicates that imaginary number must come second.
    case 2j + 4:
        pass

    # This should generate an error because the grammar
    # indicates that imaginary number must come second.
    case - 2j + 4:
        pass

    case "hi" """hi""" | r"hi" r"""hi""":
        pass

    # This should generate an error because f-strings are
    # not allowed.
    case "hi" f"""hi""":
        pass

    # This should generate an error.
    case {}:
        pass

    case {"a": 3, -3 + 4j: a30, value_obj.a: b30, **c30}:
        pass

    # This should generate an error because only one ** expression
    # can be used.
    case {"a": 3, **a31, "b": -3j, **b31}:
        pass

    # This should generate an error because ** cannot be used with
    # wildcard "_".
    case {"a": 3, **_, "b": -3}:
        pass

    case (3 as x) as y:
        pass

    case int():
        pass

    case Foo(1, a40, value_obj.b as b40, c40=3|-2 + 5j|"hi" as d40, y=[e40, f40] as g40,):
        pass
  
    # This should generate an error because positional arguments
    # cannot appear after keyword arguments.
    case Foo(1, a41, x=3, value_obj.b as b41, c41=3, y=[d41, e41] as f41):
        pass
  
    # This should generate three errors because irrefutable patterns
    # must appear only as the last entry in an or pattern.
    case (_ as x) | x:
        pass

    # This should generate an error because it's an irrefutable pattern
    # but is not the last case statement.
    case _:
        pass

    # This should generate an error because it's an irrefutable pattern
    # but is not the last case statement.
    case (x):
        pass

    case _ if value_obj:
        pass

    # This should generate an error because or patterns must target the
    # same names.
    case 3 | x:
        pass

    case _:
        pass



def func1():
    match = Foo()

    # This should be treated as an expression statement, not a match statement.
    match.x


def func2():
    match = [3]

    # This should be treated as an expression statement, not a match statement.
    match[0]

    match [0]:
        case _:
            pass

def func3():
    def match(a: int): ...

    # This should be treated as a call statement.
    match(0)

    match (0):
        case _:
            pass

def func4():
    match 1, 2, "3":
        case _:
            pass

def func5(match: Any):
    # This should be treated as a list, not a match statement.
    match[2:8, 2:8] = 0


class Point:
    def __init__(self, x: int, y: int) -> None:
        self.x = x
        self.y = y

def func6(subj: Any):
    match subj:
        # This should generate an error because a is used twice in the same pattern.
        case [a, *a]:
            pass
        
        case ([c, d] as f) | ([d, c] as f):
            pass
        
        # This should generate an error because h is used twice in the same pattern.
        case (g, 1 as h) as h:
            pass
        
        # This should generate an error because j is used twice in the same pattern.
        case Point(x=j, y=j):
            pass

def func7():
    match +1:
        case _:
            pass
        
    match -1:
        case _:
            pass

    match ~1:
        case _:
            pass