gh-106246: Allow the use of unions as match patterns #118525
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| @@ -3361,6 +3370,31 @@ class A: | |||
| w = 0 | |||
| self.assertIsNone(w) | |||
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| def test_union_type_postional_subpattern(self): | |||
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english is not my mother tongue, but postional must not to be replaced by positional?
| @@ -3,6 +3,7 @@ | |||
| import dataclasses | |||
| import enum | |||
| import inspect | |||
| from re import I | |||
| x = 0 | ||
| match x: | ||
| case IntOrStr(): | ||
| x = 1 |
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Add a test that involves a union that does not match.
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Please rename the title to use gh-106246. |
| @@ -470,6 +471,16 @@ _PyEval_MatchClass(PyThreadState *tstate, PyObject *subject, PyObject *type, | |||
| if (PyObject_IsInstance(subject, type) <= 0) { | |||
| return NULL; | |||
| } | |||
| // Subpatterns are not supported for union types: | |||
| if (_PyUnion_Check(type)) { | |||
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I don't like the fact that we call _PyUnion_Check(type) twice for no real reason.
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Could we save the result in a variable? Or would it cleaner to handle unions first?
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Is there any particular reason for disallowing subpatterns? The case for matching a union in the first place is typically because they share some relevant interface or attribute. For example: FuncDef = ast.FunctionDef | ast.AsyncFunctionDef
match node:
case FuncDef(name=name, body=body):
...instead of match node:
case ast.FunctionDef(name=name, body=body) | ast.AsyncFunctionDef(name=name, body=body):
... |
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@sobolevn @JelleZijlstra @sylvainmouquet @tmke8 I pushed a variant of this pull request that addresses the raised issues and also support subpatterns #118644. |
This didn't require many code changes. Though I'm not entirely sure about code style and whether I added enough tests.