From 36af97d97ab944b7a049ef83843152111db0ae22 Mon Sep 17 00:00:00 2001
From: Andreas Kloeckner <inform@tiker.net>
Date: Mon, 31 Oct 2022 12:33:58 -0500
Subject: [PATCH] Support PEP634-style pattern matching
---
.github/workflows/ci.yml | 5 +++-
pymbolic/primitives.py | 10 ++++++++
test/test_pattern_match.py | 51 ++++++++++++++++++++++++++++++++++++++
3 files changed, 65 insertions(+), 1 deletion(-)
create mode 100644 test/test_pattern_match.py
diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index ef12827..02e7785 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -23,6 +23,8 @@ jobs:
- name: "Main Script"
run: |
curl -L -O https://gitlab.tiker.net/inducer/ci-support/raw/main/prepare-and-run-flake8.sh
+ # FIXME Remove when we're upgrading to Python 3.10.
+ rm test/test_pattern_match.py
. ./prepare-and-run-flake8.sh pymbolic test experiments
pylint:
@@ -69,8 +71,9 @@ jobs:
# https://github.com/inducer/pymbolic/pull/66#issuecomment-950371315
pip install symengine || true
- test_py_project
+ python3 -c 'import sys, os; sys.exit(not sys.version_info < (3, 10))' && rm test/test_pattern_match.py
+ test_py_project
docs:
name: Documentation
diff --git a/pymbolic/primitives.py b/pymbolic/primitives.py
index 5ad5eb0..f5d7280 100644
--- a/pymbolic/primitives.py
+++ b/pymbolic/primitives.py
@@ -187,6 +187,11 @@ class Expression(ABC):
Expression objects are immutable.
+ .. versionchanged:: 2022.2
+
+ `PEP 634 <https://peps.python.org/pep-0634/>`__-style pattern matching
+ is now supported when Pymbolic is used under Python 3.10.
+
.. attribute:: a
.. attribute:: attr
@@ -231,6 +236,11 @@ class Expression(ABC):
def __getinitargs__(self):
pass
+ @classmethod
+ @property
+ def __match_args__(cls):
+ return cls.init_arg_names
+
@property
def init_arg_names(self):
raise NotImplementedError
diff --git a/test/test_pattern_match.py b/test/test_pattern_match.py
new file mode 100644
index 0000000..a28392d
--- /dev/null
+++ b/test/test_pattern_match.py
@@ -0,0 +1,51 @@
+__copyright__ = "Copyright (C) 2022 University of Illinois Board of Trustees"
+
+__license__ = """
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in
+all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+THE SOFTWARE.
+"""
+
+import pymbolic.primitives as p
+
+
+def test_pattern_match():
+ from pymbolic import var
+
+ x = var("x")
+ xp1 = (x+1)
+ u = xp1**5 + x
+
+ match u:
+ case p.Sum((p.Power(base, exp), other_term)):
+ assert base is xp1
+ assert exp == 5
+ assert other_term is x
+
+ case _:
+ raise AssertionError()
+
+
+if __name__ == "__main__":
+ import sys
+ if len(sys.argv) > 1:
+ exec(sys.argv[1])
+ else:
+ from pytest import main
+ main([__file__])
+
+# vim: fdm=marker
--
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