functools: Add functools.total_ordering.

This commit is the result of copying the total_ordering code and tests
over from CPython v3.7.17.
One test is disabled because it expects builtin objects to have
attributes (__lt__, __gt__, etc.).
Another test for compatibility with pickle is also disabled because
pickle compatibility is currently broken.
Bumped package version to 0.0.8.

The functools code in CPython has the following credits:

Written by Nick Coghlan <ncoghlan at gmail.com>,
Raymond Hettinger <python at rcn.com>,
and Łukasz Langa <lukasz at langa.pl>.
  Copyright (C) 2006-2013 Python Software Foundation.
See C source code for _functools credits/copyright

This work was donated by W Winfried Kretzschmar.

Signed-off-by: W Winfried Kretzschmar <winni@warrenwk.com>

python-stdlib/functools/functools.py

@@ -26,3 +26,131 @@ def reduce(function, iterable, initializer=None):
     for element in it:
         value = function(value, element)
     return value
+
+
+################################################################################
+### total_ordering class decorator
+################################################################################
+# Extracted from the CPython v3.7.17 implementation of Lib/functools.py
+#
+# Written by Nick Coghlan <ncoghlan at gmail.com>,
+# Raymond Hettinger <python at rcn.com>,
+# and Łukasz Langa <lukasz at langa.pl>.
+#   Copyright (C) 2006-2013 Python Software Foundation.
+# See C source code for _functools credits/copyright
+
+# The total ordering functions all invoke the root magic method directly
+# rather than using the corresponding operator.  This avoids possible
+# infinite recursion that could occur when the operator dispatch logic
+# detects a NotImplemented result and then calls a reflected method.
+
+def _gt_from_lt(self, other, NotImplemented=NotImplemented):
+    'Return a > b.  Computed by @total_ordering from (not a < b) and (a != b).'
+    op_result = self.__lt__(other)
+    if op_result is NotImplemented:
+        return op_result
+    return not op_result and self != other
+
+def _le_from_lt(self, other, NotImplemented=NotImplemented):
+    'Return a <= b.  Computed by @total_ordering from (a < b) or (a == b).'
+    op_result = self.__lt__(other)
+    return op_result or self == other
+
+def _ge_from_lt(self, other, NotImplemented=NotImplemented):
+    'Return a >= b.  Computed by @total_ordering from (not a < b).'
+    op_result = self.__lt__(other)
+    if op_result is NotImplemented:
+        return op_result
+    return not op_result
+
+def _ge_from_le(self, other, NotImplemented=NotImplemented):
+    'Return a >= b.  Computed by @total_ordering from (not a <= b) or (a == b).'
+    op_result = self.__le__(other)
+    if op_result is NotImplemented:
+        return op_result
+    return not op_result or self == other
+
+def _lt_from_le(self, other, NotImplemented=NotImplemented):
+    'Return a < b.  Computed by @total_ordering from (a <= b) and (a != b).'
+    op_result = self.__le__(other)
+    if op_result is NotImplemented:
+        return op_result
+    return op_result and self != other
+
+def _gt_from_le(self, other, NotImplemented=NotImplemented):
+    'Return a > b.  Computed by @total_ordering from (not a <= b).'
+    op_result = self.__le__(other)
+    if op_result is NotImplemented:
+        return op_result
+    return not op_result
+
+def _lt_from_gt(self, other, NotImplemented=NotImplemented):
+    'Return a < b.  Computed by @total_ordering from (not a > b) and (a != b).'
+    op_result = self.__gt__(other)
+    if op_result is NotImplemented:
+        return op_result
+    return not op_result and self != other
+
+def _ge_from_gt(self, other, NotImplemented=NotImplemented):
+    'Return a >= b.  Computed by @total_ordering from (a > b) or (a == b).'
+    op_result = self.__gt__(other)
+    return op_result or self == other
+
+def _le_from_gt(self, other, NotImplemented=NotImplemented):
+    'Return a <= b.  Computed by @total_ordering from (not a > b).'
+    op_result = self.__gt__(other)
+    if op_result is NotImplemented:
+        return op_result
+    return not op_result
+
+def _le_from_ge(self, other, NotImplemented=NotImplemented):
+    'Return a <= b.  Computed by @total_ordering from (not a >= b) or (a == b).'
+    op_result = self.__ge__(other)
+    if op_result is NotImplemented:
+        return op_result
+    return not op_result or self == other
+
+def _gt_from_ge(self, other, NotImplemented=NotImplemented):
+    'Return a > b.  Computed by @total_ordering from (a >= b) and (a != b).'
+    op_result = self.__ge__(other)
+    if op_result is NotImplemented:
+        return op_result
+    return op_result and self != other
+
+def _lt_from_ge(self, other, NotImplemented=NotImplemented):
+    'Return a < b.  Computed by @total_ordering from (not a >= b).'
+    op_result = self.__ge__(other)
+    if op_result is NotImplemented:
+        return op_result
+    return not op_result
+
+_convert = {
+    '__lt__': [('__gt__', _gt_from_lt),
+               ('__le__', _le_from_lt),
+               ('__ge__', _ge_from_lt)],
+    '__le__': [('__ge__', _ge_from_le),
+               ('__lt__', _lt_from_le),
+               ('__gt__', _gt_from_le)],
+    '__gt__': [('__lt__', _lt_from_gt),
+               ('__ge__', _ge_from_gt),
+               ('__le__', _le_from_gt)],
+    '__ge__': [('__le__', _le_from_ge),
+               ('__gt__', _gt_from_ge),
+               ('__lt__', _lt_from_ge)]
+}
+
+def total_ordering(cls):
+    """Class decorator that fills in missing ordering methods"""
+    # Find user-defined comparisons (not those inherited from object).
+    roots = {op for op in _convert if getattr(cls, op, None) is not getattr(object, op, None)}
+    if not roots:
+        raise ValueError('must define at least one ordering operation: < > <= >=')
+    root = max(roots)       # prefer __lt__ to __le__ to __gt__ to __ge__
+    for opname, opfunc in _convert[root]:
+        if opname not in roots:
+# function objects have no attributes in micropython
+#            opfunc.__name__ = opname
+            setattr(cls, opname, opfunc)
+    return cls
+
+

python-stdlib/functools/manifest.py

@@ -1,3 +1,3 @@
-metadata(version="0.0.7")
+metadata(version="0.0.8")
 
 module("functools.py")

python-stdlib/functools/test_total_ordering.py

@@ -0,0 +1,230 @@
+""" Test code for functools.total_ordering
+
+Copyright © 2001-2023 Python Software Foundation.  All rights reserved.
+
+This code was extracted from CPython v3.7.17 Lib/test/test_functools.py
+"""
+
+import unittest
+
+import functools
+
+class TestTotalOrdering(unittest.TestCase):
+
+    def test_total_ordering_lt(self):
+        @functools.total_ordering
+        class A:
+            def __init__(self, value):
+                self.value = value
+            def __lt__(self, other):
+                return self.value < other.value
+            def __eq__(self, other):
+                return self.value == other.value
+        self.assertTrue(A(1) < A(2))
+        self.assertTrue(A(2) > A(1))
+        self.assertTrue(A(1) <= A(2))
+        self.assertTrue(A(2) >= A(1))
+        self.assertTrue(A(2) <= A(2))
+        self.assertTrue(A(2) >= A(2))
+        self.assertFalse(A(1) > A(2))
+
+    def test_total_ordering_le(self):
+        @functools.total_ordering
+        class A:
+            def __init__(self, value):
+                self.value = value
+            def __le__(self, other):
+                return self.value <= other.value
+            def __eq__(self, other):
+                return self.value == other.value
+        self.assertTrue(A(1) < A(2))
+        self.assertTrue(A(2) > A(1))
+        self.assertTrue(A(1) <= A(2))
+        self.assertTrue(A(2) >= A(1))
+        self.assertTrue(A(2) <= A(2))
+        self.assertTrue(A(2) >= A(2))
+        self.assertFalse(A(1) >= A(2))
+
+    def test_total_ordering_gt(self):
+        @functools.total_ordering
+        class A:
+            def __init__(self, value):
+                self.value = value
+            def __gt__(self, other):
+                return self.value > other.value
+            def __eq__(self, other):
+                return self.value == other.value
+        self.assertTrue(A(1) < A(2))
+        self.assertTrue(A(2) > A(1))
+        self.assertTrue(A(1) <= A(2))
+        self.assertTrue(A(2) >= A(1))
+        self.assertTrue(A(2) <= A(2))
+        self.assertTrue(A(2) >= A(2))
+        self.assertFalse(A(2) < A(1))
+
+    def test_total_ordering_ge(self):
+        @functools.total_ordering
+        class A:
+            def __init__(self, value):
+                self.value = value
+            def __ge__(self, other):
+                return self.value >= other.value
+            def __eq__(self, other):
+                return self.value == other.value
+        self.assertTrue(A(1) < A(2))
+        self.assertTrue(A(2) > A(1))
+        self.assertTrue(A(1) <= A(2))
+        self.assertTrue(A(2) >= A(1))
+        self.assertTrue(A(2) <= A(2))
+        self.assertTrue(A(2) >= A(2))
+        self.assertFalse(A(2) <= A(1))
+
+# This test does not appear to work due to the lack of attributes on builtin types.
+# This appears to lead to the comparison operators not being inherited by default.
+#     def test_total_ordering_no_overwrite(self):
+#         # new methods should not overwrite existing
+#         import sys
+#         @functools.total_ordering
+#         class A(int):
+#             pass
+#         self.assertTrue(A(1) < A(2))
+#         self.assertTrue(A(2) > A(1))
+#         self.assertTrue(A(1) <= A(2))
+#         self.assertTrue(A(2) >= A(1))
+#         self.assertTrue(A(2) <= A(2))
+#         self.assertTrue(A(2) >= A(2))
+
+    def test_no_operations_defined(self):
+        with self.assertRaises(ValueError):
+            @functools.total_ordering
+            class A:
+                pass
+
+    def test_type_error_when_not_implemented(self):
+        # bug 10042; ensure stack overflow does not occur
+        # when decorated types return NotImplemented
+        @functools.total_ordering
+        class ImplementsLessThan:
+            def __init__(self, value):
+                self.value = value
+            def __eq__(self, other):
+                if isinstance(other, ImplementsLessThan):
+                    return self.value == other.value
+                return False
+            def __lt__(self, other):
+                if isinstance(other, ImplementsLessThan):
+                    return self.value < other.value
+                return NotImplemented
+
+        @functools.total_ordering
+        class ImplementsGreaterThan:
+            def __init__(self, value):
+                self.value = value
+            def __eq__(self, other):
+                if isinstance(other, ImplementsGreaterThan):
+                    return self.value == other.value
+                return False
+            def __gt__(self, other):
+                if isinstance(other, ImplementsGreaterThan):
+                    return self.value > other.value
+                return NotImplemented
+
+        @functools.total_ordering
+        class ImplementsLessThanEqualTo:
+            def __init__(self, value):
+                self.value = value
+            def __eq__(self, other):
+                if isinstance(other, ImplementsLessThanEqualTo):
+                    return self.value == other.value
+                return False
+            def __le__(self, other):
+                if isinstance(other, ImplementsLessThanEqualTo):
+                    return self.value <= other.value
+                return NotImplemented
+
+        @functools.total_ordering
+        class ImplementsGreaterThanEqualTo:
+            def __init__(self, value):
+                self.value = value
+            def __eq__(self, other):
+                if isinstance(other, ImplementsGreaterThanEqualTo):
+                    return self.value == other.value
+                return False
+            def __ge__(self, other):
+                if isinstance(other, ImplementsGreaterThanEqualTo):
+                    return self.value >= other.value
+                return NotImplemented
+
+        @functools.total_ordering
+        class ComparatorNotImplemented:
+            def __init__(self, value):
+                self.value = value
+            def __eq__(self, other):
+                if isinstance(other, ComparatorNotImplemented):
+                    return self.value == other.value
+                return False
+            def __lt__(self, other):
+                return NotImplemented
+
+        with self.subTest("LT < 1"), self.assertRaises(TypeError):
+            ImplementsLessThan(-1) < 1
+
+        with self.subTest("LT < LE"), self.assertRaises(TypeError):
+            ImplementsLessThan(0) < ImplementsLessThanEqualTo(0)
+
+        with self.subTest("LT < GT"), self.assertRaises(TypeError):
+            ImplementsLessThan(1) < ImplementsGreaterThan(1)
+
+        with self.subTest("LE <= LT"), self.assertRaises(TypeError):
+            ImplementsLessThanEqualTo(2) <= ImplementsLessThan(2)
+
+        with self.subTest("LE <= GE"), self.assertRaises(TypeError):
+            ImplementsLessThanEqualTo(3) <= ImplementsGreaterThanEqualTo(3)
+
+        with self.subTest("GT > GE"), self.assertRaises(TypeError):
+            ImplementsGreaterThan(4) > ImplementsGreaterThanEqualTo(4)
+
+        with self.subTest("GT > LT"), self.assertRaises(TypeError):
+            ImplementsGreaterThan(5) > ImplementsLessThan(5)
+
+        with self.subTest("GE >= GT"), self.assertRaises(TypeError):
+            ImplementsGreaterThanEqualTo(6) >= ImplementsGreaterThan(6)
+
+        with self.subTest("GE >= LE"), self.assertRaises(TypeError):
+            ImplementsGreaterThanEqualTo(7) >= ImplementsLessThanEqualTo(7)
+
+        with self.subTest("GE when equal"):
+            a = ComparatorNotImplemented(8)
+            b = ComparatorNotImplemented(8)
+            self.assertEqual(a, b)
+            with self.assertRaises(TypeError):
+                a >= b
+
+        with self.subTest("LE when equal"):
+            a = ComparatorNotImplemented(9)
+            b = ComparatorNotImplemented(9)
+            self.assertEqual(a, b)
+            with self.assertRaises(TypeError):
+                a <= b
+
+# Leaving pickle support for a later date
+#    def test_pickle(self):
+#        for proto in range(pickle.HIGHEST_PROTOCOL + 1):
+#            for name in '__lt__', '__gt__', '__le__', '__ge__':
+#                with self.subTest(method=name, proto=proto):
+#                    method = getattr(Orderable_LT, name)
+#                    method_copy = pickle.loads(pickle.dumps(method, proto))
+#                    self.assertIs(method_copy, method)
+
+# @functools.total_ordering
+# class Orderable_LT:
+#     def __init__(self, value):
+#         self.value = value
+#     def __lt__(self, other):
+#         return self.value < other.value
+#     def __eq__(self, other):
+#         return self.value == other.value
+
+if __name__ == "__main__":
+    unittest.main()
+