From e4f1172a56a9b44ef787b2e3b422e2d5f4d02146 Mon Sep 17 00:00:00 2001
From: Andreas Kloeckner <inform@tiker.net>
Date: Wed, 1 Jul 2009 14:05:20 -0400
Subject: [PATCH] Add CSECachingMapperMixin. Use it to reduce complexity of
several mappers.
---
pymbolic/mapper/__init__.py | 18 +++++++++++++++++
pymbolic/mapper/constant_folder.py | 32 +++++++++++++++++++++++-------
pymbolic/mapper/dependency.py | 6 +++---
pymbolic/primitives.py | 2 +-
4 files changed, 47 insertions(+), 11 deletions(-)
diff --git a/pymbolic/mapper/__init__.py b/pymbolic/mapper/__init__.py
index c549938..e4f1dc1 100644
--- a/pymbolic/mapper/__init__.py
+++ b/pymbolic/mapper/__init__.py
@@ -210,3 +210,21 @@ class IdentityMapper(IdentityMapperBase, RecursiveMapper):
class NonrecursiveIdentityMapper(IdentityMapperBase, Mapper):
pass
+
+
+
+
+class CSECachingMapperMixin(object):
+ def map_common_subexpression(self, expr):
+ try:
+ ccd = self._cse_cache_dict
+ except AttributeError:
+ from weakref import WeakKeyDictionary
+ ccd = self._cse_cache_dict = WeakKeyDictionary()
+
+ try:
+ return ccd[expr]
+ except KeyError:
+ result = self.map_common_subexpression_uncached(expr)
+ ccd[expr] = result
+ return result
diff --git a/pymbolic/mapper/constant_folder.py b/pymbolic/mapper/constant_folder.py
index 680375f..8e6cf07 100644
--- a/pymbolic/mapper/constant_folder.py
+++ b/pymbolic/mapper/constant_folder.py
@@ -1,4 +1,7 @@
-from pymbolic.mapper import IdentityMapper, NonrecursiveIdentityMapper
+from pymbolic.mapper import \
+ IdentityMapper, \
+ NonrecursiveIdentityMapper, \
+ CSECachingMapperMixin
@@ -61,20 +64,35 @@ class CommutativeConstantFoldingMapperBase(ConstantFoldingMapperBase):
-class ConstantFoldingMapper(ConstantFoldingMapperBase, IdentityMapper):
- pass
+class ConstantFoldingMapper(
+ CSECachingMapperMixin,
+ ConstantFoldingMapperBase,
+ IdentityMapper):
+
+ map_common_subexpression_uncached = \
+ IdentityMapper.map_common_subexpression
class NonrecursiveConstantFoldingMapper(
+ CSECachingMapperMixin,
NonrecursiveIdentityMapper,
ConstantFoldingMapperBase):
- pass
-class CommutativeConstantFoldingMapper(CommutativeConstantFoldingMapperBase,
+ map_common_subexpression_uncached = \
+ NonrecursiveIdentityMapper.map_common_subexpression
+
+class CommutativeConstantFoldingMapper(
+ CSECachingMapperMixin,
+ CommutativeConstantFoldingMapperBase,
IdentityMapper):
- pass
+
+ map_common_subexpression_uncached = \
+ IdentityMapper.map_common_subexpression
class NonrecursiveCommutativeConstantFoldingMapper(
+ CSECachingMapperMixin,
CommutativeConstantFoldingMapperBase,
NonrecursiveIdentityMapper,):
- pass
+
+ map_common_subexpression_uncached = \
+ NonrecursiveIdentityMapper.map_common_subexpression
diff --git a/pymbolic/mapper/dependency.py b/pymbolic/mapper/dependency.py
index e299c00..832cf53 100644
--- a/pymbolic/mapper/dependency.py
+++ b/pymbolic/mapper/dependency.py
@@ -1,9 +1,9 @@
-from pymbolic.mapper import CombineMapper
+from pymbolic.mapper import CombineMapper, CSECachingMapperMixin
-class DependencyMapper(CombineMapper):
+class DependencyMapper(CSECachingMapperMixin, CombineMapper):
def __init__(self,
include_subscripts=True,
include_lookups=True,
@@ -62,7 +62,7 @@ class DependencyMapper(CombineMapper):
else:
return CombineMapper.map_subscript(self, expr)
- def map_common_subexpression(self, expr):
+ def map_common_subexpression_uncached(self, expr):
if self.include_cses:
return set([expr])
else:
diff --git a/pymbolic/primitives.py b/pymbolic/primitives.py
index 7a654f1..64bd06f 100644
--- a/pymbolic/primitives.py
+++ b/pymbolic/primitives.py
@@ -156,7 +156,7 @@ class Expression(object):
Subclasses should generally not override this method, but instead
provide an implementation of L{is_equal}.
"""
- if id(self) == id(other):
+ if self is other:
return True
elif hash(self) != hash(other):
return False
--
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