Mac binaries

[jabaws.git] / website / archive / binaries / mac / src / globplot / biopython-1.50 / Bio / PropertyManager.py

diff --git a/website/archive/binaries/mac/src/globplot/biopython-1.50/Bio/PropertyManager.py b/website/archive/binaries/mac/src/globplot/biopython-1.50/Bio/PropertyManager.py
new file mode 100644 (file)
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+++ b/website/archive/binaries/mac/src/globplot/biopython-1.50/Bio/PropertyManager.py
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+# Stores properties associated with the class of an object.
+
+
+# Would it be nice to have support for more than one resolver per
+# class?  In the meanwhile, they could collude using a dispatch
+# object.
+
+# Do you need access to the actual resolver?
+
+# Resolvers get the sequence because they may do a per-object lookup.
+
+# Could cache search results for better performance.
+
+
+# Dictionary which creates dictionary elements, so lookups never fail.
+# The new elements are always dictionaries.
+class CreateDict(dict):
+    def __getitem__(self, key):
+        return self.setdefault(key,{})
+    
+class PropertyManager:
+    def __init__(self):
+        self.class_property = CreateDict()
+        self.class_property_resolver = CreateDict()
+        self.class_resolver = {}
+
+    def resolve(self, obj, property):
+        try:
+            klass = obj.__class__
+        except AttributeError:
+            raise KeyError("built-in instance")
+        
+        return self.resolve_class(klass, property)
+        
+    def resolve_class(self, klass, property):
+        # Hopefully, we'll find the hit right away
+        try:
+            return self.class_property[klass][property]
+        except KeyError:
+            pass
+
+        # Is there a property resolver?
+        try:
+            return self.class_property_resolver[klass][property](
+                self, klass, property)
+        except KeyError:
+            pass
+
+        # What about the class resolver?
+        try:
+            return self.class_resolver[klass](self, klass, property)
+        except KeyError:
+            pass
+
+        # That failed, so we walk up the class tree, depth-first and
+        # left-to-right (same as Python).  For each class, check if
+        # the property exists, then check if the property resolver
+        # exists, and finally, check for the class resolver.
+
+        bases = list(klass.__bases__)
+        while bases:
+            base = bases.pop()
+            try:
+                return self.class_property[base][property]
+            except KeyError:
+                pass
+            try:
+                return self.class_property_resolver[base][property](
+                    self, klass, property)
+            except KeyError:
+                pass
+            try:
+                return self.class_resolver[base](self, klass, property)
+            except KeyError:
+                pass
+
+            # this is why the search is depth-first/right-left
+            bases[:0] = list(base.__bases__)
+        raise KeyError("cannot find property %s for class %s" \
+                       % (property, klass))
+            
+
+default_manager = PropertyManager()