Only compute indexation ZSQLMethod parameter values when accessed.

Several ZSQLMethods do tests on parameter values, causing other parameter
values to be discarded (ie not indexed). A pseudo-code example is
  if isMovement[x]:
    append(getPrice[x])

product/ZSQLCatalog/SQLCatalog.py

@@ -22,6 +22,7 @@ from App.special_dtml import DTMLFile
 from thread import allocate_lock, get_ident
 from OFS.Folder import Folder
 from AccessControl import ClassSecurityInfo
+from AccessControl.SimpleObjectPolicies import ContainerAssertions
 from BTrees.OIBTree import OIBTree
 from App.config import getConfiguration
 from BTrees.Length import Length
@@ -244,6 +245,50 @@ class DummyDict(dict):
   def __setitem__(self, key, value):
     pass
 
+class LazyIndexationParameterList(tuple):
+  def __new__(cls, document_list, attribute, global_cache):
+    self = super(LazyIndexationParameterList, cls).__new__(cls)
+    self._document_list = document_list
+    self._attribute = attribute
+    self._global_cache = global_cache
+    return self
+
+  def __getitem__(self, index):
+    document = self._document_list[index]
+    attribute = self._attribute
+    global_cache_key = (document.uid, attribute)
+    global_cache = self._global_cache
+    if global_cache_key in global_cache:
+      value = global_cache[global_cache_key]
+    else:
+      value = getattr(document, attribute, None)
+      if callable(value):
+        try:
+          value = value()
+        except ConflictError:
+          raise
+        except Exception:
+          LOG('SQLCatalog', WARNING,
+            'Failed to call method %s on %r' % (attribute, document),
+            error=True,
+          )
+          value = None
+      global_cache[global_cache_key] = value
+    return value
+
+  def __iter__(self):
+    for index in xrange(len(self)):
+      yield self[index]
+
+  def __len__(self):
+    return len(self._document_list)
+
+  def __repr__(self):
+    return '<%s(%i documents, %r) at %x>' % (self.__class__.__name__,
+      len(self), self._attribute, id(self))
+
+ContainerAssertions[LazyIndexationParameterList] = 1
+
 related_key_definition_cache = {}
 related_key_warned_column_set = set()
 
@@ -1634,28 +1679,12 @@ class Catalog(Folder,
             method.func_code.co_varnames[:method.func_code.co_argcount]
         else:
           arguments = []
-        kw = {}
-        for arg in arguments:
-          value_list = []
-          append = value_list.append
-          for object in catalogged_object_list:
-            argument_cache_key = (object.uid, arg)
-            try:
-              value = argument_cache[argument_cache_key]
-            except KeyError:
-              try:
-                value = getattr(object, arg, None)
-                if callable(value):
-                  value = value()
-              except ConflictError:
-                raise
-              except:
-                LOG('SQLCatalog', WARNING, 'Failed to call method %s on %r' %
-                    (arg, object), error=sys.exc_info())
-                value = None
-              argument_cache[argument_cache_key] = value
-            append(value)
-          kw[arg] = value_list
+        kw = dict(
+          (x, LazyIndexationParameterList(
+            catalogged_object_list,
+            x,
+            argument_cache,
+          )) for x in arguments)
 
         # Alter/Create row
         try: