[Zope-CVS] CVS: Packages/pypes/pypes - query.py:1.18

[Casey Duncan]

Update of /cvs-repository/Packages/pypes/pypes
In directory cvs.zope.org:/tmp/cvs-serv14937

Modified Files:
	query.py 
Log Message:
Rewrite module docstring


=== Packages/pypes/pypes/query.py 1.17 => 1.18 ===
--- Packages/pypes/pypes/query.py:1.17	Mon May 31 23:05:48 2004
+++ Packages/pypes/pypes/query.py	Wed Jun  9 22:38:38 2004
@@ -13,35 +13,30 @@
 ##############################################################################
 """Pypes declarative object queries
 
-Queries consist of inputs and operations. Operations denote query search
-criteria  and output format. When executed, queries return a result which is
-the output of the query operations applied in succession to the inputs.
-
 Inputs for queries are collections of identified persistent objects in the
-database, e.g. sets, extents or query results. The inputs define the maximal
-extent of the query; the objects which will be considered by the operations.
-Queries results cannot contain objects that do not appear in the inputs, other
-than None.
+database, e.g. identity sets, extents. The inputs define the maximal
+extent of the query; the objects which will be considered during the query.
+Queries results can only contain objects that appear in the inputs.
 
-Each input must provide a name, or have a name provided for it. These names can
-be used by operations to refer to members of the cooresponding input
-collection.
+Each input must provide a name,  either via an __name__ attribute or an alias
+in the query itself. An input's name can be used in expressions to refer to 
+its members, much like a table name in a SQL query.
 
-Operations define the semantics of the query; the process performed on the
-inputs to derive the results. Operations are typically of the following kinds:
+Queries are defined by the following characteristics:
     
-  filter -- filters determine which objects occur in the results.
-  
-  join -- joins determine how members of multiple input collections are 
-          combined.
-  
-  sort -- sorts determine the order of the results.
+  inputs -- The objects to be considered by the query.
+
+  criteria -- An expression which determines the objects from the inputs will 
+              occur in the results, and in what arrangement (i.e., joins).
   
-  projection -- projections determines how the the result values are derived.
+  order -- Expressions which determine the order of the results when iterated.
   
 Operations are typically declared using Python expression strings. These
 expressions describe the operation's behavior by using the query inputs 
 and other objects provided by the calling program.
+
+Queries are processed using partial result objects. See query-engine.txt for
+more details.
 
 $Id$"""