refactoring

[rrq/rrqmisc.git] / vector / Query.h

diff --git a/vector/Query.h b/vector/Query.h
index 188a1eaae1d0383373cd1b32c8209af689b2a470..4b2fa6a08c335711a7daae02e2840d18b07a6484 100644 (file)
--- a/vector/Query.h
+++ b/vector/Query.h
@@ -1,11 +1,9 @@
 #ifndef Query_H
 #define Query_H
 
-#include <TupleSchema.h>
-#include <Relation.h>
+#include <QueryCallbacks.h>
 #include <BindingTable.h>
-
-struct QueryCallbacks;
+#include <Relation.h>
 
 /**
  * A Query is an implementation of a generic ABI over relations. It's
@@ -18,6 +16,57 @@ typedef struct Query {
     struct QueryCallbacks *def;
 } Query;
 
+/**
+ * \brief Trampoline for the callback function to reclaim the Query
+ * memory for a given Query.
+ *
+ * \param this is the specific \ref Query concerned.
+ *
+ * Ground queries recalim their own state memory. Composite
+ * queries first propagate the reclaim call to its components, and
+ * thereafter reclaim their local state memory.
+ */
+extern void Query_reclaim(Query *this);
+
+/**
+ * \brief Trampoline for the callback function to update the Binding
+ * table with a succession of alternative bindings.
+ *
+ * \param this is the specific \ref Query concerned.
+ *
+ * \param bt is the Binding table to set bindings in.
+ *
+ * \param s is the call "sub-command" for the function.
+ *
+ * \returns 1 if a new Binding is provided and 0 otherwise.
+ *
+ * This function is called repeatedly for successively obtaining
+ * the alternative bindings that satisfy the Query. The "initial"
+ * state sub-command tells the function to capture the incoming
+ * BindingTable state so that the function can later restore it
+ * upon the "restore" sub-command. Upon the "initial" command, the
+ * function also sets up the Binding table with its first Binding
+ * alternative. This is followed by a series of "subsequent"
+ * sub-command calls for the function to change the BindingTable
+ * for its succession of Binding alternatives. The function should
+ * return 1 after any successful Binding setup, and return 0 when
+ * it cannot setup any (more) Binding.
+ */
+extern int Query_next(Query *this,BindingTable *bt,enum NextState state);
+
+/**
+ * \brief Trampoline for the callback function that adds its binding
+ * names to the hashvector.
+ *
+ * \param this is the query concerned.
+ *
+ * \param hv is the HashVector for collating names.
+ */
+extern void Query_variables(Query *this,HashVector *hv);
+
+
+
+
 /**
  * \brief Creates an assignment Query.
  *
@@ -104,9 +153,38 @@ extern Query *Query_or(int n,...);
  * 
  * \related Query
  */
-extern void Query_rule(
+extern void Query_eval(
     Query *q,BindingTable *bt,
     int (*consequent)(BindingTable *bt,void *data),
     void *data );
 
+/**
+ * \brief Collect all bindings of query.
+ *
+ * \param q is the query to enumerate.
+ *
+ * \param names is the binding names to track.
+ *
+ * \param results is the result store of bindings for the names.
+ *
+ * \returns the number of results.
+ *
+ * This function evaluates the query for one round of bindings, and
+ * stores their value \ref Tuple Tuples in the given vector. The given
+ * vector is first cleared, and any item is reclaimed with \b free.
+ * Correspondingly the binding \ref Tuple Tuples are allocated with \b
+ * malloc for the caller to reclaim (possibly via a successive call to
+ * this function).
+ */
+//extern int Query_snapshot(Query *q,Tuple *names,Vector *v);
+
+/**
+ * \brief Creates an NotQuery.
+ *
+ * \param query is the query to negate.
+ *
+ * \related Query
+ */
+extern Query *Query_not(Query *values);
+
 #endif