/* PSPP - a program for statistical analysis.
- Copyright (C) 2009 Free Software Foundation, Inc.
+ Copyright (C) 2011 Free Software Foundation, Inc.
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>. */
-#ifndef INTERACTION_H
-#define INTERACTION_H
-struct interaction_variable;
-struct interaction_value;
-struct interaction_variable * interaction_variable_create (const struct variable **, int);
-void interaction_variable_destroy (struct interaction_variable *);
-struct interaction_value * interaction_value_create (const struct interaction_variable *, const union value **);
-void interaction_value_destroy (struct interaction_value *);
-size_t interaction_variable_get_n_vars (const struct interaction_variable *);
+#ifndef _INTERACTION_H__
+#define _INTERACTION_H__ 1
+
+#include <stdbool.h>
+#include "libpspp/compiler.h"
+#include "data/missing-values.h"
+
+struct ccase;
+struct interaction;
+struct string;
+struct variable;
+
+#include <stddef.h>
+
+/* An interaction is a structure containing a "product" of other variables.
+ The variables can be either string or numeric.
+
+ Interaction is commutative. That means, that from a mathematical point of
+ view, the order of the variables is irrelevant. However, for display
+ purposes, and for matching with an interaction's value the order is
+ pertinent. Therefore, when using these functions, make sure the orders of
+ variables and values match when appropriate.
+
+ Some functions for interactions will not work properly for interactions that
+ contain a given variable more than once, so this should be regarded as an
+ invariant. The functions to modify interactions don't check for this
+ invariant. */
+struct interaction
+ {
+ const struct variable **vars;
+ size_t n_vars;
+ };
+
+struct interaction *interaction_create (const struct variable *);
+struct interaction *interaction_clone (const struct interaction *);
+void interaction_destroy (struct interaction *);
+void interaction_add_variable (struct interaction *, const struct variable *);
+void interaction_dump (const struct interaction *);
+void interaction_to_string (const struct interaction *, struct string *str);
+bool interaction_is_proper_subset (const struct interaction *,
+ const struct interaction *);
+bool interaction_is_subset (const struct interaction *,
+ const struct interaction *);
+
+
+unsigned int interaction_case_hash (const struct interaction *,
+ const struct ccase *,
+ unsigned int base) WARN_UNUSED_RESULT;
+bool interaction_case_equal (const struct interaction *, const struct ccase *,
+ const struct ccase *);
+bool interaction_case_is_missing (const struct interaction *,
+ const struct ccase *, enum mv_class);
+int interaction_case_cmp_3way (const struct interaction *,
+ const struct ccase *, const struct ccase *);
#endif