Implement DATESUM, DATEDIFF functions.

[pspp-builds.git] / src / language / expressions / helpers.h

diff --git a/src/language/expressions/helpers.h b/src/language/expressions/helpers.h
index f5cfb67b65d5dae1f912b023571e3c1650a20e1a..b8fadc9d245daee3353660d15ec633751f929549 100644 (file)
--- a/src/language/expressions/helpers.h
+++ b/src/language/expressions/helpers.h
@@ -13,12 +13,15 @@
 #include <data/calendar.h>
 #include <data/case.h>
 #include <data/data-in.h>
+#include <data/data-out.h>
 #include <data/dictionary.h>
 #include <data/procedure.h>
 #include <data/settings.h>
 #include <data/value.h>
 #include <data/variable.h>
+#include <data/vector.h>
 #include <gsl-extras/gsl-extras.h>
+#include <language/expressions/public.h>
 #include <libpspp/compiler.h>
 #include <libpspp/message.h>
 #include <libpspp/misc.h>
@@ -42,20 +45,25 @@ static inline double check_errno (double x)
 #define H_MIN 60.                       /* Minutes per hour. */
 #define MIN_S 60.                       /* Seconds per minute. */
 #define WEEK_DAY 7.                     /* Days per week. */
+#define WEEK_S (WEEK_DAY * DAY_S)       /* Seconds per week. */
 
-extern const struct fixed_string empty_string;
+extern const struct substring empty_string;
 
-int compare_string (const struct fixed_string *, const struct fixed_string *);
+int compare_string (const struct substring *, const struct substring *);
 
 double expr_ymd_to_date (double year, double month, double day);
 double expr_ymd_to_ofs (double year, double month, double day);
 double expr_wkyr_to_date (double wk, double yr);
 double expr_yrday_to_date (double yr, double day);
 double expr_yrmoda (double year, double month, double day);
-
-struct fixed_string alloc_string (struct expression *, size_t length);
-struct fixed_string copy_string (struct expression *,
-                                 const char *, size_t length);
+double expr_date_difference (double date1, double date2,
+                             struct substring unit);
+double expr_date_sum (double date, double quantity, struct substring unit_name,
+                      struct substring method_name);
+
+struct substring alloc_string (struct expression *, size_t length);
+struct substring copy_string (struct expression *,
+                              const char *, size_t length);
 
 static inline bool
 is_valid (double d)