function XDATE.WKDAY (date >= DAY_S) = calendar_offset_to_wday (date / DAY_S);
function XDATE.YEAR (date >= DAY_S) = calendar_offset_to_year (date / DAY_S);
+// Date arithmetic functions.
+function DATEDIFF (date1, date2, string unit) = unimplemented;
+function DATESUM (date, quantity, string unit) = unimplemented;
+function DATESUM (date, quantity, string unit, string roll_over)
+ = unimplemented;
+
// String functions.
string function CONCAT (string a[n])
expression e;
return empty_string;
}
+absorb_miss no_opt string function VALUELABEL (var v)
+ expression e;
+ case c;
+{
+ const char *label = var_lookup_value_label (v, case_data (c, v));
+ if (label != NULL)
+ return copy_string (e, label, strlen (label));
+ else
+ return empty_string;
+}
+
// Artificial.
operator SQUARE (x) = x * x;
boolean operator NUM_TO_BOOLEAN (x)