#include "helpers.h"
#include <gsl/gsl_roots.h>
#include <gsl/gsl_sf.h>
+#include <libpspp/assertion.h>
#include <libpspp/pool.h>
#include "private.h"
return expr_ymd_to_ofs (year, month, day);
}
+\f
+/* A date unit. */
+enum date_unit
+ {
+ DATE_YEARS,
+ DATE_QUARTERS,
+ DATE_MONTHS,
+ DATE_WEEKS,
+ DATE_DAYS,
+ DATE_HOURS,
+ DATE_MINUTES,
+ DATE_SECONDS
+ };
+
+#ifndef HAVE_TRUNC
+/* Return X rounded toward zero. */
+static double
+trunc (double x)
+{
+ return x >= 0.0 ? floor (x) : ceil (x);
+}
+#endif /* !HAVE_TRUNC */
+
+/* Stores in *UNIT the unit whose name is NAME.
+ Return success. */
+static enum date_unit
+recognize_unit (struct substring name, enum date_unit *unit)
+{
+ struct unit_name
+ {
+ enum date_unit unit;
+ const struct substring name;
+ };
+ static const struct unit_name unit_names[] =
+ {
+ { DATE_YEARS, SS_LITERAL_INITIALIZER ("years") },
+ { DATE_QUARTERS, SS_LITERAL_INITIALIZER ("quarters") },
+ { DATE_MONTHS, SS_LITERAL_INITIALIZER ("months") },
+ { DATE_WEEKS, SS_LITERAL_INITIALIZER ("weeks") },
+ { DATE_DAYS, SS_LITERAL_INITIALIZER ("days") },
+ { DATE_HOURS, SS_LITERAL_INITIALIZER ("hours") },
+ { DATE_MINUTES, SS_LITERAL_INITIALIZER ("minutes") },
+ { DATE_SECONDS, SS_LITERAL_INITIALIZER ("seconds") },
+ };
+ const int unit_name_cnt = sizeof unit_names / sizeof *unit_names;
+
+ const struct unit_name *un;
+
+ for (un = unit_names; un < &unit_names[unit_name_cnt]; un++)
+ if (ss_equals_case (un->name, name))
+ {
+ *unit = un->unit;
+ return true;
+ }
+
+ msg (SE, _("Unrecognized date unit \"%.*s\". "
+ "Valid date units are \"years\", \"quarters\", \"months\", "
+ "\"weeks\", \"days\", \"hours\", \"minutes\", and \"seconds\"."),
+ (int) ss_length (name), ss_data (name));
+ return false;
+}
+
+/* Returns the number of whole years from DATE1 to DATE2,
+ where a year is defined as the same or later month, day, and
+ time of day. */
+static int
+year_diff (double date1, double date2)
+{
+ int y1, m1, d1, yd1;
+ int y2, m2, d2, yd2;
+ int diff;
+
+ assert (date2 >= date1);
+ calendar_offset_to_gregorian (date1 / DAY_S, &y1, &m1, &d1, &yd1);
+ calendar_offset_to_gregorian (date2 / DAY_S, &y2, &m2, &d2, &yd2);
+
+ diff = y2 - y1;
+ if (diff > 0)
+ {
+ int yd1 = 32 * m1 + d1;
+ int yd2 = 32 * m2 + d2;
+ if (yd2 < yd1
+ || (yd2 == yd1 && fmod (date2, DAY_S) < fmod (date1, DAY_S)))
+ diff--;
+ }
+ return diff;
+}
+
+/* Returns the number of whole months from DATE1 to DATE2,
+ where a month is defined as the same or later day and time of
+ day. */
+static int
+month_diff (double date1, double date2)
+{
+ int y1, m1, d1, yd1;
+ int y2, m2, d2, yd2;
+ int diff;
+
+ assert (date2 >= date1);
+ calendar_offset_to_gregorian (date1 / DAY_S, &y1, &m1, &d1, &yd1);
+ calendar_offset_to_gregorian (date2 / DAY_S, &y2, &m2, &d2, &yd2);
+
+ diff = ((y2 * 12) + m2) - ((y1 * 12) + m1);
+ if (diff > 0
+ && (d2 < d1
+ || (d2 == d1 && fmod (date2, DAY_S) < fmod (date1, DAY_S))))
+ diff--;
+ return diff;
+}
+
+/* Returns the number of whole quarter from DATE1 to DATE2,
+ where a quarter is defined as three months. */
+static int
+quarter_diff (double date1, double date2)
+{
+ return month_diff (date1, date2) / 3;
+}
+
+/* Returns the number of seconds in the given UNIT. */
+static int
+date_unit_duration (enum date_unit unit)
+{
+ switch (unit)
+ {
+ case DATE_WEEKS:
+ return WEEK_S;
+
+ case DATE_DAYS:
+ return DAY_S;
+
+ case DATE_HOURS:
+ return H_S;
+
+ case DATE_MINUTES:
+ return MIN_S;
+
+ case DATE_SECONDS:
+ return 1;
+
+ default:
+ NOT_REACHED ();
+ }
+}
+
+/* Returns the span from DATE to DATE2 in terms of UNIT_NAME. */
+double
+expr_date_difference (double date1, double date2, struct substring unit_name)
+{
+ enum date_unit unit;
+
+ if (!recognize_unit (unit_name, &unit))
+ return SYSMIS;
+
+ switch (unit)
+ {
+ case DATE_YEARS:
+ return (date2 >= date1
+ ? year_diff (date1, date2)
+ : -year_diff (date2, date1));
+
+ case DATE_QUARTERS:
+ return (date2 >= date1
+ ? quarter_diff (date1, date2)
+ : -quarter_diff (date2, date1));
+
+ case DATE_MONTHS:
+ return (date2 >= date1
+ ? month_diff (date1, date2)
+ : -month_diff (date2, date1));
+
+ case DATE_WEEKS:
+ case DATE_DAYS:
+ case DATE_HOURS:
+ case DATE_MINUTES:
+ case DATE_SECONDS:
+ return trunc ((date2 - date1) / date_unit_duration (unit));
+ }
+
+ NOT_REACHED ();
+}
+
+/* How to deal with days out of range for a given month. */
+enum date_sum_method
+ {
+ SUM_ROLLOVER, /* Roll them over to the next month. */
+ SUM_CLOSEST /* Use the last day of the month. */
+ };
+
+/* Stores in *METHOD the method whose name is NAME.
+ Return success. */
+static bool
+recognize_method (struct substring method_name, enum date_sum_method *method)
+{
+ if (ss_equals_case (method_name, ss_cstr ("closest")))
+ {
+ *method = SUM_CLOSEST;
+ return true;
+ }
+ else if (ss_equals_case (method_name, ss_cstr ("rollover")))
+ {
+ *method = SUM_ROLLOVER;
+ return true;
+ }
+ else
+ {
+ msg (SE, _("Invalid DATESUM method. "
+ "Valid choices are \"closest\" and \"rollover\"."));
+ return false;
+ }
+}
+
+/* Returns DATE advanced by the given number of MONTHS, with
+ day-of-month overflow resolved using METHOD. */
+static double
+add_months (double date, int months, enum date_sum_method method)
+{
+ int y, m, d, yd;
+ double output;
+
+ calendar_offset_to_gregorian (date / DAY_S, &y, &m, &d, &yd);
+ y += months / 12;
+ m += months % 12;
+ if (m < 1)
+ {
+ m += 12;
+ y--;
+ }
+ else if (m > 12)
+ {
+ m -= 12;
+ y++;
+ }
+ assert (m >= 1 && m <= 12);
+
+ if (method == SUM_CLOSEST && d > calendar_days_in_month (y, m))
+ d = calendar_days_in_month (y, m);
+
+ output = calendar_gregorian_to_offset (y, m, d, expr_error, NULL);
+ if (output != SYSMIS)
+ output = (output * DAY_S) + fmod (date, DAY_S);
+ return output;
+}
+
+/* Returns DATE advanced by the given QUANTITY of units given in
+ UNIT_NAME, with day-of-month overflow resolved using
+ METHOD_NAME. */
+double
+expr_date_sum (double date, double quantity, struct substring unit_name,
+ struct substring method_name)
+{
+ enum date_unit unit;
+ enum date_sum_method method;
+
+ if (!recognize_unit (unit_name, &unit)
+ || !recognize_method (method_name, &method))
+ return SYSMIS;
+
+ switch (unit)
+ {
+ case DATE_YEARS:
+ return add_months (date, trunc (quantity) * 12, method);
+
+ case DATE_QUARTERS:
+ return add_months (date, trunc (quantity) * 3, method);
+
+ case DATE_MONTHS:
+ return add_months (date, trunc (quantity), method);
+
+ case DATE_WEEKS:
+ case DATE_DAYS:
+ case DATE_HOURS:
+ case DATE_MINUTES:
+ case DATE_SECONDS:
+ return date + quantity * date_unit_duration (unit);
+ }
+
+ NOT_REACHED ();
+}
int
compare_string (const struct substring *a, const struct substring *b)
projects / pspp-builds.git / blobdiff