spatialtime

// This snippet demonstrates Golang formatting and parsing of ISO 8601 weeks.

import (
	"errors"
	"fmt"
	"regexp"
	"strconv"
	"time"
)

spatialtime

// This snippet demonstrates Golang formatting and parsing of
// ISO 8601 ordinal dates (4-digit year + "-" + ordinal day).
// Note: an ordinal day in this context is the nth day of
// the year, with Jan 1 being ordinal day 1 and Dec 31
// of non-leap year (a "common year") being day 365.

import (
	"time"
)

spatialtime

CREATE OR REPLACE FUNCTION parse_isoweek(isostring_in STRING) RETURN DATE 
IS 
  l_year_start DATE;
  l_year VARCHAR2(4);
  l_week VARCHAR2(2);
  l_day VARCHAR2(1);
  l_date DATE;

  --c_pattern allows for 'YYYY-Www' and 'YYYY-Www-d' formats.
  c_pattern CONSTANT VARCHAR2(33) := '^(\d{4})-W([0-5]\d)((-)([1-7]))?$';

spatialtime

CREATE OR REPLACE FUNCTION format_iso_dsinterval(interval_in INTERVAL DAY TO SECOND) RETURN VARCHAR2
IS 
  --max value ever would be 'P999999999DT59H59M59.999999999S', a 31-char string 
  l_iso VARCHAR2(31) := 'P';
  l_day NUMBER;
  l_hour NUMBER; 
  l_minute NUMBER;
  l_second NUMBER;
  
BEGIN

spatialtime

CREATE OR REPLACE FUNCTION format_iso_yminterval(interval_in INTERVAL YEAR TO MONTH) RETURN VARCHAR2
IS 
  iso_out VARCHAR2(14) := 'P';
  year NUMBER;
  month NUMBER;
  
BEGIN
    year := EXTRACT(YEAR FROM interval_in);
  IF year <> 0 THEN 
     iso_out := iso_out || year || 'Y';