commit d25645eef01a73b83e77bfb2f3d777833676140e
parent 928f2c7ad3e8daa66e513293567f2e7490d01290
Author: Byron Torres <b@torresjrjr.com>
Date: Tue, 9 Apr 2024 20:48:42 +0100
time::date: implement zflag in realize()
Diffstat:
| M | time/date/virtual.ha | | | 199 | +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++------ |
1 file changed, 186 insertions(+), 13 deletions(-)
diff --git a/time/date/virtual.ha b/time/date/virtual.ha
@@ -1,6 +1,7 @@
// SPDX-License-Identifier: MPL-2.0
// (c) Hare authors <https://harelang.org>
+use sort;
use time;
use time::chrono;
@@ -131,13 +132,13 @@ export type lack = enum u8 {
// by direct field assignments and/or with [[parse]]. Finish with [[realize]].
//
// let v = date::newvirtual();
-// v.vloc = time::chrono::UTC;
-// v.zoff = 0;
-// date::parse(&v, "Date: %Y-%m-%d", "Date: 2038-01-19")!;
-// v.hour = 03;
-// v.minute = 14;
-// v.second = 07;
-// v.nanosecond = 0;
+// v.vloc = chrono::tz("Europe/Amsterdam")!;
+// v.zoff = date::zflag::LAP_EARLY | date::zflag::GAP_END;
+// date::parse(&v, "Date: %Y-%m-%d", "Date: 2000-01-02")!;
+// v.hour = 15;
+// v.minute = 4;
+// v.second = 5;
+// v.nanosecond = 600000000;
// let d = date::realize(v)!;
//
export type virtual = struct {
@@ -151,7 +152,7 @@ export type virtual = struct {
// locality name
locname: (void | str),
// zone offset
- zoff: (void | time::duration),
+ zoff: (void | time::duration | zflag),
// zone abbreviation
zabbr: (void | str),
// all but the last two digits of the year
@@ -209,7 +210,7 @@ export fn newvirtual() virtual = virtual {
//
// let v = date::newvirtual();
// v.locname = "Europe/Amsterdam";
-// v.zoff = 1 * time::HOUR;
+// v.zoff = date::zflag::LAP_EARLY | date::zflag::GAP_END;
// date::parse(&v, // fills-in .year .month .day
// "Date: %Y-%m-%d", "Date: 2038-01-19")!;
// v.hour = 4;
@@ -259,9 +260,58 @@ export fn newvirtual() virtual = virtual {
//
// If not enough information was provided, [[insufficient]] is returned.
// If invalid information was provided, [[invalid]] is returned.
+// Any [[zflag]]s assigned to the .zoff field affect the final result.
export fn realize(
v: virtual,
locs: chrono::locality...
+) (date | insufficient | invalid | zfunresolved) = {
+ match (v.zoff) {
+ case void =>
+ return lack::ZOFF;
+ case time::duration =>
+ return realize_validzoff(v, locs...);
+ case let zf: zflag =>
+ let valid_dates = realize_validzoffs(v, locs...)?;
+ switch (len(valid_dates)) {
+ case 0 =>
+ if (0 != zf & zflag::GAP_END) {
+ return realize_gapbounds(v).1;
+ } else if (0 != zf & zflag::GAP_START) {
+ return realize_gapbounds(v).0;
+ } else {
+ return false: zfunresolved;
+ };
+ case 1 =>
+ return valid_dates[0];
+ case =>
+ if (0 != zf & zflag::LAP_LATE) {
+ return valid_dates[len(valid_dates) - 1];
+ } else if (0 != zf & zflag::LAP_EARLY) {
+ return valid_dates[0];
+ } else {
+ return true: zfunresolved;
+ };
+ };
+ };
+};
+
+fn realize_validzoff(
+ v: virtual,
+ locs: chrono::locality...
+) (date | insufficient | invalid) = {
+ let d = realize_datetimezoff(v, locs...)?;
+
+ // verify zone offset
+ if (chrono::ozone(&d).zoff != v.zoff as time::duration) {
+ return invalid;
+ };
+
+ return d;
+};
+
+fn realize_datetimezoff(
+ v: virtual,
+ locs: chrono::locality...
) (date | insufficient | invalid) = {
let lacking = 0u8;
@@ -399,11 +449,134 @@ export fn realize(
v.daytime as i64,
));
- // verify zone offset
- const z = chrono::ozone(&d);
- if (z.zoff != v.zoff as time::duration) {
+ return d;
+};
+
+fn realize_validzoffs(
+ v: virtual,
+ locs: chrono::locality...
+) ([]date | insufficient | invalid) = {
+ // check if only zoff is missing
+ v.zoff = 0o0;
+ match (realize_validzoff(v, locs...)) {
+ case (date | invalid) =>
+ void;
+ case let ins: insufficient =>
+ return ins;
+ };
+ v.zoff = void;
+
+ let dates: []date = [];
+
+ // determine .loc
+ if (v.vloc is chrono::locality) {
+ v.loc = v.vloc as chrono::locality;
+ } else if (v.locname is str) {
+ for (let loc .. locs) {
+ if (loc.name == v.locname as str) {
+ v.loc = loc;
+ v.vloc = loc;
+ break;
+ };
+ };
+ } else {
+ return insufficient::LOCALITY;
+ };
+
+ // try matching zone abbreviation
+ if (v.zabbr is str) {
+ for (let zone .. v.loc.zones) {
+ if (v.zabbr as str == zone.abbr) {
+ v.zoff = zone.zoff;
+ match (realize_validzoff(v, locs...)) {
+ case let d: date =>
+ match (sort::search(
+ dates, size(date), &d, &cmpdates,
+ )) {
+ case size =>
+ void;
+ case void =>
+ append(dates, d);
+ sort::sort(dates, size(date), &cmpdates);
+ };
+ case invalid =>
+ continue;
+ case =>
+ abort();
+ };
+ };
+ };
+
return invalid;
};
- return d;
+ // try zone offsets from locality
+ for (let zone .. v.loc.zones) {
+ v.zoff = zone.zoff;
+ match (realize_validzoff(v, locs...)) {
+ case let d: date =>
+ match (sort::search(dates, size(date), &d, &cmpdates)) {
+ case size =>
+ void;
+ case void =>
+ append(dates, d);
+ sort::sort(dates, size(date), &cmpdates);
+ };
+ case invalid =>
+ continue;
+ case =>
+ abort();
+ };
+ };
+
+ return dates;
+};
+
+fn cmpdates(a: const *opaque, b: const *opaque) int = {
+ let a = a: *date;
+ let b = b: *date;
+ return chrono::compare(a, b)!: int;
+};
+
+fn realize_gapbounds(v: virtual) (date, date) = {
+ let loc = v.vloc as chrono::locality;
+
+ let zlo: time::duration = 48 * time::HOUR;
+ let zhi: time::duration = -48 * time::HOUR;
+ for (let zone .. loc.zones) {
+ if (zone.zoff > zhi) {
+ zhi = zone.zoff;
+ };
+ if (zone.zoff < zlo) {
+ zlo = zone.zoff;
+ };
+ };
+
+ v.zoff = zhi;
+ let earliest = realize_datetimezoff(v)!;
+ let earliest = *(&earliest: *time::instant);
+
+ v.zoff = zlo;
+ let latest = realize_datetimezoff(v)!;
+ let latest = *(&latest: *time::instant);
+
+ let t = time::instant{ ... };
+ for (let tr .. loc.transitions) {
+ let is_within_bounds = (
+ time::compare(earliest, tr.when) < 0
+ && time::compare(latest, tr.when) > 0
+ );
+
+ if (is_within_bounds) {
+ t = tr.when;
+ break;
+ };
+ };
+
+ let gapstart = from_instant(loc, time::add(t, -time::NANOSECOND));
+ let gapend = from_instant(loc, t);
+
+ // TODO: check if original v falls within gapstart & gapend?
+
+ return (gapstart, gapend);
};
