commit 1eee56c7d8e852f96818ed52a8cd0504dec91b04
parent c638d82223d06dd18e71eb200ef89a5a33eed083
Author: Drew DeVault <sir@cmpwn.com>
Date: Wed, 13 Apr 2022 14:44:45 +0200
datetime: rename start_of to truncate
Signed-off-by: Drew DeVault <sir@cmpwn.com>
Diffstat:
1 file changed, 46 insertions(+), 45 deletions(-)
diff --git a/datetime/arithmetic.ha b/datetime/arithmetic.ha
@@ -3,8 +3,8 @@ use math;
use time;
use time::chrono;
-// Represents a span of time in the proleptic Gregorian calendar,
-// using relative units of time. Used for calendar arithmetic.
+// Represents a span of time in the proleptic Gregorian calendar, using relative
+// units of time. Used for calendar arithmetic.
export type period = struct {
eras: int,
years: int,
@@ -22,17 +22,16 @@ export type period = struct {
nanoseconds: i64,
};
-// Specifies behaviour during calendar arithmetic
-//
-// * DEFAULT
-// Units are added in the order of largest (years) to smallest (nanoseconds). If
-// the resulting date does not exist, the first extant date previous to the
-// initial result is returned.
+// Specifies the behaviour of calendar arithmetic.
export type calculus = enum int {
+ // Units are added in the order of largest (years) to smallest
+ // (nanoseconds). If the resulting date does not exist, the first extant
+ // date previous to the initial result is returned.
DEFAULT,
};
+// TODO: ^ Expand this
-// The various datetime units that can be used for arithmetic
+// The various datetime units that can be used for arithmetic.
export type unit = enum int {
ERA,
YEAR,
@@ -45,23 +44,23 @@ export type unit = enum int {
NANOSECOND,
};
-// Returns whether or not two dates are numerically equal
+// Returns true if two dates are numerically equal.
export fn eq(a: datetime, b: datetime) bool = {
return a.date == b.date && a.time == b.time;
};
-// Returns whether or not the first date is after the second date
+// Returns true if the first date is after the second date.
export fn is_after(a: datetime, b: datetime) bool = {
return !eq(a, b) &&
(a.date > b.date || a.date == b.date && a.time > b.time);
};
-// Returns whether or not the first date is before the second date
+// Returns true if the first date is before the second date.
export fn is_before(a: datetime, b: datetime) bool = {
return !eq(a, b) && !is_after(a, b);
};
-// Calculates the difference between two datetimes
+// Calculates the difference between two datetimes.
export fn diff(a: datetime, b: datetime) period = {
let res = period { ... };
if (eq(a, b)) {
@@ -122,8 +121,9 @@ export fn diff(a: datetime, b: datetime) period = {
return res;
};
-// Calculates the difference between two datetimes in the given unit. An integer
-// is returned, with the fractional part of the difference being discarded.
+// Calculates the difference between two datetimes using the given unit. An
+// integer is returned, with the fractional part of the difference being
+// truncated.
export fn diff_in_unit(a: datetime, b: datetime, u: unit) i64 = {
return switch (u) {
case unit::ERA =>
@@ -153,7 +153,7 @@ export fn diff_in_unit(a: datetime, b: datetime, u: unit) i64 = {
};
};
-// Returns whether or not two periods are numerically equal
+// Returns true if two periods are numerically equal.
export fn period_eq(a: period, b: period) bool = {
return a.eras == b.eras &&
a.years == b.years &&
@@ -166,9 +166,10 @@ export fn period_eq(a: period, b: period) bool = {
a.nanoseconds == b.nanoseconds;
};
-// Returns the given datetime at the start of a particular given unit, e.g.
-// the start of the day or the start of the minute.
-export fn start_of(u: unit, dt: datetime) datetime = {
+// Truncates the given datetime at the provided unit. For example, truncating to
+// the nearest [[unit::YEAR]] will set the month, day, hour, minute, seconds,
+// and nanoseconds fields to their minimum values.
+export fn truncate(dt: datetime, u: unit) datetime = {
// TODO: Replace all of the 0s for the zoffset with the actual
// zoffset once the API is solidified a bit
return switch (u) {
@@ -245,37 +246,37 @@ export fn hop(dt: datetime, pp: period...) datetime = {
if (p.years != 0) {
const dt_inc = add(new_dt, calculus::DEFAULT,
period { years = p.years, ... });
- new_dt = start_of(unit::YEAR, dt_inc);
+ new_dt = truncate(dt_inc, unit::YEAR);
};
if (p.months != 0) {
const dt_inc = add(new_dt, calculus::DEFAULT,
period { months = p.months, ... });
- new_dt = start_of(unit::MONTH, dt_inc);
+ new_dt = truncate(dt_inc, unit::MONTH);
};
if (p.weeks != 0) {
const dt_inc = add(new_dt, calculus::DEFAULT,
period { weeks = p.weeks, ... });
- new_dt = start_of(unit::WEEK, dt_inc);
+ new_dt = truncate(dt_inc, unit::WEEK);
};
if (p.days != 0) {
const dt_inc = add(new_dt, calculus::DEFAULT,
period { days = p.days, ... });
- new_dt = start_of(unit::DAY, dt_inc);
+ new_dt = truncate(dt_inc, unit::DAY);
};
if (p.hours != 0) {
const dt_inc = add(new_dt, calculus::DEFAULT,
period { hours = p.hours, ... });
- new_dt = start_of(unit::HOUR, dt_inc);
+ new_dt = truncate(dt_inc, unit::HOUR);
};
if (p.minutes != 0) {
const dt_inc = add(new_dt, calculus::DEFAULT,
period { minutes = p.minutes, ... });
- new_dt = start_of(unit::MINUTE, dt_inc);
+ new_dt = truncate(dt_inc, unit::MINUTE);
};
if (p.seconds != 0) {
const dt_inc = add(new_dt, calculus::DEFAULT,
period { seconds = p.seconds, ... });
- new_dt = start_of(unit::SECOND, dt_inc);
+ new_dt = truncate(dt_inc, unit::SECOND);
};
if (p.nanoseconds != 0) {
new_dt = add(new_dt, calculus::DEFAULT,
@@ -644,34 +645,34 @@ export fn subtract(dt: datetime, flag: calculus, pp: period...) datetime = {
};
};
-@test fn start_of() void = {
+@test fn truncate() void = {
const dt = new(chrono::UTC, 0, 1994, 08, 27, 11, 20, 01, 2)!;
- assert(eq(start_of(unit::ERA, dt),
+ assert(eq(truncate(dt, unit::ERA),
new(chrono::UTC, 0, 01, 01, 01, 00, 00, 00, 0)!),
- "invalid start_of() result");
- assert(eq(start_of(unit::YEAR, dt),
+ "invalid truncate() result");
+ assert(eq(truncate(dt, unit::YEAR),
new(chrono::UTC, 0, 1994, 01, 01, 00, 00, 00, 0)!),
- "invalid start_of() result");
- assert(eq(start_of(unit::MONTH, dt),
+ "invalid truncate() result");
+ assert(eq(truncate(dt, unit::MONTH),
new(chrono::UTC, 0, 1994, 08, 01, 00, 00, 00, 0)!),
- "invalid start_of() result");
- assert(eq(start_of(unit::WEEK, dt),
+ "invalid truncate() result");
+ assert(eq(truncate(dt, unit::WEEK),
new(chrono::UTC, 0, 1994, 08, 22, 00, 00, 00, 0)!),
- "invalid start_of() result");
- assert(eq(start_of(unit::DAY, dt),
+ "invalid truncate() result");
+ assert(eq(truncate(dt, unit::DAY),
new(chrono::UTC, 0, 1994, 08, 27, 00, 00, 00, 0)!),
- "invalid start_of() result");
- assert(eq(start_of(unit::HOUR, dt),
+ "invalid truncate() result");
+ assert(eq(truncate(dt, unit::HOUR),
new(chrono::UTC, 0, 1994, 08, 27, 11, 00, 00, 0)!),
- "invalid start_of() result");
- assert(eq(start_of(unit::MINUTE, dt),
+ "invalid truncate() result");
+ assert(eq(truncate(dt, unit::MINUTE),
new(chrono::UTC, 0, 1994, 08, 27, 11, 20, 00, 0)!),
- "invalid start_of() result");
- assert(eq(start_of(unit::SECOND, dt),
+ "invalid truncate() result");
+ assert(eq(truncate(dt, unit::SECOND),
new(chrono::UTC, 0, 1994, 08, 27, 11, 20, 01, 0)!),
- "invalid start_of() result");
- assert(eq(start_of(unit::NANOSECOND, dt), dt),
- "invalid start_of() result");
+ "invalid truncate() result");
+ assert(eq(truncate(dt, unit::NANOSECOND), dt),
+ "invalid truncate() result");
};
@test fn add() void = {
