Add basic functions.

.travis.yml

@@ -0,0 +1,9 @@
+language: go
+go:
+  - tip
+before_install:
+  - go get github.com/axw/gocov/gocov
+  - go get github.com/mattn/goveralls
+  - if ! go get code.google.com/p/go.tools/cmd/cover; then go get golang.org/x/tools/cmd/cover; fi
+script:
+    - $HOME/gopath/bin/goveralls -service=travis-ci

LICENSE

@@ -1,6 +1,6 @@
 The MIT License (MIT)
 
-Copyright (c) 2015 Kyoung-chan Lee
+Copyright (c) 2015 Kyoung-chan Lee (leekchan@gmail.com)
 
 Permission is hereby granted, free of charge, to any person obtaining a copy
 of this software and associated documentation files (the "Software"), to deal

strftime.go

@@ -0,0 +1,150 @@
+package timeutil
+
+import (
+	"fmt"
+	"time"
+)
+
+var longDayNames = []string{
+	"Sunday",
+	"Monday",
+	"Tuesday",
+	"Wednesday",
+	"Thursday",
+	"Friday",
+	"Saturday",
+}
+
+var shortDayNames = []string{
+	"Sun",
+	"Mon",
+	"Tue",
+	"Wed",
+	"Thu",
+	"Fri",
+	"Sat",
+}
+
+var shortMonthNames = []string{
+	"---",
+	"Jan",
+	"Feb",
+	"Mar",
+	"Apr",
+	"May",
+	"Jun",
+	"Jul",
+	"Aug",
+	"Sep",
+	"Oct",
+	"Nov",
+	"Dec",
+}
+
+var longMonthNames = []string{
+	"---",
+	"January",
+	"February",
+	"March",
+	"April",
+	"May",
+	"June",
+	"July",
+	"August",
+	"September",
+	"October",
+	"November",
+	"December",
+}
+
+func weekNumber(t *time.Time, char int) int {
+	weekday := int(t.Weekday())
+
+	if char == 'W' {
+		// Monday as the first day of the week
+		if weekday == 0 {
+			weekday = 6
+		} else {
+			weekday -= 1
+		}
+	}
+
+	return (t.YearDay() + 6 - weekday) / 7
+}
+
+func Strftime(t *time.Time, format string) string {
+	var result string
+
+	for i := 0; i < len(format); i++ {
+		switch format[i] {
+		case '%':
+			if i < len(format)-1 {
+				switch format[i+1] {
+				case 'a':
+					result += shortDayNames[t.Weekday()]
+				case 'A':
+					result += longDayNames[t.Weekday()]
+				case 'w':
+					result += fmt.Sprintf("%d", t.Weekday())
+				case 'd':
+					result += fmt.Sprintf("%02d", t.Day())
+				case 'b':
+					result += shortMonthNames[t.Month()]
+				case 'B':
+					result += longMonthNames[t.Month()]
+				case 'm':
+					result += fmt.Sprintf("%02d", t.Month())
+				case 'y':
+					result += fmt.Sprintf("%02d", t.Year()%100)
+				case 'Y':
+					result += fmt.Sprintf("%02d", t.Year())
+				case 'H':
+					result += fmt.Sprintf("%02d", t.Hour())
+				case 'I':
+					if t.Hour() == 0 {
+						result += fmt.Sprintf("%02d", 12)
+					} else if t.Hour() > 12 {
+						result += fmt.Sprintf("%02d", t.Hour()-12)
+					} else {
+						result += fmt.Sprintf("%02d", t.Hour())
+					}
+				case 'p':
+					if t.Hour() < 12 {
+						result += "AM"
+					} else {
+						result += "PM"
+					}
+				case 'M':
+					result += fmt.Sprintf("%02d", t.Minute())
+				case 'S':
+					result += fmt.Sprintf("%02d", t.Second())
+				case 'f':
+					result += fmt.Sprintf("%06d", t.Nanosecond()/1000)
+				case 'z':
+					result += t.Format("-0700")
+				case 'Z':
+					result += t.Location().String()
+				case 'j':
+					result += fmt.Sprintf("%03d", t.YearDay())
+				case 'U':
+					result += fmt.Sprintf("%02d", weekNumber(t, 'U'))
+				case 'W':
+					result += fmt.Sprintf("%02d", weekNumber(t, 'W'))
+				case 'c':
+					result += t.Format("Mon Jan 2 15:04:05 2006")
+				case 'x':
+					result += fmt.Sprintf("%02d/%02d/%02d", t.Month(), t.Day(), t.Year()%100)
+				case 'X':
+					result += fmt.Sprintf("%02d:%02d:%02d", t.Hour(), t.Minute(), t.Second())
+				case '%':
+					result += "%"
+				}
+				i += 1
+			}
+		default:
+			result += fmt.Sprintf("%c", format[i])
+		}
+	}
+
+	return result
+}

strftime_test.go

@@ -0,0 +1,26 @@
+package timeutil
+
+import (
+	"testing"
+	"time"
+)
+
+func TestStrftime(t *testing.T) {
+	date := time.Date(2005, 2, 3, 4, 5, 6, 7000, time.UTC)
+	AssertEqual(t, Strftime(&date,
+		"%a %A %w %d %b %B %m %y %Y %H %I %p %M %S %f %z %Z %j %U %W %c %x %X %%"),
+		"Thu Thursday 4 03 Feb February 02 05 2005 04 04 AM 05 06 000007 +0000 UTC 034 05 05 Thu Feb 3 04:05:06 2005 02/03/05 04:05:06 %")
+
+	date = time.Date(2015, 7, 2, 15, 24, 30, 35, time.UTC)
+	AssertEqual(t, Strftime(&date, "%U %W"), "26 26")
+
+	date = time.Date(1962, 3, 23, 15, 24, 30, 35, time.UTC)
+	AssertEqual(t, Strftime(&date, "%U %W"), "11 12")
+
+	date = time.Date(1989, 12, 31, 15, 24, 30, 35000, time.UTC)
+	AssertEqual(t, Strftime(&date, "%U %W"), "53 52")
+
+	AssertEqual(t, Strftime(&date,
+		"%a %A %w %d %b %B %m %y %Y %H %I %p %M %S %f %z %Z %j %U %W %c %x %X %%"),
+		"Sun Sunday 0 31 Dec December 12 89 1989 15 03 PM 24 30 000035 +0000 UTC 365 53 52 Sun Dec 31 15:24:30 1989 12/31/89 15:24:30 %")
+}

timedelta.go

@@ -0,0 +1,60 @@
+package timeutil
+
+import (
+	"time"
+)
+
+func abs(v time.Duration) time.Duration {
+	if v < 0 {
+		v *= -1
+	}
+	return v
+}
+
+type Timedelta struct {
+	days, seconds, microseconds, milliseconds, minutes, hours, weeks time.Duration
+}
+
+func (t *Timedelta) Add(t2 *Timedelta) {
+	t.days += t2.days
+	t.seconds += t2.seconds
+	t.microseconds += t2.microseconds
+	t.milliseconds += t2.milliseconds
+	t.minutes += t2.minutes
+	t.hours += t2.hours
+	t.weeks += t2.weeks
+}
+
+func (t *Timedelta) Subtract(t2 *Timedelta) {
+	t.days -= t2.days
+	t.seconds -= t2.seconds
+	t.microseconds -= t2.microseconds
+	t.milliseconds -= t2.milliseconds
+	t.minutes -= t2.minutes
+	t.hours -= t2.hours
+	t.weeks -= t2.weeks
+}
+
+func (t *Timedelta) Abs() {
+	t.days = abs(t.days)
+	t.seconds = abs(t.seconds)
+	t.microseconds = abs(t.microseconds)
+	t.milliseconds = abs(t.milliseconds)
+	t.minutes = abs(t.minutes)
+	t.hours = abs(t.hours)
+	t.weeks = abs(t.weeks)
+}
+
+func (t *Timedelta) Duration() time.Duration {
+	return t.days*24*time.Hour +
+		t.seconds*time.Second +
+		t.microseconds*time.Microsecond +
+		t.milliseconds*time.Millisecond +
+		t.minutes*time.Minute +
+		t.hours*time.Hour +
+		t.weeks*7*24*time.Hour
+}
+
+func (t *Timedelta) String() string {
+	return t.Duration().String()
+}

timedelta_test.go

@@ -0,0 +1,43 @@
+package timeutil
+
+import (
+	"reflect"
+	"testing"
+	"time"
+)
+
+func AssertEqual(t *testing.T, x, y interface{}) {
+	if !reflect.DeepEqual(x, y) {
+		t.Error("Expected ", y, ", got ", x)
+	}
+}
+
+func TestTimedelta(t *testing.T) {
+	base := time.Date(1980, 1, 6, 0, 0, 0, 0, time.UTC)
+	result := base.Add((&Timedelta{days: 1, seconds: 66355, weeks: 1722}).Duration())
+	AssertEqual(t, result.String(), "2013-01-07 18:25:55 +0000 UTC")
+
+	result = result.Add((&Timedelta{microseconds: 3, milliseconds: 10, minutes: 1}).Duration())
+	AssertEqual(t, result.String(), "2013-01-07 18:26:55.010003 +0000 UTC")
+
+	td := Timedelta{days: 10, minutes: 17, seconds: 56}
+	td2 := Timedelta{days: 15, minutes: 13, seconds: 42}
+	td.Add(&td2)
+
+	base = time.Date(2015, 2, 3, 0, 0, 0, 0, time.UTC)
+	result = base.Add(td.Duration())
+	AssertEqual(t, result.String(), "2015-02-28 00:31:38 +0000 UTC")
+
+	td.Subtract(&td2)
+
+	result = base.Add(td.Duration())
+	AssertEqual(t, result.String(), "2015-02-13 00:17:56 +0000 UTC")
+
+	AssertEqual(t, td.String(), "240h17m56s")
+
+	td = Timedelta{days: -1, seconds: -1, microseconds: -1, milliseconds: -1, minutes: -1, hours: -1, weeks: -1}
+	td2 = td
+	td.Abs()
+	td.Add(&td2)
+	AssertEqual(t, td.String(), "0")
+}