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clean up handling of numeric time zones

allow formatting of ruby-style times.

Fixes #518.

R=rsc
CC=golang-dev
https://golang.org/cl/186119
This commit is contained in:
Rob Pike 2010-01-14 11:57:38 +11:00
parent e8afb6d87f
commit d9283b27a2
2 changed files with 88 additions and 56 deletions

View File

@ -11,6 +11,8 @@ const (
numeric = iota
alphabetic
separator
plus
minus
)
// These are predefined layouts for use in Time.Format.
@ -25,6 +27,7 @@ const (
const (
ANSIC = "Mon Jan _2 15:04:05 2006"
UnixDate = "Mon Jan _2 15:04:05 MST 2006"
RubyDate = "Mon Jan 02 15:04:05 -0700 2006"
RFC850 = "Monday, 02-Jan-06 15:04:05 MST"
RFC1123 = "Mon, 02 Jan 2006 15:04:05 MST"
Kitchen = "3:04PM"
@ -56,7 +59,8 @@ const (
stdPM = "PM"
stdpm = "pm"
stdTZ = "MST"
stdISO8601TZ = "Z"
stdISO8601TZ = "Z" // prints Z for UTC
stdNumTZ = "0700" // always numeric
)
var longDayNames = []string{
@ -126,8 +130,12 @@ func charType(c uint8) int {
return numeric
case c == '_': // underscore; treated like a number when printing
return numeric
case 'a' <= c && c < 'z', 'A' <= c && c <= 'Z':
case 'a' <= c && c <= 'z', 'A' <= c && c <= 'Z':
return alphabetic
case c == '+':
return plus
case c == '-':
return minus
}
return separator
}
@ -198,19 +206,31 @@ func (t *Time) Format(layout string) string {
p = zeroPad(t.Second)
case stdZulu:
p = zeroPad(t.Hour) + zeroPad(t.Minute)
case stdISO8601TZ:
// Rather ugly special case, required because the time zone is too broken down
// in this format to recognize easily. We cheat and take "Z" to mean "the time
case stdISO8601TZ, stdNumTZ:
// Ugly special case. We cheat and take "Z" to mean "the time
// zone as formatted for ISO 8601".
if t.ZoneOffset == 0 {
zone := t.ZoneOffset / 60 // conver to minutes
if p == stdISO8601TZ && t.ZoneOffset == 0 {
p = "Z"
} else {
zone := t.ZoneOffset / 60 // minutes
if zone < 0 {
p = "-"
zone = -zone
// If the reference time is stdNumTZ (0700), the sign has already been
// emitted but may be wrong. For stdISO8601TZ we must print it.
if p == stdNumTZ && b.Len() > 0 {
soFar := b.Bytes()
if soFar[len(soFar)-1] == '-' && zone >= 0 {
// fix the sign
soFar[len(soFar)-1] = '+'
} else {
zone = -zone
}
p = ""
} else {
p = "+"
if zone < 0 {
p = "-"
zone = -zone
} else {
p = "+"
}
}
p += zeroPad(zone / 60)
p += zeroPad(zone % 60)
@ -294,8 +314,8 @@ func Parse(alayout, avalue string) (*Time, os.Error) {
rangeErrString := "" // set if a value is out of range
pmSet := false // do we need to add 12 to the hour?
// Each iteration steps along one piece
nextIsYear := false // whether next item is a Year; means we saw a minus sign.
layout, value := alayout, avalue
sign := "" // pending + or - from previous iteration
for len(layout) > 0 && len(value) > 0 {
c := layout[0]
pieceType := charType(c)
@ -303,10 +323,12 @@ func Parse(alayout, avalue string) (*Time, os.Error) {
for i = 0; i < len(layout) && charType(layout[i]) == pieceType; i++ {
}
reference := layout[0:i]
prevLayout := layout
layout = layout[i:]
if reference == "Z" {
// Ugly time zone handling.
if reference == "Z" || reference == "z" {
// Special case for ISO8601 time zone: "Z" or "-0800"
if value[0] == 'Z' {
if reference == "Z" && value[0] == 'Z' {
i = 1
} else if len(value) >= 5 {
i = 5
@ -316,6 +338,13 @@ func Parse(alayout, avalue string) (*Time, os.Error) {
} else {
c = value[0]
if charType(c) != pieceType {
// could be a minus sign introducing a negative year
if c == '-' && pieceType != minus {
value = value[1:]
sign = "-"
layout = prevLayout // don't consume reference item
continue
}
return nil, &ParseError{Layout: alayout, Value: avalue, Message: formatErr + alayout}
}
for i = 0; i < len(value) && charType(value[i]) == pieceType; i++ {
@ -323,21 +352,17 @@ func Parse(alayout, avalue string) (*Time, os.Error) {
}
p := value[0:i]
value = value[i:]
// Separators must match but:
// - initial run of spaces is treated as a single space
// - there could be a following minus sign for negative years
if pieceType == separator {
if len(p) != len(reference) {
// must be exactly a following minus sign
pp := collapseSpaces(p)
rr := collapseSpaces(reference)
if pp != rr {
if len(pp) != len(rr)+1 || p[len(pp)-1] != '-' {
return nil, &ParseError{Layout: alayout, Value: avalue, Message: formatErr + alayout}
}
nextIsYear = true
continue
}
switch pieceType {
case separator:
// Separators must match but initial run of spaces is treated as a single space.
if collapseSpaces(p) != collapseSpaces(reference) {
return nil, &ParseError{Layout: alayout, Value: avalue, Message: formatErr + alayout}
}
continue
case plus, minus:
if len(p) == 1 { // ++ or -- don't count as signs.
sign = p
continue
}
}
var err os.Error
@ -351,9 +376,8 @@ func Parse(alayout, avalue string) (*Time, os.Error) {
}
case stdLongYear:
t.Year, err = strconv.Atoi64(p)
if nextIsYear {
if sign == "-" {
t.Year = -t.Year
nextIsYear = false
}
case stdMonth:
t.Month, err = lookup(shortMonthNames, p)
@ -403,19 +427,25 @@ func Parse(alayout, avalue string) (*Time, os.Error) {
if err != nil {
t.Minute, err = strconv.Atoi(p[2:4])
}
case stdISO8601TZ:
if p == "Z" {
t.Zone = "UTC"
break
case stdISO8601TZ, stdNumTZ:
if reference == stdISO8601TZ {
if p == "Z" {
t.Zone = "UTC"
break
}
// len(p) known to be 5: "-0800"
sign = p[0:1]
p = p[1:]
} else {
// len(p) known to be 4: "0800" and sign is set
}
// len(p) known to be 5: "-0800"
var hr, min int
hr, err = strconv.Atoi(p[1:3])
hr, err = strconv.Atoi(p[0:2])
if err != nil {
min, err = strconv.Atoi(p[3:5])
min, err = strconv.Atoi(p[2:4])
}
t.ZoneOffset = (hr*60 + min) * 60 // offset is in seconds
switch p[0] {
switch sign[0] {
case '+':
case '-':
t.ZoneOffset = -t.ZoneOffset
@ -463,16 +493,13 @@ func Parse(alayout, avalue string) (*Time, os.Error) {
}
}
}
if nextIsYear {
// Means we didn't see a year when we were expecting one
return nil, &ParseError{Layout: alayout, Value: value, Message: formatErr + alayout}
}
if rangeErrString != "" {
return nil, &ParseError{alayout, avalue, reference, p, ": " + rangeErrString + " out of range"}
}
if err != nil {
return nil, &ParseError{alayout, avalue, reference, p, ""}
}
sign = ""
}
if pmSet && t.Hour < 12 {
t.Hour += 12

View File

@ -132,6 +132,7 @@ type FormatTest struct {
var formatTests = []FormatTest{
FormatTest{"ANSIC", ANSIC, "Thu Feb 4 21:00:57 2010"},
FormatTest{"UnixDate", UnixDate, "Thu Feb 4 21:00:57 PST 2010"},
FormatTest{"RubyDate", RubyDate, "Thu Feb 04 21:00:57 -0800 2010"},
FormatTest{"RFC850", RFC850, "Thursday, 04-Feb-10 21:00:57 PST"},
FormatTest{"RFC1123", RFC1123, "Thu, 04 Feb 2010 21:00:57 PST"},
FormatTest{"ISO8601", ISO8601, "2010-02-04T21:00:57-0800"},
@ -152,22 +153,26 @@ func TestFormat(t *testing.T) {
}
type ParseTest struct {
name string
format string
value string
hasTZ bool // contains a time zone
hasWD bool // contains a weekday
name string
format string
value string
hasTZ bool // contains a time zone
hasWD bool // contains a weekday
yearSign int64 // sign of year
}
var parseTests = []ParseTest{
ParseTest{"ANSIC", ANSIC, "Thu Feb 4 21:00:57 2010", false, true},
ParseTest{"UnixDate", UnixDate, "Thu Feb 4 21:00:57 PST 2010", true, true},
ParseTest{"RFC850", RFC850, "Thursday, 04-Feb-10 21:00:57 PST", true, true},
ParseTest{"RFC1123", RFC1123, "Thu, 04 Feb 2010 21:00:57 PST", true, true},
ParseTest{"ISO8601", ISO8601, "2010-02-04T21:00:57-0800", true, false},
ParseTest{"ANSIC", ANSIC, "Thu Feb 4 21:00:57 2010", false, true, 1},
ParseTest{"UnixDate", UnixDate, "Thu Feb 4 21:00:57 PST 2010", true, true, 1},
ParseTest{"RubyDate", RubyDate, "Thu Feb 04 21:00:57 -0800 2010", true, true, 1},
ParseTest{"RFC850", RFC850, "Thursday, 04-Feb-10 21:00:57 PST", true, true, 1},
ParseTest{"RFC1123", RFC1123, "Thu, 04 Feb 2010 21:00:57 PST", true, true, 1},
ParseTest{"ISO8601", ISO8601, "2010-02-04T21:00:57-0800", true, false, 1},
// Negative year
ParseTest{"ANSIC", ANSIC, "Thu Feb 4 21:00:57 -2010", false, true, -1},
// Amount of white space should not matter.
ParseTest{"ANSIC", ANSIC, "Thu Feb 4 21:00:57 2010", false, true},
ParseTest{"ANSIC", ANSIC, "Thu Feb 4 21:00:57 2010", false, true},
ParseTest{"ANSIC", ANSIC, "Thu Feb 4 21:00:57 2010", false, true, 1},
ParseTest{"ANSIC", ANSIC, "Thu Feb 4 21:00:57 2010", false, true, 1},
}
func TestParse(t *testing.T) {
@ -183,7 +188,7 @@ func TestParse(t *testing.T) {
func checkTime(time *Time, test *ParseTest, t *testing.T) {
// The time should be Thu Feb 4 21:00:57 PST 2010
if time.Year != 2010 {
if test.yearSign*time.Year != 2010 {
t.Errorf("%s: bad year: %d not %d\n", test.name, time.Year, 2010)
}
if time.Month != 2 {