Extended times lib functionality

docs/stdlib-times.md

@@ -72,6 +72,7 @@ times := import("times")
   2006" would be interpreted if it were the value; it serves as an example of
   the input format. The same interpretation will then be made to the input
   string.
+- `parseInLocation(format string, s string, loc string)`: parseInLocation is like parse but parse interprets a time as UTC; parseInLocation interprets the time as in the given location.
 - `unix(sec int, nsec int) => time`: returns the local Time corresponding to
   the given Unix time, sec seconds and nsec nanoseconds since January 1,
   1970 UTC.
@@ -88,6 +89,7 @@ times := import("times")
 - `time_month(t time) => int`: returns the month of the year specified by t.
 - `time_day(t time) => int`: returns the day of the month specified by t.
 - `time_weekday(t time) => int`: returns the day of the week specified by t.
+- `time_yearday(t time) => int`: returns the day of the year specified by t, in the range [1,365] for non-leap years, and [1,366] in leap years.
 - `time_hour(t time) => int`: returns the hour within the day specified by t,
   in the range [0, 23].
 - `time_minute(t time) => int`: returns the minute offset within the hour
@@ -114,6 +116,8 @@ times := import("times")
   t.
 - `time_string(t time) => string`: returns the time formatted using the format
   string "2006-01-02 15:04:05.999999999 -0700 MST".
+- `time_in(t time, loc string)`: returns a copy of t representing the same time instant, but with the copy's location information set to loc for display purposes.
+- `is_dst(t time)`: reports whether the time in the configured location is in Daylight Savings Time.
 - `is_zero(t time) => bool`: reports whether t represents the zero time
   instant, January 1, year 1, 00:00:00 UTC.
 - `to_local(t time) => time`: returns t with the location set to local time.

stdlib/times.go

@@ -92,6 +92,10 @@ var timesModule = map[string]tengo.Object{
 		Name:  "parse",
 		Value: timesParse,
 	}, // parse(format, str) => time
+	"parseInLocation": &tengo.UserFunction{
+		Name:  "parseInLocation",
+		Value: timesParseInLocation,
+	}, // parseInLocation(format, str, location) => time
 	"unix": &tengo.UserFunction{
 		Name:  "unix",
 		Value: timesUnix,
@@ -132,6 +136,10 @@ var timesModule = map[string]tengo.Object{
 		Name:  "time_weekday",
 		Value: timesTimeWeekday,
 	}, // time_weekday(time) => int
+	"time_yearday": &tengo.UserFunction{
+		Name:  "time_yearday",
+		Value: timesTimeYearday,
+	}, // time_yearday(time) => int
 	"time_hour": &tengo.UserFunction{
 		Name:  "time_hour",
 		Value: timesTimeHour,
@@ -168,6 +176,14 @@ var timesModule = map[string]tengo.Object{
 		Name:  "time_string",
 		Value: timesTimeString,
 	}, // time_string(time) => string
+	"time_in": &tengo.UserFunction{
+		Name:  "time_in",
+		Value: timesTimeIn,
+	}, // in(time, location) => time
+	"is_dst": &tengo.UserFunction{
+		Name:  "is_dst",
+		Value: timesIsDST,
+	}, // is_dst(time) => bool
 	"is_zero": &tengo.UserFunction{
 		Name:  "is_zero",
 		Value: timesIsZero,
@@ -555,6 +571,59 @@ func timesParse(args ...tengo.Object) (ret tengo.Object, err error) {
 	return
 }
 
+func timesParseInLocation(args ...tengo.Object) (ret tengo.Object, err error) {
+	if len(args) != 3 {
+		err = tengo.ErrWrongNumArguments
+		return
+	}
+
+	s1, ok := tengo.ToString(args[0])
+	if !ok {
+		err = tengo.ErrInvalidArgumentType{
+			Name:     "first",
+			Expected: "string(compatible)",
+			Found:    args[0].TypeName(),
+		}
+		return
+	}
+
+	s2, ok := tengo.ToString(args[1])
+	if !ok {
+		err = tengo.ErrInvalidArgumentType{
+			Name:     "second",
+			Expected: "string(compatible)",
+			Found:    args[1].TypeName(),
+		}
+		return
+	}
+
+	s3, ok := tengo.ToString(args[2])
+	if !ok {
+		err = tengo.ErrInvalidArgumentType{
+			Name:     "third",
+			Expected: "string(compatible)",
+			Found:    args[1].TypeName(),
+		}
+		return
+	}
+
+	location, err := time.LoadLocation(s3)
+	if err != nil {
+		ret = wrapError(err)
+		return
+	}
+
+	parsed, err := time.ParseInLocation(s1, s2, location)
+	if err != nil {
+		ret = wrapError(err)
+		return
+	}
+
+	ret = &tengo.Time{Value: parsed}
+
+	return
+}
+
 func timesUnix(args ...tengo.Object) (ret tengo.Object, err error) {
 	if len(args) != 2 {
 		err = tengo.ErrWrongNumArguments
@@ -853,6 +922,27 @@ func timesTimeWeekday(args ...tengo.Object) (ret tengo.Object, err error) {
 	return
 }
 
+func timesTimeYearday(args ...tengo.Object) (ret tengo.Object, err error) {
+	if len(args) != 1 {
+		err = tengo.ErrWrongNumArguments
+		return
+	}
+
+	t1, ok := tengo.ToTime(args[0])
+	if !ok {
+		err = tengo.ErrInvalidArgumentType{
+			Name:     "first",
+			Expected: "time(compatible)",
+			Found:    args[0].TypeName(),
+		}
+		return
+	}
+
+	ret = &tengo.Int{Value: int64(t1.YearDay())}
+
+	return
+}
+
 func timesTimeHour(args ...tengo.Object) (ret tengo.Object, err error) {
 	if len(args) != 1 {
 		err = tengo.ErrWrongNumArguments
@@ -1022,6 +1112,68 @@ func timesTimeFormat(args ...tengo.Object) (ret tengo.Object, err error) {
 	return
 }
 
+func timesTimeIn(args ...tengo.Object) (ret tengo.Object, err error) {
+	if len(args) != 2 {
+		err = tengo.ErrWrongNumArguments
+		return
+	}
+
+	t1, ok := tengo.ToTime(args[0])
+	if !ok {
+		err = tengo.ErrInvalidArgumentType{
+			Name:     "first",
+			Expected: "time(compatible)",
+			Found:    args[0].TypeName(),
+		}
+		return
+	}
+
+	s2, ok := tengo.ToString(args[1])
+	if !ok {
+		err = tengo.ErrInvalidArgumentType{
+			Name:     "second",
+			Expected: "string(compatible)",
+			Found:    args[1].TypeName(),
+		}
+		return
+	}
+
+	location, err := time.LoadLocation(s2)
+	if err != nil {
+		ret = wrapError(err)
+		return
+	}
+
+	ret = &tengo.Time{Value: t1.In(location)}
+
+	return
+}
+
+func timesIsDST(args ...tengo.Object) (ret tengo.Object, err error) {
+	if len(args) != 1 {
+		err = tengo.ErrWrongNumArguments
+		return
+	}
+
+	t1, ok := tengo.ToTime(args[0])
+	if !ok {
+		err = tengo.ErrInvalidArgumentType{
+			Name:     "first",
+			Expected: "time(compatible)",
+			Found:    args[0].TypeName(),
+		}
+		return
+	}
+
+	if t1.IsDST() {
+		ret = tengo.TrueValue
+	} else {
+		ret = tengo.FalseValue
+	}
+
+	return
+}
+
 func timesIsZero(args ...tengo.Object) (ret tengo.Object, err error) {
 	if len(args) != 1 {
 		err = tengo.ErrWrongNumArguments

stdlib/times_test.go

@@ -42,6 +42,9 @@ func TestTimes(t *testing.T) {
 	module(t, "times").
 		call("parse", time.RFC3339, "1982-09-28T19:21:44+07:00").
 		expect(parsed)
+	module(t, "times").
+		call("parseInLocation", time.RFC3339, "1982-09-28T19:21:44+07:00", "America/Los_Angeles").
+		expect(parsed)
 	module(t, "times").
 		call("unix", 1234325, 94493).
 		expect(time.Unix(1234325, 94493))
@@ -80,4 +83,8 @@ func TestTimes(t *testing.T) {
 	module(t, "times").call("time_location", time1).
 		expect(time1.Location().String())
 	module(t, "times").call("time_string", time1).expect(time1.String())
+	location, _ := time.LoadLocation("America/Los_Angeles")
+	module(t, "times").call("time_in", time1, "America/Los_Angeles").expect(time1.In(location))
+	module(t, "times").call("time_location", time1.In(location)).expect("America/Los_Angeles")
+	module(t, "times").call("time_in", time1, "invalid location name").expectError()
 }