Make Seconds optional, to comply with the Unix cron spec.

Day of week is now required - it was always documented as required, but silently
filled in as * if not provided.

Fixes #14

doc.go

@@ -29,7 +29,7 @@ A cron expression represents a set of times, using 6 space-separated fields.
 
 	Field name   | Mandatory? | Allowed values  | Allowed special characters
 	----------   | ---------- | --------------  | --------------------------
-	Seconds      | Yes        | 0-59            | * / , -
+	Seconds      | No         | 0-59            | * / , -
 	Minutes      | Yes        | 0-59            | * / , -
 	Hours        | Yes        | 0-23            | * / , -
 	Day of month | Yes        | 1-31            | * / , - ?

parser.go

@@ -39,15 +39,15 @@ func Parse(spec string) (_ Schedule, err error) {
 	}
 
 	// Split on whitespace.  We require 5 or 6 fields.
-	// (second) (minute) (hour) (day of month) (month) (day of week, optional)
+	// (second, optional) (minute) (hour) (day of month) (month) (day of week)
 	fields := strings.Fields(spec)
 	if len(fields) != 5 && len(fields) != 6 {
 		log.Panicf("Expected 5 or 6 fields, found %d: %s", len(fields), spec)
 	}
 
-	// If a sixth field is not provided (DayOfWeek), then it is equivalent to star.
+	// Add 0 for second field if necessary.
 	if len(fields) == 5 {
-		fields = append(fields, "*")
+		fields = append([]string{"0"}, fields...)
 	}
 
 	schedule := &SpecSchedule{
@@ -78,19 +78,17 @@ func getField(field string, r bounds) uint64 {
 // getRange returns the bits indicated by the given expression:
 //   number | number "-" number [ "/" number ]
 func getRange(expr string, r bounds) uint64 {
-
 	var (
 		start, end, step uint
 		rangeAndStep     = strings.Split(expr, "/")
 		lowAndHigh       = strings.Split(rangeAndStep[0], "-")
 		singleDigit      = len(lowAndHigh) == 1
+		extraStar        uint64
 	)
-
-	var extra_star uint64
 	if lowAndHigh[0] == "*" || lowAndHigh[0] == "?" {
 		start = r.min
 		end = r.max
-		extra_star = starBit
+		extraStar = starBit
 	} else {
 		start = parseIntOrName(lowAndHigh[0], r.names)
 		switch len(lowAndHigh) {
@@ -127,7 +125,7 @@ func getRange(expr string, r bounds) uint64 {
 		log.Panicf("Beginning of range (%d) beyond end of range (%d): %s", start, end, expr)
 	}
 
-	return getBits(start, end, step) | extra_star
+	return getBits(start, end, step) | extraStar
 }
 
 // parseIntOrName returns the (possibly-named) integer contained in expr.

parser_test.go

@@ -102,9 +102,11 @@ func TestParseSchedule(t *testing.T) {
 		expr     string
 		expected Schedule
 	}{
-		{"* 5 * * * *", every5min(time.Local)},
-		{"TZ=UTC  * 5 * * * *", every5min(time.UTC)},
-		{"TZ=Asia/Tokyo * 5 * * * *", every5min(tokyo)},
+		{"0 5 * * * *", every5min(time.Local)},
+		{"5 * * * *", every5min(time.Local)},
+		{"TZ=UTC  0 5 * * * *", every5min(time.UTC)},
+		{"TZ=UTC  5 * * * *", every5min(time.UTC)},
+		{"TZ=Asia/Tokyo 0 5 * * * *", every5min(tokyo)},
 		{"@every 5m", ConstantDelaySchedule{5 * time.Minute}},
 		{"@midnight", midnight(time.Local)},
 		{"TZ=UTC  @midnight", midnight(time.UTC)},
@@ -123,7 +125,7 @@ func TestParseSchedule(t *testing.T) {
 }
 
 func every5min(loc *time.Location) *SpecSchedule {
-	return &SpecSchedule{all(seconds), 1 << 5, all(hours), all(dom), all(months), all(dow), loc}
+	return &SpecSchedule{1 << 0, 1 << 5, all(hours), all(dom), all(months), all(dow), loc}
 }
 
 func midnight(loc *time.Location) *SpecSchedule {

spec_test.go

@@ -11,18 +11,18 @@ func TestActivation(t *testing.T) {
 		expected   bool
 	}{
 		// Every fifteen minutes.
-		{"Mon Jul 9 15:00 2012", "0 0/15 * * *", true},
-		{"Mon Jul 9 15:45 2012", "0 0/15 * * *", true},
-		{"Mon Jul 9 15:40 2012", "0 0/15 * * *", false},
+		{"Mon Jul 9 15:00 2012", "0/15 * * * *", true},
+		{"Mon Jul 9 15:45 2012", "0/15 * * * *", true},
+		{"Mon Jul 9 15:40 2012", "0/15 * * * *", false},
 
 		// Every fifteen minutes, starting at 5 minutes.
-		{"Mon Jul 9 15:05 2012", "0 5/15 * * *", true},
-		{"Mon Jul 9 15:20 2012", "0 5/15 * * *", true},
-		{"Mon Jul 9 15:50 2012", "0 5/15 * * *", true},
+		{"Mon Jul 9 15:05 2012", "5/15 * * * *", true},
+		{"Mon Jul 9 15:20 2012", "5/15 * * * *", true},
+		{"Mon Jul 9 15:50 2012", "5/15 * * * *", true},
 
 		// Named months
-		{"Sun Jul 15 15:00 2012", "0 0/15 * * Jul", true},
-		{"Sun Jul 15 15:00 2012", "0 0/15 * * Jun", false},
+		{"Sun Jul 15 15:00 2012", "0/15 * * Jul *", true},
+		{"Sun Jul 15 15:00 2012", "0/15 * * Jun *", false},
 
 		// Everything set.
 		{"Sun Jul 15 08:30 2012", "0 30 08 ? Jul Sun", true},
@@ -76,19 +76,19 @@ func TestNext(t *testing.T) {
 		expected   string
 	}{
 		// Simple cases
-		{"Mon Jul 9 14:45 2012", "0 0/15 * * *", "Mon Jul 9 15:00 2012"},
-		{"Mon Jul 9 14:59 2012", "0 0/15 * * *", "Mon Jul 9 15:00 2012"},
-		{"Mon Jul 9 14:59:59 2012", "0 0/15 * * *", "Mon Jul 9 15:00 2012"},
+		{"Mon Jul 9 14:45 2012", "0/15 * * * *", "Mon Jul 9 15:00 2012"},
+		{"Mon Jul 9 14:59 2012", "0/15 * * * *", "Mon Jul 9 15:00 2012"},
+		{"Mon Jul 9 14:59:59 2012", "0/15 * * * *", "Mon Jul 9 15:00 2012"},
 
 		// Wrap around hours
-		{"Mon Jul 9 15:45 2012", "0 20-35/15 * * *", "Mon Jul 9 16:20 2012"},
+		{"Mon Jul 9 15:45 2012", "20-35/15 * * * *", "Mon Jul 9 16:20 2012"},
 
 		// Wrap around days
-		{"Mon Jul 9 23:46 2012", "0 */15 * * *", "Tue Jul 10 00:00 2012"},
-		{"Mon Jul 9 23:45 2012", "0 20-35/15 * * *", "Tue Jul 10 00:20 2012"},
-		{"Mon Jul 9 23:35:51 2012", "15/35 20-35/15 * * *", "Tue Jul 10 00:20:15 2012"},
-		{"Mon Jul 9 23:35:51 2012", "15/35 20-35/15 1/2 * *", "Tue Jul 10 01:20:15 2012"},
-		{"Mon Jul 9 23:35:51 2012", "15/35 20-35/15 10-12 * *", "Tue Jul 10 10:20:15 2012"},
+		{"Mon Jul 9 23:46 2012", "*/15 * * * *", "Tue Jul 10 00:00 2012"},
+		{"Mon Jul 9 23:45 2012", "20-35/15 * * * *", "Tue Jul 10 00:20 2012"},
+		{"Mon Jul 9 23:35:51 2012", "15/35 20-35/15 * * * *", "Tue Jul 10 00:20:15 2012"},
+		{"Mon Jul 9 23:35:51 2012", "15/35 20-35/15 1/2 * * *", "Tue Jul 10 01:20:15 2012"},
+		{"Mon Jul 9 23:35:51 2012", "15/35 20-35/15 10-12 * * *", "Tue Jul 10 10:20:15 2012"},
 
 		{"Mon Jul 9 23:35:51 2012", "15/35 20-35/15 1/2 */2 * *", "Thu Jul 11 01:20:15 2012"},
 		{"Mon Jul 9 23:35:51 2012", "15/35 20-35/15 * 9-20 * *", "Wed Jul 10 00:20:15 2012"},