first commit

pkg/duration_fmt/units.go

@@ -0,0 +1,107 @@
+package duration_fmt
+
+import (
+	"fmt"
+	"strings"
+)
+
+// DefaultUnitsCoder default units coder using `":"` as PluralSep and `","` as UnitsSep
+var DefaultUnitsCoder = UnitsCoder{":", ","}
+
+// Unit the pair of singular and plural units
+type Unit struct {
+	Singular, Plural string
+}
+
+// Units duration units
+type Units struct {
+	Year, Week, Day, Hour, Minute,
+	Second, Millisecond, Microsecond Unit
+}
+
+// Units return a slice of units
+func (u Units) Units() []Unit {
+	return []Unit{u.Year, u.Week, u.Day, u.Hour, u.Minute,
+		u.Second, u.Millisecond, u.Microsecond}
+}
+
+// UnitsCoder the units encoder and decoder
+type UnitsCoder struct {
+	// PluralSep char to sep singular and plural pair.
+	// Example with char `":"`: `"year:year"` (english) or `"mês:meses"` (portuguese)
+	PluralSep,
+	// UnitsSep char to sep units (singular and plural pairs).
+	// Example with char `","`: `"year:year,week:weeks"` (english) or `"mês:meses,semana:semanas"` (portuguese)
+	UnitsSep string
+}
+
+// Encode encodes input Units to string
+// Examples with `UnitsCoder{PluralSep: ":", UnitsSep = ","}`
+// 	- singular and plural pair units: `"year:wers,week:weeks,day:days,hour:hours,minute:minutes,second:seconds,millisecond:millliseconds,microsecond:microsseconds"`
+func (coder UnitsCoder) Encode(units Units) string {
+	var pairs = make([]string, 8)
+	for i, u := range units.Units() {
+		pairs[i] = u.Singular + coder.PluralSep + u.Plural
+	}
+	return strings.Join(pairs, coder.UnitsSep)
+}
+
+// Decode decodes input string to Units.
+// The input must follow the following formats:
+// - Unit format (singular and plural pair)
+// 	- must singular (the plural receives 's' character as suffix)
+//	- singular and plural: separated by `PluralSep` char
+//		Example with char `":"`: `"year:year"` (english) or `"mês:meses"` (portuguese)
+// - Units format (pairs of  Year, Week, Day, Hour, Minute,
+//	Second, Millisecond and Microsecond units) separated by `UnitsSep` char
+// 	- Examples with `UnitsCoder{PluralSep: ":", UnitsSep = ","}`
+// 		- must singular units: `"year,week,day,hour,minute,second,millisecond,microsecond"`
+// 		- mixed units: `"year,week:weeks,day,hour,minute:minutes,second,millisecond,microsecond"`
+// 		- singular and plural pair units: `"year:wers,week:weeks,day:days,hour:hours,minute:minutes,second:seconds,millisecond:millliseconds,microsecond:microsseconds"`
+func (coder UnitsCoder) Decode(s string) (units Units, err error) {
+	parts := strings.Split(s, coder.UnitsSep)
+	if len(parts) != 8 {
+		err = fmt.Errorf("bad parts length")
+		return units, err
+	}
+
+	var parse = func(name, part string, u *Unit) bool {
+		ps := strings.Split(part, coder.PluralSep)
+		switch len(ps) {
+		case 1:
+			u.Singular, u.Plural = ps[0], ps[0]
+		case 2:
+			u.Singular, u.Plural = ps[0], ps[1]
+		default:
+			err = fmt.Errorf("bad unit %q pair length", name)
+			return false
+		}
+		return true
+	}
+
+	if !parse("Year", parts[0], &units.Year) {
+		return units, err
+	}
+	if !parse("Week", parts[1], &units.Week) {
+		return units, err
+	}
+	if !parse("Day", parts[2], &units.Day) {
+		return units, err
+	}
+	if !parse("Hour", parts[3], &units.Hour) {
+		return units, err
+	}
+	if !parse("Minute", parts[4], &units.Minute) {
+		return units, err
+	}
+	if !parse("Second", parts[5], &units.Second) {
+		return units, err
+	}
+	if !parse("Millisecond", parts[6], &units.Millisecond) {
+		return units, err
+	}
+	if !parse("Microsecond", parts[7], &units.Microsecond) {
+		return units, err
+	}
+	return units, err
+}