rework map and slice support

Signed-off-by: Vasiliy Tolstov <v.tolstov@unistack.org>

flag.go

@@ -53,7 +53,15 @@ func (c *flagConfig) Init(opts ...config.Option) error {
 
 		rcheck := true
 
-		switch sf.Value.Interface().(type) {
+		if !sf.Value.IsValid() {
+			continue
+		}
+		vi := sf.Value.Interface()
+		if vi == nil {
+			continue
+		}
+
+		switch vi.(type) {
 		case time.Duration:
 			err = c.flagDuration(sf.Value, fn, fv, fd)
 			rcheck = false

flag_test.go

@@ -17,6 +17,10 @@ func TestLoad(t *testing.T) {
 	os.Args = append(os.Args, "-addr", "33,44")
 	os.Args = append(os.Args, "-time", time.RFC822)
 	os.Args = append(os.Args, "-metadata", "key=20")
+	os.Args = append(os.Args, "-components", "all=info,api=debug")
+	type NestedConfig struct {
+		Value string `flag:"name=nested_value"`
+	}
 	type Config struct {
 		Broker         string            `flag:"name=broker,desc='description with, comma',default='127.0.0.1:9092'"`
 		Verbose        bool              `flag:"name=verbose,desc='verbose output',default='false'"`
@@ -27,10 +31,12 @@ func TestLoad(t *testing.T) {
 		WithoutDefault string            `flag:"name=without_default,desc='with'"`
 		WithoutDesc    string            `flag:"name=without_desc,default='without_default'"`
 		WithoutAll     string            `flag:"name=without_all"`
+		Components     map[string]string `flag:"name=components,desc='components logging'"`
+		Nested         *NestedConfig
 	}
 
 	ctx := context.Background()
-	cfg := &Config{}
+	cfg := &Config{Nested: &NestedConfig{}}
 
 	c := NewConfig(config.Struct(cfg), TimeFormat(time.RFC822))
 	if err := c.Init(); err != nil {
@@ -47,4 +53,8 @@ func TestLoad(t *testing.T) {
 	if tf := cfg.Time.Format(time.RFC822); tf != "02 Jan 06 15:04 MST" {
 		t.Fatalf("parse time error: %s != %s", tf, "02 Jan 06 15:04 MST")
 	}
+
+	if len(cfg.Components) != 2 {
+		t.Fatalf("cant parse map components %#+v", cfg)
+	}
 }

util.go

@@ -2,12 +2,131 @@ package flag
 
 import (
 	"flag"
+	"fmt"
 	"reflect"
 	"strconv"
 	"strings"
 	"time"
 )
 
+type mapValue struct {
+	v     reflect.Value
+	delim string
+	def   string
+}
+
+func (v mapValue) String() string {
+	if v.v.Kind() != reflect.Invalid {
+		var kv []string
+		it := v.v.MapRange()
+		for it.Next() {
+			k := it.Key().Interface()
+			v := it.Value().Interface()
+			kv = append(kv, fmt.Sprintf("%v=%v", k, v))
+		}
+		return strings.Join(kv, ",")
+	}
+	return v.def
+}
+
+func (v mapValue) Set(s string) error {
+	ps := strings.Split(s, v.delim)
+	if len(ps) == 0 {
+		return nil
+	}
+	v.v.Set(reflect.MakeMapWithSize(v.v.Type(), len(ps)))
+	kt := v.v.Type().Key().Kind()
+	vt := v.v.Type().Elem().Kind()
+
+	for i := 0; i < len(ps); i++ {
+		fs := strings.Split(ps[i], "=")
+		switch len(fs) {
+		case 0:
+			return nil
+		case 1:
+			if len(fs[0]) == 0 {
+				return nil
+			}
+			return ErrInvalidValue
+		case 2:
+			break
+		default:
+			return ErrInvalidValue
+		}
+		key, err := convertType(reflect.ValueOf(fs[0]), kt)
+		if err != nil {
+			return err
+		}
+		val, err := convertType(reflect.ValueOf(fs[1]), vt)
+		if err != nil {
+			return err
+		}
+		v.v.SetMapIndex(key.Convert(v.v.Type().Key()), val.Convert(v.v.Type().Elem()))
+	}
+	return nil
+}
+
+type sliceValue struct {
+	v     reflect.Value
+	delim string
+	def   string
+}
+
+func (v sliceValue) String() string {
+	if v.v.Kind() != reflect.Invalid {
+		var kv []string
+		for idx := 0; idx < v.v.Len(); idx++ {
+			kv = append(kv, fmt.Sprintf("%v", v.v.Index(idx).Interface()))
+		}
+		return strings.Join(kv, ",")
+	}
+	return v.def
+}
+
+func (v sliceValue) Set(s string) error {
+	p := strings.Split(s, v.delim)
+	v.v.Set(reflect.MakeSlice(v.v.Type(), len(p), len(p)))
+	switch v.v.Type().Elem().Kind() {
+	case reflect.Int, reflect.Int64:
+		for idx := range p {
+			i, err := strconv.ParseInt(p[idx], 10, 64)
+			if err != nil {
+				return err
+			}
+			v.v.Index(idx).SetInt(i)
+		}
+	case reflect.Uint, reflect.Uint64:
+		for idx := range p {
+			i, err := strconv.ParseUint(p[idx], 10, 64)
+			if err != nil {
+				return err
+			}
+			v.v.Index(idx).SetUint(i)
+		}
+	case reflect.Float64:
+		for idx := range p {
+			i, err := strconv.ParseFloat(p[idx], 64)
+			if err != nil {
+				return err
+			}
+			v.v.Index(idx).SetFloat(i)
+		}
+	case reflect.Bool:
+		for idx := range p {
+			i, err := strconv.ParseBool(p[idx])
+			if err != nil {
+				return err
+			}
+			v.v.Index(idx).SetBool(i)
+		}
+	case reflect.String:
+		for idx := range p {
+			v.v.Index(idx).SetString(p[idx])
+		}
+	}
+	return nil
+}
+
 func convertType(v reflect.Value, t reflect.Kind) (reflect.Value, error) {
 	switch v.Kind() {
 	case reflect.String:
@@ -51,50 +170,12 @@ func (c *flagConfig) flagSlice(v reflect.Value, fn, fv, fd string) error {
 		}
 	}
 
-	flag.Func(fn, fd, func(s string) error {
-		p := strings.Split(s, delim)
-		v.Set(reflect.MakeSlice(v.Type(), len(p), len(p)))
-		switch v.Type().Elem().Kind() {
-		case reflect.Int, reflect.Int64:
-			for idx := range p {
-				i, err := strconv.ParseInt(p[idx], 10, 64)
-				if err != nil {
+	v.Set(reflect.MakeSlice(v.Type(), 0, 0))
+	mp := &sliceValue{v: v, def: fv, delim: delim}
+	if err := mp.Set(fv); err != nil {
 		return err
 	}
-				v.Index(idx).SetInt(i)
-			}
-		case reflect.Uint, reflect.Uint64:
-			for idx := range p {
-				i, err := strconv.ParseUint(p[idx], 10, 64)
-				if err != nil {
-					return err
-				}
-				v.Index(idx).SetUint(i)
-			}
-		case reflect.Float64:
-			for idx := range p {
-				i, err := strconv.ParseFloat(p[idx], 64)
-				if err != nil {
-					return err
-				}
-				v.Index(idx).SetFloat(i)
-			}
-		case reflect.Bool:
-			for idx := range p {
-				i, err := strconv.ParseBool(p[idx])
-				if err != nil {
-					return err
-				}
-				v.Index(idx).SetBool(i)
-			}
-		case reflect.String:
-			for idx := range p {
-				v.Index(idx).SetString(p[idx])
-			}
-		}
-		return nil
-	})
-
+	flag.Var(mp, fn, fd)
 	return nil
 }
 
@@ -105,43 +186,12 @@ func (c *flagConfig) flagMap(v reflect.Value, fn, fv, fd string) error {
 			delim = d
 		}
 	}
-	flag.Func(fn, fv, func(s string) error {
-		ps := strings.Split(s, delim)
-		if len(ps) == 0 {
-			return nil
-		}
-		v.Set(reflect.MakeMapWithSize(v.Type(), len(ps)))
-		kt := v.Type().Key().Kind()
-		vt := v.Type().Elem().Kind()
-
-		for i := 0; i < len(ps); i++ {
-			fs := strings.Split(ps[i], "=")
-			switch len(fs) {
-			case 0:
-				return nil
-			case 1:
-				if len(fs[0]) == 0 {
-					return nil
-				}
-				return ErrInvalidValue
-			case 2:
-				break
-			default:
-				return ErrInvalidValue
-			}
-			key, err := convertType(reflect.ValueOf(fs[0]), kt)
-			if err != nil {
+	v.Set(reflect.MakeMapWithSize(v.Type(), 0))
+	mp := &mapValue{v: v, def: fv, delim: delim}
+	if err := mp.Set(fv); err != nil {
 		return err
 	}
-			val, err := convertType(reflect.ValueOf(fs[1]), vt)
-			if err != nil {
-				return err
-			}
-			v.SetMapIndex(key.Convert(v.Type().Key()), val.Convert(v.Type().Elem()))
-		}
-		return nil
-	})
-
+	flag.Var(mp, fn, fd)
 	return nil
 }
 
@@ -277,35 +327,74 @@ func (c *flagConfig) flagStringSlice(v reflect.Value, fn, fv, fd string) error {
 }
 
 func getFlagOpts(tf string) (string, string, string) {
-	ret := make([]string, 3)
-	vals := strings.Split(tf, ",")
-	f := 0
-	for _, val := range vals {
-		p := strings.Split(val, "=")
-		switch p[0] {
-		case "name":
-			f = 0
-		case "desc":
-			f = 1
-		case "default":
-			f = 2
-		default:
-			ret[f] += "," + val
-			continue
-		}
-		ret[f] = p[1]
-	}
+	var name, desc, def string
+	delim := ","
 
-	for idx := range ret {
-		if len(ret[idx]) == 0 {
+	var buf string
+	for idx := 0; idx < len(tf); idx++ {
+		buf += string(tf[idx])
+		switch buf {
+		case "name":
+			ndx := idx + 2
+			stop := ","
+			var quote bool
+			for ; ndx < len(tf); ndx++ {
+				if string(tf[ndx]) == stop {
+					if quote {
+						ndx++
+					}
+					break
+				}
+				if string(tf[ndx]) == "'" {
+					stop = "'"
+					quote = true
 					continue
 				}
-		if ret[idx][0] == '\'' {
-			ret[idx] = ret[idx][1:]
+				name += string(tf[ndx])
 			}
-		if ret[idx][len(ret[idx])-1] == '\'' {
-			ret[idx] = ret[idx][:len(ret[idx])-1]
+			idx = ndx
+			buf = ""
+		case "desc":
+			ndx := idx + 2
+			stop := ","
+			var quote bool
+			for ; ndx < len(tf); ndx++ {
+				if string(tf[ndx]) == stop {
+					if quote {
+						ndx++
+					}
+					break
+				}
+				if string(tf[ndx]) == "'" {
+					stop = "'"
+					quote = true
+					continue
+				}
+				desc += string(tf[ndx])
+			}
+			idx = ndx
+			buf = ""
+		case "default":
+			ndx := idx + 2
+			stop := ","
+			var quote bool
+			for ; ndx < len(tf); ndx++ {
+				if string(tf[ndx]) == stop && (stop != delim) {
+					if quote {
+						ndx++
+					}
+					break
+				}
+				if string(tf[ndx]) == "'" {
+					stop = "'"
+					quote = true
+					continue
+				}
+				def += string(tf[ndx])
+			}
+			idx = ndx
+			buf = ""
 		}
 	}
-	return ret[0], ret[1], ret[2]
+	return name, desc, def
 }