refactor: support string value alias

mapstructure.go

@@ -18,6 +18,7 @@ func (x *XConf) defaultDecoderConfig(output interface{}) *mapstructure.DecoderCo
 		WeaklyTypedInput: true,
 		ZeroFields:       true,
 		DecodeHook: mapstructure.ComposeDecodeHookFunc(
+			StringAlias(x.cc.StringAlias, x.cc.StringAliasFunc),
 			parseEnvVarStringHookFunc(x.cc.EnvBindShouldErrorWhenFailed),
 			mapstructure.StringToTimeDurationHookFunc(),
 			mapstructure.StringToSliceHookFunc(","),
@@ -26,6 +27,24 @@ func (x *XConf) defaultDecoderConfig(output interface{}) *mapstructure.DecoderCo
 	return c
 }
 
+func StringAlias(alias map[string]string, aliasFunc map[string]func(string) string) mapstructure.DecodeHookFunc {
+	return func(
+		f reflect.Type,
+		t reflect.Type,
+		data interface{}) (interface{}, error) {
+		if f.Kind() != reflect.String {
+			return data, nil
+		}
+		if v, ok := alias[data.(string)]; ok {
+			return v, nil
+		}
+		if v, ok := aliasFunc[data.(string)]; ok {
+			return v(data.(string)), nil
+		}
+		return data, nil
+	}
+}
+
 func parseEnvVarStringHookFunc(envBindShouldErrorWhenFailed bool) mapstructure.DecodeHookFunc {
 	return func(f reflect.Type, t reflect.Type, data interface{}) (interface{}, error) {
 		if f.Kind() != reflect.String {

option.go

@@ -4,7 +4,10 @@ import (
 	"flag"
 	"io"
 	"log"
+	"math"
 	"os"
+	"runtime"
+	"strconv"
 
 	"github.com/sandwich-go/xconf/xutil"
 )
@@ -78,9 +81,27 @@ func OptionsOptionDeclareWithDefault() interface{} {
 		"TagNameForDefaultValue": string(DefaultValueTagName),
 		// annotation@ReplaceFlagSetUsage(comment="是否替换FlagSet的Usage，使用xconf内置版本")
 		"ReplaceFlagSetUsage": true,
+		// annotation@StringAlias(comment="值别名")
+		"StringAlias": (map[string]string)(map[string]string{
+			"math.MaxInt":    strconv.Itoa(math.MaxInt),
+			"math.MaxInt8":   strconv.Itoa(math.MaxInt8),
+			"math.MaxInt16":  strconv.Itoa(math.MaxInt16),
+			"math.MaxInt32":  strconv.Itoa(math.MaxInt32),
+			"math.MaxInt64":  strconv.FormatInt(math.MaxInt32, 10),
+			"math.MaxUint":   strconv.FormatUint(math.MaxUint, 10),
+			"math.MaxUint8":  strconv.FormatUint(math.MaxUint8, 10),
+			"math.MaxUint16": strconv.FormatUint(math.MaxUint16, 10),
+			"math.MaxUint32": strconv.FormatUint(math.MaxUint32, 10),
+			"math.MaxUint64": strconv.FormatUint(math.MaxUint64, 10),
+		}),
+		// annotation@StringAliasFunc(comment="值别名计算逻辑")
+		"StringAliasFunc": (map[string]func(s string) string)(map[string]func(s string) string{
+			"runtime.NumCPU": func(s string) string {
+				return strconv.Itoa(runtime.NumCPU())
+			},
+		}),
 	}
 }
-
 func init() {
 	InstallOptionsWatchDog(func(cc *Options) {
 		if cc.MapMerge {

tests/conf.go

@@ -49,6 +49,8 @@ func ConfigOptionDeclareWithDefault() interface{} {
 			"test1": 100,
 			"test2": 200,
 		},
+		"ProcessCount":    int8(1),
+		"MaxUint64":       uint64(0),
 		"Int8":            int8(1),
 		"TimeDurations":   []time.Duration([]time.Duration{time.Second, time.Second}), // @MethodComment(延迟队列)
 		"DefaultEmptyMap": map[string]int{},

tests/main/c1.yaml

@@ -42,3 +42,5 @@ redis_as_pointer:
   redis_address: 127.0.0.1:6639
 redis:
   redis_address: 127.0.0.1:6638
+process_count: runtime.NumCPU
+max_uint64: math.MaxUint64

tests/main/main.go

@@ -16,5 +16,7 @@ func main() {
 	}
 	fmt.Println("cc.RedisAsPointer.RedisAddress ", cc.RedisAsPointer.RedisAddress)
 	fmt.Println("cc.Redis.RedisAddress ", cc.Redis.RedisAddress)
+	fmt.Println("cc.ProcessCount ", cc.ProcessCount)
+	fmt.Println("cc.MaxUint64 ", cc.MaxUint64)
 	xx.Usage()
 }

xcmd/commander.go

@@ -123,6 +123,7 @@ func (c *Command) Execute(ctx context.Context, args ...string) error {
 	// 默认 usage 无参
 	ff.Usage = func() {
 		c.Explain(c.Output)
+		fmt.Fprintf(c.Output, "Flags:\n")
 		xflag.PrintDefaults(ff)
 	}
 
@@ -137,7 +138,12 @@ func (c *Command) Execute(ctx context.Context, args ...string) error {
 	return err
 }
 
+const HasParsed = "xcmd_has_parsed"
+
 func parser(ctx context.Context, c *Command, ff *flag.FlagSet, args []string, next Executer) error {
+	if v := ctx.Value(HasParsed); v != nil {
+		return next(ctx, c, ff, args)
+	}
 	if c.cc.GetBind() == nil {
 		err := ff.Parse(args)
 		if err != nil {

xcmd/explain.go

@@ -25,7 +25,7 @@ func explainGroup(w io.Writer, c *Command) {
 		fmt.Fprintf(w, "Usage: %s <subcommand> <flags> <args>\n\n", strings.Join(c.usageNamePath, " "))
 	}
 	sort.Sort(byGroupName(c.commands))
-	fmt.Fprintf(w, "Available Commands:\n\n")
+	fmt.Fprintf(w, "Available Commands:\n")
 	sort.Sort(byGroupName(c.commands))
 	var level = []bool{}
 	lines := printCommand(c, level)

xcmd/main/main.go

@@ -73,6 +73,8 @@ func main() {
 	manual.UsePre(binding)
 	xcmd.AddCommand(manual)
 
+	xcmd.Add("empty")
+
 	// panicPrintErr("comamnd check with err: %v", xcmd.Check())
 	panicPrintErr("comamnd Execute with err: %v", xcmd.Execute(context.Background(), os.Args[1:]...))
 }

xcmd/parser_xconf.go

@@ -47,6 +47,7 @@ func ParserXConf(ctx context.Context, c *Command, ff *flag.FlagSet, args []strin
 	// 更新FlagSet的Usage，使用xconf内置版本
 	cc.FlagSet.Usage = func() {
 		c.Explain(c.Output)
+		fmt.Fprintf(c.Output, "Flags:\n")
 		x.UsageToWriter(c.Output, args...)
 	}
 	err := x.Parse(c.cc.GetBind())

xflag/usage.go

@@ -75,14 +75,13 @@ func GetFlagInfo(f *flag.FlagSet) (ret FlagList) {
 func PrintDefaults(f *flag.FlagSet, suffixLines ...string) {
 	lines := make([]string, 0)
 	magic := "\x00"
-	lines = append(lines, "FLAG"+"\x00"+"ENV"+"\x00"+"TYPE"+"\x00"+"USAGE")
+	lines = append(lines, "FLAG"+"\x00"+"TYPE"+"\x00"+"USAGE")
 
 	allFlag := GetFlagInfo(f)
 	for _, v := range allFlag.List {
 		line := ""
 		line = fmt.Sprintf("--%s", v.Name)
 		line += magic
-		line += magic
 		line += v.TypeName
 		line += magic
 		line += fmt.Sprintf("|%s| %s", "-", v.Usage)