Skip to content

HTTPS clone URL

Subversion checkout URL

You can clone with
or
.
Download ZIP
Branch: master
Fetching contributors…

Cannot retrieve contributors at this time

378 lines (287 sloc) 7.336 kB
// Copyright 2012 Jesse van den Kieboom. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package flags
import (
"fmt"
"reflect"
"strconv"
"strings"
"time"
)
// Marshaler is the interface implemented by types that can marshal themselves
// to a string representation of the flag.
type Marshaler interface {
// MarshalFlag marshals a flag value to its string representation.
MarshalFlag() (string, error)
}
// Unmarshaler is the interface implemented by types that can unmarshal a flag
// argument to themselves. The provided value is directly passed from the
// command line.
type Unmarshaler interface {
// UnmarshalFlag unmarshals a string value representation to the flag
// value (which therefore needs to be a pointer receiver).
UnmarshalFlag(value string) error
}
func getBase(options multiTag, base int) (int, error) {
sbase := options.Get("base")
var err error
var ivbase int64
if sbase != "" {
ivbase, err = strconv.ParseInt(sbase, 10, 32)
base = int(ivbase)
}
return base, err
}
func convertMarshal(val reflect.Value) (bool, string, error) {
// Check first for the Marshaler interface
if val.Type().NumMethod() > 0 && val.CanInterface() {
if marshaler, ok := val.Interface().(Marshaler); ok {
ret, err := marshaler.MarshalFlag()
return true, ret, err
}
}
return false, "", nil
}
func convertToString(val reflect.Value, options multiTag) (string, error) {
if ok, ret, err := convertMarshal(val); ok {
return ret, err
}
tp := val.Type()
// Support for time.Duration
if tp == reflect.TypeOf((*time.Duration)(nil)).Elem() {
stringer := val.Interface().(fmt.Stringer)
return stringer.String(), nil
}
switch tp.Kind() {
case reflect.String:
return val.String(), nil
case reflect.Bool:
if val.Bool() {
return "true", nil
}
return "false", nil
case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
base, err := getBase(options, 10)
if err != nil {
return "", err
}
return strconv.FormatInt(val.Int(), base), nil
case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64:
base, err := getBase(options, 10)
if err != nil {
return "", err
}
return strconv.FormatUint(val.Uint(), base), nil
case reflect.Float32, reflect.Float64:
return strconv.FormatFloat(val.Float(), 'g', -1, tp.Bits()), nil
case reflect.Slice:
if val.Len() == 0 {
return "", nil
}
ret := "["
for i := 0; i < val.Len(); i++ {
if i != 0 {
ret += ", "
}
item, err := convertToString(val.Index(i), options)
if err != nil {
return "", err
}
ret += item
}
return ret + "]", nil
case reflect.Map:
ret := "{"
for i, key := range val.MapKeys() {
if i != 0 {
ret += ", "
}
keyitem, err := convertToString(key, options)
if err != nil {
return "", err
}
item, err := convertToString(val.MapIndex(key), options)
if err != nil {
return "", err
}
ret += keyitem + ":" + item
}
return ret + "}", nil
case reflect.Ptr:
return convertToString(reflect.Indirect(val), options)
case reflect.Interface:
if !val.IsNil() {
return convertToString(val.Elem(), options)
}
}
return "", nil
}
func convertUnmarshal(val string, retval reflect.Value) (bool, error) {
if retval.Type().NumMethod() > 0 && retval.CanInterface() {
if unmarshaler, ok := retval.Interface().(Unmarshaler); ok {
return true, unmarshaler.UnmarshalFlag(val)
}
}
if retval.Type().Kind() != reflect.Ptr && retval.CanAddr() {
return convertUnmarshal(val, retval.Addr())
}
if retval.Type().Kind() == reflect.Interface && !retval.IsNil() {
return convertUnmarshal(val, retval.Elem())
}
return false, nil
}
func convert(val string, retval reflect.Value, options multiTag) error {
if ok, err := convertUnmarshal(val, retval); ok {
return err
}
tp := retval.Type()
// Support for time.Duration
if tp == reflect.TypeOf((*time.Duration)(nil)).Elem() {
parsed, err := time.ParseDuration(val)
if err != nil {
return err
}
retval.SetInt(int64(parsed))
return nil
}
switch tp.Kind() {
case reflect.String:
retval.SetString(val)
case reflect.Bool:
if val == "" {
retval.SetBool(true)
} else {
b, err := strconv.ParseBool(val)
if err != nil {
return err
}
retval.SetBool(b)
}
case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
base, err := getBase(options, 10)
if err != nil {
return err
}
parsed, err := strconv.ParseInt(val, base, tp.Bits())
if err != nil {
return err
}
retval.SetInt(parsed)
case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64:
base, err := getBase(options, 10)
if err != nil {
return err
}
parsed, err := strconv.ParseUint(val, base, tp.Bits())
if err != nil {
return err
}
retval.SetUint(parsed)
case reflect.Float32, reflect.Float64:
parsed, err := strconv.ParseFloat(val, tp.Bits())
if err != nil {
return err
}
retval.SetFloat(parsed)
case reflect.Slice:
elemtp := tp.Elem()
elemvalptr := reflect.New(elemtp)
elemval := reflect.Indirect(elemvalptr)
if err := convert(val, elemval, options); err != nil {
return err
}
retval.Set(reflect.Append(retval, elemval))
case reflect.Map:
parts := strings.SplitN(val, ":", 2)
key := parts[0]
var value string
if len(parts) == 2 {
value = parts[1]
}
keytp := tp.Key()
keyval := reflect.New(keytp)
if err := convert(key, keyval, options); err != nil {
return err
}
valuetp := tp.Elem()
valueval := reflect.New(valuetp)
if err := convert(value, valueval, options); err != nil {
return err
}
if retval.IsNil() {
retval.Set(reflect.MakeMap(tp))
}
retval.SetMapIndex(reflect.Indirect(keyval), reflect.Indirect(valueval))
case reflect.Ptr:
if retval.IsNil() {
retval.Set(reflect.New(retval.Type().Elem()))
}
return convert(val, reflect.Indirect(retval), options)
case reflect.Interface:
if !retval.IsNil() {
return convert(val, retval.Elem(), options)
}
}
return nil
}
func isPrint(s string) bool {
for _, c := range s {
if !strconv.IsPrint(c) {
return false
}
}
return true
}
func quoteIfNeeded(s string) string {
if !isPrint(s) {
return strconv.Quote(s)
}
return s
}
func quoteIfNeededV(s []string) []string {
ret := make([]string, len(s))
for i, v := range s {
ret[i] = quoteIfNeeded(v)
}
return ret
}
func quoteV(s []string) []string {
ret := make([]string, len(s))
for i, v := range s {
ret[i] = strconv.Quote(v)
}
return ret
}
func unquoteIfPossible(s string) (string, error) {
if len(s) == 0 || s[0] != '"' {
return s, nil
}
return strconv.Unquote(s)
}
func wrapText(s string, l int, prefix string) string {
// Basic text wrapping of s at spaces to fit in l
var ret string
s = strings.TrimSpace(s)
for len(s) > l {
// Try to split on space
suffix := ""
pos := strings.LastIndex(s[:l], " ")
if pos < 0 {
pos = l - 1
suffix = "-\n"
}
if len(ret) != 0 {
ret += "\n" + prefix
}
ret += strings.TrimSpace(s[:pos]) + suffix
s = strings.TrimSpace(s[pos:])
}
if len(s) > 0 {
if len(ret) != 0 {
ret += "\n" + prefix
}
return ret + s
}
return ret
}
Jump to Line
Something went wrong with that request. Please try again.