string array

stringarray.go

import (
	"encoding/json"
	"strings"
)

type String struct {
	isArray   bool
	stringVal string
	arrayVal  []string
}

func (a *String) UnmarshalJSON(data []byte) error {
	if data[0] == '[' {
		a.isArray = true
		return json.Unmarshal(data, &a.arrayVal)
	}
	return json.Unmarshal(data, &a.stringVal)
}

func (a *String) MarshalJSON() ([]byte, error) {
	if a.isArray {
		return json.Marshal(&a.arrayVal)
	}
	return json.Marshal(&a.stringVal)
}

func (a String) IsArray() bool {
	return a.isArray
}

func (a String) ToArray() []string {
	return a.arrayVal[:]
}

func (a String) ToString() string {
	return a.stringVal
}

func (a String) MustToArray() []string {
	if !a.isArray {
		return []string{a.ToString()}
	}
	return a.ToArray()
}

func (a String) Length() int {
	if a.isArray {
		return len(a.arrayVal)
	}
	return 1
}

func (a String) String() string {
	if a.isArray {
		return strings.Join(a.arrayVal, ",")
	}
	return a.stringVal
}

func (a String) Clone() *String {
	newA := &String{isArray: a.isArray}
	if a.isArray {
		newA.arrayVal = make([]string, len(a.arrayVal))
		copy(newA.arrayVal, a.arrayVal)
	} else {
		newA.stringVal = a.stringVal
	}
	return newA
}

func (a String) Foreach(fn func(s string)) {
	array := a.MustToArray()
	for _, s := range array {
		fn(s)
	}
}

func (a String) Map(fn func(s string) string) *String {
	if a.IsArray() {
		array := make([]string, len(a.arrayVal))
		for i, s := range a.arrayVal {
			array[i] = fn(s)
		}
		return NewString(array...)
	} else {
		return NewString(fn(a.stringVal))
	}
}

func (a String) Join(delimiter string) string {
	return strings.Join(a.MustToArray(), delimiter)
}

func NewString(str ...string) *String {
	if len(str) > 1 {
		a := &String{isArray: true, arrayVal: str}
		return a
	}
	return &String{stringVal: str[0]}
}