go-enum/generator/enum_string.tmpl

{{- define "enum_string"}}
const (
{{- $enumName := .enum.Name -}}
{{- $enumType := .enum.Type -}}
{{- $vars := dict "lastoffset" "0" -}}
{{ range $rIndex, $value := .enum.Values }}
	{{ if eq $value.Name "_"}}// Skipped value.{{else}}// {{$value.PrefixedName}} is a {{$enumName}} of type {{$value.RawName}}.{{end}}
	{{- if $value.Comment}}
	// {{$value.Comment}}
	{{- end}}
    {{$value.PrefixedName}} {{$enumName}} = "{{$value.RawName}}"
{{- end}}
)

{{if .names -}}
var ErrInvalid{{.enum.Name}} = fmt.Errorf("not a valid {{.enum.Name}}, try [%s]", strings.Join(_{{.enum.Name}}Names, ", "))
{{- else -}}
var ErrInvalid{{.enum.Name}} = errors.New("not a valid {{.enum.Name}}")
{{- end}}

{{ if .names }}var _{{.enum.Name}}Names = {{namify .enum}}

// {{.enum.Name}}Names returns a list of possible string values of {{.enum.Name}}.
func {{.enum.Name}}Names() []string {
	tmp := make([]string, len(_{{.enum.Name}}Names))
	copy(tmp, _{{.enum.Name}}Names)
	return tmp
}
{{ end -}}

// String implements the Stringer interface.
func (x {{.enum.Name}}) String() string {
	return string(x)
}

// IsValid returns whether the string contained is a valid {{.enum.Name}}.
func (x {{.enum.Name}}) IsValid() bool {
	_, err := Parse{{.enum.Name}}(string(x))
	return err == nil
}

var _{{.enum.Name}}Value = {{ unmapify .enum .lowercase }}

// Parse{{.enum.Name}} attempts to convert a string to a {{.enum.Name}}.
func Parse{{.enum.Name}}(name string) ({{.enum.Name}}, error) {
	if x, ok := _{{.enum.Name}}Value[name]; ok {
		return x, nil
	}{{if .nocase }}
	// Case insensitive parse, do a separate lookup to prevent unnecessary cost of lowercasing a string if we don't need to.
	if x, ok := _{{.enum.Name}}Value[strings.ToLower(name)]; ok {
		return x, nil
	}{{- end}}

	return {{.enum.Name}}(""), fmt.Errorf("%s is %w", name, ErrInvalid{{.enum.Name}})
}

{{ if .mustparse }}
// MustParse{{.enum.Name}} converts a string to a {{.enum.Name}}, and panics if is not valid.
func MustParse{{.enum.Name}}(name string) {{.enum.Name}} {
	val, err := Parse{{.enum.Name}}(name)
	if err != nil {
		panic(err)
	}
	return val
}
{{end}}

{{ if .ptr }}
func (x {{.enum.Name}}) Ptr() *{{.enum.Name}} {
	return &x
}
{{end}}

{{ if .marshal }}
// MarshalText implements the text marshaller method.
func (x {{.enum.Name}}) MarshalText() ([]byte, error) {
	return []byte(string(x)), nil
}

// UnmarshalText implements the text unmarshaller method.
func (x *{{.enum.Name}}) UnmarshalText(text []byte) error {
	tmp, err := Parse{{.enum.Name}}(string(text))
	if err != nil {
		return err
	}
	*x = tmp
	return nil
}
{{end}}

{{ if or .sql .sqlint .sqluint .sqlnullint .sqlnullstr}}
var Err{{.enum.Name}}NilPtr = errors.New("value pointer is nil") // one per type for package clashes

{{ if or .sqlint .sqluint .sqlnullint }}
var _{{.enum.Name}}SqlValues = map[{{.enum.Name}}]{{if .enum.Unsigned}}u{{end}}int64{
{{- $enumName := .enum.Name -}}
{{- $enumType := .enum.Type -}}
{{ range $rIndex, $value := .enum.Values }}
    {{$value.PrefixedName}}: {{$value.Value}},
{{- end}}
}

var _{{.enum.Name}}SqlScan = map[{{if .enum.Unsigned}}u{{end}}int64]{{.enum.Name}}{
{{- $enumName := .enum.Name -}}
{{- $enumType := .enum.Type -}}
{{ range $rIndex, $value := .enum.Values }}
    {{$value.Value}}: {{$value.PrefixedName}},
{{- end}}
}
{{end}}

{{- if or .sqluint .sqlint .sqlnullint }}
func (x *{{.enum.Name}}) parseSqlInt(v int64) error{
	val, ok := _{{.enum.Name}}SqlScan[{{if .enum.Unsigned}}uint64({{end}}v{{if .enum.Unsigned}}){{end}}]
	if !ok{
		return ErrInvalid{{.enum.Name}}
	}
	*x = val
	return nil
}

func (x *{{.enum.Name}}) parseSqlUInt(v uint64) error{
	val, ok := _{{.enum.Name}}SqlScan[{{if not .enum.Unsigned}}int64({{end}}v{{if not .enum.Unsigned}}){{end}}]
	if !ok{
		return ErrInvalid{{.enum.Name}}
	}
	*x = val
	return nil
}

func (x *{{.enum.Name}}) parseSqlFloat64(v float64) error{
	val, ok := _{{.enum.Name}}SqlScan[{{if .enum.Unsigned}}u{{end}}int64(v)]
	if !ok{
		return ErrInvalid{{.enum.Name}}
	}
	*x = val
	return nil
}

func (x *{{.enum.Name}}) parseSqlString(v string)error{
	// Assume enum first
	parsed, err := Parse{{.enum.Name}}(v)
	if err != nil{
		// Assume integer
		parsedVal, err := strconv.Parse{{if .enum.Unsigned}}Ui{{else}}I{{end}}nt(v, 10, 64)
		if err != nil{
			return err
		}
		return x.parseSql{{if .enum.Unsigned}}U{{end}}Int(parsedVal)
	}
	*x = parsed
	return nil
}
{{end}}



// Scan implements the Scanner interface.
func (x *{{.enum.Name}}) Scan(value interface{}) (err error) {
	if value == nil {
		*x = {{.enum.Name}}("")
		return
	}

	// A wider range of scannable types.
	// driver.Value values at the top of the list for expediency
	switch v := value.(type) {
	{{- if or .sqlint .sqluint .sqlnullint}}
	case int64:
		err = x.parseSqlInt(v)
	case string:
		err = x.parseSqlString(v)
	case []byte:
		err = x.parseSqlString(string(v))
	case {{.enum.Name}}:
		*x = v
	case int:
		err = x.parseSqlInt(int64(v))
	case *{{.enum.Name}}:
		if v == nil{
			return Err{{.enum.Name}}NilPtr
		}
		*x = *v
	case uint:
		err = x.parseSqlUInt(uint64(v))
	case uint64:
		err = x.parseSqlUInt(v)
	case *int:
		if v == nil{
			return Err{{.enum.Name}}NilPtr
		}
		err = x.parseSqlInt(int64(*v))
	case *int64:
		if v == nil{
			return Err{{.enum.Name}}NilPtr
		}
		err = x.parseSqlInt(*v)
	case float64: // json marshals everything as a float64 if it's a number
		err = x.parseSqlFloat64(v)
	case *float64: // json marshals everything as a float64 if it's a number
		if v == nil{
			return Err{{.enum.Name}}NilPtr
		}
		err = x.parseSqlFloat64(*v)
	case *uint:
		if v == nil{
			return Err{{.enum.Name}}NilPtr
		}
		err = x.parseSqlUInt(uint64(*v))
	case *uint64:
		if v == nil{
			return Err{{.enum.Name}}NilPtr
		}
		err = x.parseSqlUInt(*v)
	case *string:
		if v == nil{
			return Err{{.enum.Name}}NilPtr
		}
		err = x.parseSqlString(*v)
	{{else}}
	case string:
		*x, err = Parse{{.enum.Name}}(v)
	case []byte:
		*x, err = Parse{{.enum.Name}}(string(v))
	case {{.enum.Name}}:
		*x = v
	case *{{.enum.Name}}:
		if v == nil{
			return Err{{.enum.Name}}NilPtr
		}
		*x = *v
	case *string:
		if v == nil{
			return Err{{.enum.Name}}NilPtr
		}
		*x, err = Parse{{.enum.Name}}(*v)
	{{end}}
	default:
		return errors.New("invalid type for {{.enum.Name}}")
	}
	
	return 
}

{{ if or .sqlint .sqluint .sqlnullint }}
// Value implements the driver Valuer interface.
func (x {{.enum.Name}}) Value() (driver.Value, error) {
	valid, err := Parse{{.enum.Name}}(string(x))
	if err != nil{
		return nil, err
	}
	val, ok := _{{.enum.Name}}SqlValues[valid]
	if !ok{
		return nil, fmt.Errorf("%s is %w", string(x), ErrInvalid{{.enum.Name}})
	}
	return {{ if .enum.Unsigned}}int64(val){{else}}val{{end}}, nil
}
{{ else }}
// Value implements the driver Valuer interface.
func (x {{.enum.Name}}) Value() (driver.Value, error) {
	valid, err := Parse{{.enum.Name}}(string(x))
	if err != nil{
		return nil, err
	}
	return string(valid), nil
}
{{end}}

{{end}}


{{ if .flag }}
// Set implements the Golang flag.Value interface func.
func (x *{{.enum.Name}}) Set(val string) error {
	v, err := Parse{{.enum.Name}}(val)
	*x = v
	return err
}

// Get implements the Golang flag.Getter interface func.
func (x *{{.enum.Name}}) Get() interface{} {
	return *x
}

// Type implements the github.com/spf13/pFlag Value interface.
func (x *{{.enum.Name}}) Type() string {
	return "{{.enum.Name}}"
}
{{end}}

{{ if or .sqlnullint .sqlnullstr }}

type Null{{.enum.Name}} struct{
	{{.enum.Name}}	{{.enum.Name}}
	Valid 					bool{{/* Add some info as to whether this value was set during unmarshalling or not */}}{{if .marshal }}
	Set							bool{{ end }}
}

func NewNull{{.enum.Name}}(val interface{}) (x Null{{.enum.Name}}) {
	err := x.Scan(val) // yes, we ignore this error, it will just be an invalid value.
	_ = err // make any errcheck linters happy
	return
}

// Scan implements the Scanner interface.
func (x *Null{{.enum.Name}}) Scan(value interface{}) (err error) {
	if value == nil {
		x.{{.enum.Name}}, x.Valid = {{.enum.Name}}(""), false
		return
	}

	err = x.{{.enum.Name}}.Scan(value)
	x.Valid = (err == nil)
	return
}

// Value implements the driver Valuer interface.
func (x Null{{.enum.Name}}) Value() (driver.Value, error) {
	if !x.Valid{
		return nil, nil
	}
	// return underlying enum's value after null is checked
	return x.{{.enum.Name}}.Value()
}

{{ if .marshal }}
// MarshalJSON correctly serializes a Null{{.enum.Name}} to JSON.
func (n Null{{.enum.Name}}) MarshalJSON() ([]byte, error) {
	const nullStr = "null"
	if n.Valid {
		return json.Marshal(n.{{.enum.Name}})
	}
	return []byte(nullStr), nil
}

// UnmarshalJSON correctly deserializes a Null{{.enum.Name}} from JSON.
func (n *Null{{.enum.Name}}) UnmarshalJSON(b []byte) error {
	n.Set = true
	var x interface{}
	err := json.Unmarshal(b, &x)
	if err != nil{
		return err
	}
	err = n.Scan(x)
	return err
}
{{ end }}

{{ end }}

{{ if and .sqlnullint .sqlnullstr }}
type Null{{.enum.Name}}Str struct {
	Null{{.enum.Name}}
}

func NewNull{{.enum.Name}}Str(val interface{}) (x Null{{.enum.Name}}Str) {
	x.Scan(val) // yes, we ignore this error, it will just be an invalid value.
	return
}

// Value implements the driver Valuer interface.
func (x Null{{.enum.Name}}Str) Value() (driver.Value, error) {
	if !x.Valid{
		return nil, nil
	}
	return x.{{.enum.Name}}.String(), nil
}
{{ if .marshal }}
// MarshalJSON correctly serializes a Null{{.enum.Name}} to JSON.
func (n Null{{.enum.Name}}Str) MarshalJSON() ([]byte, error) {
	const nullStr = "null"
	if n.Valid {
		return json.Marshal(n.{{.enum.Name}})
	}
	return []byte(nullStr), nil
}

// UnmarshalJSON correctly deserializes a Null{{.enum.Name}} from JSON.
func (n *Null{{.enum.Name}}Str) UnmarshalJSON(b []byte) error {
	n.Set = true
	var x interface{}
	err := json.Unmarshal(b, &x)
	if err != nil{
		return err
	}
	err = n.Scan(x)
	return err
}
{{ end }}
{{ end }}

{{end}}