Change template

jsonenums.go

@@ -16,7 +16,6 @@
 // Given the name of a (signed or unsigned) integer type T that has constants
 // defined, jsonenums will create a new self-contained Go source file implementing
 //
-//  func (t T) String() string
 //  func (t T) MarshalJSON() ([]byte, error)
 //  func (t *T) UnmarshalJSON([]byte) error
 //
@@ -47,7 +46,6 @@
 // in the same directory will create the file pill_jsonenums.go, in package painkiller,
 // containing a definition of
 //
-//  func (r Pill) String() string
 //  func (r Pill) MarshalJSON() ([]byte, error)
 //  func (r *Pill) UnmarshalJSON([]byte) error
 //

template.go

@@ -18,7 +18,7 @@ package main
 import "text/template"
 
 var generatedTmpl = template.Must(template.New("generated").Parse(`
-// generated by jsonenums {{.Command}}; DO NOT EDIT
+// Code generated by "jsonenums {{.Command}}"; DO NOT EDIT.
 
 package {{.PackageName}}
 
@@ -30,32 +30,28 @@ import (
 {{range $typename, $values := .TypesAndValues}}
 
 var (
+	_{{$typename}}NameToValue map[string]{{$typename}}
+	_{{$typename}}ValueToName map[{{$typename}}]string
+)
+
+func init() {
 	_{{$typename}}NameToValue = map[string]{{$typename}} {
-        {{range $values}}"{{.}}": {{.}},
+		{{range $values}}{{.}}.String(): {{.}},
 		{{end}}
 	}
 
 	_{{$typename}}ValueToName = map[{{$typename}}]string {
-        {{range $values}}{{.}}: "{{.}}",
+		{{range $values}}{{.}}: {{.}}.String(),
 		{{end}}
 	}
-)
-
-func init() {
-    var v {{$typename}}
-    if _, ok := interface{}(v).(fmt.Stringer); ok {
-        _{{$typename}}NameToValue = map[string]{{$typename}} {
-            {{range $values}}interface{}({{.}}).(fmt.Stringer).String(): {{.}},
-            {{end}}
-        }
-    }
 }
 
-// MarshalJSON is generated so {{$typename}} satisfies json.Marshaler.
+// MarshalJSON implements json.Marshaler
 func (r {{$typename}}) MarshalJSON() ([]byte, error) {
 	if s, ok := interface{}(r).(fmt.Stringer); ok {
 		return json.Marshal(s.String())
 	}
+
 	s, ok := _{{$typename}}ValueToName[r]
 	if !ok {
 		return nil, fmt.Errorf("invalid {{$typename}}: %d", r)
@@ -63,16 +59,18 @@ func (r {{$typename}}) MarshalJSON() ([]byte, error) {
 	return json.Marshal(s)
 }
 
-// UnmarshalJSON is generated so {{$typename}} satisfies json.Unmarshaler.
+// UnmarshalJSON implements json.Unmarshaler
 func (r *{{$typename}}) UnmarshalJSON(data []byte) error {
 	var s string
 	if err := json.Unmarshal(data, &s); err != nil {
 		return fmt.Errorf("{{$typename}} should be a string, got %s", data)
 	}
+
 	v, ok := _{{$typename}}NameToValue[s]
 	if !ok {
-        return fmt.Errorf("invalid {{$typename}} %q", s)
+		return fmt.Errorf("invalid value: %s", s)
 	}
+
 	*r = v
 	return nil
 }