Merge pull request #125 from noisyscanner/master

Add lowerCamelCase naming strategy

README.md

@@ -49,6 +49,8 @@ Usage of easyjson:
     	process the whole package instead of just the given file
   -snake_case
     	use snake_case names instead of CamelCase by default
+  -lower_camel_case
+        use lowerCamelCase instead of CamelCase by default
   -stubs
     	only generate stubs for marshaler/unmarshaler funcs
 ```

bootstrap/bootstrap.go

@@ -24,6 +24,7 @@ type Generator struct {
 
 	NoStdMarshalers bool
 	SnakeCase       bool
+	LowerCamelCase  bool
 	OmitEmpty       bool
 
 	OutName   string
@@ -110,6 +111,9 @@ func (g *Generator) writeMain() (path string, err error) {
 	if g.SnakeCase {
 		fmt.Fprintln(f, "  g.UseSnakeCase()")
 	}
+	if g.LowerCamelCase {
+		fmt.Fprintln(f, "  g.UseLowerCamelCase()")
+	}
 	if g.OmitEmpty {
 		fmt.Fprintln(f, "  g.OmitEmpty()")
 	}

easyjson/main.go

@@ -18,6 +18,7 @@ import (
 
 var buildTags = flag.String("build_tags", "", "build tags to add to generated file")
 var snakeCase = flag.Bool("snake_case", false, "use snake_case names instead of CamelCase by default")
+var lowerCamelCase = flag.Bool("lower_camel_case", false, "use lowerCamelCase names instead of CamelCase by default")
 var noStdMarshalers = flag.Bool("no_std_marshalers", false, "don't generate MarshalJSON/UnmarshalJSON funcs")
 var omitEmpty = flag.Bool("omit_empty", false, "omit empty fields by default")
 var allStructs = flag.Bool("all", false, "generate marshaler/unmarshalers for all structs in a file")
@@ -59,6 +60,7 @@ func generate(fname string) (err error) {
 		PkgName:         p.PkgName,
 		Types:           p.StructNames,
 		SnakeCase:       *snakeCase,
+		LowerCamelCase:  *lowerCamelCase,
 		NoStdMarshalers: *noStdMarshalers,
 		OmitEmpty:       *omitEmpty,
 		LeaveTemps:      *leaveTemps,

gen/generator.go

@@ -99,6 +99,11 @@ func (g *Generator) UseSnakeCase() {
 	g.fieldNamer = SnakeCaseFieldNamer{}
 }
 
+// UseLowerCamelCase sets lowerCamelCase field naming strategy.
+func (g *Generator) UseLowerCamelCase() {
+	g.fieldNamer = LowerCamelCaseFieldNamer{}
+}
+
 // NoStdMarshalers instructs not to generate standard MarshalJSON/UnmarshalJSON
 // methods (only the custom interface).
 func (g *Generator) NoStdMarshalers() {
@@ -374,6 +379,74 @@ func (DefaultFieldNamer) GetJSONFieldName(t reflect.Type, f reflect.StructField)
 	}
 }
 
+// LowerCamelCaseFieldNamer
+type LowerCamelCaseFieldNamer struct {}
+
+func isLower(b byte) bool {
+	return b <= 122 && b >= 97
+}
+
+func isUpper(b byte) bool {
+	return b >= 65 && b <= 90
+}
+
+func isNumeric(b byte) bool {
+	return b >= 48 && b <= 57
+}
+// convert HTTPRestClient to httpRestClient
+func lowerFirst(s string) string {
+	if s == "" {
+		return ""
+	}
+
+	str := ""
+	strlen := len(s)
+
+	/**
+	  Loop each char
+	  If is uppercase:
+	    If is first char, LOWER it
+	    If the following char is lower, LEAVE it
+	    If the following char is upper OR numeric, LOWER it
+	    If is the end of string, LEAVE it
+	  Else lowercase
+	 */
+
+	foundLower := false
+	for i := range s {
+		ch := s[i]
+		if isUpper(ch) {
+			if i == 0 {
+				str += string(ch + 32)
+			} else if !foundLower { // Currently just a stream of capitals, eg JSONRESTS[erver]
+				if strlen > (i+1) && isLower(s[i+1]) {
+					// Next char is lower, keep this a capital
+					str += string(ch)
+				} else {
+					// Either at end of string or next char is capital
+					str += string(ch + 32)
+				}
+			} else {
+				str += string(ch)
+			}
+		} else {
+			foundLower = true
+			str += string(ch)
+		}
+	}
+
+	return str
+}
+
+func (LowerCamelCaseFieldNamer) GetJSONFieldName(t reflect.Type, f reflect.StructField) string {
+	jsonName := strings.Split(f.Tag.Get("json"), ",")[0]
+	if jsonName != "" {
+		return jsonName
+	} else {
+		return lowerFirst(f.Name)
+	}
+}
+
 // SnakeCaseFieldNamer implements CamelCase to snake_case conversion for fields names.
 type SnakeCaseFieldNamer struct{}
 

gen/generator_test.go

@@ -28,6 +28,28 @@ func TestCamelToSnake(t *testing.T) {
 	}
 }
 
+func TestCamelToLowerCamel(t *testing.T) {
+	for i, test := range []struct {
+		In, Out string
+	}{
+		{"", ""},
+		{"A", "a"},
+		{"SimpleExample", "simpleExample"},
+		{"internalField", "internalField"},
+
+		{"SomeHTTPStuff", "someHTTPStuff"},
+		{"WriteJSON", "writeJSON"},
+		{"HTTP2Server", "http2Server"},
+
+		{"JSONHTTPRPCServer", "jsonhttprpcServer"}, // nothing can be done here without a dictionary
+	} {
+		got := lowerFirst(test.In)
+		if got != test.Out {
+			t.Errorf("[%d] lowerFirst(%s) = %s; want %s", i, test.In, got, test.Out)
+		}
+	}
+}
+
 func TestJoinFunctionNameParts(t *testing.T) {
 	for i, test := range []struct {
 		keepFirst bool