Rename confusing method names LHS and RHS

I confused left and right in f709571
somehow or other.

protoc-gen-grpc-gateway/descriptor/types.go

@@ -216,10 +216,10 @@ type Body struct {
 	FieldPath FieldPath
 }
 
-// RHS returns a right-hand-side expression in go to be used to initialize method request object.
+// AssignableExpr returns an assignable expression in Go to be used to initialize method request object.
 // It starts with "msgExpr", which is the go expression of the method request object.
-func (b Body) RHS(msgExpr string) string {
-	return b.FieldPath.RHS(msgExpr)
+func (b Body) AssignableExpr(msgExpr string) string {
+	return b.FieldPath.AssignableExpr(msgExpr)
 }
 
 // FieldPath is a path to a field from a request message.
@@ -242,20 +242,20 @@ func (p FieldPath) IsNestedProto3() bool {
 	return false
 }
 
-// RHS is a right-hand-side expression in go to be used to assign a value to the target field.
+// AssignableExpr is an assignable expression in Go to be used to assign a value to the target field.
 // It starts with "msgExpr", which is the go expression of the method request object.
-func (p FieldPath) RHS(msgExpr string) string {
+func (p FieldPath) AssignableExpr(msgExpr string) string {
 	l := len(p)
 	if l == 0 {
 		return msgExpr
 	}
 	components := []string{msgExpr}
 	for i, c := range p {
 		if i == l-1 {
-			components = append(components, c.RHS())
+			components = append(components, c.AssignableExpr())
 			continue
 		}
-		components = append(components, c.LHS())
+		components = append(components, c.ValueExpr())
 	}
 	return strings.Join(components, ".")
 }
@@ -269,13 +269,13 @@ type FieldPathComponent struct {
 	Target *Field
 }
 
-// RHS returns a right-hand-side expression in go for this field.
-func (c FieldPathComponent) RHS() string {
+// AssignableExpr returns an assignable expression in go for this field.
+func (c FieldPathComponent) AssignableExpr() string {
 	return gogen.CamelCase(c.Name)
 }
 
-// LHS returns a left-hand-side expression in go for this field.
-func (c FieldPathComponent) LHS() string {
+// ValueExpr returns an expression in go for this field.
+func (c FieldPathComponent) ValueExpr() string {
 	if c.Target.Message.File.proto2() {
 		return fmt.Sprintf("Get%s()", gogen.CamelCase(c.Name))
 	}

protoc-gen-grpc-gateway/descriptor/types_test.go

@@ -161,22 +161,22 @@ func TestFieldPath(t *testing.T) {
 		Name:   "nest_field",
 		Target: nest2.Fields[0],
 	}
-	if got, want := c1.LHS(), "GetNestField()"; got != want {
-		t.Errorf("c1.LHS() = %q; want %q", got, want)
+	if got, want := c1.ValueExpr(), "GetNestField()"; got != want {
+		t.Errorf("c1.ValueExpr() = %q; want %q", got, want)
 	}
-	if got, want := c1.RHS(), "NestField"; got != want {
-		t.Errorf("c1.RHS() = %q; want %q", got, want)
+	if got, want := c1.AssignableExpr(), "NestField"; got != want {
+		t.Errorf("c1.AssignableExpr() = %q; want %q", got, want)
 	}
 
 	c2 := FieldPathComponent{
 		Name:   "nest2_field",
 		Target: nest.Fields[0],
 	}
-	if got, want := c2.LHS(), "Nest2Field"; got != want {
-		t.Errorf("c2.LHS() = %q; want %q", got, want)
+	if got, want := c2.ValueExpr(), "Nest2Field"; got != want {
+		t.Errorf("c2.ValueExpr() = %q; want %q", got, want)
 	}
-	if got, want := c2.LHS(), "Nest2Field"; got != want {
-		t.Errorf("c2.LHS() = %q; want %q", got, want)
+	if got, want := c2.ValueExpr(), "Nest2Field"; got != want {
+		t.Errorf("c2.ValueExpr() = %q; want %q", got, want)
 	}
 
 	fp := FieldPath{
@@ -185,8 +185,8 @@ func TestFieldPath(t *testing.T) {
 			Target: nest.Fields[1],
 		},
 	}
-	if got, want := fp.RHS("resp"), "resp.GetNestField().Nest2Field.GetNestField().TerminalField"; got != want {
-		t.Errorf("fp.RHS(%q) = %q; want %q", "resp", got, want)
+	if got, want := fp.AssignableExpr("resp"), "resp.GetNestField().Nest2Field.GetNestField().TerminalField"; got != want {
+		t.Errorf("fp.AssignableExpr(%q) = %q; want %q", "resp", got, want)
 	}
 
 	fp2 := FieldPath{
@@ -195,12 +195,12 @@ func TestFieldPath(t *testing.T) {
 			Target: nest2.Fields[1],
 		},
 	}
-	if got, want := fp2.RHS("resp"), "resp.Nest2Field.GetNestField().Nest2Field.TerminalField"; got != want {
-		t.Errorf("fp2.RHS(%q) = %q; want %q", "resp", got, want)
+	if got, want := fp2.AssignableExpr("resp"), "resp.Nest2Field.GetNestField().Nest2Field.TerminalField"; got != want {
+		t.Errorf("fp2.AssignableExpr(%q) = %q; want %q", "resp", got, want)
 	}
 
 	var fpEmpty FieldPath
-	if got, want := fpEmpty.RHS("resp"), "resp"; got != want {
-		t.Errorf("fpEmpty.RHS(%q) = %q; want %q", "resp", got, want)
+	if got, want := fpEmpty.AssignableExpr("resp"), "resp"; got != want {
+		t.Errorf("fpEmpty.AssignableExpr(%q) = %q; want %q", "resp", got, want)
 	}
 }

protoc-gen-grpc-gateway/gengateway/template.go

@@ -208,7 +208,7 @@ var (
 	var metadata runtime.ServerMetadata
 {{if .Body}}
 	if req.ContentLength > 0 {
-		if err := marshaler.NewDecoder(req.Body).Decode(&{{.Body.RHS "protoReq"}}); err != nil {
+		if err := marshaler.NewDecoder(req.Body).Decode(&{{.Body.AssignableExpr "protoReq"}}); err != nil {
 			return nil, metadata, status.Errorf(codes.InvalidArgument, "%v", err)
 		}
 	}
@@ -228,7 +228,7 @@ var (
 {{if $param.IsNestedProto3 }}
 	err = runtime.PopulateFieldFromPath(&protoReq, {{$param | printf "%q"}}, val)
 {{else}}
-	{{$param.RHS "protoReq"}}, err = {{$param.ConvertFuncExpr}}(val)
+	{{$param.AssignableExpr "protoReq"}}, err = {{$param.ConvertFuncExpr}}(val)
 {{end}}
 	if err != nil {
 		return nil, metadata, status.Errorf(codes.InvalidArgument, "type mismatch, parameter: %s, error: %v", {{$param | printf "%q"}}, err)