docutil: Add Transport.Has() for inclusion judgements

gen/gen.go

@@ -102,7 +102,7 @@ func (g *Generator) Generate(srcFilename, interfaceName string) (files []*genera
 		return nil, err
 	}
 
-	newSpec, transports, err := httpparser.Parse(data, g.opts.SnakeCase)
+	newSpec, transport, err := httpparser.Parse(data, g.opts.SnakeCase)
 	if err != nil {
 		return nil, err
 	}
@@ -114,54 +114,31 @@ func (g *Generator) Generate(srcFilename, interfaceName string) (files []*genera
 	}
 	files = append(files, epFile)
 
-	switch mergeTransports(transports) {
-	case docutil.TransportHTTP:
-		httpFiles, err := g.generateHTTP(data, spec)
-		if err != nil {
-			return files, err
-		}
-		files = append(files, httpFiles...)
-
-	case docutil.TransportGRPC:
-		grpcFiles, err := g.generateGRPC(data)
-		if err != nil {
-			return files, err
-		}
-		files = append(files, grpcFiles...)
-
-	case docutil.TransportEvent:
-		eventFiles, err := g.generateEvent(data, spec)
-		if err != nil {
-			return files, err
-		}
-		files = append(files, eventFiles...)
-
-	case docutil.TransportCron:
-		cronFiles, err := g.generateCron(data, spec)
-		if err != nil {
-			return files, err
-		}
-		files = append(files, cronFiles...)
-
-	case docutil.TransportAll:
+	if transport.Has(docutil.TransportHTTP) {
 		httpFiles, err := g.generateHTTP(data, spec)
 		if err != nil {
 			return files, err
 		}
 		files = append(files, httpFiles...)
+	}
 
+	if transport.Has(docutil.TransportGRPC) {
 		grpcFiles, err := g.generateGRPC(data)
 		if err != nil {
 			return files, err
 		}
 		files = append(files, grpcFiles...)
+	}
 
+	if transport.Has(docutil.TransportEvent) {
 		eventFiles, err := g.generateEvent(data, spec)
 		if err != nil {
 			return files, err
 		}
 		files = append(files, eventFiles...)
+	}
 
+	if transport.Has(docutil.TransportCron) {
 		cronFiles, err := g.generateCron(data, spec)
 		if err != nil {
 			return files, err
@@ -375,13 +352,6 @@ func (g *Generator) getPkgInfo(dir string) *generator.PkgInfo {
 	return pkgInfo
 }
 
-func mergeTransports(transports []docutil.Transport) (result docutil.Transport) {
-	for _, t := range transports {
-		result = result | t
-	}
-	return result
-}
-
 func ensureDir(path string) error {
 	return os.MkdirAll(path, 0755)
 }

gen/http/parser/parser.go

@@ -24,19 +24,19 @@ var (
 	rePathVarName = regexp.MustCompile(`{(\w+)}`)
 )
 
-func Parse(data *ifacetool.Data, snakeCase bool) (*spec.Specification, []docutil.Transport, error) {
+func Parse(data *ifacetool.Data, snakeCase bool) (*spec.Specification, docutil.Transport, error) {
 	anno, err := annotation.ParseInterfaceAnnotation(data.InterfaceDoc)
 	if err != nil {
-		return nil, nil, err
+		return nil, 0, err
 	}
 
 	s := &spec.Specification{
 		Metadata: anno.Metadata,
 	}
 
 	var (
-		transports []docutil.Transport
-		opBuilder  = &OpBuilder{
+		transport docutil.Transport
+		opBuilder = &OpBuilder{
 			snakeCase: snakeCase,
 			aliases:   anno.Aliases,
 		}
@@ -46,14 +46,14 @@ func Parse(data *ifacetool.Data, snakeCase bool) (*spec.Specification, []docutil
 		doc := docutil.Doc(m.Doc).JoinComments()
 		m.Doc = doc // Replace the original doc with joined doc.
 
-		transport := doc.Transport()
-		if transport == 0 {
+		t := doc.Transport()
+		if t == 0 {
 			// Empty transport indicates that there are no annotations.
 			continue
 		}
-		transports = append(transports, transport)
+		transport |= t
 
-		if transport&docutil.TransportHTTP != docutil.TransportHTTP {
+		if !t.Has(docutil.TransportHTTP) {
 			// Add operations for generating endpoint code for gRPC.
 			op := spec.NewOperation(m.Name, m.Name, annotation.GetDescriptionFromDoc(m.Doc))
 			for _, arg := range m.Params {
@@ -65,13 +65,13 @@ func Parse(data *ifacetool.Data, snakeCase bool) (*spec.Specification, []docutil
 
 		ops, err := opBuilder.Build(m)
 		if err != nil {
-			return nil, nil, err
+			return nil, 0, err
 		}
 
 		s.Operations = append(s.Operations, ops...)
 	}
 
-	return s, transports, nil
+	return s, transport, nil
 }
 
 type OpBuilder struct {

gen/util/docutil/docutil.go

@@ -8,12 +8,15 @@ import (
 
 type Transport int
 
+func (t Transport) Has(o Transport) bool {
+	return t&o == o
+}
+
 const (
 	TransportHTTP  Transport = 0b0001
 	TransportGRPC  Transport = 0b0010
 	TransportEvent Transport = 0b0100
 	TransportCron  Transport = 0b1000
-	TransportAll   Transport = 0b1111
 )
 
 type Doc []string