Path: Add new interfaces

Also expose component builder to outside

Signed-off-by: Richard Kosegi <richard.kosegi@gmail.com>

path/builder.go

@@ -32,17 +32,26 @@ func (b *builder) Build() Path {
 }
 
 func (b *builder) Append(opts ...AppendOpt) Builder {
+	b.components = append(b.components, *buildComponent(opts...))
+	return b
+}
+
+// NewBuilder creates new Builder
+func NewBuilder() Builder {
+	return &builder{}
+}
+
+func buildComponent(opts ...AppendOpt) *component {
 	if len(opts) == 0 {
 		panic("no append option provided by caller")
 	}
 	c := &component{}
 	for _, opt := range opts {
 		opt(c)
 	}
-	b.components = append(b.components, *c)
-	return b
+	return c
 }
 
-func NewBuilder() Builder {
-	return &builder{}
+func BuildComponent(opts ...AppendOpt) Component {
+	return buildComponent(opts...)
 }

path/builder_test.go

@@ -49,7 +49,7 @@ func TestBuilderAppendNoOption(t *testing.T) {
 	defer func() {
 		recover()
 	}()
-	NewBuilder().Append()
+	BuildComponent()
 	assert.Fail(t, "should not be here")
 }
 

path/types.go

@@ -63,3 +63,15 @@ type Path interface {
 }
 
 type AppendOpt func(*component)
+
+// Parser interface is implemented by different Path syntax parsers.
+type Parser interface {
+	// Parse parses source string into Path
+	Parse(string) (Path, error)
+}
+
+// Serializer is interface that allows to serialize Path into lexical form
+type Serializer interface {
+	// Serialize serializes path into lexical representation
+	Serialize(Path) string
+}