Initial drop of the parse package for DSL parsing support
Change-Id: I39e2b0b7b36f68930527968e19aaf1d16cf60dc3
diff --git a/parse/fragment.go b/parse/fragment.go
new file mode 100644
index 0000000..d74b328
--- /dev/null
+++ b/parse/fragment.go
@@ -0,0 +1,55 @@
+// Copyright (C) 2014 The Android Open Source Project
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package parse
+
+import "io"
+
+// Fragment is a component of a cst that is backed by a token.
+// This includes Nodes and all forms of space and comment.
+type Fragment interface {
+ // Token returns the underlying token of this node.
+ Token() Token
+ // Write is used to write the underlying token out to the writer.
+ WriteTo(io.Writer) error
+}
+
+// Separator is a list type to manage fragments that were skipped.
+type Separator []Fragment
+
+type fragment struct {
+ token Token
+}
+
+func (s Separator) WriteTo(w io.Writer) error {
+ for _, n := range s {
+ if err := n.WriteTo(w); err != nil {
+ return err
+ }
+ }
+ return nil
+}
+
+func (n *fragment) Token() Token {
+ return n.token
+}
+
+func (n *fragment) SetToken(token Token) {
+ n.token = token
+}
+
+func (n *fragment) WriteTo(w io.Writer) error {
+ _, err := io.WriteString(w, n.Token().String())
+ return err
+}
