1 files changed, 50 insertions, 0 deletions
diff --git a/pkg/query/query.go b/pkg/query/query.go
new file mode 100644
index 0000000..b712370
--- /dev/null
+++ b/pkg/query/query.go
@@ -0,0 +1,50 @@
+package query
+
+
+type Node struct {
+	Parent   *Node
+	Children []*Node
+	Token
+}
+
+type AST struct {
+	root Node
+	size uint64
+}
+
+// Walk an ast depth first
+func (T AST) dfWalk() func() (*Node, bool) {
+	stack := nodeStack{make([]*Node, 0, T.size)}
+	stack.Push(&T.root)
+
+	return func() (*Node, bool) {
+		n := stack.Pop()
+		for _, child := range n.Children {
+			stack.Push(child)
+		}
+
+		if stack.IsEmpty() {
+			return n, false
+		}
+		return n, true
+	}
+}
+
+// Walk an ast breadth first
+func (T AST) bfWalk() func() (*Node, bool) {
+	queue := nodeQueue{}
+	queue.buf = make([]*Node, 0, T.size)
+	queue.Enqueue(&T.root)
+
+	return func() (*Node, bool) {
+		n, err := queue.Dequeue()
+		if err != nil {
+			return nil, false
+		}
+
+		for _, child := range n.Children {
+			queue.Enqueue(child)
+		}
+		return n, true
+	}
+}