Parser: groundwork

1 files changed, 72 insertions, 2 deletions

diff --git a/src/tree.rs b/src/tree.rs
index 0924f38d0..2ac25e795 100644
--- a/src/tree.rs
+++ b/src/tree.rs
@@ -1,4 +1,4 @@
-use text::{TextUnit};
+use text::{TextUnit, TextRange};
 use syntax_kinds::syntax_info;
 
 use std::fmt;
@@ -28,4 +28,74 @@ pub(crate) struct SyntaxInfo {
 pub struct Token {
     pub kind: SyntaxKind,
     pub len: TextUnit,
-}
\ No newline at end of file
+}
+
+pub struct File {
+        text: String,
+        nodes: Vec<NodeData>,
+}
+
+impl File {
+        pub fn root<'f>(&'f self) -> Node<'f> {
+                assert!(!self.nodes.is_empty());
+                Node { file: self, idx: NodeIdx(0) }
+        }
+}
+
+#[derive(Clone, Copy)]
+pub struct Node<'f> {
+        file: &'f File,
+        idx: NodeIdx,
+}
+
+impl<'f> Node<'f> {
+        pub fn kind(&self) -> SyntaxKind {
+                self.data().kind
+        }
+
+        pub fn text(&self) -> &'f str {
+                let range = self.data().range;
+                &self.file.text.as_str()[range]
+        }
+
+        pub fn parent(&self) -> Option<Node<'f>> {
+                self.as_node(self.data().parent)
+        }
+
+        pub fn children(&self) -> Children<'f> {
+                Children { next: self.as_node(self.data().first_child) }
+        }
+
+        fn data(&self) -> &'f NodeData {
+                &self.file.nodes[self.idx.0 as usize]
+        }
+
+        fn as_node(&self, idx: Option<NodeIdx>) -> Option<Node<'f>> {
+                idx.map(|idx| Node { file: self.file, idx })
+        }
+}
+
+pub struct Children<'f> {
+        next: Option<Node<'f>>,
+}
+
+impl<'f> Iterator for Children<'f> {
+        type Item = Node<'f>;
+
+        fn next(&mut self) -> Option<Node<'f>> {
+                let next = self.next;
+                self.next = next.and_then(|node| node.as_node(node.data().next_sibling));
+                next
+        }
+}
+
+#[derive(Clone, Copy)]
+struct NodeIdx(u32);
+
+struct NodeData {
+        kind: SyntaxKind,
+        range: TextRange,
+        parent: Option<NodeIdx>,
+        first_child: Option<NodeIdx>,
+        next_sibling: Option<NodeIdx>,
+}