1 files changed, 22 insertions, 461 deletions

diff --git a/crates/ra_syntax/src/syntax_node.rs b/crates/ra_syntax/src/syntax_node.rs
index c42045d77..689dbefde 100644
--- a/crates/ra_syntax/src/syntax_node.rs
+++ b/crates/ra_syntax/src/syntax_node.rs
@@ -6,15 +6,12 @@
 //! The *real* implementation is in the (language-agnostic) `rowan` crate, this
 //! modules just wraps its API.
 
-use std::{fmt, iter::successors, ops::RangeInclusive};
-
 use ra_parser::ParseError;
-use rowan::GreenNodeBuilder;
+use rowan::{GreenNodeBuilder, Language};
 
 use crate::{
     syntax_error::{SyntaxError, SyntaxErrorKind},
-    AstNode, Parse, SmolStr, SourceFile, SyntaxKind, SyntaxNodePtr, SyntaxText, TextRange,
-    TextUnit,
+    Parse, SmolStr, SyntaxKind, TextUnit,
 };
 
 pub use rowan::WalkEvent;
@@ -28,465 +25,27 @@ pub enum InsertPosition<T> {
     After(T),
 }
 
-#[derive(PartialEq, Eq, Hash, Clone)]
-pub struct SyntaxNode(pub(crate) rowan::cursor::SyntaxNode);
-
-impl fmt::Debug for SyntaxNode {
-    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
-        if f.alternate() {
-            let mut level = 0;
-            for event in self.preorder_with_tokens() {
-                match event {
-                    WalkEvent::Enter(element) => {
-                        for _ in 0..level {
-                            write!(f, "  ")?;
-                        }
-                        match element {
-                            SyntaxElement::Node(node) => writeln!(f, "{:?}", node)?,
-                            SyntaxElement::Token(token) => writeln!(f, "{:?}", token)?,
-                        }
-                        level += 1;
-                    }
-                    WalkEvent::Leave(_) => level -= 1,
-                }
-            }
-            assert_eq!(level, 0);
-            Ok(())
-        } else {
-            write!(f, "{:?}@{:?}", self.kind(), self.text_range())
-        }
-    }
-}
-
-impl fmt::Display for SyntaxNode {
-    fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
-        fmt::Display::fmt(&self.text(), fmt)
-    }
-}
-
-#[derive(Debug, Clone, Copy, PartialEq, Eq)]
-pub enum Direction {
-    Next,
-    Prev,
-}
-
-impl SyntaxNode {
-    pub(crate) fn new(green: GreenNode) -> SyntaxNode {
-        let inner = rowan::cursor::SyntaxNode::new_root(green);
-        SyntaxNode(inner)
-    }
-
-    pub fn kind(&self) -> SyntaxKind {
-        self.0.kind().0.into()
-    }
-
-    pub fn text_range(&self) -> TextRange {
-        self.0.text_range()
-    }
-
-    pub fn text(&self) -> SyntaxText {
-        SyntaxText::new(self.clone())
-    }
-
-    pub fn parent(&self) -> Option<SyntaxNode> {
-        self.0.parent().map(SyntaxNode)
-    }
-
-    pub fn first_child(&self) -> Option<SyntaxNode> {
-        self.0.first_child().map(SyntaxNode)
-    }
-
-    pub fn first_child_or_token(&self) -> Option<SyntaxElement> {
-        self.0.first_child_or_token().map(SyntaxElement::new)
-    }
-
-    pub fn last_child(&self) -> Option<SyntaxNode> {
-        self.0.last_child().map(SyntaxNode)
-    }
-
-    pub fn last_child_or_token(&self) -> Option<SyntaxElement> {
-        self.0.last_child_or_token().map(SyntaxElement::new)
-    }
-
-    pub fn next_sibling(&self) -> Option<SyntaxNode> {
-        self.0.next_sibling().map(SyntaxNode)
-    }
-
-    pub fn next_sibling_or_token(&self) -> Option<SyntaxElement> {
-        self.0.next_sibling_or_token().map(SyntaxElement::new)
-    }
-
-    pub fn prev_sibling(&self) -> Option<SyntaxNode> {
-        self.0.prev_sibling().map(SyntaxNode)
-    }
-
-    pub fn prev_sibling_or_token(&self) -> Option<SyntaxElement> {
-        self.0.prev_sibling_or_token().map(SyntaxElement::new)
-    }
-
-    pub fn children(&self) -> SyntaxNodeChildren {
-        SyntaxNodeChildren(self.0.children())
-    }
-
-    pub fn children_with_tokens(&self) -> SyntaxElementChildren {
-        SyntaxElementChildren(self.0.children_with_tokens())
-    }
-
-    pub fn first_token(&self) -> Option<SyntaxToken> {
-        self.0.first_token().map(SyntaxToken)
-    }
-
-    pub fn last_token(&self) -> Option<SyntaxToken> {
-        self.0.last_token().map(SyntaxToken)
-    }
-
-    pub fn ancestors(&self) -> impl Iterator<Item = SyntaxNode> {
-        successors(Some(self.clone()), |node| node.parent())
-    }
-
-    pub fn descendants(&self) -> impl Iterator<Item = SyntaxNode> {
-        self.preorder().filter_map(|event| match event {
-            WalkEvent::Enter(node) => Some(node),
-            WalkEvent::Leave(_) => None,
-        })
-    }
-
-    pub fn descendants_with_tokens(&self) -> impl Iterator<Item = SyntaxElement> {
-        self.preorder_with_tokens().filter_map(|event| match event {
-            WalkEvent::Enter(it) => Some(it),
-            WalkEvent::Leave(_) => None,
-        })
-    }
-
-    pub fn siblings(&self, direction: Direction) -> impl Iterator<Item = SyntaxNode> {
-        successors(Some(self.clone()), move |node| match direction {
-            Direction::Next => node.next_sibling(),
-            Direction::Prev => node.prev_sibling(),
-        })
-    }
-
-    pub fn siblings_with_tokens(
-        &self,
-        direction: Direction,
-    ) -> impl Iterator<Item = SyntaxElement> {
-        let me: SyntaxElement = self.clone().into();
-        successors(Some(me), move |el| match direction {
-            Direction::Next => el.next_sibling_or_token(),
-            Direction::Prev => el.prev_sibling_or_token(),
-        })
-    }
+#[derive(Debug, Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash)]
+pub enum RustLanguage {}
+impl Language for RustLanguage {
+    type Kind = SyntaxKind;
 
-    pub fn preorder(&self) -> impl Iterator<Item = WalkEvent<SyntaxNode>> {
-        self.0.preorder().map(|event| match event {
-            WalkEvent::Enter(n) => WalkEvent::Enter(SyntaxNode(n)),
-            WalkEvent::Leave(n) => WalkEvent::Leave(SyntaxNode(n)),
-        })
+    fn kind_from_raw(raw: rowan::cursor::SyntaxKind) -> SyntaxKind {
+        SyntaxKind::from(raw.0)
     }
 
-    pub fn preorder_with_tokens(&self) -> impl Iterator<Item = WalkEvent<SyntaxElement>> {
-        self.0.preorder_with_tokens().map(|event| match event {
-            WalkEvent::Enter(n) => WalkEvent::Enter(SyntaxElement::new(n)),
-            WalkEvent::Leave(n) => WalkEvent::Leave(SyntaxElement::new(n)),
-        })
-    }
-
-    pub(crate) fn replace_with(&self, replacement: GreenNode) -> GreenNode {
-        self.0.replace_with(replacement)
-    }
-
-    /// Adds specified children (tokens or nodes) to the current node at the
-    /// specific position.
-    ///
-    /// This is a type-unsafe low-level editing API, if you need to use it,
-    /// prefer to create a type-safe abstraction on top of it instead.
-    pub fn insert_children(
-        &self,
-        position: InsertPosition<SyntaxElement>,
-        to_insert: impl Iterator<Item = SyntaxElement>,
-    ) -> SyntaxNode {
-        let mut delta = TextUnit::default();
-        let to_insert = to_insert.map(|element| {
-            delta += element.text_len();
-            to_green_element(element)
-        });
-
-        let old_children = self.0.green().children();
-
-        let new_children = match &position {
-            InsertPosition::First => {
-                to_insert.chain(old_children.iter().cloned()).collect::<Box<[_]>>()
-            }
-            InsertPosition::Last => {
-                old_children.iter().cloned().chain(to_insert).collect::<Box<[_]>>()
-            }
-            InsertPosition::Before(anchor) | InsertPosition::After(anchor) => {
-                let take_anchor = if let InsertPosition::After(_) = position { 1 } else { 0 };
-                let split_at = self.position_of_child(anchor.clone()) + take_anchor;
-                let (before, after) = old_children.split_at(split_at);
-                before
-                    .iter()
-                    .cloned()
-                    .chain(to_insert)
-                    .chain(after.iter().cloned())
-                    .collect::<Box<[_]>>()
-            }
-        };
-
-        self.with_children(new_children)
-    }
-
-    /// Replaces all nodes in `to_delete` with nodes from `to_insert`
-    ///
-    /// This is a type-unsafe low-level editing API, if you need to use it,
-    /// prefer to create a type-safe abstraction on top of it instead.
-    pub fn replace_children(
-        &self,
-        to_delete: RangeInclusive<SyntaxElement>,
-        to_insert: impl Iterator<Item = SyntaxElement>,
-    ) -> SyntaxNode {
-        let start = self.position_of_child(to_delete.start().clone());
-        let end = self.position_of_child(to_delete.end().clone());
-        let old_children = self.0.green().children();
-
-        let new_children = old_children[..start]
-            .iter()
-            .cloned()
-            .chain(to_insert.map(to_green_element))
-            .chain(old_children[end + 1..].iter().cloned())
-            .collect::<Box<[_]>>();
-        self.with_children(new_children)
-    }
-
-    fn with_children(&self, new_children: Box<[rowan::GreenElement]>) -> SyntaxNode {
-        let len = new_children.iter().map(|it| it.text_len()).sum::<TextUnit>();
-        let new_node = GreenNode::new(rowan::SyntaxKind(self.kind() as u16), new_children);
-        let new_file_node = self.replace_with(new_node);
-        let file = SourceFile::new(new_file_node);
-
-        // FIXME: use a more elegant way to re-fetch the node (#1185), make
-        // `range` private afterwards
-        let mut ptr = SyntaxNodePtr::new(self);
-        ptr.range = TextRange::offset_len(ptr.range().start(), len);
-        ptr.to_node(file.syntax()).to_owned()
-    }
-
-    fn position_of_child(&self, child: SyntaxElement) -> usize {
-        self.children_with_tokens()
-            .position(|it| it == child)
-            .expect("element is not a child of current element")
+    fn kind_to_raw(kind: SyntaxKind) -> rowan::cursor::SyntaxKind {
+        rowan::cursor::SyntaxKind(kind.into())
     }
 }
 
-fn to_green_element(element: SyntaxElement) -> rowan::GreenElement {
-    match element {
-        SyntaxElement::Node(node) => node.0.green().clone().into(),
-        SyntaxElement::Token(tok) => {
-            GreenToken::new(rowan::SyntaxKind(tok.kind() as u16), tok.text().clone()).into()
-        }
-    }
-}
-
-#[derive(Clone, PartialEq, Eq, Hash)]
-pub struct SyntaxToken(pub(crate) rowan::cursor::SyntaxToken);
-
-impl fmt::Debug for SyntaxToken {
-    fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
-        write!(fmt, "{:?}@{:?}", self.kind(), self.text_range())?;
-        if self.text().len() < 25 {
-            return write!(fmt, " {:?}", self.text());
-        }
-        let text = self.text().as_str();
-        for idx in 21..25 {
-            if text.is_char_boundary(idx) {
-                let text = format!("{} ...", &text[..idx]);
-                return write!(fmt, " {:?}", text);
-            }
-        }
-        unreachable!()
-    }
-}
+pub type SyntaxNode = rowan::SyntaxNode<RustLanguage>;
+pub type SyntaxToken = rowan::SyntaxToken<RustLanguage>;
+pub type SyntaxElement = rowan::NodeOrToken<SyntaxNode, SyntaxToken>;
+pub type SyntaxNodeChildren = rowan::SyntaxNodeChildren<RustLanguage>;
+pub type SyntaxElementChildren = rowan::SyntaxElementChildren<RustLanguage>;
 
-impl fmt::Display for SyntaxToken {
-    fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
-        fmt::Display::fmt(self.text(), fmt)
-    }
-}
-
-impl SyntaxToken {
-    pub fn kind(&self) -> SyntaxKind {
-        self.0.kind().0.into()
-    }
-
-    pub fn text(&self) -> &SmolStr {
-        self.0.text()
-    }
-
-    pub fn text_range(&self) -> TextRange {
-        self.0.text_range()
-    }
-
-    pub fn parent(&self) -> SyntaxNode {
-        SyntaxNode(self.0.parent())
-    }
-
-    pub fn next_sibling_or_token(&self) -> Option<SyntaxElement> {
-        self.0.next_sibling_or_token().map(SyntaxElement::new)
-    }
-
-    pub fn prev_sibling_or_token(&self) -> Option<SyntaxElement> {
-        self.0.prev_sibling_or_token().map(SyntaxElement::new)
-    }
-
-    pub fn siblings_with_tokens(
-        &self,
-        direction: Direction,
-    ) -> impl Iterator<Item = SyntaxElement> {
-        let me: SyntaxElement = self.clone().into();
-        successors(Some(me), move |el| match direction {
-            Direction::Next => el.next_sibling_or_token(),
-            Direction::Prev => el.prev_sibling_or_token(),
-        })
-    }
-
-    pub fn next_token(&self) -> Option<SyntaxToken> {
-        self.0.next_token().map(SyntaxToken)
-    }
-
-    pub fn prev_token(&self) -> Option<SyntaxToken> {
-        self.0.prev_token().map(SyntaxToken)
-    }
-
-    pub(crate) fn replace_with(&self, new_token: GreenToken) -> GreenNode {
-        self.0.replace_with(new_token)
-    }
-}
-
-#[derive(Debug, PartialEq, Eq, Hash, Clone)]
-pub enum SyntaxElement {
-    Node(SyntaxNode),
-    Token(SyntaxToken),
-}
-
-impl From<SyntaxNode> for SyntaxElement {
-    fn from(node: SyntaxNode) -> Self {
-        SyntaxElement::Node(node)
-    }
-}
-
-impl From<SyntaxToken> for SyntaxElement {
-    fn from(token: SyntaxToken) -> Self {
-        SyntaxElement::Token(token)
-    }
-}
-
-impl fmt::Display for SyntaxElement {
-    fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
-        match self {
-            SyntaxElement::Node(it) => fmt::Display::fmt(it, fmt),
-            SyntaxElement::Token(it) => fmt::Display::fmt(it, fmt),
-        }
-    }
-}
-
-impl SyntaxElement {
-    pub(crate) fn new(el: rowan::cursor::SyntaxElement) -> Self {
-        match el {
-            rowan::cursor::SyntaxElement::Node(it) => SyntaxElement::Node(SyntaxNode(it)),
-            rowan::cursor::SyntaxElement::Token(it) => SyntaxElement::Token(SyntaxToken(it)),
-        }
-    }
-
-    pub fn kind(&self) -> SyntaxKind {
-        match self {
-            SyntaxElement::Node(it) => it.kind(),
-            SyntaxElement::Token(it) => it.kind(),
-        }
-    }
-
-    pub fn as_node(&self) -> Option<&SyntaxNode> {
-        match self {
-            SyntaxElement::Node(node) => Some(node),
-            SyntaxElement::Token(_) => None,
-        }
-    }
-
-    pub fn into_node(self) -> Option<SyntaxNode> {
-        match self {
-            SyntaxElement::Node(node) => Some(node),
-            SyntaxElement::Token(_) => None,
-        }
-    }
-
-    pub fn as_token(&self) -> Option<&SyntaxToken> {
-        match self {
-            SyntaxElement::Node(_) => None,
-            SyntaxElement::Token(token) => Some(token),
-        }
-    }
-
-    pub fn into_token(self) -> Option<SyntaxToken> {
-        match self {
-            SyntaxElement::Node(_) => None,
-            SyntaxElement::Token(token) => Some(token),
-        }
-    }
-
-    pub fn next_sibling_or_token(&self) -> Option<SyntaxElement> {
-        match self {
-            SyntaxElement::Node(it) => it.next_sibling_or_token(),
-            SyntaxElement::Token(it) => it.next_sibling_or_token(),
-        }
-    }
-
-    pub fn prev_sibling_or_token(&self) -> Option<SyntaxElement> {
-        match self {
-            SyntaxElement::Node(it) => it.prev_sibling_or_token(),
-            SyntaxElement::Token(it) => it.prev_sibling_or_token(),
-        }
-    }
-
-    pub fn ancestors(&self) -> impl Iterator<Item = SyntaxNode> {
-        match self {
-            SyntaxElement::Node(it) => it.clone(),
-            SyntaxElement::Token(it) => it.parent(),
-        }
-        .ancestors()
-    }
-
-    pub fn text_range(&self) -> TextRange {
-        match self {
-            SyntaxElement::Node(it) => it.text_range(),
-            SyntaxElement::Token(it) => it.text_range(),
-        }
-    }
-
-    fn text_len(&self) -> TextUnit {
-        match self {
-            SyntaxElement::Node(node) => node.0.green().text_len(),
-            SyntaxElement::Token(token) => TextUnit::of_str(token.0.text()),
-        }
-    }
-}
-
-#[derive(Clone, Debug)]
-pub struct SyntaxNodeChildren(rowan::cursor::SyntaxNodeChildren);
-
-impl Iterator for SyntaxNodeChildren {
-    type Item = SyntaxNode;
-    fn next(&mut self) -> Option<SyntaxNode> {
-        self.0.next().map(SyntaxNode)
-    }
-}
-
-#[derive(Clone, Debug)]
-pub struct SyntaxElementChildren(rowan::cursor::SyntaxElementChildren);
-
-impl Iterator for SyntaxElementChildren {
-    type Item = SyntaxElement;
-    fn next(&mut self) -> Option<SyntaxElement> {
-        self.0.next().map(SyntaxElement::new)
-    }
-}
+pub use rowan::{Direction, NodeOrToken};
 
 pub struct SyntaxTreeBuilder {
     errors: Vec<SyntaxError>,
@@ -507,19 +66,21 @@ impl SyntaxTreeBuilder {
 
     pub fn finish(self) -> Parse<SyntaxNode> {
         let (green, errors) = self.finish_raw();
-        let node = SyntaxNode::new(green);
+        let node = SyntaxNode::new_root(green);
         if cfg!(debug_assertions) {
             crate::validation::validate_block_structure(&node);
         }
-        Parse::new(node.0.green().clone(), errors)
+        Parse::new(node.green().clone(), errors)
     }
 
     pub fn token(&mut self, kind: SyntaxKind, text: SmolStr) {
-        self.inner.token(rowan::SyntaxKind(kind.into()), text)
+        let kind = RustLanguage::kind_to_raw(kind);
+        self.inner.token(kind, text)
     }
 
     pub fn start_node(&mut self, kind: SyntaxKind) {
-        self.inner.start_node(rowan::SyntaxKind(kind.into()))
+        let kind = RustLanguage::kind_to_raw(kind);
+        self.inner.start_node(kind)
     }
 
     pub fn finish_node(&mut self) {