4 files changed, 13 insertions, 110 deletions

diff --git a/Cargo.lock b/Cargo.lock
index fd1fb5ea5..80fbda23c 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -674,7 +674,7 @@ dependencies = [
  "drop_bomb 0.1.4 (registry+https://github.com/rust-lang/crates.io-index)",
  "itertools 0.7.8 (registry+https://github.com/rust-lang/crates.io-index)",
  "parking_lot 0.6.4 (registry+https://github.com/rust-lang/crates.io-index)",
- "rowan 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)",
+ "rowan 0.1.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "test_utils 0.1.0",
  "text_unit 0.1.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "unicode-xid 0.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -795,7 +795,7 @@ dependencies = [
 
 [[package]]
 name = "rowan"
-version = "0.1.1"
+version = "0.1.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
  "parking_lot 0.6.4 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -1346,7 +1346,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 "checksum relative-path 0.4.0 (registry+https://github.com/rust-lang/crates.io-index)" = "0e7790c7f1cc73d831d28dc5a7deb316a006e7848e6a7f467cdb10a0a9e0fb1c"
 "checksum remove_dir_all 0.5.1 (registry+https://github.com/rust-lang/crates.io-index)" = "3488ba1b9a2084d38645c4c08276a1752dcbf2c7130d74f1569681ad5d2799c5"
 "checksum ron 0.4.0 (registry+https://github.com/rust-lang/crates.io-index)" = "c48677d8a9247a4e0d1f3f9cb4b0a8e29167fdc3c04f383a5e669cd7a960ae0f"
-"checksum rowan 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)" = "4bb1f952404091f61bfea7cd09c564090a0fcee3d22223f98084e8756e01c04d"
+"checksum rowan 0.1.2 (registry+https://github.com/rust-lang/crates.io-index)" = "795b1c830f5335e89f93415315518e9727307308c44c1e5adebe8a38f856c334"
 "checksum rustc-demangle 0.1.9 (registry+https://github.com/rust-lang/crates.io-index)" = "bcfe5b13211b4d78e5c2cadfebd7769197d95c639c35a50057eb4c05de811395"
 "checksum rustc-hash 1.0.1 (registry+https://github.com/rust-lang/crates.io-index)" = "7540fc8b0c49f096ee9c961cda096467dce8084bec6bdca2fc83895fd9b28cb8"
 "checksum rustc_version 0.2.3 (registry+https://github.com/rust-lang/crates.io-index)" = "138e3e0acb6c9fb258b19b67cb8abd63c00679d2851805ea151465464fe9030a"
diff --git a/crates/ra_syntax/Cargo.toml b/crates/ra_syntax/Cargo.toml
index de4b25e67..97d259570 100644
--- a/crates/ra_syntax/Cargo.toml
+++ b/crates/ra_syntax/Cargo.toml
@@ -12,7 +12,7 @@ unicode-xid = "0.1.0"
 itertools = "0.7.8"
 drop_bomb = "0.1.4"
 parking_lot = "0.6.0"
-rowan = "0.1.1"
+rowan = "0.1.2"
 text_unit = "0.1.5"
 
 [dev-dependencies]
diff --git a/crates/ra_syntax/src/algo/mod.rs b/crates/ra_syntax/src/algo/mod.rs
index faf5a6211..4b3548ea9 100644
--- a/crates/ra_syntax/src/algo/mod.rs
+++ b/crates/ra_syntax/src/algo/mod.rs
@@ -1,116 +1,19 @@
 pub mod visit;
-// pub mod walk;
 
-use crate::{text_utils::contains_offset_nonstrict, SyntaxNodeRef, TextRange, TextUnit};
+use crate::{SyntaxNode, SyntaxNodeRef, TextRange, TextUnit};
 
-pub fn find_leaf_at_offset(node: SyntaxNodeRef, offset: TextUnit) -> LeafAtOffset {
-    let range = node.range();
-    assert!(
-        contains_offset_nonstrict(range, offset),
-        "Bad offset: range {:?} offset {:?}",
-        range,
-        offset
-    );
-    if range.is_empty() {
-        return LeafAtOffset::None;
-    }
-
-    if node.is_leaf() {
-        return LeafAtOffset::Single(node);
-    }
-
-    let mut children = node.children().filter(|child| {
-        let child_range = child.range();
-        !child_range.is_empty() && contains_offset_nonstrict(child_range, offset)
-    });
-
-    let left = children.next().unwrap();
-    let right = children.next();
-    assert!(children.next().is_none());
-
-    if let Some(right) = right {
-        match (
-            find_leaf_at_offset(left, offset),
-            find_leaf_at_offset(right, offset),
-        ) {
-            (LeafAtOffset::Single(left), LeafAtOffset::Single(right)) => {
-                LeafAtOffset::Between(left, right)
-            }
-            _ => unreachable!(),
-        }
-    } else {
-        find_leaf_at_offset(left, offset)
-    }
-}
-
-#[derive(Clone, Debug)]
-pub enum LeafAtOffset<'a> {
-    None,
-    Single(SyntaxNodeRef<'a>),
-    Between(SyntaxNodeRef<'a>, SyntaxNodeRef<'a>),
-}
+pub use rowan::LeafAtOffset;
 
-impl<'a> LeafAtOffset<'a> {
-    pub fn right_biased(self) -> Option<SyntaxNodeRef<'a>> {
-        match self {
-            LeafAtOffset::None => None,
-            LeafAtOffset::Single(node) => Some(node),
-            LeafAtOffset::Between(_, right) => Some(right),
-        }
-    }
-
-    pub fn left_biased(self) -> Option<SyntaxNodeRef<'a>> {
-        match self {
-            LeafAtOffset::None => None,
-            LeafAtOffset::Single(node) => Some(node),
-            LeafAtOffset::Between(left, _) => Some(left),
-        }
-    }
-}
-
-impl<'f> Iterator for LeafAtOffset<'f> {
-    type Item = SyntaxNodeRef<'f>;
-
-    fn next(&mut self) -> Option<SyntaxNodeRef<'f>> {
-        match *self {
-            LeafAtOffset::None => None,
-            LeafAtOffset::Single(node) => {
-                *self = LeafAtOffset::None;
-                Some(node)
-            }
-            LeafAtOffset::Between(left, right) => {
-                *self = LeafAtOffset::Single(right);
-                Some(left)
-            }
-        }
+pub fn find_leaf_at_offset(node: SyntaxNodeRef, offset: TextUnit) -> LeafAtOffset<SyntaxNodeRef> {
+    match node.0.leaf_at_offset(offset) {
+        LeafAtOffset::None => LeafAtOffset::None,
+        LeafAtOffset::Single(n) => LeafAtOffset::Single(SyntaxNode(n)),
+        LeafAtOffset::Between(l, r) => LeafAtOffset::Between(SyntaxNode(l), SyntaxNode(r)),
     }
 }
 
 pub fn find_covering_node(root: SyntaxNodeRef, range: TextRange) -> SyntaxNodeRef {
-    assert!(
-        range.is_subrange(&root.range()),
-        "node range: {:?}, target range: {:?}",
-        root.range(),
-        range,
-    );
-    let (left, right) = match (
-        find_leaf_at_offset(root, range.start()).right_biased(),
-        find_leaf_at_offset(root, range.end()).left_biased(),
-    ) {
-        (Some(l), Some(r)) => (l, r),
-        _ => return root,
-    };
-
-    common_ancestor(left, right)
-}
-
-fn common_ancestor<'a>(n1: SyntaxNodeRef<'a>, n2: SyntaxNodeRef<'a>) -> SyntaxNodeRef<'a> {
-    for p in n1.ancestors() {
-        if n2.ancestors().any(|a| a == p) {
-            return p;
-        }
-    }
-    panic!("Can't find common ancestor of {:?} and {:?}", n1, n2)
+    SyntaxNode(root.0.covering_node(range))
 }
 
 pub fn generate<T>(seed: Option<T>, step: impl Fn(&T) -> Option<T>) -> impl Iterator<Item = T> {
diff --git a/crates/ra_syntax/src/yellow/mod.rs b/crates/ra_syntax/src/yellow/mod.rs
index 6da948648..cacd89dc8 100644
--- a/crates/ra_syntax/src/yellow/mod.rs
+++ b/crates/ra_syntax/src/yellow/mod.rs
@@ -27,7 +27,7 @@ pub type RefRoot<'a> = ::rowan::RefRoot<'a, RaTypes>;
 pub type GreenNode = ::rowan::GreenNode<RaTypes>;
 
 #[derive(Clone, Copy)]
-pub struct SyntaxNode<R: TreeRoot<RaTypes> = OwnedRoot>(::rowan::SyntaxNode<RaTypes, R>);
+pub struct SyntaxNode<R: TreeRoot<RaTypes> = OwnedRoot>(pub(crate) ::rowan::SyntaxNode<RaTypes, R>);
 pub type SyntaxNodeRef<'a> = SyntaxNode<RefRoot<'a>>;
 
 impl<R1, R2> PartialEq<SyntaxNode<R1>> for SyntaxNode<R2>