3 files changed, 8 insertions, 80 deletions

diff --git a/crates/ra_vfs/Cargo.toml b/crates/ra_vfs/Cargo.toml
index 7c170cdfc..e637063c9 100644
--- a/crates/ra_vfs/Cargo.toml
+++ b/crates/ra_vfs/Cargo.toml
@@ -12,6 +12,7 @@ crossbeam-channel = "0.3.5"
 log = "0.4.6"
 
 thread_worker = { path = "../thread_worker" }
+ra_arena = { path = "../ra_arena" }
 
 [dev-dependencies]
 tempfile = "3"
diff --git a/crates/ra_vfs/src/arena.rs b/crates/ra_vfs/src/arena.rs
deleted file mode 100644
index 6b42ae26d..000000000
--- a/crates/ra_vfs/src/arena.rs
+++ /dev/null
@@ -1,53 +0,0 @@
-use std::{
-    marker::PhantomData,
-    ops::{Index, IndexMut},
-};
-
-#[derive(Clone, Debug)]
-pub(crate) struct Arena<ID: ArenaId, T> {
-    data: Vec<T>,
-    _ty: PhantomData<ID>,
-}
-
-pub(crate) trait ArenaId {
-    fn from_u32(id: u32) -> Self;
-    fn to_u32(self) -> u32;
-}
-
-impl<ID: ArenaId, T> Arena<ID, T> {
-    pub fn alloc(&mut self, value: T) -> ID {
-        let id = self.data.len() as u32;
-        self.data.push(value);
-        ID::from_u32(id)
-    }
-    pub fn iter<'a>(&'a self) -> impl Iterator<Item = (ID, &'a T)> {
-        self.data
-            .iter()
-            .enumerate()
-            .map(|(idx, value)| (ID::from_u32(idx as u32), value))
-    }
-}
-
-impl<ID: ArenaId, T> Default for Arena<ID, T> {
-    fn default() -> Arena<ID, T> {
-        Arena {
-            data: Vec::new(),
-            _ty: PhantomData,
-        }
-    }
-}
-
-impl<ID: ArenaId, T> Index<ID> for Arena<ID, T> {
-    type Output = T;
-    fn index(&self, idx: ID) -> &T {
-        let idx = idx.to_u32() as usize;
-        &self.data[idx]
-    }
-}
-
-impl<ID: ArenaId, T> IndexMut<ID> for Arena<ID, T> {
-    fn index_mut(&mut self, idx: ID) -> &mut T {
-        let idx = idx.to_u32() as usize;
-        &mut self.data[idx]
-    }
-}
diff --git a/crates/ra_vfs/src/lib.rs b/crates/ra_vfs/src/lib.rs
index 5bbc3e993..cdea18d73 100644
--- a/crates/ra_vfs/src/lib.rs
+++ b/crates/ra_vfs/src/lib.rs
@@ -13,7 +13,6 @@
 //! VFS is based on a concept of roots: a set of directories on the file system
 //! which are watched for changes. Typically, there will be a root for each
 //! Cargo package.
-mod arena;
 mod io;
 
 use std::{
@@ -32,10 +31,7 @@ use relative_path::RelativePathBuf;
 use crossbeam_channel::Receiver;
 use walkdir::DirEntry;
 use thread_worker::WorkerHandle;
-
-use crate::{
-    arena::{ArenaId, Arena},
-};
+use ra_arena::{Arena, RawId, impl_arena_id};
 
 pub use crate::io::TaskResult as VfsTask;
 
@@ -68,29 +64,13 @@ fn has_rs_extension(p: &Path) -> bool {
     p.extension() == Some(OsStr::new("rs"))
 }
 
-#[derive(Clone, Copy, PartialEq, Eq, Debug, Hash)]
-pub struct VfsRoot(pub u32);
-
-impl ArenaId for VfsRoot {
-    fn from_u32(idx: u32) -> VfsRoot {
-        VfsRoot(idx)
-    }
-    fn to_u32(self) -> u32 {
-        self.0
-    }
-}
-
-#[derive(Clone, Copy, PartialEq, Eq, Debug, Hash)]
-pub struct VfsFile(pub u32);
+#[derive(Debug, Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash)]
+pub struct VfsRoot(pub RawId);
+impl_arena_id!(VfsRoot);
 
-impl ArenaId for VfsFile {
-    fn from_u32(idx: u32) -> VfsFile {
-        VfsFile(idx)
-    }
-    fn to_u32(self) -> u32 {
-        self.0
-    }
-}
+#[derive(Debug, Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash)]
+pub struct VfsFile(pub RawId);
+impl_arena_id!(VfsFile);
 
 struct VfsFileData {
     root: VfsRoot,