1 files changed, 100 insertions, 0 deletions

diff --git a/crates/ra_syntax/src/yellow/mod.rs b/crates/ra_syntax/src/yellow/mod.rs
new file mode 100644
index 000000000..0596e702f
--- /dev/null
+++ b/crates/ra_syntax/src/yellow/mod.rs
@@ -0,0 +1,100 @@
+mod builder;
+mod green;
+mod red;
+mod syntax;
+mod syntax_text;
+
+use std::{
+    sync::Arc,
+    ptr,
+};
+pub use self::syntax::{SyntaxNode, SyntaxNodeRef, SyntaxError, SyntaxNodeChildren};
+pub(crate) use self::{
+    builder::GreenBuilder,
+    green::GreenNode,
+    red::RedNode,
+    syntax_text::SyntaxText,
+};
+
+#[derive(Debug)]
+pub struct SyntaxRoot {
+    red: RedNode,
+    pub(crate) errors: Vec<SyntaxError>,
+}
+
+pub trait TreeRoot: Clone + Send + Sync {
+    fn borrowed(&self) -> RefRoot;
+    fn owned(&self) -> OwnedRoot;
+
+    #[doc(hidden)]
+    fn syntax_root(&self) -> &SyntaxRoot;
+}
+#[derive(Clone, Debug)]
+pub struct OwnedRoot(Arc<SyntaxRoot>);
+#[derive(Clone, Copy, Debug)]
+pub struct RefRoot<'a>(&'a OwnedRoot); // TODO: shared_from_this instead of double indirection
+
+impl<'a> RefRoot<'a> {
+    fn syntax_root(&self) -> &'a SyntaxRoot {
+        self.0.syntax_root()
+    }
+}
+
+impl TreeRoot for OwnedRoot {
+    fn borrowed(&self) -> RefRoot {
+        RefRoot(&self)
+    }
+    fn owned(&self) -> OwnedRoot {
+        self.clone()
+    }
+
+    fn syntax_root(&self) -> &SyntaxRoot {
+        &*self.0
+    }
+}
+
+impl<'a> TreeRoot for RefRoot<'a> {
+    fn borrowed(&self) -> RefRoot {
+        *self
+    }
+    fn owned(&self) -> OwnedRoot {
+        self.0.clone()
+    }
+    fn syntax_root(&self) -> &SyntaxRoot {
+        self.0.syntax_root()
+    }
+}
+
+impl SyntaxRoot {
+    pub(crate) fn new(green: GreenNode, errors: Vec<SyntaxError>) -> SyntaxRoot {
+        SyntaxRoot {
+            red: RedNode::new_root(green),
+            errors,
+        }
+    }
+}
+
+#[derive(Clone, Copy, PartialEq, Eq, Debug, Hash)]
+pub(crate) struct RedPtr(ptr::NonNull<RedNode>);
+
+unsafe impl Send for RedPtr {}
+
+unsafe impl Sync for RedPtr {}
+
+impl RedPtr {
+    fn new(red: &RedNode) -> RedPtr {
+        RedPtr(red.into())
+    }
+
+    unsafe fn get<'a>(self, _root: &'a SyntaxRoot) -> &'a RedNode {
+        &*self.0.as_ptr()
+    }
+}
+
+#[test]
+fn assert_send_sync() {
+    fn f<T: Send + Sync>() {}
+    f::<GreenNode>();
+    f::<RedNode>();
+    f::<SyntaxNode>();
+}