22 files changed, 353 insertions, 261 deletions

diff --git a/crates/ra_hir/src/adt.rs b/crates/ra_hir/src/adt.rs
index c6463235c..b75adda84 100644
--- a/crates/ra_hir/src/adt.rs
+++ b/crates/ra_hir/src/adt.rs
@@ -42,7 +42,7 @@ pub struct StructData {
 }
 
 impl StructData {
-    pub(crate) fn new(struct_def: ast::StructDef) -> StructData {
+    pub(crate) fn new(struct_def: &ast::StructDef) -> StructData {
         let name = struct_def.name().map(|n| n.as_name());
         let variant_data = VariantData::new(struct_def.flavor());
         let variant_data = Arc::new(variant_data);
@@ -87,7 +87,7 @@ pub struct EnumData {
 }
 
 impl EnumData {
-    pub(crate) fn new(enum_def: ast::EnumDef) -> Self {
+    pub(crate) fn new(enum_def: &ast::EnumDef) -> Self {
         let name = enum_def.name().map(|n| n.as_name());
         let variants = if let Some(evl) = enum_def.variant_list() {
             evl.variants()
@@ -171,24 +171,21 @@ impl VariantData {
         }
     }
     pub fn is_struct(&self) -> bool {
-        if let VariantData::Struct(..) = *self {
-            true
-        } else {
-            false
+        match self {
+            VariantData::Struct(..) => true,
+            _ => false,
         }
     }
     pub fn is_tuple(&self) -> bool {
-        if let VariantData::Tuple(..) = *self {
-            true
-        } else {
-            false
+        match self {
+            VariantData::Tuple(..) => true,
+            _ => false,
         }
     }
     pub fn is_unit(&self) -> bool {
-        if let VariantData::Unit = *self {
-            true
-        } else {
-            false
+        match self {
+            VariantData::Unit => true,
+            _ => false,
         }
     }
 }
diff --git a/crates/ra_hir/src/code_model_api.rs b/crates/ra_hir/src/code_model_api.rs
index 09b532f74..43cddb504 100644
--- a/crates/ra_hir/src/code_model_api.rs
+++ b/crates/ra_hir/src/code_model_api.rs
@@ -1,6 +1,6 @@
 use relative_path::RelativePathBuf;
 use ra_db::{CrateId, Cancelable, FileId};
-use ra_syntax::{ast, SyntaxNode};
+use ra_syntax::{ast, TreePtr, SyntaxNode};
 
 use crate::{Name, db::HirDatabase, DefId, Path, PerNs, nameres::ModuleScope};
 
@@ -36,8 +36,8 @@ pub struct Module {
 }
 
 pub enum ModuleSource {
-    SourceFile(ast::SourceFileNode),
-    Module(ast::ModuleNode),
+    SourceFile(TreePtr<ast::SourceFile>),
+    Module(TreePtr<ast::Module>),
 }
 
 #[derive(Clone, Debug, Hash, PartialEq, Eq)]
@@ -66,7 +66,7 @@ impl Module {
     pub fn declaration_source(
         &self,
         db: &impl HirDatabase,
-    ) -> Cancelable<Option<(FileId, ast::ModuleNode)>> {
+    ) -> Cancelable<Option<(FileId, TreePtr<ast::Module>)>> {
         self.declaration_source_impl(db)
     }
 
@@ -104,7 +104,10 @@ impl Module {
     pub fn resolve_path(&self, db: &impl HirDatabase, path: &Path) -> Cancelable<PerNs<DefId>> {
         self.resolve_path_impl(db, path)
     }
-    pub fn problems(&self, db: &impl HirDatabase) -> Cancelable<Vec<(SyntaxNode, Problem)>> {
+    pub fn problems(
+        &self,
+        db: &impl HirDatabase,
+    ) -> Cancelable<Vec<(TreePtr<SyntaxNode>, Problem)>> {
         self.problems_impl(db)
     }
 }
diff --git a/crates/ra_hir/src/code_model_impl/module.rs b/crates/ra_hir/src/code_model_impl/module.rs
index eb35779f1..0d22c9dbe 100644
--- a/crates/ra_hir/src/code_model_impl/module.rs
+++ b/crates/ra_hir/src/code_model_impl/module.rs
@@ -1,5 +1,5 @@
 use ra_db::{Cancelable, SourceRootId, FileId};
-use ra_syntax::{ast, SyntaxNode, AstNode};
+use ra_syntax::{ast, SyntaxNode, AstNode, TreePtr};
 
 use crate::{
     Module, ModuleSource, Problem,
@@ -43,12 +43,11 @@ impl Module {
         let loc = self.def_id.loc(db);
         let file_id = loc.source_item_id.file_id.as_original_file();
         let syntax_node = db.file_item(loc.source_item_id);
-        let syntax_node = syntax_node.borrowed();
-        let module_source = if let Some(source_file) = ast::SourceFile::cast(syntax_node) {
-            ModuleSource::SourceFile(source_file.owned())
+        let module_source = if let Some(source_file) = ast::SourceFile::cast(&syntax_node) {
+            ModuleSource::SourceFile(source_file.to_owned())
         } else {
-            let module = ast::Module::cast(syntax_node).unwrap();
-            ModuleSource::Module(module.owned())
+            let module = ast::Module::cast(&syntax_node).unwrap();
+            ModuleSource::Module(module.to_owned())
         };
         Ok((file_id, module_source))
     }
@@ -56,7 +55,7 @@ impl Module {
     pub fn declaration_source_impl(
         &self,
         db: &impl HirDatabase,
-    ) -> Cancelable<Option<(FileId, ast::ModuleNode)>> {
+    ) -> Cancelable<Option<(FileId, TreePtr<ast::Module>)>> {
         let loc = self.def_id.loc(db);
         let module_tree = db.module_tree(loc.source_root_id)?;
         let link = ctry!(loc.module_id.parent_link(&module_tree));
@@ -146,7 +145,10 @@ impl Module {
         }
         Ok(curr_per_ns)
     }
-    pub fn problems_impl(&self, db: &impl HirDatabase) -> Cancelable<Vec<(SyntaxNode, Problem)>> {
+    pub fn problems_impl(
+        &self,
+        db: &impl HirDatabase,
+    ) -> Cancelable<Vec<(TreePtr<SyntaxNode>, Problem)>> {
         let loc = self.def_id.loc(db);
         let module_tree = db.module_tree(loc.source_root_id)?;
         Ok(loc.module_id.problems(&module_tree, db))
diff --git a/crates/ra_hir/src/db.rs b/crates/ra_hir/src/db.rs
index 04249400b..03e65387d 100644
--- a/crates/ra_hir/src/db.rs
+++ b/crates/ra_hir/src/db.rs
@@ -1,6 +1,6 @@
 use std::sync::Arc;
 
-use ra_syntax::{SyntaxNode, SourceFileNode};
+use ra_syntax::{SyntaxNode, TreePtr, SourceFile};
 use ra_db::{SourceRootId, LocationIntener, SyntaxDatabase, Cancelable};
 
 use crate::{
@@ -22,7 +22,7 @@ pub trait HirDatabase: SyntaxDatabase
     + AsRef<LocationIntener<DefLoc, DefId>>
     + AsRef<LocationIntener<MacroCallLoc, MacroCallId>>
 {
-    fn hir_source_file(file_id: HirFileId) -> SourceFileNode {
+    fn hir_source_file(file_id: HirFileId) -> TreePtr<SourceFile> {
         type HirSourceFileQuery;
         use fn HirFileId::hir_source_file;
     }
@@ -66,7 +66,7 @@ pub trait HirDatabase: SyntaxDatabase
         use fn query_definitions::file_items;
     }
 
-    fn file_item(source_item_id: SourceItemId) -> SyntaxNode {
+    fn file_item(source_item_id: SourceItemId) -> TreePtr<SyntaxNode> {
         type FileItemQuery;
         use fn query_definitions::file_item;
     }
diff --git a/crates/ra_hir/src/expr.rs b/crates/ra_hir/src/expr.rs
index b0063cad2..4c54449ef 100644
--- a/crates/ra_hir/src/expr.rs
+++ b/crates/ra_hir/src/expr.rs
@@ -77,7 +77,7 @@ impl BodySyntaxMapping {
     pub fn syntax_expr(&self, ptr: LocalSyntaxPtr) -> Option<ExprId> {
         self.expr_syntax_mapping.get(&ptr).cloned()
     }
-    pub fn node_expr(&self, node: ast::Expr) -> Option<ExprId> {
+    pub fn node_expr(&self, node: &ast::Expr) -> Option<ExprId> {
         self.expr_syntax_mapping
             .get(&LocalSyntaxPtr::new(node.syntax()))
             .cloned()
@@ -88,7 +88,7 @@ impl BodySyntaxMapping {
     pub fn syntax_pat(&self, ptr: LocalSyntaxPtr) -> Option<PatId> {
         self.pat_syntax_mapping.get(&ptr).cloned()
     }
-    pub fn node_pat(&self, node: ast::Pat) -> Option<PatId> {
+    pub fn node_pat(&self, node: &ast::Pat) -> Option<PatId> {
         self.pat_syntax_mapping
             .get(&LocalSyntaxPtr::new(node.syntax()))
             .cloned()
@@ -373,10 +373,10 @@ impl ExprCollector {
         self.exprs.alloc(block)
     }
 
-    fn collect_expr(&mut self, expr: ast::Expr) -> ExprId {
+    fn collect_expr(&mut self, expr: &ast::Expr) -> ExprId {
         let syntax_ptr = LocalSyntaxPtr::new(expr.syntax());
-        match expr {
-            ast::Expr::IfExpr(e) => {
+        match expr.kind() {
+            ast::ExprKind::IfExpr(e) => {
                 if let Some(pat) = e.condition().and_then(|c| c.pat()) {
                     // if let -- desugar to match
                     let pat = self.collect_pat(pat);
@@ -419,12 +419,12 @@ impl ExprCollector {
                     )
                 }
             }
-            ast::Expr::BlockExpr(e) => self.collect_block_opt(e.block()),
-            ast::Expr::LoopExpr(e) => {
+            ast::ExprKind::BlockExpr(e) => self.collect_block_opt(e.block()),
+            ast::ExprKind::LoopExpr(e) => {
                 let body = self.collect_block_opt(e.loop_body());
                 self.alloc_expr(Expr::Loop { body }, syntax_ptr)
             }
-            ast::Expr::WhileExpr(e) => {
+            ast::ExprKind::WhileExpr(e) => {
                 let condition = if let Some(condition) = e.condition() {
                     if condition.pat().is_none() {
                         self.collect_expr_opt(condition.expr())
@@ -438,7 +438,7 @@ impl ExprCollector {
                 let body = self.collect_block_opt(e.loop_body());
                 self.alloc_expr(Expr::While { condition, body }, syntax_ptr)
             }
-            ast::Expr::ForExpr(e) => {
+            ast::ExprKind::ForExpr(e) => {
                 let iterable = self.collect_expr_opt(e.iterable());
                 let pat = self.collect_pat_opt(e.pat());
                 let body = self.collect_block_opt(e.loop_body());
@@ -451,7 +451,7 @@ impl ExprCollector {
                     syntax_ptr,
                 )
             }
-            ast::Expr::CallExpr(e) => {
+            ast::ExprKind::CallExpr(e) => {
                 let callee = self.collect_expr_opt(e.expr());
                 let args = if let Some(arg_list) = e.arg_list() {
                     arg_list.args().map(|e| self.collect_expr(e)).collect()
@@ -460,7 +460,7 @@ impl ExprCollector {
                 };
                 self.alloc_expr(Expr::Call { callee, args }, syntax_ptr)
             }
-            ast::Expr::MethodCallExpr(e) => {
+            ast::ExprKind::MethodCallExpr(e) => {
                 let receiver = self.collect_expr_opt(e.expr());
                 let args = if let Some(arg_list) = e.arg_list() {
                     arg_list.args().map(|e| self.collect_expr(e)).collect()
@@ -480,7 +480,7 @@ impl ExprCollector {
                     syntax_ptr,
                 )
             }
-            ast::Expr::MatchExpr(e) => {
+            ast::ExprKind::MatchExpr(e) => {
                 let expr = self.collect_expr_opt(e.expr());
                 let arms = if let Some(match_arm_list) = e.match_arm_list() {
                     match_arm_list
@@ -495,7 +495,7 @@ impl ExprCollector {
                 };
                 self.alloc_expr(Expr::Match { expr, arms }, syntax_ptr)
             }
-            ast::Expr::PathExpr(e) => {
+            ast::ExprKind::PathExpr(e) => {
                 let path = e
                     .path()
                     .and_then(Path::from_ast)
@@ -503,25 +503,25 @@ impl ExprCollector {
                     .unwrap_or(Expr::Missing);
                 self.alloc_expr(path, syntax_ptr)
             }
-            ast::Expr::ContinueExpr(_e) => {
+            ast::ExprKind::ContinueExpr(_e) => {
                 // TODO: labels
                 self.alloc_expr(Expr::Continue, syntax_ptr)
             }
-            ast::Expr::BreakExpr(e) => {
+            ast::ExprKind::BreakExpr(e) => {
                 let expr = e.expr().map(|e| self.collect_expr(e));
                 self.alloc_expr(Expr::Break { expr }, syntax_ptr)
             }
-            ast::Expr::ParenExpr(e) => {
+            ast::ExprKind::ParenExpr(e) => {
                 let inner = self.collect_expr_opt(e.expr());
                 // make the paren expr point to the inner expression as well
                 self.expr_syntax_mapping.insert(syntax_ptr, inner);
                 inner
             }
-            ast::Expr::ReturnExpr(e) => {
+            ast::ExprKind::ReturnExpr(e) => {
                 let expr = e.expr().map(|e| self.collect_expr(e));
                 self.alloc_expr(Expr::Return { expr }, syntax_ptr)
             }
-            ast::Expr::StructLit(e) => {
+            ast::ExprKind::StructLit(e) => {
                 let path = e.path().and_then(Path::from_ast);
                 let fields = if let Some(nfl) = e.named_field_list() {
                     nfl.fields()
@@ -558,7 +558,7 @@ impl ExprCollector {
                     syntax_ptr,
                 )
             }
-            ast::Expr::FieldExpr(e) => {
+            ast::ExprKind::FieldExpr(e) => {
                 let expr = self.collect_expr_opt(e.expr());
                 let name = e
                     .name_ref()
@@ -566,26 +566,26 @@ impl ExprCollector {
                     .unwrap_or_else(Name::missing);
                 self.alloc_expr(Expr::Field { expr, name }, syntax_ptr)
             }
-            ast::Expr::TryExpr(e) => {
+            ast::ExprKind::TryExpr(e) => {
                 let expr = self.collect_expr_opt(e.expr());
                 self.alloc_expr(Expr::Try { expr }, syntax_ptr)
             }
-            ast::Expr::CastExpr(e) => {
+            ast::ExprKind::CastExpr(e) => {
                 let expr = self.collect_expr_opt(e.expr());
                 let type_ref = TypeRef::from_ast_opt(e.type_ref());
                 self.alloc_expr(Expr::Cast { expr, type_ref }, syntax_ptr)
             }
-            ast::Expr::RefExpr(e) => {
+            ast::ExprKind::RefExpr(e) => {
                 let expr = self.collect_expr_opt(e.expr());
                 let mutability = Mutability::from_mutable(e.is_mut());
                 self.alloc_expr(Expr::Ref { expr, mutability }, syntax_ptr)
             }
-            ast::Expr::PrefixExpr(e) => {
+            ast::ExprKind::PrefixExpr(e) => {
                 let expr = self.collect_expr_opt(e.expr());
                 let op = e.op();
                 self.alloc_expr(Expr::UnaryOp { expr, op }, syntax_ptr)
             }
-            ast::Expr::LambdaExpr(e) => {
+            ast::ExprKind::LambdaExpr(e) => {
                 let mut args = Vec::new();
                 let mut arg_types = Vec::new();
                 if let Some(pl) = e.param_list() {
@@ -606,7 +606,7 @@ impl ExprCollector {
                     syntax_ptr,
                 )
             }
-            ast::Expr::BinExpr(e) => {
+            ast::ExprKind::BinExpr(e) => {
                 let lhs = self.collect_expr_opt(e.lhs());
                 let rhs = self.collect_expr_opt(e.rhs());
                 let op = e.op();
@@ -614,16 +614,16 @@ impl ExprCollector {
             }
 
             // TODO implement HIR for these:
-            ast::Expr::Label(_e) => self.alloc_expr(Expr::Missing, syntax_ptr),
-            ast::Expr::IndexExpr(_e) => self.alloc_expr(Expr::Missing, syntax_ptr),
-            ast::Expr::TupleExpr(_e) => self.alloc_expr(Expr::Missing, syntax_ptr),
-            ast::Expr::ArrayExpr(_e) => self.alloc_expr(Expr::Missing, syntax_ptr),
-            ast::Expr::RangeExpr(_e) => self.alloc_expr(Expr::Missing, syntax_ptr),
-            ast::Expr::Literal(_e) => self.alloc_expr(Expr::Missing, syntax_ptr),
+            ast::ExprKind::Label(_e) => self.alloc_expr(Expr::Missing, syntax_ptr),
+            ast::ExprKind::IndexExpr(_e) => self.alloc_expr(Expr::Missing, syntax_ptr),
+            ast::ExprKind::TupleExpr(_e) => self.alloc_expr(Expr::Missing, syntax_ptr),
+            ast::ExprKind::ArrayExpr(_e) => self.alloc_expr(Expr::Missing, syntax_ptr),
+            ast::ExprKind::RangeExpr(_e) => self.alloc_expr(Expr::Missing, syntax_ptr),
+            ast::ExprKind::Literal(_e) => self.alloc_expr(Expr::Missing, syntax_ptr),
         }
     }
 
-    fn collect_expr_opt(&mut self, expr: Option<ast::Expr>) -> ExprId {
+    fn collect_expr_opt(&mut self, expr: Option<&ast::Expr>) -> ExprId {
         if let Some(expr) = expr {
             self.collect_expr(expr)
         } else {
@@ -631,11 +631,11 @@ impl ExprCollector {
         }
     }
 
-    fn collect_block(&mut self, block: ast::Block) -> ExprId {
+    fn collect_block(&mut self, block: &ast::Block) -> ExprId {
         let statements = block
             .statements()
-            .map(|s| match s {
-                ast::Stmt::LetStmt(stmt) => {
+            .map(|s| match s.kind() {
+                ast::StmtKind::LetStmt(stmt) => {
                     let pat = self.collect_pat_opt(stmt.pat());
                     let type_ref = stmt.type_ref().map(TypeRef::from_ast);
                     let initializer = stmt.initializer().map(|e| self.collect_expr(e));
@@ -645,7 +645,9 @@ impl ExprCollector {
                         initializer,
                     }
                 }
-                ast::Stmt::ExprStmt(stmt) => Statement::Expr(self.collect_expr_opt(stmt.expr())),
+                ast::StmtKind::ExprStmt(stmt) => {
+                    Statement::Expr(self.collect_expr_opt(stmt.expr()))
+                }
             })
             .collect();
         let tail = block.expr().map(|e| self.collect_expr(e));
@@ -655,7 +657,7 @@ impl ExprCollector {
         )
     }
 
-    fn collect_block_opt(&mut self, block: Option<ast::Block>) -> ExprId {
+    fn collect_block_opt(&mut self, block: Option<&ast::Block>) -> ExprId {
         if let Some(block) = block {
             self.collect_block(block)
         } else {
@@ -663,17 +665,17 @@ impl ExprCollector {
         }
     }
 
-    fn collect_pat(&mut self, pat: ast::Pat) -> PatId {
+    fn collect_pat(&mut self, pat: &ast::Pat) -> PatId {
         let syntax_ptr = LocalSyntaxPtr::new(pat.syntax());
-        match pat {
-            ast::Pat::BindPat(bp) => {
+        match pat.kind() {
+            ast::PatKind::BindPat(bp) => {
                 let name = bp
                     .name()
                     .map(|nr| nr.as_name())
                     .unwrap_or_else(Name::missing);
                 self.alloc_pat(Pat::Bind { name }, syntax_ptr)
             }
-            ast::Pat::TupleStructPat(p) => {
+            ast::PatKind::TupleStructPat(p) => {
                 let path = p.path().and_then(Path::from_ast);
                 let args = p.args().map(|p| self.collect_pat(p)).collect();
                 self.alloc_pat(Pat::TupleStruct { path, args }, syntax_ptr)
@@ -685,7 +687,7 @@ impl ExprCollector {
         }
     }
 
-    fn collect_pat_opt(&mut self, pat: Option<ast::Pat>) -> PatId {
+    fn collect_pat_opt(&mut self, pat: Option<&ast::Pat>) -> PatId {
         if let Some(pat) = pat {
             self.collect_pat(pat)
         } else {
@@ -710,7 +712,7 @@ impl ExprCollector {
     }
 }
 
-pub(crate) fn collect_fn_body_syntax(node: ast::FnDef) -> BodySyntaxMapping {
+pub(crate) fn collect_fn_body_syntax(node: &ast::FnDef) -> BodySyntaxMapping {
     let mut collector = ExprCollector::new();
 
     let args = if let Some(param_list) = node.param_list() {
@@ -758,9 +760,7 @@ pub(crate) fn body_syntax_mapping(
     let body_syntax_mapping = match def {
         Def::Function(f) => {
             let node = f.syntax(db);
-            let node = node.borrowed();
-
-            collect_fn_body_syntax(node)
+            collect_fn_body_syntax(&node)
         }
         // TODO: consts, etc.
         _ => panic!("Trying to get body for item type without body"),
diff --git a/crates/ra_hir/src/function.rs b/crates/ra_hir/src/function.rs
index 4627be071..81b790c5f 100644
--- a/crates/ra_hir/src/function.rs
+++ b/crates/ra_hir/src/function.rs
@@ -7,7 +7,7 @@ use std::{
 
 use ra_db::Cancelable;
 use ra_syntax::{
-    TextRange, TextUnit,
+    TextRange, TextUnit, TreePtr,
     ast::{self, AstNode, DocCommentsOwner, NameOwner},
 };
 
@@ -29,11 +29,11 @@ impl Function {
         self.def_id
     }
 
-    pub fn syntax(&self, db: &impl HirDatabase) -> ast::FnDefNode {
+    pub fn syntax(&self, db: &impl HirDatabase) -> TreePtr<ast::FnDef> {
         let def_loc = self.def_id.loc(db);
         assert!(def_loc.kind == DefKind::Function);
         let syntax = db.file_item(def_loc.source_item_id);
-        ast::FnDef::cast(syntax.borrowed()).unwrap().owned()
+        ast::FnDef::cast(&syntax).unwrap().to_owned()
     }
 
     pub fn body(&self, db: &impl HirDatabase) -> Cancelable<Arc<Body>> {
@@ -59,7 +59,7 @@ impl Function {
 
     pub fn signature_info(&self, db: &impl HirDatabase) -> Option<FnSignatureInfo> {
         let syntax = self.syntax(db);
-        FnSignatureInfo::new(syntax.borrowed())
+        FnSignatureInfo::new(&syntax)
     }
 
     pub fn infer(&self, db: &impl HirDatabase) -> Cancelable<Arc<InferenceResult>> {
@@ -99,8 +99,7 @@ impl FnSignature {
 
 pub(crate) fn fn_signature(db: &impl HirDatabase, def_id: DefId) -> Arc<FnSignature> {
     let func = Function::new(def_id);
-    let syntax = func.syntax(db);
-    let node = syntax.borrowed();
+    let node = func.syntax(db);
     let mut args = Vec::new();
     if let Some(param_list) = node.param_list() {
         if let Some(self_param) = param_list.self_param() {
@@ -144,7 +143,7 @@ pub struct FnSignatureInfo {
 }
 
 impl FnSignatureInfo {
-    fn new(node: ast::FnDef) -> Option<Self> {
+    fn new(node: &ast::FnDef) -> Option<Self> {
         let name = node.name()?.text().to_string();
 
         let mut doc = None;
@@ -207,7 +206,7 @@ impl FnSignatureInfo {
         })
     }
 
-    fn extract_doc_comments(node: ast::FnDef) -> Option<(TextRange, String)> {
+    fn extract_doc_comments(node: &ast::FnDef) -> Option<(TextRange, String)> {
         if node.doc_comments().count() == 0 {
             return None;
         }
@@ -227,7 +226,7 @@ impl FnSignatureInfo {
         Some((range, comment_text))
     }
 
-    fn param_list(node: ast::FnDef) -> Vec<String> {
+    fn param_list(node: &ast::FnDef) -> Vec<String> {
         let mut res = vec![];
         if let Some(param_list) = node.param_list() {
             if let Some(self_param) = param_list.self_param() {
diff --git a/crates/ra_hir/src/function/scope.rs b/crates/ra_hir/src/function/scope.rs
index 0a12f0b35..699784f71 100644
--- a/crates/ra_hir/src/function/scope.rs
+++ b/crates/ra_hir/src/function/scope.rs
@@ -3,7 +3,7 @@ use std::sync::Arc;
 use rustc_hash::{FxHashMap, FxHashSet};
 
 use ra_syntax::{
-    AstNode, SyntaxNodeRef, TextUnit, TextRange,
+    AstNode, SyntaxNode, TextUnit, TextRange,
     algo::generate,
     ast,
 };
@@ -127,7 +127,7 @@ impl ScopeEntryWithSyntax {
 }
 
 impl ScopesWithSyntaxMapping {
-    pub fn scope_chain<'a>(&'a self, node: SyntaxNodeRef) -> impl Iterator<Item = ScopeId> + 'a {
+    pub fn scope_chain<'a>(&'a self, node: &SyntaxNode) -> impl Iterator<Item = ScopeId> + 'a {
         generate(self.scope_for(node), move |&scope| {
             self.scopes.scopes[scope].parent
         })
@@ -178,7 +178,7 @@ impl ScopesWithSyntaxMapping {
             .unwrap_or(original_scope)
     }
 
-    pub fn resolve_local_name(&self, name_ref: ast::NameRef) -> Option<ScopeEntryWithSyntax> {
+    pub fn resolve_local_name(&self, name_ref: &ast::NameRef) -> Option<ScopeEntryWithSyntax> {
         let mut shadowed = FxHashSet::default();
         let name = name_ref.as_name();
         let ret = self
@@ -195,7 +195,7 @@ impl ScopesWithSyntaxMapping {
         })
     }
 
-    pub fn find_all_refs(&self, pat: ast::BindPat) -> Vec<ReferenceDescriptor> {
+    pub fn find_all_refs(&self, pat: &ast::BindPat) -> Vec<ReferenceDescriptor> {
         let fn_def = pat.syntax().ancestors().find_map(ast::FnDef::cast).unwrap();
         let name_ptr = LocalSyntaxPtr::new(pat.syntax());
         fn_def
@@ -213,7 +213,7 @@ impl ScopesWithSyntaxMapping {
             .collect()
     }
 
-    fn scope_for(&self, node: SyntaxNodeRef) -> Option<ScopeId> {
+    fn scope_for(&self, node: &SyntaxNode) -> Option<ScopeId> {
         node.ancestors()
             .map(LocalSyntaxPtr::new)
             .filter_map(|ptr| self.syntax_mapping.syntax_expr(ptr))
@@ -309,7 +309,7 @@ pub struct ReferenceDescriptor {
 #[cfg(test)]
 mod tests {
     use ra_editor::find_node_at_offset;
-    use ra_syntax::SourceFileNode;
+    use ra_syntax::SourceFile;
     use test_utils::{extract_offset, assert_eq_text};
 
     use crate::expr;
@@ -326,9 +326,9 @@ mod tests {
             buf.push_str(&code[off..]);
             buf
         };
-        let file = SourceFileNode::parse(&code);
-        let marker: ast::PathExpr = find_node_at_offset(file.syntax(), off).unwrap();
-        let fn_def: ast::FnDef = find_node_at_offset(file.syntax(), off).unwrap();
+        let file = SourceFile::parse(&code);
+        let marker: &ast::PathExpr = find_node_at_offset(file.syntax(), off).unwrap();
+        let fn_def: &ast::FnDef = find_node_at_offset(file.syntax(), off).unwrap();
         let body_hir = expr::collect_fn_body_syntax(fn_def);
         let scopes = FnScopes::new(Arc::clone(body_hir.body()));
         let scopes = ScopesWithSyntaxMapping {
@@ -422,9 +422,9 @@ mod tests {
 
     fn do_check_local_name(code: &str, expected_offset: u32) {
         let (off, code) = extract_offset(code);
-        let file = SourceFileNode::parse(&code);
-        let fn_def: ast::FnDef = find_node_at_offset(file.syntax(), off).unwrap();
-        let name_ref: ast::NameRef = find_node_at_offset(file.syntax(), off).unwrap();
+        let file = SourceFile::parse(&code);
+        let fn_def: &ast::FnDef = find_node_at_offset(file.syntax(), off).unwrap();
+        let name_ref: &ast::NameRef = find_node_at_offset(file.syntax(), off).unwrap();
 
         let body_hir = expr::collect_fn_body_syntax(fn_def);
         let scopes = FnScopes::new(Arc::clone(body_hir.body()));
diff --git a/crates/ra_hir/src/ids.rs b/crates/ra_hir/src/ids.rs
index c7391ee05..730a3e542 100644
--- a/crates/ra_hir/src/ids.rs
+++ b/crates/ra_hir/src/ids.rs
@@ -1,5 +1,5 @@
 use ra_db::{SourceRootId, LocationIntener, Cancelable, FileId};
-use ra_syntax::{SourceFileNode, SyntaxKind, SyntaxNode, SyntaxNodeRef, SourceFile, AstNode, ast};
+use ra_syntax::{TreePtr, SyntaxKind, SyntaxNode, SourceFile, AstNode, ast};
 use ra_arena::{Arena, RawId, impl_arena_id};
 
 use crate::{HirDatabase, PerNs, ModuleId, Def, Function, Struct, Enum, ImplBlock, Crate};
@@ -55,7 +55,10 @@ impl HirFileId {
         }
     }
 
-    pub(crate) fn hir_source_file(db: &impl HirDatabase, file_id: HirFileId) -> SourceFileNode {
+    pub(crate) fn hir_source_file(
+        db: &impl HirDatabase,
+        file_id: HirFileId,
+    ) -> TreePtr<SourceFile> {
         match file_id.0 {
             HirFileIdRepr::File(file_id) => db.source_file(file_id),
             HirFileIdRepr::Macro(m) => {
@@ -63,7 +66,7 @@ impl HirFileId {
                     return exp.file();
                 }
                 // returning an empty string looks fishy...
-                SourceFileNode::parse("")
+                SourceFile::parse("")
             }
         }
     }
@@ -233,11 +236,11 @@ pub struct SourceItemId {
 #[derive(Debug, PartialEq, Eq)]
 pub struct SourceFileItems {
     file_id: HirFileId,
-    arena: Arena<SourceFileItemId, SyntaxNode>,
+    arena: Arena<SourceFileItemId, TreePtr<SyntaxNode>>,
 }
 
 impl SourceFileItems {
-    pub(crate) fn new(file_id: HirFileId, source_file: SourceFile) -> SourceFileItems {
+    pub(crate) fn new(file_id: HirFileId, source_file: &SourceFile) -> SourceFileItems {
         let mut res = SourceFileItems {
             file_id,
             arena: Arena::default(),
@@ -246,20 +249,20 @@ impl SourceFileItems {
         res
     }
 
-    fn init(&mut self, source_file: SourceFile) {
+    fn init(&mut self, source_file: &SourceFile) {
         source_file.syntax().descendants().for_each(|it| {
             if let Some(module_item) = ast::ModuleItem::cast(it) {
-                self.alloc(module_item.syntax().owned());
+                self.alloc(module_item.syntax().to_owned());
             } else if let Some(macro_call) = ast::MacroCall::cast(it) {
-                self.alloc(macro_call.syntax().owned());
+                self.alloc(macro_call.syntax().to_owned());
             }
         });
     }
 
-    fn alloc(&mut self, item: SyntaxNode) -> SourceFileItemId {
+    fn alloc(&mut self, item: TreePtr<SyntaxNode>) -> SourceFileItemId {
         self.arena.alloc(item)
     }
-    pub(crate) fn id_of(&self, file_id: HirFileId, item: SyntaxNodeRef) -> SourceFileItemId {
+    pub(crate) fn id_of(&self, file_id: HirFileId, item: &SyntaxNode) -> SourceFileItemId {
         assert_eq!(
             self.file_id, file_id,
             "SourceFileItems: wrong file, expected {:?}, got {:?}",
@@ -267,8 +270,8 @@ impl SourceFileItems {
         );
         self.id_of_unchecked(item)
     }
-    pub(crate) fn id_of_unchecked(&self, item: SyntaxNodeRef) -> SourceFileItemId {
-        if let Some((id, _)) = self.arena.iter().find(|(_id, i)| i.borrowed() == item) {
+    pub(crate) fn id_of_unchecked(&self, item: &SyntaxNode) -> SourceFileItemId {
+        if let Some((id, _)) = self.arena.iter().find(|(_id, i)| *i == item) {
             return id;
         }
         // This should not happen. Let's try to give a sensible diagnostics.
diff --git a/crates/ra_hir/src/impl_block.rs b/crates/ra_hir/src/impl_block.rs
index 7ce8d17e6..bb0ad84e4 100644
--- a/crates/ra_hir/src/impl_block.rs
+++ b/crates/ra_hir/src/impl_block.rs
@@ -62,7 +62,7 @@ impl ImplData {
         db: &impl AsRef<LocationIntener<DefLoc, DefId>>,
         file_items: &SourceFileItems,
         module: &Module,
-        node: ast::ImplBlock,
+        node: &ast::ImplBlock,
     ) -> Self {
         let target_trait = node.target_type().map(TypeRef::from_ast);
         let target_type = TypeRef::from_ast_opt(node.target_type());
@@ -71,10 +71,10 @@ impl ImplData {
             item_list
                 .impl_items()
                 .map(|item_node| {
-                    let kind = match item_node {
-                        ast::ImplItem::FnDef(..) => DefKind::Function,
-                        ast::ImplItem::ConstDef(..) => DefKind::Item,
-                        ast::ImplItem::TypeDef(..) => DefKind::Item,
+                    let kind = match item_node.kind() {
+                        ast::ImplItemKind::FnDef(..) => DefKind::Function,
+                        ast::ImplItemKind::ConstDef(..) => DefKind::Item,
+                        ast::ImplItemKind::TypeDef(..) => DefKind::Item,
                     };
                     let item_id = file_items.id_of_unchecked(item_node.syntax());
                     let source_item_id = SourceItemId {
@@ -87,10 +87,10 @@ impl ImplData {
                         ..module_loc
                     };
                     let def_id = def_loc.id(db);
-                    match item_node {
-                        ast::ImplItem::FnDef(..) => ImplItem::Method(Function::new(def_id)),
-                        ast::ImplItem::ConstDef(..) => ImplItem::Const(def_id),
-                        ast::ImplItem::TypeDef(..) => ImplItem::Type(def_id),
+                    match item_node.kind() {
+                        ast::ImplItemKind::FnDef(..) => ImplItem::Method(Function::new(def_id)),
+                        ast::ImplItemKind::ConstDef(..) => ImplItem::Const(def_id),
+                        ast::ImplItemKind::TypeDef(..) => ImplItem::Type(def_id),
                     }
                 })
                 .collect()
@@ -152,8 +152,8 @@ impl ModuleImplBlocks {
     fn collect(&mut self, db: &impl HirDatabase, module: Module) -> Cancelable<()> {
         let (file_id, module_source) = module.defenition_source(db)?;
         let node = match &module_source {
-            ModuleSource::SourceFile(node) => node.borrowed().syntax(),
-            ModuleSource::Module(node) => node.borrowed().syntax(),
+            ModuleSource::SourceFile(node) => node.syntax(),
+            ModuleSource::Module(node) => node.syntax(),
         };
 
         let source_file_items = db.file_items(file_id.into());
diff --git a/crates/ra_hir/src/macros.rs b/crates/ra_hir/src/macros.rs
index 1b378c977..eb1c86091 100644
--- a/crates/ra_hir/src/macros.rs
+++ b/crates/ra_hir/src/macros.rs
@@ -11,7 +11,7 @@ use std::sync::Arc;
 
 use ra_db::LocalSyntaxPtr;
 use ra_syntax::{
-    TextRange, TextUnit, SourceFileNode, AstNode, SyntaxNode,
+    TextRange, TextUnit, SourceFile, AstNode, SyntaxNode, TreePtr,
     ast::{self, NameOwner},
 };
 
@@ -28,14 +28,14 @@ pub enum MacroDef {
 impl MacroDef {
     /// Expands macro call, returning the expansion and offset to be used to
     /// convert ranges between expansion and original source.
-    pub fn ast_expand(macro_call: ast::MacroCall) -> Option<(TextUnit, MacroExpansion)> {
+    pub fn ast_expand(macro_call: &ast::MacroCall) -> Option<(TextUnit, MacroExpansion)> {
         let (def, input) = MacroDef::from_call(macro_call)?;
         let exp = def.expand(input)?;
         let off = macro_call.token_tree()?.syntax().range().start();
         Some((off, exp))
     }
 
-    fn from_call(macro_call: ast::MacroCall) -> Option<(MacroDef, MacroInput)> {
+    fn from_call(macro_call: &ast::MacroCall) -> Option<(MacroDef, MacroInput)> {
         let def = {
             let path = macro_call.path()?;
             let name_ref = path.segment()?.name_ref()?;
@@ -77,7 +77,7 @@ impl MacroDef {
                 }}",
             input.text
         );
-        let file = SourceFileNode::parse(&text);
+        let file = SourceFile::parse(&text);
         let match_expr = file.syntax().descendants().find_map(ast::MatchExpr::cast)?;
         let match_arg = match_expr.expr()?;
         let ptr = LocalSyntaxPtr::new(match_arg.syntax());
@@ -92,7 +92,7 @@ impl MacroDef {
     }
     fn expand_vec(self, input: MacroInput) -> Option<MacroExpansion> {
         let text = format!(r"fn dummy() {{ {}; }}", input.text);
-        let file = SourceFileNode::parse(&text);
+        let file = SourceFile::parse(&text);
         let array_expr = file.syntax().descendants().find_map(ast::ArrayExpr::cast)?;
         let ptr = LocalSyntaxPtr::new(array_expr.syntax());
         let src_range = TextRange::offset_len(0.into(), TextUnit::of_str(&input.text));
@@ -116,7 +116,7 @@ impl MacroDef {
         }
         let src_range = TextRange::offset_len((pos as u32).into(), TextUnit::of_str(&trait_name));
         let text = format!(r"trait {} {{ }}", trait_name);
-        let file = SourceFileNode::parse(&text);
+        let file = SourceFile::parse(&text);
         let trait_def = file.syntax().descendants().find_map(ast::TraitDef::cast)?;
         let name = trait_def.name()?;
         let ptr = LocalSyntaxPtr::new(trait_def.syntax());
@@ -152,11 +152,11 @@ pub struct MacroExpansion {
 impl MacroExpansion {
     // FIXME: does not really make sense, macro expansion is not neccessary a
     // whole file. See `MacroExpansion::ptr` as well.
-    pub(crate) fn file(&self) -> SourceFileNode {
-        SourceFileNode::parse(&self.text)
+    pub(crate) fn file(&self) -> TreePtr<SourceFile> {
+        SourceFile::parse(&self.text)
     }
 
-    pub fn syntax(&self) -> SyntaxNode {
+    pub fn syntax(&self) -> TreePtr<SyntaxNode> {
         self.ptr.resolve(&self.file())
     }
     /// Maps range in the source code to the range in the expanded code.
@@ -191,8 +191,7 @@ pub(crate) fn expand_macro_invocation(
 ) -> Option<Arc<MacroExpansion>> {
     let loc = invoc.loc(db);
     let syntax = db.file_item(loc.source_item_id);
-    let syntax = syntax.borrowed();
-    let macro_call = ast::MacroCall::cast(syntax).unwrap();
+    let macro_call = ast::MacroCall::cast(&syntax).unwrap();
 
     let (def, input) = MacroDef::from_call(macro_call)?;
     def.expand(input).map(Arc::new)
diff --git a/crates/ra_hir/src/module_tree.rs b/crates/ra_hir/src/module_tree.rs
index c7a442319..91aab5c74 100644
--- a/crates/ra_hir/src/module_tree.rs
+++ b/crates/ra_hir/src/module_tree.rs
@@ -5,9 +5,9 @@ use arrayvec::ArrayVec;
 use relative_path::RelativePathBuf;
 use ra_db::{FileId, SourceRootId, Cancelable, SourceRoot};
 use ra_syntax::{
+    SyntaxNode, TreePtr,
     algo::generate,
     ast::{self, AstNode, NameOwner},
-    SyntaxNode,
 };
 use ra_arena::{Arena, RawId, impl_arena_id};
 
@@ -19,12 +19,11 @@ impl ModuleSource {
         source_item_id: SourceItemId,
     ) -> ModuleSource {
         let module_syntax = db.file_item(source_item_id);
-        let module_syntax = module_syntax.borrowed();
-        if let Some(source_file) = ast::SourceFile::cast(module_syntax) {
-            ModuleSource::SourceFile(source_file.owned())
-        } else if let Some(module) = ast::Module::cast(module_syntax) {
+        if let Some(source_file) = ast::SourceFile::cast(&module_syntax) {
+            ModuleSource::SourceFile(source_file.to_owned())
+        } else if let Some(module) = ast::Module::cast(&module_syntax) {
             assert!(module.item_list().is_some(), "expected inline module");
-            ModuleSource::Module(module.owned())
+            ModuleSource::Module(module.to_owned())
         } else {
             panic!("expected file or inline module")
         }
@@ -49,19 +48,18 @@ impl Submodule {
         let module_source = ModuleSource::from_source_item_id(db, source);
         let submodules = match module_source {
             ModuleSource::SourceFile(source_file) => {
-                collect_submodules(file_id, &file_items, source_file.borrowed())
+                collect_submodules(file_id, &file_items, &*source_file)
             }
             ModuleSource::Module(module) => {
-                let module = module.borrowed();
                 collect_submodules(file_id, &file_items, module.item_list().unwrap())
             }
         };
         return Ok(Arc::new(submodules));
 
-        fn collect_submodules<'a>(
+        fn collect_submodules(
             file_id: HirFileId,
             file_items: &SourceFileItems,
-            root: impl ast::ModuleItemOwner<'a>,
+            root: &impl ast::ModuleItemOwner,
         ) -> Vec<Submodule> {
             modules(root)
                 .map(|(name, m)| Submodule {
@@ -120,8 +118,8 @@ impl ModuleTree {
         source_root: SourceRootId,
     ) -> Cancelable<Arc<ModuleTree>> {
         db.check_canceled()?;
-        let res = create_module_tree(db, source_root)?;
-        Ok(Arc::new(res))
+        let res = create_module_tree(db, source_root);
+        Ok(Arc::new(res?))
     }
 
     pub(crate) fn modules<'a>(&'a self) -> impl Iterator<Item = ModuleId> + 'a {
@@ -172,14 +170,14 @@ impl ModuleId {
         self,
         tree: &ModuleTree,
         db: &impl HirDatabase,
-    ) -> Vec<(SyntaxNode, Problem)> {
+    ) -> Vec<(TreePtr<SyntaxNode>, Problem)> {
         tree.mods[self]
             .children
             .iter()
             .filter_map(|&link| {
                 let p = tree.links[link].problem.clone()?;
                 let s = link.source(tree, db);
-                let s = s.borrowed().name().unwrap().syntax().owned();
+                let s = s.name().unwrap().syntax().to_owned();
                 Some((s, p))
             })
             .collect()
@@ -193,11 +191,9 @@ impl LinkId {
     pub(crate) fn name(self, tree: &ModuleTree) -> &Name {
         &tree.links[self].name
     }
-    pub(crate) fn source(self, tree: &ModuleTree, db: &impl HirDatabase) -> ast::ModuleNode {
+    pub(crate) fn source(self, tree: &ModuleTree, db: &impl HirDatabase) -> TreePtr<ast::Module> {
         let syntax_node = db.file_item(tree.links[self].source);
-        ast::ModuleNode::cast(syntax_node.borrowed())
-            .unwrap()
-            .owned()
+        ast::Module::cast(&syntax_node).unwrap().to_owned()
     }
 }
 
@@ -213,12 +209,10 @@ impl ModuleTree {
     }
 }
 
-fn modules<'a>(
-    root: impl ast::ModuleItemOwner<'a>,
-) -> impl Iterator<Item = (Name, ast::Module<'a>)> {
+fn modules(root: &impl ast::ModuleItemOwner) -> impl Iterator<Item = (Name, &ast::Module)> {
     root.items()
-        .filter_map(|item| match item {
-            ast::ModuleItem::Module(m) => Some(m),
+        .filter_map(|item| match item.kind() {
+            ast::ModuleItemKind::Module(m) => Some(m),
             _ => None,
         })
         .filter_map(|module| {
diff --git a/crates/ra_hir/src/name.rs b/crates/ra_hir/src/name.rs
index 90229bc54..3e6ce8b95 100644
--- a/crates/ra_hir/src/name.rs
+++ b/crates/ra_hir/src/name.rs
@@ -59,6 +59,9 @@ impl Name {
             "u128" => KnownName::U128,
             "f32" => KnownName::F32,
             "f64" => KnownName::F64,
+            "bool" => KnownName::Bool,
+            "char" => KnownName::Char,
+            "str" => KnownName::Str,
             "Self" => KnownName::SelfType,
             "self" => KnownName::SelfParam,
             _ => return None,
@@ -71,15 +74,15 @@ pub(crate) trait AsName {
     fn as_name(&self) -> Name;
 }
 
-impl AsName for ast::NameRef<'_> {
+impl AsName for ast::NameRef {
     fn as_name(&self) -> Name {
-        Name::new(self.text())
+        Name::new(self.text().clone())
     }
 }
 
-impl AsName for ast::Name<'_> {
+impl AsName for ast::Name {
     fn as_name(&self) -> Name {
-        Name::new(self.text())
+        Name::new(self.text().clone())
     }
 }
 
@@ -113,6 +116,10 @@ pub(crate) enum KnownName {
     F32,
     F64,
 
+    Bool,
+    Char,
+    Str,
+
     SelfType,
     SelfParam,
 }
diff --git a/crates/ra_hir/src/nameres.rs b/crates/ra_hir/src/nameres.rs
index bd66b5d2c..4181bf4b8 100644
--- a/crates/ra_hir/src/nameres.rs
+++ b/crates/ra_hir/src/nameres.rs
@@ -103,7 +103,7 @@ impl NamedImport {
             item_id: Some(self.file_item_id),
         };
         let syntax = db.file_item(source_item_id);
-        let offset = syntax.borrowed().range().start();
+        let offset = syntax.range().start();
         self.relative_range + offset
     }
 }
@@ -215,45 +215,45 @@ impl InputModuleItems {
         &mut self,
         file_id: HirFileId,
         file_items: &SourceFileItems,
-        item: ast::ModuleItem,
+        item: &ast::ModuleItem,
     ) -> Option<()> {
-        match item {
-            ast::ModuleItem::StructDef(it) => {
+        match item.kind() {
+            ast::ModuleItemKind::StructDef(it) => {
                 self.items.push(ModuleItem::new(file_id, file_items, it)?)
             }
-            ast::ModuleItem::EnumDef(it) => {
+            ast::ModuleItemKind::EnumDef(it) => {
                 self.items.push(ModuleItem::new(file_id, file_items, it)?)
             }
-            ast::ModuleItem::FnDef(it) => {
+            ast::ModuleItemKind::FnDef(it) => {
                 self.items.push(ModuleItem::new(file_id, file_items, it)?)
             }
-            ast::ModuleItem::TraitDef(it) => {
+            ast::ModuleItemKind::TraitDef(it) => {
                 self.items.push(ModuleItem::new(file_id, file_items, it)?)
             }
-            ast::ModuleItem::TypeDef(it) => {
+            ast::ModuleItemKind::TypeDef(it) => {
                 self.items.push(ModuleItem::new(file_id, file_items, it)?)
             }
-            ast::ModuleItem::ImplBlock(_) => {
+            ast::ModuleItemKind::ImplBlock(_) => {
                 // impls don't define items
             }
-            ast::ModuleItem::UseItem(it) => self.add_use_item(file_items, it),
-            ast::ModuleItem::ExternCrateItem(_) => {
+            ast::ModuleItemKind::UseItem(it) => self.add_use_item(file_items, it),
+            ast::ModuleItemKind::ExternCrateItem(_) => {
                 // TODO
             }
-            ast::ModuleItem::ConstDef(it) => {
+            ast::ModuleItemKind::ConstDef(it) => {
                 self.items.push(ModuleItem::new(file_id, file_items, it)?)
             }
-            ast::ModuleItem::StaticDef(it) => {
+            ast::ModuleItemKind::StaticDef(it) => {
                 self.items.push(ModuleItem::new(file_id, file_items, it)?)
             }
-            ast::ModuleItem::Module(it) => {
+            ast::ModuleItemKind::Module(it) => {
                 self.items.push(ModuleItem::new(file_id, file_items, it)?)
             }
         }
         Some(())
     }
 
-    fn add_use_item(&mut self, file_items: &SourceFileItems, item: ast::UseItem) {
+    fn add_use_item(&mut self, file_items: &SourceFileItems, item: &ast::UseItem) {
         let file_item_id = file_items.id_of_unchecked(item.syntax());
         let start_offset = item.syntax().range().start();
         Path::expand_use_item(item, |path, range| {
@@ -270,10 +270,10 @@ impl InputModuleItems {
 }
 
 impl ModuleItem {
-    fn new<'a>(
+    fn new(
         file_id: HirFileId,
         file_items: &SourceFileItems,
-        item: impl ast::NameOwner<'a>,
+        item: &impl ast::NameOwner,
     ) -> Option<ModuleItem> {
         let name = item.name()?.as_name();
         let kind = item.syntax().kind();
diff --git a/crates/ra_hir/src/path.rs b/crates/ra_hir/src/path.rs
index dcf4cf8b6..6f0b0da97 100644
--- a/crates/ra_hir/src/path.rs
+++ b/crates/ra_hir/src/path.rs
@@ -18,14 +18,14 @@ pub enum PathKind {
 
 impl Path {
     /// Calls `cb` with all paths, represented by this use item.
-    pub fn expand_use_item(item: ast::UseItem, mut cb: impl FnMut(Path, Option<TextRange>)) {
+    pub fn expand_use_item(item: &ast::UseItem, mut cb: impl FnMut(Path, Option<TextRange>)) {
         if let Some(tree) = item.use_tree() {
             expand_use_tree(None, tree, &mut cb);
         }
     }
 
     /// Converts an `ast::Path` to `Path`. Works with use trees.
-    pub fn from_ast(mut path: ast::Path) -> Option<Path> {
+    pub fn from_ast(mut path: &ast::Path) -> Option<Path> {
         let mut kind = PathKind::Plain;
         let mut segments = Vec::new();
         loop {
@@ -53,7 +53,7 @@ impl Path {
         segments.reverse();
         return Some(Path { kind, segments });
 
-        fn qualifier(path: ast::Path) -> Option<ast::Path> {
+        fn qualifier(path: &ast::Path) -> Option<&ast::Path> {
             if let Some(q) = path.qualifier() {
                 return Some(q);
             }
@@ -66,7 +66,7 @@ impl Path {
     }
 
     /// Converts an `ast::NameRef` into a single-identifier `Path`.
-    pub fn from_name_ref(name_ref: ast::NameRef) -> Path {
+    pub fn from_name_ref(name_ref: &ast::NameRef) -> Path {
         name_ref.as_name().into()
     }
 
@@ -100,7 +100,7 @@ impl From<Name> for Path {
 
 fn expand_use_tree(
     prefix: Option<Path>,
-    tree: ast::UseTree,
+    tree: &ast::UseTree,
     cb: &mut impl FnMut(Path, Option<TextRange>),
 ) {
     if let Some(use_tree_list) = tree.use_tree_list() {
@@ -146,7 +146,7 @@ fn expand_use_tree(
     }
 }
 
-fn convert_path(prefix: Option<Path>, path: ast::Path) -> Option<Path> {
+fn convert_path(prefix: Option<Path>, path: &ast::Path) -> Option<Path> {
     let prefix = if let Some(qual) = path.qualifier() {
         Some(convert_path(prefix, qual)?)
     } else {
diff --git a/crates/ra_hir/src/query_definitions.rs b/crates/ra_hir/src/query_definitions.rs
index 8f2c40669..380ea5410 100644
--- a/crates/ra_hir/src/query_definitions.rs
+++ b/crates/ra_hir/src/query_definitions.rs
@@ -5,7 +5,7 @@ use std::{
 
 use rustc_hash::FxHashMap;
 use ra_syntax::{
-    AstNode, SyntaxNode,
+    AstNode, SyntaxNode, TreePtr,
     ast::{self, ModuleItemOwner}
 };
 use ra_db::{SourceRootId, Cancelable,};
@@ -31,30 +31,34 @@ pub(super) fn struct_data(db: &impl HirDatabase, def_id: DefId) -> Cancelable<Ar
     assert!(def_loc.kind == DefKind::Struct);
     let syntax = db.file_item(def_loc.source_item_id);
     let struct_def =
-        ast::StructDef::cast(syntax.borrowed()).expect("struct def should point to StructDef node");
-    Ok(Arc::new(StructData::new(struct_def.borrowed())))
+        ast::StructDef::cast(&syntax).expect("struct def should point to StructDef node");
+    Ok(Arc::new(StructData::new(struct_def)))
 }
 
 pub(super) fn enum_data(db: &impl HirDatabase, def_id: DefId) -> Cancelable<Arc<EnumData>> {
     let def_loc = def_id.loc(db);
     assert!(def_loc.kind == DefKind::Enum);
     let syntax = db.file_item(def_loc.source_item_id);
-    let enum_def =
-        ast::EnumDef::cast(syntax.borrowed()).expect("enum def should point to EnumDef node");
-    Ok(Arc::new(EnumData::new(enum_def.borrowed())))
+    let enum_def = ast::EnumDef::cast(&syntax).expect("enum def should point to EnumDef node");
+    Ok(Arc::new(EnumData::new(enum_def)))
 }
 
 pub(super) fn file_items(db: &impl HirDatabase, file_id: HirFileId) -> Arc<SourceFileItems> {
     let source_file = db.hir_source_file(file_id);
-    let source_file = source_file.borrowed();
-    let res = SourceFileItems::new(file_id, source_file);
+    let res = SourceFileItems::new(file_id, &source_file);
     Arc::new(res)
 }
 
-pub(super) fn file_item(db: &impl HirDatabase, source_item_id: SourceItemId) -> SyntaxNode {
+pub(super) fn file_item(
+    db: &impl HirDatabase,
+    source_item_id: SourceItemId,
+) -> TreePtr<SyntaxNode> {
     match source_item_id.item_id {
-        Some(id) => db.file_items(source_item_id.file_id)[id].clone(),
-        None => db.hir_source_file(source_item_id.file_id).syntax().owned(),
+        Some(id) => db.file_items(source_item_id.file_id)[id].to_owned(),
+        None => db
+            .hir_source_file(source_item_id.file_id)
+            .syntax()
+            .to_owned(),
     }
 }
 
@@ -88,7 +92,7 @@ pub(super) fn input_module_items(
                     let file_id = HirFileId::from(id);
                     let file_items = db.file_items(file_id);
                     //FIXME: expand recursively
-                    for item in db.hir_source_file(file_id).borrowed().items() {
+                    for item in db.hir_source_file(file_id).items() {
                         acc.add_item(file_id, &file_items, item);
                     }
                 }
@@ -98,9 +102,9 @@ pub(super) fn input_module_items(
 
     let mut res = InputModuleItems::default();
     match source {
-        ModuleSource::SourceFile(it) => fill(&mut res, &mut it.borrowed().items_with_macros()),
+        ModuleSource::SourceFile(it) => fill(&mut res, &mut it.items_with_macros()),
         ModuleSource::Module(it) => {
-            if let Some(item_list) = it.borrowed().item_list() {
+            if let Some(item_list) = it.item_list() {
                 fill(&mut res, &mut item_list.items_with_macros())
             }
         }
diff --git a/crates/ra_hir/src/source_binder.rs b/crates/ra_hir/src/source_binder.rs
index 4c14650c0..59a803761 100644
--- a/crates/ra_hir/src/source_binder.rs
+++ b/crates/ra_hir/src/source_binder.rs
@@ -8,7 +8,7 @@
 use ra_db::{FileId, FilePosition, Cancelable};
 use ra_editor::find_node_at_offset;
 use ra_syntax::{
-    SmolStr, TextRange, SyntaxNodeRef,
+    SmolStr, TextRange, SyntaxNode,
     ast::{self, AstNode, NameOwner},
 };
 
@@ -30,7 +30,7 @@ pub fn module_from_file_id(db: &impl HirDatabase, file_id: FileId) -> Cancelable
 pub fn module_from_declaration(
     db: &impl HirDatabase,
     file_id: FileId,
-    decl: ast::Module,
+    decl: &ast::Module,
 ) -> Cancelable<Option<Module>> {
     let parent_module = module_from_file_id(db, file_id)?;
     let child_name = decl.name();
@@ -60,7 +60,7 @@ pub fn module_from_position(
 fn module_from_inline(
     db: &impl HirDatabase,
     file_id: FileId,
-    module: ast::Module,
+    module: &ast::Module,
 ) -> Cancelable<Option<Module>> {
     assert!(!module.has_semi());
     let file_id = file_id.into();
@@ -77,7 +77,7 @@ fn module_from_inline(
 pub fn module_from_child_node(
     db: &impl HirDatabase,
     file_id: FileId,
-    child: SyntaxNodeRef,
+    child: &SyntaxNode,
 ) -> Cancelable<Option<Module>> {
     if let Some(m) = child
         .ancestors()
@@ -112,7 +112,7 @@ pub fn function_from_position(
 pub fn function_from_source(
     db: &impl HirDatabase,
     file_id: FileId,
-    fn_def: ast::FnDef,
+    fn_def: &ast::FnDef,
 ) -> Cancelable<Option<Function>> {
     let module = ctry!(module_from_child_node(db, file_id, fn_def.syntax())?);
     let res = function_from_module(db, &module, fn_def);
@@ -122,7 +122,7 @@ pub fn function_from_source(
 pub fn function_from_module(
     db: &impl HirDatabase,
     module: &Module,
-    fn_def: ast::FnDef,
+    fn_def: &ast::FnDef,
 ) -> Function {
     let loc = module.def_id.loc(db);
     let file_id = loc.source_item_id.file_id;
@@ -144,7 +144,7 @@ pub fn function_from_module(
 pub fn function_from_child_node(
     db: &impl HirDatabase,
     file_id: FileId,
-    node: SyntaxNodeRef,
+    node: &SyntaxNode,
 ) -> Cancelable<Option<Function>> {
     let fn_def = ctry!(node.ancestors().find_map(ast::FnDef::cast));
     function_from_source(db, file_id, fn_def)
@@ -170,15 +170,14 @@ pub fn macro_symbols(
         if let Some(exp) = db.expand_macro_invocation(macro_call_id) {
             let loc = macro_call_id.loc(db);
             let syntax = db.file_item(loc.source_item_id);
-            let syntax = syntax.borrowed();
-            let macro_call = ast::MacroCall::cast(syntax).unwrap();
+            let macro_call = ast::MacroCall::cast(&syntax).unwrap();
             let off = macro_call.token_tree().unwrap().syntax().range().start();
             let file = exp.file();
             for trait_def in file.syntax().descendants().filter_map(ast::TraitDef::cast) {
                 if let Some(name) = trait_def.name() {
                     let dst_range = name.syntax().range();
                     if let Some(src_range) = exp.map_range_back(dst_range) {
-                        res.push((name.text(), src_range + off))
+                        res.push((name.text().clone(), src_range + off))
                     }
                 }
             }
diff --git a/crates/ra_hir/src/ty.rs b/crates/ra_hir/src/ty.rs
index bba8527b7..8adeedddb 100644
--- a/crates/ra_hir/src/ty.rs
+++ b/crates/ra_hir/src/ty.rs
@@ -308,7 +308,13 @@ impl Ty {
         path: &Path,
     ) -> Cancelable<Self> {
         if let Some(name) = path.as_ident() {
-            if let Some(int_ty) = primitive::IntTy::from_name(name) {
+            if let Some(KnownName::Bool) = name.as_known_name() {
+                return Ok(Ty::Bool);
+            } else if let Some(KnownName::Char) = name.as_known_name() {
+                return Ok(Ty::Char);
+            } else if let Some(KnownName::Str) = name.as_known_name() {
+                return Ok(Ty::Str);
+            } else if let Some(int_ty) = primitive::IntTy::from_name(name) {
                 return Ok(Ty::Int(int_ty));
             } else if let Some(uint_ty) = primitive::UintTy::from_name(name) {
                 return Ok(Ty::Uint(uint_ty));
@@ -527,9 +533,7 @@ struct InferenceContext<'a, D: HirDatabase> {
     return_ty: Ty,
 }
 
-// helper function that determines whether a binary operator
-// always returns a boolean
-fn is_boolean_operator(op: BinaryOp) -> bool {
+fn binary_op_return_ty(op: BinaryOp, rhs_ty: Ty) -> Ty {
     match op {
         BinaryOp::BooleanOr
         | BinaryOp::BooleanAnd
@@ -537,7 +541,70 @@ fn is_boolean_operator(op: BinaryOp) -> bool {
         | BinaryOp::LesserEqualTest
         | BinaryOp::GreaterEqualTest
         | BinaryOp::LesserTest
-        | BinaryOp::GreaterTest => true,
+        | BinaryOp::GreaterTest => Ty::Bool,
+        BinaryOp::Assignment
+        | BinaryOp::AddAssign
+        | BinaryOp::SubAssign
+        | BinaryOp::DivAssign
+        | BinaryOp::MulAssign
+        | BinaryOp::RemAssign
+        | BinaryOp::ShrAssign
+        | BinaryOp::ShlAssign
+        | BinaryOp::BitAndAssign
+        | BinaryOp::BitOrAssign
+        | BinaryOp::BitXorAssign => Ty::unit(),
+        BinaryOp::Addition
+        | BinaryOp::Subtraction
+        | BinaryOp::Multiplication
+        | BinaryOp::Division
+        | BinaryOp::Remainder
+        | BinaryOp::LeftShift
+        | BinaryOp::RightShift
+        | BinaryOp::BitwiseAnd
+        | BinaryOp::BitwiseOr
+        | BinaryOp::BitwiseXor => match rhs_ty {
+            Ty::Uint(..) | Ty::Int(..) | Ty::Float(..) => rhs_ty,
+            _ => Ty::Unknown,
+        },
+        BinaryOp::RangeRightOpen | BinaryOp::RangeRightClosed => Ty::Unknown,
+    }
+}
+
+fn binary_op_rhs_expectation(op: BinaryOp, lhs_ty: Ty) -> Ty {
+    match op {
+        BinaryOp::BooleanAnd | BinaryOp::BooleanOr => Ty::Bool,
+        BinaryOp::Assignment | BinaryOp::EqualityTest => match lhs_ty {
+            Ty::Uint(..) | Ty::Int(..) | Ty::Float(..) | Ty::Str | Ty::Char | Ty::Bool => lhs_ty,
+            _ => Ty::Unknown,
+        },
+        BinaryOp::LesserEqualTest
+        | BinaryOp::GreaterEqualTest
+        | BinaryOp::LesserTest
+        | BinaryOp::GreaterTest
+        | BinaryOp::AddAssign
+        | BinaryOp::SubAssign
+        | BinaryOp::DivAssign
+        | BinaryOp::MulAssign
+        | BinaryOp::RemAssign
+        | BinaryOp::ShrAssign
+        | BinaryOp::ShlAssign
+        | BinaryOp::BitAndAssign
+        | BinaryOp::BitOrAssign
+        | BinaryOp::BitXorAssign
+        | BinaryOp::Addition
+        | BinaryOp::Subtraction
+        | BinaryOp::Multiplication
+        | BinaryOp::Division
+        | BinaryOp::Remainder
+        | BinaryOp::LeftShift
+        | BinaryOp::RightShift
+        | BinaryOp::BitwiseAnd
+        | BinaryOp::BitwiseOr
+        | BinaryOp::BitwiseXor => match lhs_ty {
+            Ty::Uint(..) | Ty::Int(..) | Ty::Float(..) => lhs_ty,
+            _ => Ty::Unknown,
+        },
+        _ => Ty::Unknown,
     }
 }
 
@@ -889,20 +956,20 @@ impl<'a, D: HirDatabase> InferenceContext<'a, D> {
             }
             Expr::BinaryOp { lhs, rhs, op } => match op {
                 Some(op) => {
-                    let subtype_expectation = match op {
+                    let lhs_expectation = match op {
                         BinaryOp::BooleanAnd | BinaryOp::BooleanOr => {
                             Expectation::has_type(Ty::Bool)
                         }
                         _ => Expectation::none(),
                     };
-                    let _lhs_ty = self.infer_expr(*lhs, &subtype_expectation)?;
-                    let _rhs_ty = self.infer_expr(*rhs, &subtype_expectation)?;
-
-                    if is_boolean_operator(*op) {
-                        Ty::Bool
-                    } else {
-                        Ty::Unknown
-                    }
+                    let lhs_ty = self.infer_expr(*lhs, &lhs_expectation)?;
+                    // TODO: find implementation of trait corresponding to operation
+                    // symbol and resolve associated `Output` type
+                    let rhs_expectation = binary_op_rhs_expectation(*op, lhs_ty);
+                    let rhs_ty = self.infer_expr(*rhs, &Expectation::has_type(rhs_expectation))?;
+
+                    // TODO: similar as above, return ty is often associated trait type
+                    binary_op_return_ty(*op, rhs_ty)
                 }
                 _ => Ty::Unknown,
             },
diff --git a/crates/ra_hir/src/ty/tests.rs b/crates/ra_hir/src/ty/tests.rs
index e6c7e225b..2749d740c 100644
--- a/crates/ra_hir/src/ty/tests.rs
+++ b/crates/ra_hir/src/ty/tests.rs
@@ -157,7 +157,7 @@ impl S {
 }
 
 #[test]
-fn infer_boolean_op() {
+fn infer_binary_op() {
     check_inference(
         r#"
 fn f(x: bool) -> i32 {
@@ -168,15 +168,18 @@ fn test() {
     let x = a && b;
     let y = true || false;
     let z = x == y;
-    let h = CONST_1 <= CONST_2;
+    let minus_forty: isize = -40isize;
+    let h = minus_forty <= CONST_2;
     let c = f(z || y) + 5;
     let d = b;
-    let e = 3i32 && "hello world";
+    let g = minus_forty ^= i;
+    let ten: usize = 10;
+    let ten_is_eleven = ten == some_num;
 
-    10 < 3
+    ten < 3
 }
 "#,
-        "boolean_op.txt",
+        "binary_op.txt",
     );
 }
 
diff --git a/crates/ra_hir/src/ty/tests/data/basics.txt b/crates/ra_hir/src/ty/tests/data/basics.txt
index 8ea244ba8..ac7faae0a 100644
--- a/crates/ra_hir/src/ty/tests/data/basics.txt
+++ b/crates/ra_hir/src/ty/tests/data/basics.txt
@@ -1,12 +1,12 @@
 [9; 10) 'a': u32
 [17; 18) 'b': isize
 [27; 28) 'c': !
-[33; 34) 'd': &[unknown]
+[33; 34) 'd': &str
 [42; 121) '{     ...f32; }': ()
 [48; 49) 'a': u32
 [55; 56) 'b': isize
 [62; 63) 'c': !
-[69; 70) 'd': &[unknown]
+[69; 70) 'd': &str
 [76; 82) '1usize': [unknown]
 [88; 94) '1isize': [unknown]
 [100; 106) '"test"': [unknown]
diff --git a/crates/ra_hir/src/ty/tests/data/binary_op.txt b/crates/ra_hir/src/ty/tests/data/binary_op.txt
new file mode 100644
index 000000000..0fb9dc097
--- /dev/null
+++ b/crates/ra_hir/src/ty/tests/data/binary_op.txt
@@ -0,0 +1,46 @@
+[6; 7) 'x': bool
+[22; 34) '{     0i32 }': i32
+[28; 32) '0i32': i32
+[46; 342) '{     ... < 3 }': bool
+[56; 57) 'x': bool
+[60; 61) 'a': bool
+[60; 66) 'a && b': bool
+[65; 66) 'b': bool
+[76; 77) 'y': bool
+[80; 84) 'true': bool
+[80; 93) 'true || false': bool
+[88; 93) 'false': bool
+[103; 104) 'z': bool
+[107; 108) 'x': bool
+[107; 113) 'x == y': bool
+[112; 113) 'y': bool
+[123; 134) 'minus_forty': isize
+[144; 152) '-40isize': isize
+[145; 152) '40isize': [unknown]
+[162; 163) 'h': bool
+[166; 177) 'minus_forty': isize
+[166; 188) 'minus_...ONST_2': bool
+[181; 188) 'CONST_2': isize
+[198; 199) 'c': i32
+[202; 203) 'f': fn(bool,) -> i32
+[202; 211) 'f(z || y)': i32
+[202; 215) 'f(z || y) + 5': i32
+[204; 205) 'z': bool
+[204; 210) 'z || y': bool
+[209; 210) 'y': bool
+[214; 215) '5': i32
+[225; 226) 'd': [unknown]
+[229; 230) 'b': [unknown]
+[240; 241) 'g': ()
+[244; 255) 'minus_forty': isize
+[244; 260) 'minus_...y ^= i': ()
+[259; 260) 'i': isize
+[270; 273) 'ten': usize
+[283; 285) '10': usize
+[295; 308) 'ten_is_eleven': bool
+[311; 314) 'ten': usize
+[311; 326) 'ten == some_num': bool
+[318; 326) 'some_num': usize
+[333; 336) 'ten': usize
+[333; 340) 'ten < 3': bool
+[339; 340) '3': usize
diff --git a/crates/ra_hir/src/ty/tests/data/boolean_op.txt b/crates/ra_hir/src/ty/tests/data/boolean_op.txt
deleted file mode 100644
index cce8d68fb..000000000
--- a/crates/ra_hir/src/ty/tests/data/boolean_op.txt
+++ /dev/null
@@ -1,31 +0,0 @@
-[6; 7) 'x': [unknown]
-[22; 34) '{     0i32 }': i32
-[28; 32) '0i32': i32
-[46; 237) '{     ... < 3 }': bool
-[56; 57) 'x': bool
-[60; 61) 'a': bool
-[60; 66) 'a && b': bool
-[65; 66) 'b': bool
-[76; 77) 'y': bool
-[80; 84) 'true': bool
-[80; 93) 'true || false': bool
-[88; 93) 'false': bool
-[103; 104) 'z': bool
-[107; 108) 'x': bool
-[107; 113) 'x == y': bool
-[112; 113) 'y': bool
-[123; 124) 'h': bool
-[127; 134) 'CONST_1': [unknown]
-[127; 145) 'CONST_...ONST_2': bool
-[138; 145) 'CONST_2': [unknown]
-[155; 156) 'c': [unknown]
-[159; 172) 'f(z || y) + 5': [unknown]
-[182; 183) 'd': [unknown]
-[186; 187) 'b': [unknown]
-[197; 198) 'e': bool
-[201; 205) '3i32': bool
-[201; 222) '3i32 &...world"': bool
-[209; 222) '"hello world"': bool
-[229; 231) '10': [unknown]
-[229; 235) '10 < 3': bool
-[234; 235) '3': [unknown]
diff --git a/crates/ra_hir/src/type_ref.rs b/crates/ra_hir/src/type_ref.rs
index 859f330c2..c9db4e0a5 100644
--- a/crates/ra_hir/src/type_ref.rs
+++ b/crates/ra_hir/src/type_ref.rs
@@ -56,9 +56,9 @@ pub enum TypeRef {
 
 impl TypeRef {
     /// Converts an `ast::TypeRef` to a `hir::TypeRef`.
-    pub(crate) fn from_ast(node: ast::TypeRef) -> Self {
-        use ra_syntax::ast::TypeRef::*;
-        match node {
+    pub(crate) fn from_ast(node: &ast::TypeRef) -> Self {
+        use ra_syntax::ast::TypeRefKind::*;
+        match node.kind() {
             ParenType(inner) => TypeRef::from_ast_opt(inner.type_ref()),
             TupleType(inner) => TypeRef::Tuple(inner.fields().map(TypeRef::from_ast).collect()),
             NeverType(..) => TypeRef::Never,
@@ -100,7 +100,7 @@ impl TypeRef {
         }
     }
 
-    pub(crate) fn from_ast_opt(node: Option<ast::TypeRef>) -> Self {
+    pub(crate) fn from_ast_opt(node: Option<&ast::TypeRef>) -> Self {
         if let Some(node) = node {
             TypeRef::from_ast(node)
         } else {