70 files changed, 781 insertions, 241 deletions

diff --git a/Cargo.lock b/Cargo.lock
index ff24b9dc8..65ffff90a 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -5,7 +5,7 @@ name = "aho-corasick"
 version = "0.6.9"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
- "memchr 2.1.3 (registry+https://github.com/rust-lang/crates.io-index)",
+ "memchr 2.2.0 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
@@ -667,12 +667,8 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 
 [[package]]
 name = "memchr"
-version = "2.1.3"
+version = "2.2.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-dependencies = [
- "cfg-if 0.1.6 (registry+https://github.com/rust-lang/crates.io-index)",
- "libc 0.2.48 (registry+https://github.com/rust-lang/crates.io-index)",
-]
 
 [[package]]
 name = "memmap"
@@ -786,7 +782,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 
 [[package]]
 name = "num_cpus"
-version = "1.9.0"
+version = "1.10.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
  "libc 0.2.48 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -1042,7 +1038,7 @@ dependencies = [
  "ra_syntax 0.1.0",
  "ra_text_edit 0.1.0",
  "rustc-hash 1.0.1 (registry+https://github.com/rust-lang/crates.io-index)",
- "superslice 0.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "superslice 1.0.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "test_utils 0.1.0",
 ]
 
@@ -1266,7 +1262,7 @@ dependencies = [
  "crossbeam-deque 0.2.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "lazy_static 1.2.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "libc 0.2.48 (registry+https://github.com/rust-lang/crates.io-index)",
- "num_cpus 1.9.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "num_cpus 1.10.0 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
@@ -1296,7 +1292,7 @@ version = "1.1.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
  "aho-corasick 0.6.9 (registry+https://github.com/rust-lang/crates.io-index)",
- "memchr 2.1.3 (registry+https://github.com/rust-lang/crates.io-index)",
+ "memchr 2.2.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "regex-syntax 0.6.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "thread_local 0.3.6 (registry+https://github.com/rust-lang/crates.io-index)",
  "utf8-ranges 1.0.2 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -1530,7 +1526,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 
 [[package]]
 name = "superslice"
-version = "0.1.0"
+version = "1.0.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 
 [[package]]
@@ -1664,7 +1660,7 @@ name = "threadpool"
 version = "1.7.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
- "num_cpus 1.9.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "num_cpus 1.10.0 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
@@ -1997,7 +1993,7 @@ dependencies = [
 "checksum lsp-types 0.55.3 (registry+https://github.com/rust-lang/crates.io-index)" = "9092adbc87fcf30f9d371ecea86dafee55e56f282ee19ca282384e3a04926ba9"
 "checksum maplit 1.0.1 (registry+https://github.com/rust-lang/crates.io-index)" = "08cbb6b4fef96b6d77bfc40ec491b1690c779e77b05cd9f07f787ed376fd4c43"
 "checksum matches 0.1.8 (registry+https://github.com/rust-lang/crates.io-index)" = "7ffc5c5338469d4d3ea17d269fa8ea3512ad247247c30bd2df69e68309ed0a08"
-"checksum memchr 2.1.3 (registry+https://github.com/rust-lang/crates.io-index)" = "e1dd4eaac298c32ce07eb6ed9242eda7d82955b9170b7d6db59b2e02cc63fcb8"
+"checksum memchr 2.2.0 (registry+https://github.com/rust-lang/crates.io-index)" = "2efc7bc57c883d4a4d6e3246905283d8dae951bb3bd32f49d6ef297f546e1c39"
 "checksum memmap 0.6.2 (registry+https://github.com/rust-lang/crates.io-index)" = "e2ffa2c986de11a9df78620c01eeaaf27d94d3ff02bf81bfcca953102dd0c6ff"
 "checksum memoffset 0.2.1 (registry+https://github.com/rust-lang/crates.io-index)" = "0f9dc261e2b62d7a622bf416ea3c5245cdd5d9a7fcc428c0d06804dfce1775b3"
 "checksum mio 0.6.16 (registry+https://github.com/rust-lang/crates.io-index)" = "71646331f2619b1026cc302f87a2b8b648d5c6dd6937846a16cc8ce0f347f432"
@@ -2009,7 +2005,7 @@ dependencies = [
 "checksum num-derive 0.2.4 (registry+https://github.com/rust-lang/crates.io-index)" = "d9fe8fcafd1b86a37ce8a1cfa15ae504817e0c8c2e7ad42767371461ac1d316d"
 "checksum num-integer 0.1.39 (registry+https://github.com/rust-lang/crates.io-index)" = "e83d528d2677f0518c570baf2b7abdcf0cd2d248860b68507bdcb3e91d4c0cea"
 "checksum num-traits 0.2.6 (registry+https://github.com/rust-lang/crates.io-index)" = "0b3a5d7cc97d6d30d8b9bc8fa19bf45349ffe46241e8816f50f62f6d6aaabee1"
-"checksum num_cpus 1.9.0 (registry+https://github.com/rust-lang/crates.io-index)" = "5a69d464bdc213aaaff628444e99578ede64e9c854025aa43b9796530afa9238"
+"checksum num_cpus 1.10.0 (registry+https://github.com/rust-lang/crates.io-index)" = "1a23f0ed30a54abaa0c7e83b1d2d87ada7c3c23078d1d87815af3e3b6385fbba"
 "checksum number_prefix 0.2.8 (registry+https://github.com/rust-lang/crates.io-index)" = "dbf9993e59c894e3c08aa1c2712914e9e6bf1fcbfc6bef283e2183df345a4fee"
 "checksum owning_ref 0.4.0 (registry+https://github.com/rust-lang/crates.io-index)" = "49a4b8ea2179e6a2e27411d3bca09ca6dd630821cf6894c6c7c8467a8ee7ef13"
 "checksum parking_lot 0.7.1 (registry+https://github.com/rust-lang/crates.io-index)" = "ab41b4aed082705d1056416ae4468b6ea99d52599ecf3169b00088d43113e337"
@@ -2067,7 +2063,7 @@ dependencies = [
 "checksum spin 0.4.10 (registry+https://github.com/rust-lang/crates.io-index)" = "ceac490aa12c567115b40b7b7fceca03a6c9d53d5defea066123debc83c5dc1f"
 "checksum stable_deref_trait 1.1.1 (registry+https://github.com/rust-lang/crates.io-index)" = "dba1a27d3efae4351c8051072d619e3ade2820635c3958d826bfea39d59b54c8"
 "checksum strsim 0.7.0 (registry+https://github.com/rust-lang/crates.io-index)" = "bb4f380125926a99e52bc279241539c018323fab05ad6368b56f93d9369ff550"
-"checksum superslice 0.1.0 (registry+https://github.com/rust-lang/crates.io-index)" = "b50b13d42370e0f5fc62eafdd5c2d20065eaf5458dab215ff3e20e63eea96b30"
+"checksum superslice 1.0.0 (registry+https://github.com/rust-lang/crates.io-index)" = "ab16ced94dbd8a46c82fd81e3ed9a8727dac2977ea869d217bcc4ea1f122e81f"
 "checksum syn 0.15.26 (registry+https://github.com/rust-lang/crates.io-index)" = "f92e629aa1d9c827b2bb8297046c1ccffc57c99b947a680d3ccff1f136a3bee9"
 "checksum synstructure 0.10.1 (registry+https://github.com/rust-lang/crates.io-index)" = "73687139bf99285483c96ac0add482c3776528beac1d97d444f6e91f203a2015"
 "checksum tempfile 3.0.6 (registry+https://github.com/rust-lang/crates.io-index)" = "37daa55a7240c4931c84559f03b3cad7d19535840d1c4a0cc4e9b2fb0dcf70ff"
diff --git a/README.md b/README.md
index cffc00953..15da30f2d 100644
--- a/README.md
+++ b/README.md
@@ -3,12 +3,10 @@
 [![Build Status](https://travis-ci.org/rust-analyzer/rust-analyzer.svg?branch=master)](https://travis-ci.org/rust-analyzer/rust-analyzer)
 
 Rust Analyzer is an **experimental** modular compiler frontend for the Rust
-language, which aims to lay a foundation for excellent IDE support.
+language. It is a part of a larger rls-2.0 effort to create excellent IDE
+support for Rust. If you want to get involved, check rls-2.0 working group repository:
 
-It doesn't implement much of compiler functionality yet, but the white-space
-preserving Rust parser works, and there are significant chunks of overall
-architecture (indexing, on-demand & lazy computation, snapshotable world view)
-in place. Some basic IDE functionality is provided via a language server.
+https://github.com/rust-analyzer/WG-rls2.0
 
 Work on the Rust Analyzer is sponsored by
 
@@ -41,37 +39,15 @@ features (some of which are VS Code specific).
 
 See [these instructions](./DEBUGGING.md) on how to debug the vscode extension and the lsp server.
 
-## Current Status and Plans
-
-Rust analyzer aims to fill the same niche as the official [Rust Language
-Server](https://github.com/rust-lang-nursery/rls), but uses a significantly
-different architecture. More details can be found [in this
-thread](https://internals.rust-lang.org/t/2019-strategy-for-rustc-and-the-rls/8361),
-but the core issue is that RLS works in the "wait until user stops typing, run
-the build process, save the results of the analysis" mode, which arguably is the
-wrong foundation for IDE.
-
-Rust Analyzer is an experimental project at the moment, there's exactly zero
-guarantees that it becomes production-ready one day.
+## Getting in touch
 
-The near/mid term plan is to work independently of the main rustc compiler and
-implement at least simplistic versions of name resolution, macro expansion and
-type inference. The purpose is two fold:
+We are on the rust-lang Zulip!
 
-- to quickly bootstrap usable and useful language server: solution that covers
-  80% of Rust code will be useful for IDEs, and will be vastly simpler than 100%
-  solution.
+https://rust-lang.zulipchat.com/#narrow/stream/185405-t-compiler.2Frls-2.2E0
 
-- to understand how the consumer-side of compiler API should look like
-  (especially it's on-demand aspects). If you have `get_expression_type`
-  function, you can write a ton of purely-IDE features on top of it, even if the
-  function is only partially correct. Pluging in the precise function afterwards
-  should just make IDE features more reliable.
+## Contributing
 
-The long term plan is to merge with the mainline rustc compiler, probably around
-the HIR boundary? That is, use rust analyzer for parsing, macro expansion and
-related bits of name resolution, but leave the rest (including type inference
-and trait selection) to the existing rustc.
+See [CONTRIBUTING.md](./CONTRIBUTING.md) and [ARCHITECTURE.md](./ARCHITECTURE.md)
 
 ## Supported LSP features
 
@@ -146,15 +122,6 @@ and trait selection) to the existing rustc.
 - [x] [textDocument/prepareRename](https://microsoft.github.io/language-server-protocol/specification#textDocument_prepareRename)
 - [x] [textDocument/foldingRange](https://microsoft.github.io/language-server-protocol/specification#textDocument_foldingRange)
 
-## Getting in touch
-
-We have a Discord server dedicated to compilers and language servers
-implemented in Rust: [https://discord.gg/sx3RQZB](https://discord.gg/sx3RQZB).
-
-## Contributing
-
-See [CONTRIBUTING.md](./CONTRIBUTING.md) and [ARCHITECTURE.md](./ARCHITECTURE.md)
-
 ## License
 
 Rust analyzer is primarily distributed under the terms of both the MIT
diff --git a/crates/ra_assists/src/auto_import.rs b/crates/ra_assists/src/auto_import.rs
index b251c9369..52c2a0b2b 100644
--- a/crates/ra_assists/src/auto_import.rs
+++ b/crates/ra_assists/src/auto_import.rs
@@ -1,6 +1,6 @@
 use hir::db::HirDatabase;
 use ra_syntax::{
-    ast, AstNode, SyntaxNode, Direction, TextRange,
+    ast::{ self, NameOwner }, AstNode, SyntaxNode, Direction, TextRange,
     SyntaxKind::{ PATH, PATH_SEGMENT, COLONCOLON, COMMA }
 };
 use crate::assist_ctx::{AssistCtx, Assist, AssistBuilder};
@@ -345,9 +345,9 @@ fn best_action_for_target<'b, 'a: 'b>(
     match best_action {
         Some(action) => return action,
         None => {
-            // We have no action we no use item was found in container so we find
+            // We have no action and no UseItem was found in container so we find
             // another item and we use it as anchor.
-            // If there are not items, we choose the target path itself as anchor.
+            // If there are no items, we choose the target path itself as anchor.
             let anchor = container
                 .children()
                 .find_map(ast::ModuleItem::cast)
@@ -480,6 +480,24 @@ fn make_assist_add_nested_import(
     }
 }
 
+fn apply_auto_import<'a>(
+    container: &SyntaxNode,
+    path: &ast::Path,
+    target: &[&'a ast::PathSegment],
+    edit: &mut AssistBuilder,
+) {
+    let action = best_action_for_target(container, path, target);
+    make_assist(&action, target, edit);
+    if let (Some(first), Some(last)) = (target.first(), target.last()) {
+        // Here we are assuming the assist will provide a  correct use statement
+        // so we can delete the path qualifier
+        edit.delete(TextRange::from_to(
+            first.syntax().range().start(),
+            last.syntax().range().start(),
+        ));
+    }
+}
+
 pub(crate) fn auto_import(mut ctx: AssistCtx<impl HirDatabase>) -> Option<Assist> {
     let node = ctx.covering_node();
     let current_file = node.ancestors().find_map(ast::SourceFile::cast)?;
@@ -495,18 +513,20 @@ pub(crate) fn auto_import(mut ctx: AssistCtx<impl HirDatabase>) -> Option<Assist
         return None;
     }
 
-    ctx.add_action(format!("import {} in the current file", fmt_segments(&segments)), |edit| {
-        let action = best_action_for_target(current_file.syntax(), path, &segments);
-        make_assist(&action, segments.as_slice(), edit);
-        if let Some(last_segment) = path.segment() {
-            // Here we are assuming the assist will provide a  correct use statement
-            // so we can delete the path qualifier
-            edit.delete(TextRange::from_to(
-                path.syntax().range().start(),
-                last_segment.syntax().range().start(),
-            ));
+    if let Some(module) = path.syntax().ancestors().find_map(ast::Module::cast) {
+        if let (Some(item_list), Some(name)) = (module.item_list(), module.name()) {
+            ctx.add_action(
+                format!("import {} in mod {}", fmt_segments(&segments), name.text()),
+                |edit| {
+                    apply_auto_import(item_list.syntax(), path, &segments, edit);
+                },
+            );
         }
-    });
+    } else {
+        ctx.add_action(format!("import {} in the current file", fmt_segments(&segments)), |edit| {
+            apply_auto_import(current_file.syntax(), path, &segments, edit);
+        });
+    }
 
     ctx.build()
 }
@@ -532,6 +552,21 @@ Debug<|>
     }
 
     #[test]
+    fn test_auto_import_file_add_use_no_anchor_2seg() {
+        check_assist(
+            auto_import,
+            "
+std::fmt<|>::Debug
+    ",
+            "
+use std::fmt;
+
+fmt<|>::Debug
+    ",
+        );
+    }
+
+    #[test]
     fn test_auto_import_file_add_use() {
         check_assist(
             auto_import,
@@ -728,4 +763,37 @@ impl foo<|> for Foo {
 ",
         );
     }
+
+    #[test]
+    fn test_auto_import_not_applicable_in_use() {
+        check_assist_not_applicable(
+            auto_import,
+            "
+use std::fmt<|>;
+",
+        );
+    }
+
+    #[test]
+    fn test_auto_import_file_add_use_no_anchor_in_mod_mod() {
+        check_assist(
+            auto_import,
+            "
+mod foo {
+    mod bar {
+        std::fmt::Debug<|>
+    }
+}
+    ",
+            "
+mod foo {
+    mod bar {
+        use std::fmt::Debug;
+
+        Debug<|>
+    }
+}
+    ",
+        );
+    }
 }
diff --git a/crates/ra_assists/src/lib.rs b/crates/ra_assists/src/lib.rs
index c607a5142..7bd9b5ae6 100644
--- a/crates/ra_assists/src/lib.rs
+++ b/crates/ra_assists/src/lib.rs
@@ -1,4 +1,4 @@
-//! `ra_assits` crate provides a bunch of code assists, aslo known as code
+//! `ra_assits` crate provides a bunch of code assists, also known as code
 //! actions (in LSP) or intentions (in IntelliJ).
 //!
 //! An assist is a micro-refactoring, which is automatically activated in
diff --git a/crates/ra_assists/src/remove_dbg.rs b/crates/ra_assists/src/remove_dbg.rs
index db260c6ca..2bed270a1 100644
--- a/crates/ra_assists/src/remove_dbg.rs
+++ b/crates/ra_assists/src/remove_dbg.rs
@@ -17,9 +17,9 @@ pub(crate) fn remove_dbg(mut ctx: AssistCtx<impl HirDatabase>) -> Option<Assist>
 
     let macro_range = macro_call.syntax().range();
 
-    // If the cursor is inside the macrocall, we'll try to maintain
-    // the cursor position by subtracting the length of dbg!( from the start
-    // of the filerange, otherwise we'll default to using the start of the macrocall
+    // If the cursor is inside the macro call, we'll try to maintain the cursor
+    // position by subtracting the length of dbg!( from the start of the file
+    // range, otherwise we'll default to using the start of the macro call
     let cursor_pos = {
         let file_range = ctx.frange.range;
 
@@ -61,7 +61,7 @@ fn is_valid_macrocall(macro_call: &ast::MacroCall, macro_name: &str) -> Option<b
     let path = macro_call.path()?;
     let name_ref = path.segment()?.name_ref()?;
 
-    // Make sure it is actually a dbg-macrocall, dbg followed by !
+    // Make sure it is actually a dbg-macro call, dbg followed by !
     let excl = path.syntax().next_sibling()?;
 
     if name_ref.text() != macro_name || excl.kind() != EXCL {
diff --git a/crates/ra_db/src/cancellation.rs b/crates/ra_db/src/cancellation.rs
index 439080075..7420a1976 100644
--- a/crates/ra_db/src/cancellation.rs
+++ b/crates/ra_db/src/cancellation.rs
@@ -15,7 +15,7 @@
 //! any background processing (this bit is handled by salsa, see the
 //! `BaseDatabase::check_canceled` method).
 
-/// An "error" signifing that the operation was canceled.
+/// An "error" signifying that the operation was canceled.
 #[derive(Clone, PartialEq, Eq, Hash)]
 pub struct Canceled {
     _private: (),
diff --git a/crates/ra_db/src/input.rs b/crates/ra_db/src/input.rs
index 8decc65c5..e45a510b3 100644
--- a/crates/ra_db/src/input.rs
+++ b/crates/ra_db/src/input.rs
@@ -56,15 +56,31 @@ pub struct CyclicDependencies;
 #[derive(Debug, Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash)]
 pub struct CrateId(pub u32);
 
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
+pub enum Edition {
+    Edition2018,
+    Edition2015,
+}
+
+impl Edition {
+    pub fn from_string(s: &str) -> Edition {
+        match s {
+            "2015" => Edition::Edition2015,
+            "2018" | _ => Edition::Edition2018,
+        }
+    }
+}
+
 #[derive(Debug, Clone, PartialEq, Eq)]
 struct CrateData {
     file_id: FileId,
+    edition: Edition,
     dependencies: Vec<Dependency>,
 }
 
 impl CrateData {
-    fn new(file_id: FileId) -> CrateData {
-        CrateData { file_id, dependencies: Vec::new() }
+    fn new(file_id: FileId, edition: Edition) -> CrateData {
+        CrateData { file_id, edition, dependencies: Vec::new() }
     }
 
     fn add_dep(&mut self, name: SmolStr, crate_id: CrateId) {
@@ -85,9 +101,9 @@ impl Dependency {
 }
 
 impl CrateGraph {
-    pub fn add_crate_root(&mut self, file_id: FileId) -> CrateId {
+    pub fn add_crate_root(&mut self, file_id: FileId, edition: Edition) -> CrateId {
         let crate_id = CrateId(self.arena.len() as u32);
-        let prev = self.arena.insert(crate_id, CrateData::new(file_id));
+        let prev = self.arena.insert(crate_id, CrateData::new(file_id, edition));
         assert!(prev.is_none());
         crate_id
     }
@@ -112,6 +128,10 @@ impl CrateGraph {
         self.arena[&crate_id].file_id
     }
 
+    pub fn edition(&self, crate_id: CrateId) -> Edition {
+        self.arena[&crate_id].edition
+    }
+
     // TODO: this only finds one crate with the given root; we could have multiple
     pub fn crate_id_for_crate_root(&self, file_id: FileId) -> Option<CrateId> {
         let (&crate_id, _) = self.arena.iter().find(|(_crate_id, data)| data.file_id == file_id)?;
@@ -159,14 +179,14 @@ impl CrateGraph {
 
 #[cfg(test)]
 mod tests {
-    use super::{CrateGraph, FileId, SmolStr};
+    use super::{CrateGraph, FileId, SmolStr, Edition::Edition2018};
 
     #[test]
-    fn it_should_painc_because_of_cycle_dependencies() {
+    fn it_should_panic_because_of_cycle_dependencies() {
         let mut graph = CrateGraph::default();
-        let crate1 = graph.add_crate_root(FileId(1u32));
-        let crate2 = graph.add_crate_root(FileId(2u32));
-        let crate3 = graph.add_crate_root(FileId(3u32));
+        let crate1 = graph.add_crate_root(FileId(1u32), Edition2018);
+        let crate2 = graph.add_crate_root(FileId(2u32), Edition2018);
+        let crate3 = graph.add_crate_root(FileId(3u32), Edition2018);
         assert!(graph.add_dep(crate1, SmolStr::new("crate2"), crate2).is_ok());
         assert!(graph.add_dep(crate2, SmolStr::new("crate3"), crate3).is_ok());
         assert!(graph.add_dep(crate3, SmolStr::new("crate1"), crate1).is_err());
@@ -175,9 +195,9 @@ mod tests {
     #[test]
     fn it_works() {
         let mut graph = CrateGraph::default();
-        let crate1 = graph.add_crate_root(FileId(1u32));
-        let crate2 = graph.add_crate_root(FileId(2u32));
-        let crate3 = graph.add_crate_root(FileId(3u32));
+        let crate1 = graph.add_crate_root(FileId(1u32), Edition2018);
+        let crate2 = graph.add_crate_root(FileId(2u32), Edition2018);
+        let crate3 = graph.add_crate_root(FileId(3u32), Edition2018);
         assert!(graph.add_dep(crate1, SmolStr::new("crate2"), crate2).is_ok());
         assert!(graph.add_dep(crate2, SmolStr::new("crate3"), crate3).is_ok());
     }
diff --git a/crates/ra_db/src/lib.rs b/crates/ra_db/src/lib.rs
index 31442713d..e006c6d27 100644
--- a/crates/ra_db/src/lib.rs
+++ b/crates/ra_db/src/lib.rs
@@ -14,7 +14,7 @@ pub use ::salsa as salsa;
 pub use crate::{
     cancellation::Canceled,
     input::{
-        FileId, CrateId, SourceRoot, SourceRootId, CrateGraph, Dependency,
+        FileId, CrateId, SourceRoot, SourceRootId, CrateGraph, Dependency, Edition,
     },
     loc2id::LocationIntener,
 };
diff --git a/crates/ra_hir/src/code_model_api.rs b/crates/ra_hir/src/code_model_api.rs
index 94a08aa63..fb7ad0867 100644
--- a/crates/ra_hir/src/code_model_api.rs
+++ b/crates/ra_hir/src/code_model_api.rs
@@ -1,7 +1,7 @@
 use std::sync::Arc;
 
 use relative_path::RelativePathBuf;
-use ra_db::{CrateId, FileId, SourceRootId};
+use ra_db::{CrateId, FileId, SourceRootId, Edition};
 use ra_syntax::{ast::self, TreeArc, SyntaxNode};
 
 use crate::{
@@ -38,13 +38,20 @@ impl Crate {
     pub fn crate_id(&self) -> CrateId {
         self.crate_id
     }
+
     pub fn dependencies(&self, db: &impl PersistentHirDatabase) -> Vec<CrateDependency> {
         self.dependencies_impl(db)
     }
+
     pub fn root_module(&self, db: &impl PersistentHirDatabase) -> Option<Module> {
         self.root_module_impl(db)
     }
 
+    pub fn edition(&self, db: &impl PersistentHirDatabase) -> Edition {
+        let crate_graph = db.crate_graph();
+        crate_graph.edition(self.crate_id)
+    }
+
     // TODO: should this be in source_binder?
     pub fn source_root_crates(
         db: &impl PersistentHirDatabase,
@@ -134,7 +141,7 @@ impl Module {
 
     /// Topmost parent of this module. Every module has a `crate_root`, but some
     /// might be missing `krate`. This can happen if a module's file is not included
-    /// in the module tree of any target in Cargo.toml.
+    /// in the module tree of any target in `Cargo.toml`.
     pub fn crate_root(&self, db: &impl PersistentHirDatabase) -> Module {
         self.crate_root_impl(db)
     }
@@ -351,7 +358,7 @@ impl Enum {
         db.type_for_def((*self).into())
     }
 
-    // TODO move to a more general type
+    // TODO: move to a more general type
     /// Builds a resolver for type references inside this struct.
     pub fn resolver(&self, db: &impl HirDatabase) -> Resolver {
         // take the outer scope...
@@ -495,7 +502,7 @@ impl Function {
         db.generic_params((*self).into())
     }
 
-    // TODO move to a more general type for 'body-having' items
+    // TODO: move to a more general type for 'body-having' items
     /// Builds a resolver for code inside this item.
     pub fn resolver(&self, db: &impl HirDatabase) -> Resolver {
         // take the outer scope...
diff --git a/crates/ra_hir/src/expr/scope.rs b/crates/ra_hir/src/expr/scope.rs
index 44d5c2429..bb8d50db8 100644
--- a/crates/ra_hir/src/expr/scope.rs
+++ b/crates/ra_hir/src/expr/scope.rs
@@ -84,7 +84,7 @@ impl ExprScopes {
     fn add_bindings(&mut self, body: &Body, scope: ScopeId, pat: PatId) {
         match &body[pat] {
             Pat::Bind { name, .. } => {
-                // bind can have a subpattern, but it's actually not allowed
+                // bind can have a sub pattern, but it's actually not allowed
                 // to bind to things in there
                 let entry = ScopeEntry { name: name.clone(), pat };
                 self.scopes[scope].entries.push(entry)
diff --git a/crates/ra_hir/src/ids.rs b/crates/ra_hir/src/ids.rs
index d3fa7d266..8d81d5ebf 100644
--- a/crates/ra_hir/src/ids.rs
+++ b/crates/ra_hir/src/ids.rs
@@ -46,24 +46,24 @@ impl HirInterner {
 /// This module defines a bunch of ids we are using. The most important ones are
 /// probably `HirFileId` and `DefId`.
 
-/// Input to the analyzer is a set of files, where each file is indentified by
+/// Input to the analyzer is a set of files, where each file is identified by
 /// `FileId` and contains source code. However, another source of source code in
 /// Rust are macros: each macro can be thought of as producing a "temporary
 /// file". To assign an id to such a file, we use the id of the macro call that
 /// produced the file. So, a `HirFileId` is either a `FileId` (source code
 /// written by user), or a `MacroCallId` (source code produced by macro).
 ///
-/// What is a `MacroCallId`? Simplifying, it's a `HirFileId` of a file containin
-/// the call plus the offset of the macro call in the file. Note that this is a
-/// recursive definition! However, the size_of of `HirFileId` is finite
-/// (because everything bottoms out at the real `FileId`) and small
+/// What is a `MacroCallId`? Simplifying, it's a `HirFileId` of a file
+/// containing the call plus the offset of the macro call in the file. Note that
+/// this is a recursive definition! However, the size_of of `HirFileId` is
+/// finite (because everything bottoms out at the real `FileId`) and small
 /// (`MacroCallId` uses the location interner).
 #[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
 pub struct HirFileId(HirFileIdRepr);
 
 impl HirFileId {
     /// For macro-expansion files, returns the file original source file the
-    /// expansionoriginated from.
+    /// expansion originated from.
     pub fn original_file(self, db: &impl PersistentHirDatabase) -> FileId {
         match self.0 {
             HirFileIdRepr::File(file_id) => file_id,
@@ -324,9 +324,9 @@ impl SourceFileItems {
 
     fn init(&mut self, source_file: &SourceFile) {
         // By walking the tree in bread-first order we make sure that parents
-        // get lower ids then children. That is, addding a new child does not
+        // get lower ids then children. That is, adding a new child does not
         // change parent's id. This means that, say, adding a new function to a
-        // trait does not chage ids of top-level items, which helps caching.
+        // trait does not change ids of top-level items, which helps caching.
         bfs(source_file.syntax(), |it| {
             if let Some(module_item) = ast::ModuleItem::cast(it) {
                 self.alloc(module_item.syntax());
diff --git a/crates/ra_hir/src/macros.rs b/crates/ra_hir/src/macros.rs
index dd477e9f9..45128c7df 100644
--- a/crates/ra_hir/src/macros.rs
+++ b/crates/ra_hir/src/macros.rs
@@ -67,7 +67,7 @@ impl MacroDef {
     }
 }
 
-#[derive(Debug, Clone, PartialEq, Eq, Hash)]
+#[derive(Debug, Clone, PartialEq, Eq)]
 pub struct MacroInput {
     // Should be token trees
     pub text: String,
diff --git a/crates/ra_hir/src/marks.rs b/crates/ra_hir/src/marks.rs
index 50d4e824c..16852a6a1 100644
--- a/crates/ra_hir/src/marks.rs
+++ b/crates/ra_hir/src/marks.rs
@@ -6,4 +6,5 @@ test_utils::marks!(
     type_var_resolves_to_int_var
     glob_enum
     glob_across_crates
+    std_prelude
 );
diff --git a/crates/ra_hir/src/mock.rs b/crates/ra_hir/src/mock.rs
index 5ca870867..f1cad77c5 100644
--- a/crates/ra_hir/src/mock.rs
+++ b/crates/ra_hir/src/mock.rs
@@ -3,6 +3,7 @@ use std::{sync::Arc, panic};
 use parking_lot::Mutex;
 use ra_db::{
     FilePosition, FileId, CrateGraph, SourceRoot, SourceRootId, SourceDatabase, salsa,
+    Edition,
 };
 use relative_path::RelativePathBuf;
 use test_utils::{parse_fixture, CURSOR_MARKER, extract_offset};
@@ -58,12 +59,12 @@ impl MockDatabase {
     pub fn set_crate_graph_from_fixture(&mut self, graph: CrateGraphFixture) {
         let mut ids = FxHashMap::default();
         let mut crate_graph = CrateGraph::default();
-        for (crate_name, (crate_root, _)) in graph.0.iter() {
+        for (crate_name, (crate_root, edition, _)) in graph.0.iter() {
             let crate_root = self.file_id_of(&crate_root);
-            let crate_id = crate_graph.add_crate_root(crate_root);
+            let crate_id = crate_graph.add_crate_root(crate_root, *edition);
             ids.insert(crate_name, crate_id);
         }
-        for (crate_name, (_, deps)) in graph.0.iter() {
+        for (crate_name, (_, _, deps)) in graph.0.iter() {
             let from = ids[crate_name];
             for dep in deps {
                 let to = ids[dep];
@@ -144,7 +145,7 @@ impl MockDatabase {
 
         if is_crate_root {
             let mut crate_graph = CrateGraph::default();
-            crate_graph.add_crate_root(file_id);
+            crate_graph.add_crate_root(file_id, Edition::Edition2018);
             self.set_crate_graph(Arc::new(crate_graph));
         }
         file_id
@@ -232,16 +233,19 @@ impl MockDatabase {
 }
 
 #[derive(Default)]
-pub struct CrateGraphFixture(pub FxHashMap<String, (String, Vec<String>)>);
+pub struct CrateGraphFixture(pub FxHashMap<String, (String, Edition, Vec<String>)>);
 
 #[macro_export]
 macro_rules! crate_graph {
-    ($($crate_name:literal: ($crate_path:literal, [$($dep:literal),*]),)*) => {{
+    ($($crate_name:literal: ($crate_path:literal, $($edition:literal,)? [$($dep:literal),*]),)*) => {{
         let mut res = $crate::mock::CrateGraphFixture::default();
         $(
+            #[allow(unused_mut, unused_assignments)]
+            let mut edition = ra_db::Edition::Edition2018;
+            $(edition = ra_db::Edition::from_string($edition);)?
             res.0.insert(
                 $crate_name.to_string(),
-                ($crate_path.to_string(), vec![$($dep.to_string()),*])
+                ($crate_path.to_string(), edition, vec![$($dep.to_string()),*])
             );
         )*
         res
diff --git a/crates/ra_hir/src/nameres.rs b/crates/ra_hir/src/nameres.rs
index 261ebdf97..e35b4b129 100644
--- a/crates/ra_hir/src/nameres.rs
+++ b/crates/ra_hir/src/nameres.rs
@@ -18,9 +18,11 @@ pub(crate) mod lower;
 
 use std::{time, sync::Arc};
 
+use rustc_hash::{FxHashMap, FxHashSet};
+
 use ra_arena::map::ArenaMap;
+use ra_db::Edition;
 use test_utils::tested_by;
-use rustc_hash::{FxHashMap, FxHashSet};
 
 use crate::{
     Module, ModuleDef,
@@ -32,8 +34,13 @@ use crate::{
 
 /// `ItemMap` is the result of module name resolution. It contains, for each
 /// module, the set of visible items.
-#[derive(Default, Debug, PartialEq, Eq)]
+#[derive(Debug, PartialEq, Eq)]
 pub struct ItemMap {
+    edition: Edition,
+    /// The prelude module for this crate. This either comes from an import
+    /// marked with the `prelude_import` attribute, or (in the normal case) from
+    /// a dependency (`std` or `core`).
+    pub(crate) prelude: Option<Module>,
     pub(crate) extern_prelude: FxHashMap<Name, ModuleDef>,
     per_module: ArenaMap<ModuleId, ModuleScope>,
 }
@@ -176,7 +183,12 @@ where
             module_tree,
             processed_imports: FxHashSet::default(),
             glob_imports: FxHashMap::default(),
-            result: ItemMap::default(),
+            result: ItemMap {
+                edition: krate.edition(db),
+                prelude: None,
+                extern_prelude: FxHashMap::default(),
+                per_module: ArenaMap::default(),
+            },
         }
     }
 
@@ -211,6 +223,13 @@ where
             if let Some(module) = dep.krate.root_module(self.db) {
                 self.result.extern_prelude.insert(dep.name.clone(), module.into());
             }
+            // look for the prelude
+            if self.result.prelude.is_none() {
+                let item_map = self.db.item_map(dep.krate);
+                if item_map.prelude.is_some() {
+                    self.result.prelude = item_map.prelude;
+                }
+            }
         }
     }
 
@@ -266,10 +285,20 @@ where
         import_id: ImportId,
         import: &ImportData,
     ) -> ReachedFixedPoint {
-        log::debug!("resolving import: {:?}", import);
+        log::debug!("resolving import: {:?} ({:?})", import, self.result.edition);
         let original_module = Module { krate: self.krate, module_id };
-        let (def, reached_fixedpoint) =
-            self.result.resolve_path_fp(self.db, original_module, &import.path);
+
+        let (def, reached_fixedpoint) = if import.is_extern_crate {
+            let res = self.result.resolve_name_in_extern_prelude(
+                &import
+                    .path
+                    .as_ident()
+                    .expect("extern crate should have been desugared to one-element path"),
+            );
+            (res, if res.is_none() { ReachedFixedPoint::No } else { ReachedFixedPoint::Yes })
+        } else {
+            self.result.resolve_path_fp(self.db, ResolveMode::Import, original_module, &import.path)
+        };
 
         if reached_fixedpoint != ReachedFixedPoint::Yes {
             return reached_fixedpoint;
@@ -279,7 +308,10 @@ where
             log::debug!("glob import: {:?}", import);
             match def.take_types() {
                 Some(ModuleDef::Module(m)) => {
-                    if m.krate != self.krate {
+                    if import.is_prelude {
+                        tested_by!(std_prelude);
+                        self.result.prelude = Some(m);
+                    } else if m.krate != self.krate {
                         tested_by!(glob_across_crates);
                         // glob import from other crate => we can just import everything once
                         let item_map = self.db.item_map(m.krate);
@@ -404,6 +436,12 @@ where
 }
 
 #[derive(Debug, Clone, Copy, PartialEq, Eq)]
+enum ResolveMode {
+    Import,
+    Other,
+}
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
 enum ReachedFixedPoint {
     Yes,
     No,
@@ -431,15 +469,61 @@ impl ItemMap {
         original_module: Module,
         path: &Path,
     ) -> PerNs<ModuleDef> {
-        self.resolve_path_fp(db, original_module, path).0
+        self.resolve_path_fp(db, ResolveMode::Other, original_module, path).0
+    }
+
+    fn resolve_in_prelude(
+        &self,
+        db: &impl PersistentHirDatabase,
+        original_module: Module,
+        name: &Name,
+    ) -> PerNs<ModuleDef> {
+        if let Some(prelude) = self.prelude {
+            let resolution = if prelude.krate == original_module.krate {
+                self[prelude.module_id].items.get(name).cloned()
+            } else {
+                db.item_map(prelude.krate)[prelude.module_id].items.get(name).cloned()
+            };
+            resolution.map(|r| r.def).unwrap_or_else(PerNs::none)
+        } else {
+            PerNs::none()
+        }
     }
 
-    pub(crate) fn resolve_name_in_module(&self, module: Module, name: &Name) -> PerNs<ModuleDef> {
+    pub(crate) fn resolve_name_in_module(
+        &self,
+        db: &impl PersistentHirDatabase,
+        module: Module,
+        name: &Name,
+    ) -> PerNs<ModuleDef> {
+        // Resolve in:
+        //  - current module / scope
+        //  - extern prelude
+        //  - std prelude
         let from_scope = self[module.module_id].items.get(name).map_or(PerNs::none(), |it| it.def);
         let from_extern_prelude =
             self.extern_prelude.get(name).map_or(PerNs::none(), |&it| PerNs::types(it));
+        let from_prelude = self.resolve_in_prelude(db, module, name);
+
+        from_scope.or(from_extern_prelude).or(from_prelude)
+    }
+
+    fn resolve_name_in_extern_prelude(&self, name: &Name) -> PerNs<ModuleDef> {
+        self.extern_prelude.get(name).map_or(PerNs::none(), |&it| PerNs::types(it))
+    }
 
-        from_scope.or(from_extern_prelude)
+    fn resolve_name_in_crate_root_or_extern_prelude(
+        &self,
+        db: &impl PersistentHirDatabase,
+        module: Module,
+        name: &Name,
+    ) -> PerNs<ModuleDef> {
+        let crate_root = module.crate_root(db);
+        let from_crate_root =
+            self[crate_root.module_id].items.get(name).map_or(PerNs::none(), |it| it.def);
+        let from_extern_prelude = self.resolve_name_in_extern_prelude(name);
+
+        from_crate_root.or(from_extern_prelude)
     }
 
     // Returns Yes if we are sure that additions to `ItemMap` wouldn't change
@@ -447,6 +531,7 @@ impl ItemMap {
     fn resolve_path_fp(
         &self,
         db: &impl PersistentHirDatabase,
+        mode: ResolveMode,
         original_module: Module,
         path: &Path,
     ) -> (PerNs<ModuleDef>, ReachedFixedPoint) {
@@ -454,12 +539,32 @@ impl ItemMap {
         let mut curr_per_ns: PerNs<ModuleDef> = match path.kind {
             PathKind::Crate => PerNs::types(original_module.crate_root(db).into()),
             PathKind::Self_ => PerNs::types(original_module.into()),
+            // plain import or absolute path in 2015: crate-relative with
+            // fallback to extern prelude (with the simplification in
+            // rust-lang/rust#57745)
+            // TODO there must be a nicer way to write this condition
+            PathKind::Plain | PathKind::Abs
+                if self.edition == Edition::Edition2015
+                    && (path.kind == PathKind::Abs || mode == ResolveMode::Import) =>
+            {
+                let segment = match segments.next() {
+                    Some((_, segment)) => segment,
+                    None => return (PerNs::none(), ReachedFixedPoint::Yes),
+                };
+                log::debug!("resolving {:?} in crate root (+ extern prelude)", segment);
+                self.resolve_name_in_crate_root_or_extern_prelude(
+                    db,
+                    original_module,
+                    &segment.name,
+                )
+            }
             PathKind::Plain => {
                 let segment = match segments.next() {
                     Some((_, segment)) => segment,
                     None => return (PerNs::none(), ReachedFixedPoint::Yes),
                 };
-                self.resolve_name_in_module(original_module, &segment.name)
+                log::debug!("resolving {:?} in module", segment);
+                self.resolve_name_in_module(db, original_module, &segment.name)
             }
             PathKind::Super => {
                 if let Some(p) = original_module.parent(db) {
@@ -490,7 +595,7 @@ impl ItemMap {
                 None => {
                     // we still have path segments left, but the path so far
                     // didn't resolve in the types namespace => no resolution
-                    // (don't break here because curr_per_ns might contain
+                    // (don't break here because `curr_per_ns` might contain
                     // something in the value namespace, and it would be wrong
                     // to return that)
                     return (PerNs::none(), ReachedFixedPoint::No);
diff --git a/crates/ra_hir/src/nameres/lower.rs b/crates/ra_hir/src/nameres/lower.rs
index 7e9a3de2b..81d80654c 100644
--- a/crates/ra_hir/src/nameres/lower.rs
+++ b/crates/ra_hir/src/nameres/lower.rs
@@ -2,13 +2,13 @@ use std::sync::Arc;
 
 use ra_syntax::{
     AstNode, SourceFile, TreeArc, AstPtr,
-    ast::{self, ModuleItemOwner, NameOwner},
+    ast::{self, ModuleItemOwner, NameOwner, AttrsOwner},
 };
 use ra_arena::{Arena, RawId, impl_arena_id, map::ArenaMap};
 use rustc_hash::FxHashMap;
 
 use crate::{
-    SourceItemId, Path, PathKind, ModuleSource, Name,
+    SourceItemId, Path, ModuleSource, Name,
     HirFileId, MacroCallLoc, AsName, PerNs, Function,
     ModuleDef, Module, Struct, Enum, Const, Static, Trait, Type,
     ids::LocationCtx, PersistentHirDatabase,
@@ -23,6 +23,7 @@ pub(super) struct ImportData {
     pub(super) path: Path,
     pub(super) alias: Option<Name>,
     pub(super) is_glob: bool,
+    pub(super) is_prelude: bool,
     pub(super) is_extern_crate: bool,
 }
 
@@ -179,18 +180,14 @@ impl LoweredModule {
                 self.add_use_item(source_map, it);
             }
             ast::ModuleItemKind::ExternCrateItem(it) => {
-                // Lower `extern crate x` to `use ::x`. This is kind of cheating
-                // and only works if we always interpret absolute paths in the
-                // 2018 style; otherwise `::x` could also refer to a module in
-                // the crate root.
                 if let Some(name_ref) = it.name_ref() {
-                    let mut path = Path::from_name_ref(name_ref);
-                    path.kind = PathKind::Abs;
+                    let path = Path::from_name_ref(name_ref);
                     let alias = it.alias().and_then(|a| a.name()).map(AsName::as_name);
                     self.imports.alloc(ImportData {
                         path,
                         alias,
                         is_glob: false,
+                        is_prelude: false,
                         is_extern_crate: true,
                     });
                 }
@@ -208,17 +205,20 @@ impl LoweredModule {
                 }
             }
             ast::ModuleItemKind::Module(_) => {
-                // modules are handled separately direclty by nameres
+                // modules are handled separately directly by name res
             }
         };
     }
 
     fn add_use_item(&mut self, source_map: &mut ImportSourceMap, item: &ast::UseItem) {
+        let is_prelude =
+            item.attrs().any(|attr| attr.as_atom().map(|s| s == "prelude_import").unwrap_or(false));
         Path::expand_use_item(item, |path, segment, alias| {
             let import = self.imports.alloc(ImportData {
                 path,
                 alias,
                 is_glob: segment.is_none(),
+                is_prelude,
                 is_extern_crate: false,
             });
             if let Some(segment) = segment {
diff --git a/crates/ra_hir/src/nameres/tests.rs b/crates/ra_hir/src/nameres/tests.rs
index 6dbe759d1..6402c89c0 100644
--- a/crates/ra_hir/src/nameres/tests.rs
+++ b/crates/ra_hir/src/nameres/tests.rs
@@ -266,6 +266,45 @@ fn glob_across_crates() {
 }
 
 #[test]
+fn edition_2015_imports() {
+    let mut db = MockDatabase::with_files(
+        "
+        //- /main.rs
+        mod foo;
+        mod bar;
+
+        //- /bar.rs
+        struct Bar;
+
+        //- /foo.rs
+        use bar::Bar;
+        use other_crate::FromLib;
+
+        //- /lib.rs
+        struct FromLib;
+    ",
+    );
+    db.set_crate_graph_from_fixture(crate_graph! {
+        "main": ("/main.rs", "2015", ["other_crate"]),
+        "other_crate": ("/lib.rs", "2018", []),
+    });
+    let foo_id = db.file_id_of("/foo.rs");
+
+    let module = crate::source_binder::module_from_file_id(&db, foo_id).unwrap();
+    let krate = module.krate(&db).unwrap();
+    let item_map = db.item_map(krate);
+
+    check_module_item_map(
+        &item_map,
+        module.module_id,
+        "
+            Bar: t v
+            FromLib: t v
+        ",
+    );
+}
+
+#[test]
 fn module_resolution_works_for_non_standard_filenames() {
     let mut db = MockDatabase::with_files(
         "
@@ -297,6 +336,43 @@ fn module_resolution_works_for_non_standard_filenames() {
 }
 
 #[test]
+fn std_prelude() {
+    covers!(std_prelude);
+    let mut db = MockDatabase::with_files(
+        "
+        //- /main.rs
+        use Foo::*;
+
+        //- /lib.rs
+        mod prelude;
+        #[prelude_import]
+        use prelude::*;
+
+        //- /prelude.rs
+        pub enum Foo { Bar, Baz };
+    ",
+    );
+    db.set_crate_graph_from_fixture(crate_graph! {
+        "main": ("/main.rs", ["test_crate"]),
+        "test_crate": ("/lib.rs", []),
+    });
+    let main_id = db.file_id_of("/main.rs");
+
+    let module = crate::source_binder::module_from_file_id(&db, main_id).unwrap();
+    let krate = module.krate(&db).unwrap();
+    let item_map = db.item_map(krate);
+
+    check_module_item_map(
+        &item_map,
+        module.module_id,
+        "
+            Bar: t v
+            Baz: t v
+        ",
+    );
+}
+
+#[test]
 fn name_res_works_for_broken_modules() {
     covers!(name_res_works_for_broken_modules);
     let (item_map, module_id) = item_map(
@@ -467,6 +543,42 @@ fn extern_crate_rename() {
 }
 
 #[test]
+fn extern_crate_rename_2015_edition() {
+    let mut db = MockDatabase::with_files(
+        "
+        //- /main.rs
+        extern crate alloc as alloc_crate;
+
+        mod alloc;
+        mod sync;
+
+        //- /sync.rs
+        use alloc_crate::Arc;
+
+        //- /lib.rs
+        struct Arc;
+        ",
+    );
+    db.set_crate_graph_from_fixture(crate_graph! {
+        "main": ("/main.rs", "2015", ["alloc"]),
+        "alloc": ("/lib.rs", []),
+    });
+    let sync_id = db.file_id_of("/sync.rs");
+
+    let module = crate::source_binder::module_from_file_id(&db, sync_id).unwrap();
+    let krate = module.krate(&db).unwrap();
+    let item_map = db.item_map(krate);
+
+    check_module_item_map(
+        &item_map,
+        module.module_id,
+        "
+        Arc: t v
+        ",
+    );
+}
+
+#[test]
 fn import_across_source_roots() {
     let mut db = MockDatabase::with_files(
         "
diff --git a/crates/ra_hir/src/path.rs b/crates/ra_hir/src/path.rs
index 6a24c8aa7..8ed54607a 100644
--- a/crates/ra_hir/src/path.rs
+++ b/crates/ra_hir/src/path.rs
@@ -97,7 +97,7 @@ impl Path {
                 return Some(q);
             }
             // TODO: this bottom up traversal is not too precise.
-            // Should we handle do a top-down analysiss, recording results?
+            // Should we handle do a top-down analysis, recording results?
             let use_tree_list = path.syntax().ancestors().find_map(ast::UseTreeList::cast)?;
             let use_tree = use_tree_list.parent_use_tree();
             use_tree.path()
diff --git a/crates/ra_hir/src/resolve.rs b/crates/ra_hir/src/resolve.rs
index 40c860cf4..91a531801 100644
--- a/crates/ra_hir/src/resolve.rs
+++ b/crates/ra_hir/src/resolve.rs
@@ -56,10 +56,10 @@ pub enum Resolution {
 }
 
 impl Resolver {
-    pub fn resolve_name(&self, name: &Name) -> PerNs<Resolution> {
+    pub fn resolve_name(&self, db: &impl HirDatabase, name: &Name) -> PerNs<Resolution> {
         let mut resolution = PerNs::none();
         for scope in self.scopes.iter().rev() {
-            resolution = resolution.or(scope.resolve_name(name));
+            resolution = resolution.or(scope.resolve_name(db, name));
             if resolution.is_both() {
                 return resolution;
             }
@@ -69,9 +69,9 @@ impl Resolver {
 
     pub fn resolve_path(&self, db: &impl HirDatabase, path: &Path) -> PerNs<Resolution> {
         if let Some(name) = path.as_ident() {
-            self.resolve_name(name)
+            self.resolve_name(db, name)
         } else if path.is_self() {
-            self.resolve_name(&Name::self_param())
+            self.resolve_name(db, &Name::self_param())
         } else {
             let (item_map, module) = match self.module() {
                 Some(m) => m,
@@ -82,10 +82,10 @@ impl Resolver {
         }
     }
 
-    pub fn all_names(&self) -> FxHashMap<Name, PerNs<Resolution>> {
+    pub fn all_names(&self, db: &impl HirDatabase) -> FxHashMap<Name, PerNs<Resolution>> {
         let mut names = FxHashMap::default();
         for scope in self.scopes.iter().rev() {
-            scope.collect_names(&mut |name, res| {
+            scope.collect_names(db, &mut |name, res| {
                 let current: &mut PerNs<Resolution> = names.entry(name).or_default();
                 if current.types.is_none() {
                     current.types = res.types;
@@ -143,13 +143,13 @@ impl Resolver {
 }
 
 impl Scope {
-    fn resolve_name(&self, name: &Name) -> PerNs<Resolution> {
+    fn resolve_name(&self, db: &impl HirDatabase, name: &Name) -> PerNs<Resolution> {
         match self {
             Scope::ModuleScope(m) => {
                 if let Some(KnownName::SelfParam) = name.as_known_name() {
                     PerNs::types(Resolution::Def(m.module.into()))
                 } else {
-                    m.item_map.resolve_name_in_module(m.module, name).map(Resolution::Def)
+                    m.item_map.resolve_name_in_module(db, m.module, name).map(Resolution::Def)
                 }
             }
             Scope::GenericParams(gp) => match gp.find_by_name(name) {
@@ -174,7 +174,7 @@ impl Scope {
         }
     }
 
-    fn collect_names(&self, f: &mut dyn FnMut(Name, PerNs<Resolution>)) {
+    fn collect_names(&self, db: &impl HirDatabase, f: &mut dyn FnMut(Name, PerNs<Resolution>)) {
         match self {
             Scope::ModuleScope(m) => {
                 // TODO: should we provide `self` here?
@@ -190,6 +190,12 @@ impl Scope {
                 m.item_map.extern_prelude.iter().for_each(|(name, def)| {
                     f(name.clone(), PerNs::types(Resolution::Def(*def)));
                 });
+                if let Some(prelude) = m.item_map.prelude {
+                    let prelude_item_map = db.item_map(prelude.krate);
+                    prelude_item_map[prelude.module_id].entries().for_each(|(name, res)| {
+                        f(name.clone(), res.def.map(Resolution::Def));
+                    });
+                }
             }
             Scope::GenericParams(gp) => {
                 for param in &gp.params {
diff --git a/crates/ra_hir/src/ty.rs b/crates/ra_hir/src/ty.rs
index 2dc1de41a..f28a7e731 100644
--- a/crates/ra_hir/src/ty.rs
+++ b/crates/ra_hir/src/ty.rs
@@ -450,7 +450,6 @@ impl Ty {
     }
 
     pub fn walk(&self, f: &mut impl FnMut(&Ty)) {
-        f(self);
         match self {
             Ty::Slice(t) | Ty::Array(t) => t.walk(f),
             Ty::RawPtr(t, _) => t.walk(f),
@@ -490,10 +489,10 @@ impl Ty {
             | Ty::Infer(_)
             | Ty::Unknown => {}
         }
+        f(self);
     }
 
     fn walk_mut(&mut self, f: &mut impl FnMut(&mut Ty)) {
-        f(self);
         match self {
             Ty::Slice(t) | Ty::Array(t) => Arc::make_mut(t).walk_mut(f),
             Ty::RawPtr(t, _) => Arc::make_mut(t).walk_mut(f),
@@ -544,6 +543,7 @@ impl Ty {
             | Ty::Infer(_)
             | Ty::Unknown => {}
         }
+        f(self);
     }
 
     fn fold(mut self, f: &mut impl FnMut(Ty) -> Ty) -> Ty {
diff --git a/crates/ra_hir/src/ty/snapshots/tests__infer_nested_generics_crash.snap b/crates/ra_hir/src/ty/snapshots/tests__infer_nested_generics_crash.snap
new file mode 100644
index 000000000..209454a91
--- /dev/null
+++ b/crates/ra_hir/src/ty/snapshots/tests__infer_nested_generics_crash.snap
@@ -0,0 +1,12 @@
+---
+created: "2019-02-11T21:59:04.302375838Z"
+creator: [email protected]
+source: crates/ra_hir/src/ty/tests.rs
+expression: "&result"
+---
+[92; 106) 'query_response': Canonical<QueryResponse<R>>
+[137; 167) '{     ...lue; }': ()
+[143; 164) '&query....value': &QueryResponse<R>
+[144; 158) 'query_response': Canonical<QueryResponse<R>>
+[144; 164) 'query_....value': QueryResponse<R>
+
diff --git a/crates/ra_hir/src/ty/tests.rs b/crates/ra_hir/src/ty/tests.rs
index e64fd2749..203f1fe4d 100644
--- a/crates/ra_hir/src/ty/tests.rs
+++ b/crates/ra_hir/src/ty/tests.rs
@@ -719,6 +719,25 @@ fn extra_compiler_flags() {
     );
 }
 
+#[test]
+fn infer_nested_generics_crash() {
+    // another crash found typechecking rustc
+    check_inference(
+        "infer_nested_generics_crash",
+        r#"
+struct Canonical<V> {
+    value: V,
+}
+struct QueryResponse<V> {
+    value: V,
+}
+fn test<R>(query_response: Canonical<QueryResponse<R>>) {
+    &query_response.value;
+}
+"#,
+    );
+}
+
 fn infer(content: &str) -> String {
     let (db, _, file_id) = MockDatabase::with_single_file(content);
     let source_file = db.parse(file_id);
diff --git a/crates/ra_ide_api/src/completion.rs b/crates/ra_ide_api/src/completion.rs
index 83c243944..4a38d62bb 100644
--- a/crates/ra_ide_api/src/completion.rs
+++ b/crates/ra_ide_api/src/completion.rs
@@ -30,7 +30,7 @@ pub use crate::completion::completion_item::{CompletionItem, CompletionItemKind,
 /// incomplete and can look really weird.
 ///
 /// Once the context is collected, we run a series of completion routines which
-/// look at the context and produce completion items. One subtelty about this
+/// look at the context and produce completion items. One subtlety about this
 /// phase is that completion engine should not filter by the substring which is
 /// already present, it should give all possible variants for the identifier at
 /// the caret. In other words, for
@@ -71,6 +71,7 @@ pub fn function_label(node: &ast::FnDef) -> Option<String> {
             .children()
             .filter(|child| !child.range().is_subrange(&body_range)) // Filter out body
             .filter(|child| ast::Comment::cast(child).is_none()) // Filter out comments
+            .filter(|child| ast::Attr::cast(child).is_none()) // Filter out attributes
             .map(|node| node.text().to_string())
             .collect();
         label
@@ -86,6 +87,7 @@ pub fn const_label(node: &ast::ConstDef) -> String {
         .syntax()
         .children()
         .filter(|child| ast::Comment::cast(child).is_none())
+        .filter(|child| ast::Attr::cast(child).is_none())
         .map(|node| node.text().to_string())
         .collect();
 
@@ -97,6 +99,7 @@ pub fn type_label(node: &ast::TypeDef) -> String {
         .syntax()
         .children()
         .filter(|child| ast::Comment::cast(child).is_none())
+        .filter(|child| ast::Attr::cast(child).is_none())
         .map(|node| node.text().to_string())
         .collect();
 
diff --git a/crates/ra_ide_api/src/completion/complete_dot.rs b/crates/ra_ide_api/src/completion/complete_dot.rs
index a673dbdcf..be839345f 100644
--- a/crates/ra_ide_api/src/completion/complete_dot.rs
+++ b/crates/ra_ide_api/src/completion/complete_dot.rs
@@ -180,6 +180,26 @@ mod tests {
     }
 
     #[test]
+    fn test_method_attr_filtering() {
+        check_ref_completion(
+            "method_attr_filtering",
+            r"
+            struct A {}
+            impl A {
+                #[inline]
+                fn the_method(&self) {
+                    let x = 1;
+                    let y = 2;
+                }
+            }
+            fn foo(a: A) {
+               a.<|>
+            }
+            ",
+        );
+    }
+
+    #[test]
     fn test_tuple_field_completion() {
         check_ref_completion(
             "tuple_field_completion",
diff --git a/crates/ra_ide_api/src/completion/complete_fn_param.rs b/crates/ra_ide_api/src/completion/complete_fn_param.rs
index 43532226f..4d6416284 100644
--- a/crates/ra_ide_api/src/completion/complete_fn_param.rs
+++ b/crates/ra_ide_api/src/completion/complete_fn_param.rs
@@ -7,7 +7,7 @@ use rustc_hash::FxHashMap;
 
 use crate::completion::{CompletionContext, Completions, CompletionKind, CompletionItem};
 
-/// Complete repeated parametes, both name and type. For example, if all
+/// Complete repeated parameters, both name and type. For example, if all
 /// functions in a file have a `spam: &mut Spam` parameter, a completion with
 /// `spam: &mut Spam` insert text/label and `spam` lookup string will be
 /// suggested.
diff --git a/crates/ra_ide_api/src/completion/complete_scope.rs b/crates/ra_ide_api/src/completion/complete_scope.rs
index 445788407..eeaf26d93 100644
--- a/crates/ra_ide_api/src/completion/complete_scope.rs
+++ b/crates/ra_ide_api/src/completion/complete_scope.rs
@@ -4,7 +4,7 @@ pub(super) fn complete_scope(acc: &mut Completions, ctx: &CompletionContext) {
     if !ctx.is_trivial_path {
         return;
     }
-    let names = ctx.resolver.all_names();
+    let names = ctx.resolver.all_names(ctx.db);
 
     names.into_iter().for_each(|(name, res)| {
         CompletionItem::new(CompletionKind::Reference, ctx.source_range(), name.to_string())
@@ -165,4 +165,23 @@ mod tests {
     fn completes_self_in_methods() {
         check_reference_completion("self_in_methods", r"impl S { fn foo(&self) { <|> } }")
     }
+
+    #[test]
+    fn completes_prelude() {
+        check_reference_completion(
+            "completes_prelude",
+            "
+            //- /main.rs
+            fn foo() { let x: <|> }
+
+            //- /std/lib.rs
+            #[prelude_import]
+            use prelude::*;
+
+            mod prelude {
+                struct Option;
+            }
+            ",
+        );
+    }
 }
diff --git a/crates/ra_ide_api/src/completion/snapshots/completion_item__completes_prelude.snap b/crates/ra_ide_api/src/completion/snapshots/completion_item__completes_prelude.snap
new file mode 100644
index 000000000..2b5a1a8ea
--- /dev/null
+++ b/crates/ra_ide_api/src/completion/snapshots/completion_item__completes_prelude.snap
@@ -0,0 +1,54 @@
+---
+created: "2019-02-13T19:52:43.734834624Z"
+creator: [email protected]
+source: crates/ra_ide_api/src/completion/completion_item.rs
+expression: kind_completions
+---
+[
+    CompletionItem {
+        completion_kind: Reference,
+        label: "Option",
+        kind: Some(
+            Struct
+        ),
+        detail: None,
+        documentation: None,
+        lookup: None,
+        insert_text: None,
+        insert_text_format: PlainText,
+        source_range: [18; 18),
+        text_edit: None
+    },
+    CompletionItem {
+        completion_kind: Reference,
+        label: "foo",
+        kind: Some(
+            Function
+        ),
+        detail: Some(
+            "fn foo()"
+        ),
+        documentation: None,
+        lookup: None,
+        insert_text: Some(
+            "foo()$0"
+        ),
+        insert_text_format: Snippet,
+        source_range: [18; 18),
+        text_edit: None
+    },
+    CompletionItem {
+        completion_kind: Reference,
+        label: "std",
+        kind: Some(
+            Module
+        ),
+        detail: None,
+        documentation: None,
+        lookup: None,
+        insert_text: None,
+        insert_text_format: PlainText,
+        source_range: [18; 18),
+        text_edit: None
+    }
+]
diff --git a/crates/ra_ide_api/src/completion/snapshots/completion_item__method_attr_filtering.snap b/crates/ra_ide_api/src/completion/snapshots/completion_item__method_attr_filtering.snap
new file mode 100644
index 000000000..46f9fa971
--- /dev/null
+++ b/crates/ra_ide_api/src/completion/snapshots/completion_item__method_attr_filtering.snap
@@ -0,0 +1,26 @@
+---
+created: "2019-02-12T18:32:09.428929418Z"
+creator: [email protected]
+source: crates/ra_ide_api/src/completion/completion_item.rs
+expression: kind_completions
+---
+[
+    CompletionItem {
+        completion_kind: Reference,
+        label: "the_method",
+        kind: Some(
+            Method
+        ),
+        detail: Some(
+            "fn the_method(&self)"
+        ),
+        documentation: None,
+        lookup: None,
+        insert_text: Some(
+            "the_method()$0"
+        ),
+        insert_text_format: Snippet,
+        source_range: [249; 249),
+        text_edit: None
+    }
+]
diff --git a/crates/ra_ide_api/src/goto_definition.rs b/crates/ra_ide_api/src/goto_definition.rs
index 413720960..96ed8c8e9 100644
--- a/crates/ra_ide_api/src/goto_definition.rs
+++ b/crates/ra_ide_api/src/goto_definition.rs
@@ -93,10 +93,10 @@ pub(crate) fn reference_definition(
                 return Exact(nav);
             }
             Some(Resolution::GenericParam(..)) => {
-                // TODO go to the generic param def
+                // TODO: go to the generic param def
             }
             Some(Resolution::SelfType(_impl_block)) => {
-                // TODO go to the implemented type
+                // TODO: go to the implemented type
             }
             None => {}
         }
@@ -133,8 +133,8 @@ mod tests {
 
     use crate::mock_analysis::analysis_and_position;
 
-    fn check_goto(fixuture: &str, expected: &str) {
-        let (analysis, pos) = analysis_and_position(fixuture);
+    fn check_goto(fixture: &str, expected: &str) {
+        let (analysis, pos) = analysis_and_position(fixture);
 
         let mut navs = analysis.goto_definition(pos).unwrap().unwrap().info;
         assert_eq!(navs.len(), 1);
diff --git a/crates/ra_ide_api/src/hover.rs b/crates/ra_ide_api/src/hover.rs
index 60b81567c..0888ab6de 100644
--- a/crates/ra_ide_api/src/hover.rs
+++ b/crates/ra_ide_api/src/hover.rs
@@ -71,8 +71,8 @@ pub(crate) fn type_of(db: &RootDatabase, frange: FileRange) -> Option<String> {
     }
 }
 
-// FIXME: this should not really use navigation target. Rather, approximatelly
-// resovled symbol should return a `DefId`.
+// FIXME: this should not really use navigation target. Rather, approximately
+// resolved symbol should return a `DefId`.
 fn doc_text_for(db: &RootDatabase, nav: NavigationTarget) -> Option<String> {
     match (nav.description(db), nav.docs(db)) {
         (Some(desc), Some(docs)) => Some("```rust\n".to_string() + &*desc + "\n```\n\n" + &*docs),
diff --git a/crates/ra_ide_api/src/impls.rs b/crates/ra_ide_api/src/impls.rs
index 444c4aeb2..681bd808d 100644
--- a/crates/ra_ide_api/src/impls.rs
+++ b/crates/ra_ide_api/src/impls.rs
@@ -78,8 +78,8 @@ fn impls_for_trait(
 mod tests {
     use crate::mock_analysis::analysis_and_position;
 
-    fn check_goto(fixuture: &str, expected: &[&str]) {
-        let (analysis, pos) = analysis_and_position(fixuture);
+    fn check_goto(fixture: &str, expected: &[&str]) {
+        let (analysis, pos) = analysis_and_position(fixture);
 
         let navs = analysis.goto_implementation(pos).unwrap().unwrap().info;
         assert_eq!(navs.len(), expected.len());
diff --git a/crates/ra_ide_api/src/lib.rs b/crates/ra_ide_api/src/lib.rs
index 2d090d9b4..d77a56ce8 100644
--- a/crates/ra_ide_api/src/lib.rs
+++ b/crates/ra_ide_api/src/lib.rs
@@ -7,7 +7,7 @@
 //! However, IDE specific bits of the analysis (most notably completion) happen
 //! in this crate.
 //!
-//! The sibling `ra_ide_api_light` handles thouse bits of IDE functionality
+//! The sibling `ra_ide_api_light` handles those bits of IDE functionality
 //! which are restricted to a single file and need only syntax.
 
 // For proving that RootDatabase is RefUnwindSafe.
@@ -62,12 +62,13 @@ pub use ra_ide_api_light::{
     LineIndex, LineCol, translate_offset_with_edit,
 };
 pub use ra_db::{
-    Canceled, CrateGraph, CrateId, FileId, FilePosition, FileRange, SourceRootId
+    Canceled, CrateGraph, CrateId, FileId, FilePosition, FileRange, SourceRootId,
+    Edition
 };
 pub use hir::Documentation;
 
 // We use jemalloc mainly to get heap usage statistics, actual performance
-// differnece is not measures.
+// difference is not measures.
 #[cfg(feature = "jemalloc")]
 #[global_allocator]
 static ALLOC: jemallocator::Jemalloc = jemallocator::Jemalloc;
@@ -221,12 +222,12 @@ impl Analysis {
         self.db.line_index(file_id)
     }
 
-    /// Selects the next syntactic nodes encopasing the range.
+    /// Selects the next syntactic nodes encompassing the range.
     pub fn extend_selection(&self, frange: FileRange) -> Cancelable<TextRange> {
         self.with_db(|db| extend_selection::extend_selection(db, frange))
     }
 
-    /// Returns position of the mathcing brace (all types of braces are
+    /// Returns position of the matching brace (all types of braces are
     /// supported).
     pub fn matching_brace(&self, position: FilePosition) -> Option<TextUnit> {
         let file = self.db.parse(position.file_id);
@@ -316,7 +317,7 @@ impl Analysis {
         self.with_db(|db| references::find_all_refs(db, position))
     }
 
-    /// Returns a short text descrbing element at position.
+    /// Returns a short text describing element at position.
     pub fn hover(&self, position: FilePosition) -> Cancelable<Option<RangeInfo<String>>> {
         self.with_db(|db| hover::hover(db, position))
     }
diff --git a/crates/ra_ide_api/src/mock_analysis.rs b/crates/ra_ide_api/src/mock_analysis.rs
index 8d8603062..550d69641 100644
--- a/crates/ra_ide_api/src/mock_analysis.rs
+++ b/crates/ra_ide_api/src/mock_analysis.rs
@@ -3,7 +3,7 @@ use std::sync::Arc;
 use relative_path::RelativePathBuf;
 use test_utils::{extract_offset, extract_range, parse_fixture, CURSOR_MARKER};
 
-use crate::{Analysis, AnalysisChange, AnalysisHost, CrateGraph, FileId, FilePosition, FileRange, SourceRootId};
+use crate::{Analysis, AnalysisChange, AnalysisHost, CrateGraph, FileId, FilePosition, FileRange, SourceRootId, Edition::Edition2018};
 
 /// Mock analysis is used in test to bootstrap an AnalysisHost/Analysis
 /// from a set of in-memory files.
@@ -18,7 +18,7 @@ impl MockAnalysis {
     }
     /// Creates `MockAnalysis` using a fixture data in the following format:
     ///
-    /// ```notrust
+    /// ```rust,ignore
     /// //- /main.rs
     /// mod foo;
     /// fn main() {}
@@ -89,9 +89,9 @@ impl MockAnalysis {
             let path = RelativePathBuf::from_path(&path[1..]).unwrap();
             let file_id = FileId(i as u32 + 1);
             if path == "/lib.rs" || path == "/main.rs" {
-                root_crate = Some(crate_graph.add_crate_root(file_id));
+                root_crate = Some(crate_graph.add_crate_root(file_id, Edition2018));
             } else if path.ends_with("/lib.rs") {
-                let other_crate = crate_graph.add_crate_root(file_id);
+                let other_crate = crate_graph.add_crate_root(file_id, Edition2018);
                 let crate_name = path.parent().unwrap().file_name().unwrap();
                 if let Some(root_crate) = root_crate {
                     crate_graph.add_dep(root_crate, crate_name.into(), other_crate).unwrap();
diff --git a/crates/ra_ide_api/src/navigation_target.rs b/crates/ra_ide_api/src/navigation_target.rs
index a2e4b6506..c559dca11 100644
--- a/crates/ra_ide_api/src/navigation_target.rs
+++ b/crates/ra_ide_api/src/navigation_target.rs
@@ -19,6 +19,7 @@ pub struct NavigationTarget {
     kind: SyntaxKind,
     full_range: TextRange,
     focus_range: Option<TextRange>,
+    container_name: Option<SmolStr>,
 }
 
 impl NavigationTarget {
@@ -26,6 +27,10 @@ impl NavigationTarget {
         &self.name
     }
 
+    pub fn container_name(&self) -> Option<&SmolStr> {
+        self.container_name.as_ref()
+    }
+
     pub fn kind(&self) -> SyntaxKind {
         self.kind
     }
@@ -53,6 +58,7 @@ impl NavigationTarget {
             kind: symbol.ptr.kind(),
             full_range: symbol.ptr.range(),
             focus_range: None,
+            container_name: symbol.container_name.clone(),
         }
     }
 
@@ -67,6 +73,7 @@ impl NavigationTarget {
             full_range: ptr.range(),
             focus_range: None,
             kind: NAME,
+            container_name: None,
         }
     }
 
@@ -170,6 +177,9 @@ impl NavigationTarget {
         if let Some(focus_range) = self.focus_range() {
             buf.push_str(&format!(" {:?}", focus_range))
         }
+        if let Some(container_name) = self.container_name() {
+            buf.push_str(&format!(" {:?}", container_name))
+        }
         buf
     }
 
@@ -192,6 +202,7 @@ impl NavigationTarget {
             full_range: node.range(),
             focus_range,
             // ptr: Some(LocalSyntaxPtr::new(node)),
+            container_name: None,
         }
     }
 }
diff --git a/crates/ra_ide_api/src/references.rs b/crates/ra_ide_api/src/references.rs
index 2cb1cc9be..ca145f3e4 100644
--- a/crates/ra_ide_api/src/references.rs
+++ b/crates/ra_ide_api/src/references.rs
@@ -295,17 +295,17 @@ mod tests {
     fn test_rename(text: &str, new_name: &str, expected: &str) {
         let (analysis, position) = single_file_with_position(text);
         let source_change = analysis.rename(position, new_name).unwrap();
-        let mut text_edit_bulder = ra_text_edit::TextEditBuilder::default();
+        let mut text_edit_builder = ra_text_edit::TextEditBuilder::default();
         let mut file_id: Option<FileId> = None;
         if let Some(change) = source_change {
             for edit in change.source_file_edits {
                 file_id = Some(edit.file_id);
                 for atom in edit.edit.as_atoms() {
-                    text_edit_bulder.replace(atom.delete, atom.insert.clone());
+                    text_edit_builder.replace(atom.delete, atom.insert.clone());
                 }
             }
         }
-        let result = text_edit_bulder.finish().apply(&*analysis.file_text(file_id.unwrap()));
+        let result = text_edit_builder.finish().apply(&*analysis.file_text(file_id.unwrap()));
         assert_eq_text!(expected, &*result);
     }
 }
diff --git a/crates/ra_ide_api/src/symbol_index.rs b/crates/ra_ide_api/src/symbol_index.rs
index de0f46134..afb10fa92 100644
--- a/crates/ra_ide_api/src/symbol_index.rs
+++ b/crates/ra_ide_api/src/symbol_index.rs
@@ -5,20 +5,20 @@
 //! symbols. The backbone of the index is the **awesome** `fst` crate by
 //! @BurntSushi.
 //!
-//! In a nutshell, you give a set of strings to the `fst`, and it builds a
+//! In a nutshell, you give a set of strings to `fst`, and it builds a
 //! finite state machine describing this set of strings. The strings which
 //! could fuzzy-match a pattern can also be described by a finite state machine.
-//! What is freakingly cool is that you can now traverse both state machines in
+//! What is freaking cool is that you can now traverse both state machines in
 //! lock-step to enumerate the strings which are both in the input set and
 //! fuzz-match the query. Or, more formally, given two languages described by
-//! fsts, one can build an product fst which describes the intersection of the
+//! FSTs, one can build a product FST which describes the intersection of the
 //! languages.
 //!
 //! `fst` does not support cheap updating of the index, but it supports unioning
-//! of state machines. So, to account for changing source code, we build an fst
-//! for each library (which is assumed to never change) and an fst for each rust
+//! of state machines. So, to account for changing source code, we build an FST
+//! for each library (which is assumed to never change) and an FST for each Rust
 //! file in the current workspace, and run a query against the union of all
-//! those fsts.
+//! those FSTs.
 use std::{
     cmp::Ordering,
     hash::{Hash, Hasher},
@@ -32,6 +32,7 @@ use ra_syntax::{
     algo::{visit::{visitor, Visitor}, find_covering_node},
     SyntaxKind::{self, *},
     ast::{self, NameOwner},
+    WalkEvent,
 };
 use ra_db::{
     SourceRootId, SourceDatabase,
@@ -62,17 +63,14 @@ pub(crate) trait SymbolsDatabase: hir::db::HirDatabase {
 fn file_symbols(db: &impl SymbolsDatabase, file_id: FileId) -> Arc<SymbolIndex> {
     db.check_canceled();
     let source_file = db.parse(file_id);
-    let mut symbols = source_file
-        .syntax()
-        .descendants()
-        .filter_map(to_symbol)
-        .map(move |(name, ptr)| FileSymbol { name, ptr, file_id })
-        .collect::<Vec<_>>();
+
+    let mut symbols = source_file_to_file_symbols(&source_file, file_id);
 
     for (name, text_range) in hir::source_binder::macro_symbols(db, file_id) {
         let node = find_covering_node(source_file.syntax(), text_range);
         let ptr = SyntaxNodePtr::new(node);
-        symbols.push(FileSymbol { file_id, name, ptr })
+        // TODO: Should we get container name for macro symbols?
+        symbols.push(FileSymbol { file_id, name, ptr, container_name: None })
     }
 
     Arc::new(SymbolIndex::new(symbols))
@@ -158,13 +156,7 @@ impl SymbolIndex {
         files: impl ParallelIterator<Item = (FileId, TreeArc<SourceFile>)>,
     ) -> SymbolIndex {
         let symbols = files
-            .flat_map(|(file_id, file)| {
-                file.syntax()
-                    .descendants()
-                    .filter_map(to_symbol)
-                    .map(move |(name, ptr)| FileSymbol { name, ptr, file_id })
-                    .collect::<Vec<_>>()
-            })
+            .flat_map(|(file_id, file)| source_file_to_file_symbols(&file, file_id))
             .collect::<Vec<_>>();
         SymbolIndex::new(symbols)
     }
@@ -215,12 +207,40 @@ pub(crate) struct FileSymbol {
     pub(crate) file_id: FileId,
     pub(crate) name: SmolStr,
     pub(crate) ptr: SyntaxNodePtr,
+    pub(crate) container_name: Option<SmolStr>,
+}
+
+fn source_file_to_file_symbols(source_file: &SourceFile, file_id: FileId) -> Vec<FileSymbol> {
+    let mut symbols = Vec::new();
+    let mut stack = Vec::new();
+
+    for event in source_file.syntax().preorder() {
+        match event {
+            WalkEvent::Enter(node) => {
+                if let Some(mut symbol) = to_file_symbol(node, file_id) {
+                    symbol.container_name = stack.last().cloned();
+
+                    stack.push(symbol.name.clone());
+                    symbols.push(symbol);
+                }
+            }
+
+            WalkEvent::Leave(node) => {
+                if to_symbol(node).is_some() {
+                    stack.pop();
+                }
+            }
+        }
+    }
+
+    symbols
 }
 
 fn to_symbol(node: &SyntaxNode) -> Option<(SmolStr, SyntaxNodePtr)> {
     fn decl<N: NameOwner>(node: &N) -> Option<(SmolStr, SyntaxNodePtr)> {
         let name = node.name()?.text().clone();
         let ptr = SyntaxNodePtr::new(node.syntax());
+
         Some((name, ptr))
     }
     visitor()
@@ -234,3 +254,7 @@ fn to_symbol(node: &SyntaxNode) -> Option<(SmolStr, SyntaxNodePtr)> {
         .visit(decl::<ast::StaticDef>)
         .accept(node)?
 }
+
+fn to_file_symbol(node: &SyntaxNode, file_id: FileId) -> Option<FileSymbol> {
+    to_symbol(node).map(move |(name, ptr)| FileSymbol { name, ptr, file_id, container_name: None })
+}
diff --git a/crates/ra_ide_api/tests/test/main.rs b/crates/ra_ide_api/tests/test/main.rs
index 7d1695cfd..0526f7584 100644
--- a/crates/ra_ide_api/tests/test/main.rs
+++ b/crates/ra_ide_api/tests/test/main.rs
@@ -1,9 +1,9 @@
 use insta::assert_debug_snapshot_matches;
 use ra_ide_api::{
     mock_analysis::{single_file, single_file_with_position, MockAnalysis},
-    AnalysisChange, CrateGraph, FileId, Query,
+    AnalysisChange, CrateGraph, Edition::Edition2018, FileId, Query, NavigationTarget
 };
-use ra_syntax::TextRange;
+use ra_syntax::{TextRange, SmolStr};
 
 #[test]
 fn test_unresolved_module_diagnostic() {
@@ -36,7 +36,7 @@ fn test_resolve_crate_root() {
     assert!(host.analysis().crate_for(mod_file).unwrap().is_empty());
 
     let mut crate_graph = CrateGraph::default();
-    let crate_id = crate_graph.add_crate_root(root_file);
+    let crate_id = crate_graph.add_crate_root(root_file, Edition2018);
     let mut change = AnalysisChange::new();
     change.set_crate_graph(crate_graph);
     host.apply_change(change);
@@ -49,6 +49,11 @@ fn get_all_refs(text: &str) -> Vec<(FileId, TextRange)> {
     analysis.find_all_refs(position).unwrap()
 }
 
+fn get_symbols_matching(text: &str, query: &str) -> Vec<NavigationTarget> {
+    let (analysis, _) = single_file(text);
+    analysis.symbol_search(Query::new(query.into())).unwrap()
+}
+
 #[test]
 fn test_find_all_refs_for_local() {
     let code = r#"
@@ -91,6 +96,49 @@ fn test_find_all_refs_for_fn_param() {
 }
 
 #[test]
+fn test_world_symbols_with_no_container() {
+    let code = r#"
+    enum FooInner { }
+    "#;
+
+    let mut symbols = get_symbols_matching(code, "FooInner");
+
+    let s = symbols.pop().unwrap();
+
+    assert_eq!(s.name(), "FooInner");
+    assert!(s.container_name().is_none());
+}
+
+#[test]
+fn test_world_symbols_include_container_name() {
+    let code = r#"
+fn foo() {
+    enum FooInner { }
+}
+    "#;
+
+    let mut symbols = get_symbols_matching(code, "FooInner");
+
+    let s = symbols.pop().unwrap();
+
+    assert_eq!(s.name(), "FooInner");
+    assert_eq!(s.container_name(), Some(&SmolStr::new("foo")));
+
+    let code = r#"
+mod foo {
+    struct FooInner;
+}
+    "#;
+
+    let mut symbols = get_symbols_matching(code, "FooInner");
+
+    let s = symbols.pop().unwrap();
+
+    assert_eq!(s.name(), "FooInner");
+    assert_eq!(s.container_name(), Some(&SmolStr::new("foo")));
+}
+
+#[test]
 #[ignore]
 fn world_symbols_include_stuff_from_macros() {
     let (analysis, _) = single_file(
diff --git a/crates/ra_ide_api_light/Cargo.toml b/crates/ra_ide_api_light/Cargo.toml
index 0735e6ae1..29c1f4639 100644
--- a/crates/ra_ide_api_light/Cargo.toml
+++ b/crates/ra_ide_api_light/Cargo.toml
@@ -7,7 +7,7 @@ publish = false
 
 [dependencies]
 itertools = "0.8.0"
-superslice = "0.1.0"
+superslice = "1.0.0"
 join_to_string = "0.1.1"
 rustc-hash = "1.0"
 
diff --git a/crates/ra_lsp_server/src/main_loop/handlers.rs b/crates/ra_lsp_server/src/main_loop/handlers.rs
index 0cdb39c32..09d896c40 100644
--- a/crates/ra_lsp_server/src/main_loop/handlers.rs
+++ b/crates/ra_lsp_server/src/main_loop/handlers.rs
@@ -190,7 +190,7 @@ pub fn handle_workspace_symbol(
                 name: nav.name().to_string(),
                 kind: nav.kind().conv(),
                 location: nav.try_conv_with(world)?,
-                container_name: None,
+                container_name: nav.container_name().map(|v| v.to_string()),
                 deprecated: None,
             };
             res.push(info);
diff --git a/crates/ra_mbe/src/lib.rs b/crates/ra_mbe/src/lib.rs
index ec2fd1eb5..cdca3cafb 100644
--- a/crates/ra_mbe/src/lib.rs
+++ b/crates/ra_mbe/src/lib.rs
@@ -109,7 +109,7 @@ mod tests {
 
     use super::*;
 
-    // Good first issue (although a slightly chellegning one):
+    // Good first issue (although a slightly challenging one):
     //
     // * Pick a random test from here
     //   https://github.com/intellij-rust/intellij-rust/blob/c4e9feee4ad46e7953b1948c112533360b6087bb/src/test/kotlin/org/rust/lang/core/macros/RsMacroExpansionTest.kt
@@ -171,8 +171,8 @@ impl_froms!(TokenTree: Leaf, Subtree);
 
         let (invocation_tt, _) = ast_to_token_tree(macro_invocation.token_tree().unwrap()).unwrap();
 
-        let expaned = rules.expand(&invocation_tt).unwrap();
-        assert_eq!(expaned.to_string(), expansion);
+        let expanded = rules.expand(&invocation_tt).unwrap();
+        assert_eq!(expanded.to_string(), expansion);
     }
 
     #[test]
diff --git a/crates/ra_mbe/src/mbe_expander.rs b/crates/ra_mbe/src/mbe_expander.rs
index f6177f078..1acba86ea 100644
--- a/crates/ra_mbe/src/mbe_expander.rs
+++ b/crates/ra_mbe/src/mbe_expander.rs
@@ -58,7 +58,7 @@ fn expand_rule(rule: &crate::Rule, input: &tt::Subtree) -> Option<tt::Subtree> {
 ///
 /// The other side of the puzzle is `expand_subtree`, where we use the bindings
 /// to substitute meta variables in the output template. When expanding, we
-/// maintain a `nesteing` stack of indicies whihc tells us which occurence from
+/// maintain a `nesting` stack of indices which tells us which occurrence from
 /// the `Bindings` we should take. We push to the stack when we enter a
 /// repetition.
 ///
diff --git a/crates/ra_project_model/src/cargo_workspace.rs b/crates/ra_project_model/src/cargo_workspace.rs
index 8adf463a6..81cb506b7 100644
--- a/crates/ra_project_model/src/cargo_workspace.rs
+++ b/crates/ra_project_model/src/cargo_workspace.rs
@@ -4,6 +4,7 @@ use cargo_metadata::{MetadataCommand, CargoOpt};
 use ra_arena::{Arena, RawId, impl_arena_id};
 use rustc_hash::FxHashMap;
 use failure::format_err;
+use ra_db::Edition;
 
 use crate::Result;
 
@@ -12,7 +13,7 @@ use crate::Result;
 ///
 /// Note that internally, rust analyzer uses a different structure:
 /// `CrateGraph`. `CrateGraph` is lower-level: it knows only about the crates,
-/// while this knows about `Pacakges` & `Targets`: purely cargo-related
+/// while this knows about `Packages` & `Targets`: purely cargo-related
 /// concepts.
 #[derive(Debug, Clone)]
 pub struct CargoWorkspace {
@@ -35,6 +36,7 @@ struct PackageData {
     targets: Vec<Target>,
     is_member: bool,
     dependencies: Vec<PackageDependency>,
+    edition: Edition,
 }
 
 #[derive(Debug, Clone)]
@@ -84,6 +86,9 @@ impl Package {
     pub fn root(self, ws: &CargoWorkspace) -> &Path {
         ws.packages[self].manifest.parent().unwrap()
     }
+    pub fn edition(self, ws: &CargoWorkspace) -> Edition {
+        ws.packages[self].edition
+    }
     pub fn targets<'a>(self, ws: &'a CargoWorkspace) -> impl Iterator<Item = Target> + 'a {
         ws.packages[self].targets.iter().cloned()
     }
@@ -135,6 +140,7 @@ impl CargoWorkspace {
                 manifest: meta_pkg.manifest_path.clone(),
                 targets: Vec::new(),
                 is_member,
+                edition: Edition::from_string(&meta_pkg.edition),
                 dependencies: Vec::new(),
             });
             let pkg_data = &mut packages[pkg];
diff --git a/crates/ra_project_model/src/lib.rs b/crates/ra_project_model/src/lib.rs
index 3b1e07149..1b18ac836 100644
--- a/crates/ra_project_model/src/lib.rs
+++ b/crates/ra_project_model/src/lib.rs
@@ -6,7 +6,7 @@ use std::path::{Path, PathBuf};
 use failure::bail;
 use rustc_hash::FxHashMap;
 
-use ra_db::{CrateGraph, FileId};
+use ra_db::{CrateGraph, FileId, Edition};
 
 pub use crate::{
     cargo_workspace::{CargoWorkspace, Package, Target, TargetKind},
@@ -36,7 +36,8 @@ impl ProjectWorkspace {
         let mut sysroot_crates = FxHashMap::default();
         for krate in self.sysroot.crates() {
             if let Some(file_id) = load(krate.root(&self.sysroot)) {
-                sysroot_crates.insert(krate, crate_graph.add_crate_root(file_id));
+                sysroot_crates
+                    .insert(krate, crate_graph.add_crate_root(file_id, Edition::Edition2015));
             }
         }
         for from in self.sysroot.crates() {
@@ -62,7 +63,8 @@ impl ProjectWorkspace {
             for tgt in pkg.targets(&self.cargo) {
                 let root = tgt.root(&self.cargo);
                 if let Some(file_id) = load(root) {
-                    let crate_id = crate_graph.add_crate_root(file_id);
+                    let edition = pkg.edition(&self.cargo);
+                    let crate_id = crate_graph.add_crate_root(file_id, edition);
                     if tgt.kind(&self.cargo) == TargetKind::Lib {
                         lib_tgt = Some(crate_id);
                         pkg_to_lib_crate.insert(pkg, crate_id);
diff --git a/crates/ra_syntax/src/ast.rs b/crates/ra_syntax/src/ast.rs
index cf5cfecc2..22105d6c9 100644
--- a/crates/ra_syntax/src/ast.rs
+++ b/crates/ra_syntax/src/ast.rs
@@ -6,7 +6,7 @@ use itertools::Itertools;
 
 pub use self::generated::*;
 use crate::{
-    yellow::{SyntaxNode, SyntaxNodeChildren, TreeArc, RaTypes},
+    syntax_node::{SyntaxNode, SyntaxNodeChildren, TreeArc, RaTypes},
     SmolStr,
     SyntaxKind::*,
 };
diff --git a/crates/ra_syntax/src/ast/generated.rs b/crates/ra_syntax/src/ast/generated.rs
index d2b080743..7c5e8ce5e 100644
--- a/crates/ra_syntax/src/ast/generated.rs
+++ b/crates/ra_syntax/src/ast/generated.rs
@@ -13,7 +13,7 @@ use rowan::TransparentNewType;
 
 use crate::{
     SyntaxNode, SyntaxKind::*,
-    yellow::{RaTypes, TreeArc},
+    syntax_node::{RaTypes, TreeArc},
     ast::{self, AstNode},
 };
 
@@ -4210,6 +4210,7 @@ impl ToOwned for UseItem {
 }
 
 
+impl ast::AttrsOwner for UseItem {}
 impl UseItem {
     pub fn use_tree(&self) -> Option<&UseTree> {
         super::child_opt(self)
diff --git a/crates/ra_syntax/src/ast/generated.rs.tera b/crates/ra_syntax/src/ast/generated.rs.tera
index ea0fc35fd..ca7a28581 100644
--- a/crates/ra_syntax/src/ast/generated.rs.tera
+++ b/crates/ra_syntax/src/ast/generated.rs.tera
@@ -15,7 +15,7 @@ use rowan::TransparentNewType;
 
 use crate::{
     SyntaxNode, SyntaxKind::*,
-    yellow::{RaTypes, TreeArc},
+    syntax_node::{RaTypes, TreeArc},
     ast::{self, AstNode},
 };
 {% for node, methods in ast %}
diff --git a/crates/ra_syntax/src/grammar.ron b/crates/ra_syntax/src/grammar.ron
index 2e4b2d776..304bc5909 100644
--- a/crates/ra_syntax/src/grammar.ron
+++ b/crates/ra_syntax/src/grammar.ron
@@ -596,7 +596,8 @@ Grammar(
             options: [ "Pat", "TypeRef" ],
         ),
         "UseItem": (
-            options: [ "UseTree" ]
+            traits: ["AttrsOwner"],
+            options: [ "UseTree" ],
         ),
         "UseTree": (
             options: [ "Path", "UseTreeList", "Alias" ]
diff --git a/crates/ra_syntax/src/lib.rs b/crates/ra_syntax/src/lib.rs
index 088b2f5d7..cbba1d4ae 100644
--- a/crates/ra_syntax/src/lib.rs
+++ b/crates/ra_syntax/src/lib.rs
@@ -30,7 +30,7 @@ mod syntax_kinds;
 /// Utilities for simple uses of the parser.
 pub mod utils;
 mod validation;
-mod yellow;
+mod syntax_node;
 mod ptr;
 
 pub use rowan::{SmolStr, TextRange, TextUnit};
@@ -38,12 +38,12 @@ pub use crate::{
     ast::AstNode,
     lexer::{tokenize, Token},
     syntax_kinds::SyntaxKind,
-    yellow::{Direction, SyntaxError, SyntaxNode, WalkEvent, Location, TreeArc},
+    syntax_node::{Direction, SyntaxError, SyntaxNode, WalkEvent, Location, TreeArc},
     ptr::{SyntaxNodePtr, AstPtr},
 };
 
 use ra_text_edit::AtomTextEdit;
-use crate::yellow::GreenNode;
+use crate::syntax_node::GreenNode;
 
 /// `SourceFile` represents a parse tree for a single Rust file.
 pub use crate::ast::SourceFile;
@@ -61,7 +61,7 @@ impl SourceFile {
     pub fn parse(text: &str) -> TreeArc<SourceFile> {
         let tokens = tokenize(&text);
         let (green, errors) =
-            parser_impl::parse_with(yellow::GreenBuilder::new(), text, &tokens, grammar::root);
+            parser_impl::parse_with(syntax_node::GreenBuilder::new(), text, &tokens, grammar::root);
         SourceFile::new(green, errors)
     }
 
diff --git a/crates/ra_syntax/src/parser_impl.rs b/crates/ra_syntax/src/parser_impl.rs
index f255dc23b..d99615d72 100644
--- a/crates/ra_syntax/src/parser_impl.rs
+++ b/crates/ra_syntax/src/parser_impl.rs
@@ -11,7 +11,7 @@ use crate::{
         input::{InputPosition, ParserInput},
     },
     SmolStr,
-    yellow::syntax_error::{
+    syntax_node::syntax_error::{
         ParseError,
         SyntaxError,
     },
diff --git a/crates/ra_syntax/src/parser_impl/event.rs b/crates/ra_syntax/src/parser_impl/event.rs
index 677876ab5..b45830c61 100644
--- a/crates/ra_syntax/src/parser_impl/event.rs
+++ b/crates/ra_syntax/src/parser_impl/event.rs
@@ -13,7 +13,7 @@ use crate::{
     SmolStr,
     SyntaxKind::{self, *},
     TextRange, TextUnit,
-    yellow::syntax_error::{
+    syntax_node::syntax_error::{
         ParseError,
         SyntaxError,
         SyntaxErrorKind,
diff --git a/crates/ra_syntax/src/reparsing.rs b/crates/ra_syntax/src/reparsing.rs
index c5c609ad5..dd751465c 100644
--- a/crates/ra_syntax/src/reparsing.rs
+++ b/crates/ra_syntax/src/reparsing.rs
@@ -3,7 +3,7 @@ use crate::grammar;
 use crate::lexer::{tokenize, Token};
 use crate::parser_api::Parser;
 use crate::parser_impl;
-use crate::yellow::{self, GreenNode, SyntaxError, SyntaxNode};
+use crate::syntax_node::{self, GreenNode, SyntaxError, SyntaxNode};
 use crate::{SyntaxKind::*, TextRange, TextUnit};
 use ra_text_edit::AtomTextEdit;
 
@@ -56,7 +56,7 @@ fn reparse_block<'node>(
         return None;
     }
     let (green, new_errors) =
-        parser_impl::parse_with(yellow::GreenBuilder::new(), &text, &tokens, reparser);
+        parser_impl::parse_with(syntax_node::GreenBuilder::new(), &text, &tokens, reparser);
     Some((node, green, new_errors))
 }
 
diff --git a/crates/ra_syntax/src/yellow.rs b/crates/ra_syntax/src/syntax_node.rs
index ed48739f8..ed48739f8 100644
--- a/crates/ra_syntax/src/yellow.rs
+++ b/crates/ra_syntax/src/syntax_node.rs
diff --git a/crates/ra_syntax/src/yellow/builder.rs b/crates/ra_syntax/src/syntax_node/builder.rs
index e8b9112d4..8abd0f051 100644
--- a/crates/ra_syntax/src/yellow/builder.rs
+++ b/crates/ra_syntax/src/syntax_node/builder.rs
@@ -1,6 +1,6 @@
 use crate::{
     parser_impl::Sink,
-    yellow::{GreenNode, RaTypes, SyntaxError},
+    syntax_node::{GreenNode, RaTypes, SyntaxError},
     SmolStr, SyntaxKind,
 };
 use rowan::GreenNodeBuilder;
diff --git a/crates/ra_syntax/src/yellow/syntax_error.rs b/crates/ra_syntax/src/syntax_node/syntax_error.rs
index 412cf82cc..412cf82cc 100644
--- a/crates/ra_syntax/src/yellow/syntax_error.rs
+++ b/crates/ra_syntax/src/syntax_node/syntax_error.rs
diff --git a/crates/ra_syntax/src/yellow/syntax_text.rs b/crates/ra_syntax/src/syntax_node/syntax_text.rs
index 84e5b231a..84e5b231a 100644
--- a/crates/ra_syntax/src/yellow/syntax_text.rs
+++ b/crates/ra_syntax/src/syntax_node/syntax_text.rs
diff --git a/crates/ra_syntax/src/validation.rs b/crates/ra_syntax/src/validation.rs
index ac6cc3dd6..10672d6bf 100644
--- a/crates/ra_syntax/src/validation.rs
+++ b/crates/ra_syntax/src/validation.rs
@@ -5,7 +5,7 @@ mod string;
 mod block;
 
 use crate::{
-    SourceFile, yellow::SyntaxError, AstNode,
+    SourceFile, syntax_node::SyntaxError, AstNode,
     ast,
     algo::visit::{visitor_ctx, VisitorCtx},
 };
diff --git a/crates/ra_syntax/src/validation/block.rs b/crates/ra_syntax/src/validation/block.rs
index 4e77c15b6..de949d967 100644
--- a/crates/ra_syntax/src/validation/block.rs
+++ b/crates/ra_syntax/src/validation/block.rs
@@ -1,6 +1,6 @@
 use crate::{SyntaxKind::*,
     ast::{self, AttrsOwner, AstNode},
-    yellow::{
+    syntax_node::{
         SyntaxError,
         SyntaxErrorKind::*,
     },
diff --git a/crates/ra_syntax/src/validation/byte.rs b/crates/ra_syntax/src/validation/byte.rs
index d51fabcf9..acdc12552 100644
--- a/crates/ra_syntax/src/validation/byte.rs
+++ b/crates/ra_syntax/src/validation/byte.rs
@@ -5,7 +5,7 @@ use crate::{
     string_lexing::{self, StringComponentKind},
     TextRange,
     validation::char,
-    yellow::{
+    syntax_node::{
         SyntaxError,
         SyntaxErrorKind::*,
     },
diff --git a/crates/ra_syntax/src/validation/byte_string.rs b/crates/ra_syntax/src/validation/byte_string.rs
index 7abe8f330..69a98b640 100644
--- a/crates/ra_syntax/src/validation/byte_string.rs
+++ b/crates/ra_syntax/src/validation/byte_string.rs
@@ -1,7 +1,7 @@
 use crate::{
     ast::{self, AstNode, AstToken},
     string_lexing::{self, StringComponentKind},
-    yellow::{
+    syntax_node::{
         SyntaxError,
         SyntaxErrorKind::*,
     },
diff --git a/crates/ra_syntax/src/validation/char.rs b/crates/ra_syntax/src/validation/char.rs
index 012594db3..26c15e36d 100644
--- a/crates/ra_syntax/src/validation/char.rs
+++ b/crates/ra_syntax/src/validation/char.rs
@@ -8,7 +8,7 @@ use crate::{
     ast::{self, AstNode, AstToken},
     string_lexing::{self, StringComponentKind},
     TextRange,
-    yellow::{
+    syntax_node::{
         SyntaxError,
         SyntaxErrorKind::*,
     },
diff --git a/crates/ra_syntax/src/validation/string.rs b/crates/ra_syntax/src/validation/string.rs
index 4fd7fffdf..2f7f9c7c4 100644
--- a/crates/ra_syntax/src/validation/string.rs
+++ b/crates/ra_syntax/src/validation/string.rs
@@ -1,7 +1,7 @@
 use crate::{
     ast::{self, AstNode, AstToken},
     string_lexing,
-    yellow::{
+    syntax_node::{
         SyntaxError,
         SyntaxErrorKind::*,
     },
diff --git a/crates/ra_syntax/tests/data/parser/fuzz-failures/0000.rs b/crates/ra_syntax/tests/data/parser/fuzz-failures/0000.rs
index 59cd11495..e0437d163 100644
--- a/crates/ra_syntax/tests/data/parser/fuzz-failures/0000.rs
+++ b/crates/ra_syntax/tests/data/parser/fuzz-failures/0000.rs
@@ -5,7 +5,7 @@
     }
     pub fn parse(text: &str) -> File {
         let tokens = tokenize(&text);
-        let (green, errors) = parser_impl::parse_with::<yellow::GreenBuilder>(
+        let (green, errors) = parser_impl::parse_with::<syntax_node::GreenBuilder>(
             text, &tokens, grammar::root,
         );
         File::new(green, errors)
@@ -24,7 +24,7 @@
         if !is_balanced(&tokens) {
             return None;
         }
-        let (green, new_errors) = parser_impl::parse_with::<yellow::GreenBuilder>(
+        let (green, new_errors) = parser_impl::parse_with::<syntax_node::GreenBuilder>(
             &te2t, &tokens, reparser,
         );
         let green_root = node.replace_with(green);
diff --git a/crates/ra_tt/src/lib.rs b/crates/ra_tt/src/lib.rs
index c1f37b889..0b0b9b4d2 100644
--- a/crates/ra_tt/src/lib.rs
+++ b/crates/ra_tt/src/lib.rs
@@ -33,14 +33,14 @@ impl TokenId {
     }
 }
 
-#[derive(Debug, Clone)]
+#[derive(Debug, Clone, PartialEq, Eq)]
 pub enum TokenTree {
     Leaf(Leaf),
     Subtree(Subtree),
 }
 impl_froms!(TokenTree: Leaf, Subtree);
 
-#[derive(Debug, Clone)]
+#[derive(Debug, Clone, PartialEq, Eq)]
 pub enum Leaf {
     Literal(Literal),
     Punct(Punct),
@@ -48,7 +48,7 @@ pub enum Leaf {
 }
 impl_froms!(Leaf: Literal, Punct, Ident);
 
-#[derive(Debug, Clone)]
+#[derive(Debug, Clone, PartialEq, Eq)]
 pub struct Subtree {
     pub delimiter: Delimiter,
     pub token_trees: Vec<TokenTree>,
@@ -62,7 +62,7 @@ pub enum Delimiter {
     None,
 }
 
-#[derive(Debug, Clone)]
+#[derive(Debug, Clone, PartialEq, Eq)]
 pub struct Literal {
     pub text: SmolStr,
 }
@@ -79,7 +79,7 @@ pub enum Spacing {
     Joint,
 }
 
-#[derive(Debug, Clone)]
+#[derive(Debug, Clone, PartialEq, Eq)]
 pub struct Ident {
     pub text: SmolStr,
     pub id: TokenId,
diff --git a/crates/ra_vfs/src/io.rs b/crates/ra_vfs/src/io.rs
index dc0b84d5a..3952b200b 100644
--- a/crates/ra_vfs/src/io.rs
+++ b/crates/ra_vfs/src/io.rs
@@ -169,7 +169,7 @@ fn convert_notify_event(event: DebouncedEvent, sender: &Sender<(PathBuf, ChangeK
             // ignore
         }
         DebouncedEvent::Rescan => {
-            // TODO rescan all roots
+            // TODO: rescan all roots
         }
         DebouncedEvent::Create(path) => {
             sender.send((path, ChangeKind::Create)).unwrap();
@@ -185,7 +185,7 @@ fn convert_notify_event(event: DebouncedEvent, sender: &Sender<(PathBuf, ChangeK
             sender.send((dst, ChangeKind::Create)).unwrap();
         }
         DebouncedEvent::Error(err, path) => {
-            // TODO should we reload the file contents?
+            // TODO: should we reload the file contents?
             log::warn!("watcher error \"{}\", {:?}", err, path);
         }
     }
diff --git a/crates/ra_vfs/src/lib.rs b/crates/ra_vfs/src/lib.rs
index d589a254b..f07657db6 100644
--- a/crates/ra_vfs/src/lib.rs
+++ b/crates/ra_vfs/src/lib.rs
@@ -7,8 +7,10 @@
 //!
 //! It is also responsible for watching the disk for changes, and for merging
 //! editor state (modified, unsaved files) with disk state.
-//! TODO: Some LSP clients support watching the disk, so this crate should
-//! to support custom watcher events (related to https://github.com/rust-analyzer/rust-analyzer/issues/131)
+//!
+//! TODO: Some LSP clients support watching the disk, so this crate should to
+//! support custom watcher events (related to
+//! <https://github.com/rust-analyzer/rust-analyzer/issues/131>)
 //!
 //! 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
@@ -225,12 +227,12 @@ impl Vfs {
                 let mut cur_files = Vec::new();
                 // While we were scanning the root in the background, a file might have
                 // been open in the editor, so we need to account for that.
-                let exising = self.root2files[root]
+                let existing = self.root2files[root]
                     .iter()
                     .map(|&file| (self.files[file].path.clone(), file))
                     .collect::<FxHashMap<_, _>>();
                 for (path, text) in files {
-                    if let Some(&file) = exising.get(&path) {
+                    if let Some(&file) = existing.get(&path) {
                         let text = Arc::clone(&self.files[file].text);
                         cur_files.push((file, path, text));
                         continue;
@@ -335,7 +337,7 @@ impl Vfs {
         mem::replace(&mut self.pending_changes, Vec::new())
     }
 
-    /// Sutdown the VFS and terminate the background watching thread.
+    /// Shutdown the VFS and terminate the background watching thread.
     pub fn shutdown(self) -> thread::Result<()> {
         self.worker.shutdown()
     }
@@ -360,7 +362,7 @@ impl Vfs {
     }
 
     fn remove_file(&mut self, file: VfsFile) {
-        //FIXME: use arena with removal
+        // FIXME: use arena with removal
         self.files[file].text = Default::default();
         self.files[file].path = Default::default();
         let root = self.files[file].root;
diff --git a/crates/test_utils/src/lib.rs b/crates/test_utils/src/lib.rs
index 09fc2e659..4d83af00c 100644
--- a/crates/test_utils/src/lib.rs
+++ b/crates/test_utils/src/lib.rs
@@ -113,9 +113,9 @@ pub struct FixtureEntry {
     pub text: String,
 }
 
-/// Parses text wich looks like this:
+/// Parses text which looks like this:
 ///
-///  ```notrust
+///  ```rust,ignore
 ///  //- some meta
 ///  line 1
 ///  line 2
diff --git a/crates/test_utils/src/marks.rs b/crates/test_utils/src/marks.rs
index d2a84643c..107432926 100644
--- a/crates/test_utils/src/marks.rs
+++ b/crates/test_utils/src/marks.rs
@@ -1,10 +1,10 @@
 //! This module implements manually tracked test coverage, which useful for
 //! quickly finding a test responsible for testing a particular bit of code.
 //!
-//! See https://matklad.github.io/2018/06/18/a-trick-for-test-maintenance.html
+//! See <https://matklad.github.io/2018/06/18/a-trick-for-test-maintenance.html>
 //! for details, but the TL;DR is that you write your test as
 //!
-//! ```no-run
+//! ```rust,no_run
 //! #[test]
 //! fn test_foo() {
 //!     covers!(test_foo);
@@ -13,7 +13,9 @@
 //!
 //! and in the code under test you write
 //!
-//! ```no-run
+//! ```rust,no_run
+//! # use test_utils::tested_by;
+//! # fn some_condition() -> bool { true }
 //! fn foo() {
 //!     if some_condition() {
 //!         tested_by!(test_foo);
diff --git a/crates/thread_worker/src/lib.rs b/crates/thread_worker/src/lib.rs
index ca0aad136..a522a0843 100644
--- a/crates/thread_worker/src/lib.rs
+++ b/crates/thread_worker/src/lib.rs
@@ -65,7 +65,7 @@ impl WorkerHandle {
     }
 }
 
-/// Sets up worker channels in a deadlock-avoind way.
+/// Sets up worker channels in a deadlock-avoiding way.
 /// If one sets both input and output buffers to a fixed size,
 /// a worker might get stuck.
 fn worker_chan<I, O>(buf: usize) -> (Worker<I, O>, Receiver<I>, Sender<O>) {
diff --git a/editors/README.md b/editors/README.md
index eb1004914..6e1189cad 100644
--- a/editors/README.md
+++ b/editors/README.md
@@ -5,6 +5,9 @@ In order to build the VS Code plugin, you need to have node.js and npm with
 a minimum version of 10 installed. Please refer to
 [node.js and npm documentation](https://nodejs.org) for installation instructions.
 
+You will also need the most recent version of VS Code: we don't try to
+maintain compatibility with older versions yet.
+
 The experimental VS Code plugin can then be built and installed by executing the
 following commands:
 
diff --git a/editors/code/package.json b/editors/code/package.json
index 045d372e7..4fc2cb754 100644
--- a/editors/code/package.json
+++ b/editors/code/package.json
@@ -13,7 +13,7 @@
         "Other"
     ],
     "engines": {
-        "vscode": "^1.30.0"
+        "vscode": "^1.31.0"
     },
     "scripts": {
         "vscode:prepublish": "npm run compile",