36 files changed, 1498 insertions, 949 deletions

diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
deleted file mode 100644
index a2efc7afa..000000000
--- a/CONTRIBUTING.md
+++ /dev/null
@@ -1,18 +0,0 @@
-The project is in its early stages: contributions are welcome and would be
-**very** helpful, but the project is not _yet_ optimized for contribution.
-Moreover, it is doubly experimental, so there's no guarantee that any work here
-would reach production.
-
-To get an idea of how rust-analyzer works, take a look at the [ARCHITECTURE.md](./ARCHITECTURE.md)
-document.
-
-Useful labels on the issue tracker:
-  * [E-mentor](https://github.com/rust-analyzer/rust-analyzer/issues?q=is%3Aopen+is%3Aissue+label%3AE-mentor)
-    issues have links to the code in question and tests,
-  * [E-easy](https://github.com/rust-analyzer/rust-analyzer/issues?q=is%3Aopen+is%3Aissue+label%3AE-easy),
-    [E-medium](https://github.com/rust-analyzer/rust-analyzer/issues?q=is%3Aopen+is%3Aissue+label%3AE-medium),
-    [E-hard](https://github.com/rust-analyzer/rust-analyzer/issues?q=is%3Aopen+is%3Aissue+label%3AE-hard),
-    labels are *estimates* for how hard would be to write a fix.
-
-There's no formal PR check list: everything that passes CI (we use [bors](https://bors.tech/)) is valid,
-but it's a good idea to write nice commit messages, test code thoroughly, maintain consistent style, etc.
diff --git a/Cargo.lock b/Cargo.lock
index 55bef8cb9..50fe1fa23 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -945,6 +945,7 @@ dependencies = [
  "ra_batch 0.1.0",
  "ra_db 0.1.0",
  "ra_hir 0.1.0",
+ "ra_ide_api 0.1.0",
  "ra_ide_api_light 0.1.0",
  "ra_syntax 0.1.0",
  "tools 0.1.0",
diff --git a/README.md b/README.md
index 5bc90a3f0..3a0c9dee1 100644
--- a/README.md
+++ b/README.md
@@ -13,32 +13,37 @@ Work on the Rust Analyzer is sponsored by
 
 [![Ferrous Systems](https://ferrous-systems.com/images/ferrous-logo-text.svg)](https://ferrous-systems.com/)
 
-## Quick Start
+## Language Server Quick Start
 
-Rust analyzer builds on Rust >= 1.31.0 and uses the 2018 edition.
+Rust Analyzer is a work-in-progress, so you'll have to build it from source, and
+you might encounter critical bugs. That said, it is complete enough to provide a
+useful IDE experience and some people use it as a daily driver.
 
-```
-# run tests
-$ cargo test
+To build rust-analyzer, you need:
 
-# show syntax tree of a Rust file
-$ cargo run --package ra_cli parse < crates/ra_syntax/src/lib.rs
+* latest stable rust for language server itself
+* latest stable npm and VS Code for VS Code extension (`code` should be in path)
 
-# show symbols of a Rust file
-$ cargo run --package ra_cli symbols < crates/ra_syntax/src/lib.rs
+For setup for other editors, see [./docs/user](./docs/user).
 
-# install the language server
-$ cargo install-lsp
-or
-$ cargo install --path crates/ra_lsp_server
 ```
+# clone the repo
+$ git clone https://github.com/rust-analyzer/rust-analyzer && cd rust-analyzer
+
+# install both the language server and VS Code extension
+$ cargo install-code
 
-See [these instructions](./editors/README.md) for VS Code setup and the list of
-features (some of which are VS Code specific).
+# alternatively, install only the server. Binary name is `ra_lsp_server`.
+$ cargo install-lsp
+```
+## Documentation
 
-## Debugging
+If you want to **contribute** to rust-analyzer or just curious about how things work
+under the hood, check the [./docs/dev](./docs/dev) folder.
 
-See [these instructions](./DEBUGGING.md) on how to debug the vscode extension and the lsp server.
+If you want to **use** rust-analyzer's language server with your editor of
+choice, check [./docs/user](./docs/user) folder. It also contains some tips & tricks to help
+you be more productive when using rust-analyzer.
 
 ## Getting in touch
 
@@ -46,83 +51,6 @@ We are on the rust-lang Zulip!
 
 https://rust-lang.zulipchat.com/#narrow/stream/185405-t-compiler.2Frls-2.2E0
 
-## Contributing
-
-See [CONTRIBUTING.md](./CONTRIBUTING.md) and [ARCHITECTURE.md](./ARCHITECTURE.md)
-
-## Supported LSP features
-
-### General
-- [x] [initialize](https://microsoft.github.io/language-server-protocol/specification#initialize)
-- [x] [initialized](https://microsoft.github.io/language-server-protocol/specification#initialized)
-- [x] [shutdown](https://microsoft.github.io/language-server-protocol/specification#shutdown)
-- [ ] [exit](https://microsoft.github.io/language-server-protocol/specification#exit)
-- [x] [$/cancelRequest](https://microsoft.github.io/language-server-protocol/specification#cancelRequest)
-
-### Workspace
-- [ ] [workspace/workspaceFolders](https://microsoft.github.io/language-server-protocol/specification#workspace_workspaceFolders)
-- [ ] [workspace/didChangeWorkspaceFolders](https://microsoft.github.io/language-server-protocol/specification#workspace_didChangeWorkspaceFolders)
-- [x] [workspace/didChangeConfiguration](https://microsoft.github.io/language-server-protocol/specification#workspace_didChangeConfiguration)
-- [ ] [workspace/configuration](https://microsoft.github.io/language-server-protocol/specification#workspace_configuration)
-- [x] [workspace/didChangeWatchedFiles](https://microsoft.github.io/language-server-protocol/specification#workspace_didChangeWatchedFiles)
-- [x] [workspace/symbol](https://microsoft.github.io/language-server-protocol/specification#workspace_symbol)
-- [x] [workspace/executeCommand](https://microsoft.github.io/language-server-protocol/specification#workspace_executeCommand)
- - `apply_code_action`
-- [ ] [workspace/applyEdit](https://microsoft.github.io/language-server-protocol/specification#workspace_applyEdit)
-
-### Text Synchronization
-- [x] [textDocument/didOpen](https://microsoft.github.io/language-server-protocol/specification#textDocument_didOpen)
-- [x] [textDocument/didChange](https://microsoft.github.io/language-server-protocol/specification#textDocument_didChange)
-- [ ] [textDocument/willSave](https://microsoft.github.io/language-server-protocol/specification#textDocument_willSave)
-- [ ] [textDocument/willSaveWaitUntil](https://microsoft.github.io/language-server-protocol/specification#textDocument_willSaveWaitUntil)
-- [x] [textDocument/didSave](https://microsoft.github.io/language-server-protocol/specification#textDocument_didSave)
-- [x] [textDocument/didClose](https://microsoft.github.io/language-server-protocol/specification#textDocument_didClose)
-
-### Diagnostics
-- [x] [textDocument/publishDiagnostics](https://microsoft.github.io/language-server-protocol/specification#textDocument_publishDiagnostics)
-
-### Lanuguage Features
-- [x] [textDocument/completion](https://microsoft.github.io/language-server-protocol/specification#textDocument_completion)
- - open close: false
- - change: Full
- - will save: false
- - will save wait until: false
- - save: false
-- [x] [completionItem/resolve](https://microsoft.github.io/language-server-protocol/specification#completionItem_resolve)
- - resolve provider: none
- - trigger characters: `:`, `.`
-- [x] [textDocument/hover](https://microsoft.github.io/language-server-protocol/specification#textDocument_hover)
-- [x] [textDocument/signatureHelp](https://microsoft.github.io/language-server-protocol/specification#textDocument_signatureHelp)
- - trigger characters: `(`,  `,`,  `)`
-- [ ] [textDocument/declaration](https://microsoft.github.io/language-server-protocol/specification#textDocument_declaration)
-- [x] [textDocument/definition](https://microsoft.github.io/language-server-protocol/specification#textDocument_definition)
-- [ ] [textDocument/typeDefinition](https://microsoft.github.io/language-server-protocol/specification#textDocument_typeDefinition)
-- [x] [textDocument/implementation](https://microsoft.github.io/language-server-protocol/specification#textDocument_implementation)
-- [x] [textDocument/references](https://microsoft.github.io/language-server-protocol/specification#textDocument_references)
-- [x] [textDocument/documentHighlight](https://microsoft.github.io/language-server-protocol/specification#textDocument_documentHighlight)
-- [x] [textDocument/documentSymbol](https://microsoft.github.io/language-server-protocol/specification#textDocument_documentSymbol)
-- [x] [textDocument/codeAction](https://microsoft.github.io/language-server-protocol/specification#textDocument_codeAction)
- - rust-analyzer.syntaxTree
- - rust-analyzer.extendSelection
- - rust-analyzer.matchingBrace
- - rust-analyzer.parentModule
- - rust-analyzer.joinLines
- - rust-analyzer.run
- - rust-analyzer.analyzerStatus
-- [x] [textDocument/codeLens](https://microsoft.github.io/language-server-protocol/specification#textDocument_codeLens)
-- [ ] [textDocument/documentLink](https://microsoft.github.io/language-server-protocol/specification#codeLens_resolve)
-- [ ] [documentLink/resolve](https://microsoft.github.io/language-server-protocol/specification#documentLink_resolve)
-- [ ] [textDocument/documentColor](https://microsoft.github.io/language-server-protocol/specification#textDocument_documentColor)
-- [ ] [textDocument/colorPresentation](https://microsoft.github.io/language-server-protocol/specification#textDocument_colorPresentation)
-- [x] [textDocument/formatting](https://microsoft.github.io/language-server-protocol/specification#textDocument_formatting)
-- [ ] [textDocument/rangeFormatting](https://microsoft.github.io/language-server-protocol/specification#textDocument_rangeFormatting)
-- [x] [textDocument/onTypeFormatting](https://microsoft.github.io/language-server-protocol/specification#textDocument_onTypeFormatting)
- - first trigger character: `=`
- - more trigger character `.`
-- [x] [textDocument/rename](https://microsoft.github.io/language-server-protocol/specification#textDocument_rename)
-- [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)
-
 ## License
 
 Rust analyzer is primarily distributed under the terms of both the MIT
diff --git a/ROADMAP.md b/ROADMAP.md
deleted file mode 100644
index 3856ebc5b..000000000
--- a/ROADMAP.md
+++ /dev/null
@@ -1,77 +0,0 @@
-# Rust Analyzer Roadmap 01
-
-Written on 2018-11-06, extends approximately to February 2019.
-After that, we should coordinate with the compiler/rls developers to align goals and share code and experience.
-
-
-# Overall Goals
-
-The mission is:
-  * Provide an excellent "code analyzed as you type" IDE experience for the Rust language,
-  * Implement the bulk of the features in Rust itself.
-
-
-High-level architecture constraints:
-  * Long-term, replace the current rustc frontend.
-    It's *obvious* that the code should be shared, but OTOH, all great IDEs started as from-scratch rewrites.
-  * Don't hard-code a particular protocol or mode of operation.
-    Produce a library which could be used for implementing an LSP server, or for in-process embedding.
-  * As long as possible, stick with stable Rust.
-
-
-# Current Goals
-
-Ideally, we would be coordinating with the compiler/rls teams, but they are busy working on making Rust 2018 at the moment.
-The sync-up point will happen some time after the edition, probably early 2019.
-In the meantime, the goal is to **experiment**, specifically, to figure out how a from-scratch written RLS might look like.
-
-
-## Data Storage and Protocol implementation
-
-The fundamental part of any architecture is who owns which data, how the data is mutated and how the data is exposed to user.
-For storage we use the [salsa](http://github.com/salsa-rs/salsa) library, which provides a solid model that seems to be the way to go.
-
-Modification to source files is mostly driven by the language client, but we also should support watching the file system. The current
-file watching implementation is a stub.
-
-**Action Item:** implement reliable file watching service.
-
-We also should extract LSP bits as a reusable library. There's already `gen_lsp_server`, but it is pretty limited.
-
-**Action Item:** try using `gen_lsp_server` in more than one language server, for example for TOML and Nix.
-
-The ideal architecture for `gen_lsp_server` is still unclear. I'd rather avoid futures: they bring significant runtime complexity
-(call stacks become insane) and the performance benefits are negligible for our use case (one thread per request is perfectly OK given
-the low amount of requests a language server receives). The current interface is based on crossbeam-channel, but it's not clear
-if that is the best choice.
-
-
-## Low-effort, high payoff features
-
-Implementing 20% of type inference will give use 80% of completion.
-Thus it makes sense to partially implement name resolution, type inference and trait matching, even though there is a chance that
-this code is replaced later on when we integrate with the compiler
-
-Specifically, we need to:
-
-* **Action Item:** implement path resolution, so that we get completion in imports and such.
-* **Action Item:** implement simple type inference, so that we get completion for inherent methods.
-* **Action Item:** implement nicer completion infrastructure, so that we have icons, snippets, doc comments, after insert callbacks, ...
-
-
-## Dragons to kill
-
-To make experiments most effective, we should try to prototype solutions for the hardest problems.
-In the case of Rust, the two hardest problems are:
-  * Conditional compilation and source/model mismatch.
-    A single source file might correspond to several entities in the semantic model.
-    For example, different cfg flags produce effectively different crates from the same source.
-  * Macros are intertwined with name resolution in a single fix-point iteration algorithm.
-    This is just plain hard to implement, but also interacts poorly with on-demand.
-
-
-For the first bullet point, we need to design descriptors infra and explicit mapping step between sources and semantic model, which is intentionally fuzzy in one direction.
-The **action item** here is basically "write code, see what works, keep high-level picture in mind".
-
-For the second bullet point, there's hope that salsa with its deep memoization will result in a fast enough solution even without being fully on-demand.
-Again, the **action item** is to write the code and see what works. Salsa itself uses macros heavily, so it should be a great test.
diff --git a/crates/ra_cli/Cargo.toml b/crates/ra_cli/Cargo.toml
index ff30bf0b3..4c666f556 100644
--- a/crates/ra_cli/Cargo.toml
+++ b/crates/ra_cli/Cargo.toml
@@ -13,6 +13,7 @@ flexi_logger = "0.11.0"
 indicatif = "0.11.0"
 
 ra_syntax = { path = "../ra_syntax" }
+ra_ide_api = { path = "../ra_ide_api" }
 ra_ide_api_light = { path = "../ra_ide_api_light" }
 tools = { path = "../tools" }
 ra_batch = { path = "../ra_batch" }
diff --git a/crates/ra_cli/src/main.rs b/crates/ra_cli/src/main.rs
index 294f4b8af..5285f1f28 100644
--- a/crates/ra_cli/src/main.rs
+++ b/crates/ra_cli/src/main.rs
@@ -4,7 +4,8 @@ use std::{fs, io::Read, path::Path, time::Instant};
 
 use clap::{App, Arg, SubCommand};
 use join_to_string::join;
-use ra_ide_api_light::{extend_selection, file_structure};
+use ra_ide_api::{Analysis, FileRange};
+use ra_ide_api_light::file_structure;
 use ra_syntax::{SourceFile, TextRange, TreeArc, AstNode};
 use tools::collect_tests;
 use flexi_logger::Logger;
@@ -59,8 +60,8 @@ fn main() -> Result<()> {
         ("extend-selection", Some(matches)) => {
             let start: u32 = matches.value_of("start").unwrap().parse()?;
             let end: u32 = matches.value_of("end").unwrap().parse()?;
-            let file = file()?;
-            let sels = selections(&file, start, end);
+            let text = read_stdin()?;
+            let sels = selections(text, start, end);
             println!("{}", sels)
         }
         ("analysis-stats", Some(matches)) => {
@@ -98,12 +99,17 @@ fn render_test(file: &Path, line: usize) -> Result<(String, String)> {
     Ok((test.text, tree))
 }
 
-fn selections(file: &SourceFile, start: u32, end: u32) -> String {
+fn selections(text: String, start: u32, end: u32) -> String {
+    let (analysis, file_id) = Analysis::from_single_file(text);
     let mut ranges = Vec::new();
-    let mut cur = Some(TextRange::from_to((start - 1).into(), (end - 1).into()));
-    while let Some(r) = cur {
-        ranges.push(r);
-        cur = extend_selection(file.syntax(), r);
+    let mut range = TextRange::from_to((start - 1).into(), (end - 1).into());
+    loop {
+        ranges.push(range);
+        let next = analysis.extend_selection(FileRange { file_id, range }).unwrap();
+        if range == next {
+            break;
+        }
+        range = next;
     }
     let ranges = ranges
         .iter()
diff --git a/crates/ra_db/src/lib.rs b/crates/ra_db/src/lib.rs
index e006c6d27..f3389c91f 100644
--- a/crates/ra_db/src/lib.rs
+++ b/crates/ra_db/src/lib.rs
@@ -16,7 +16,7 @@ pub use crate::{
     input::{
         FileId, CrateId, SourceRoot, SourceRootId, CrateGraph, Dependency, Edition,
     },
-    loc2id::LocationIntener,
+    loc2id::LocationInterner,
 };
 
 pub trait CheckCanceled: panic::RefUnwindSafe {
diff --git a/crates/ra_db/src/loc2id.rs b/crates/ra_db/src/loc2id.rs
index d27fa7682..eae64a4eb 100644
--- a/crates/ra_db/src/loc2id.rs
+++ b/crates/ra_db/src/loc2id.rs
@@ -59,7 +59,7 @@ where
 }
 
 #[derive(Debug)]
-pub struct LocationIntener<LOC, ID>
+pub struct LocationInterner<LOC, ID>
 where
     ID: ArenaId + Clone,
     LOC: Clone + Eq + Hash,
@@ -67,7 +67,7 @@ where
     map: Mutex<Loc2IdMap<LOC, ID>>,
 }
 
-impl<LOC, ID> panic::RefUnwindSafe for LocationIntener<LOC, ID>
+impl<LOC, ID> panic::RefUnwindSafe for LocationInterner<LOC, ID>
 where
     ID: ArenaId + Clone,
     LOC: Clone + Eq + Hash,
@@ -76,17 +76,17 @@ where
 {
 }
 
-impl<LOC, ID> Default for LocationIntener<LOC, ID>
+impl<LOC, ID> Default for LocationInterner<LOC, ID>
 where
     ID: ArenaId + Clone,
     LOC: Clone + Eq + Hash,
 {
     fn default() -> Self {
-        LocationIntener { map: Default::default() }
+        LocationInterner { map: Default::default() }
     }
 }
 
-impl<LOC, ID> LocationIntener<LOC, ID>
+impl<LOC, ID> LocationInterner<LOC, ID>
 where
     ID: ArenaId + Clone,
     LOC: Clone + Eq + Hash,
diff --git a/crates/ra_hir/src/expr.rs b/crates/ra_hir/src/expr.rs
index 6c7489e63..486314cc5 100644
--- a/crates/ra_hir/src/expr.rs
+++ b/crates/ra_hir/src/expr.rs
@@ -723,8 +723,7 @@ impl ExprCollector {
 
                 let lit = match child.flavor() {
                     LiteralFlavor::IntNumber { suffix } => {
-                        let known_name =
-                            suffix.map(Name::new).and_then(|name| UncertainIntTy::from_name(&name));
+                        let known_name = suffix.and_then(|it| UncertainIntTy::from_suffix(&it));
 
                         Literal::Int(
                             Default::default(),
@@ -732,9 +731,7 @@ impl ExprCollector {
                         )
                     }
                     LiteralFlavor::FloatNumber { suffix } => {
-                        let known_name = suffix
-                            .map(Name::new)
-                            .and_then(|name| UncertainFloatTy::from_name(&name));
+                        let known_name = suffix.and_then(|it| UncertainFloatTy::from_suffix(&it));
 
                         Literal::Float(
                             Default::default(),
diff --git a/crates/ra_hir/src/ids.rs b/crates/ra_hir/src/ids.rs
index 9596488d3..3d0a881c2 100644
--- a/crates/ra_hir/src/ids.rs
+++ b/crates/ra_hir/src/ids.rs
@@ -4,7 +4,7 @@ use std::{
     sync::Arc,
 };
 
-use ra_db::{LocationIntener, FileId};
+use ra_db::{LocationInterner, FileId};
 use ra_syntax::{TreeArc, SyntaxNode, SourceFile, AstNode, SyntaxNodePtr, ast};
 use ra_arena::{Arena, RawId, ArenaId, impl_arena_id};
 
@@ -15,14 +15,14 @@ use crate::{
 
 #[derive(Debug, Default)]
 pub struct HirInterner {
-    macros: LocationIntener<MacroCallLoc, MacroCallId>,
-    fns: LocationIntener<ItemLoc<ast::FnDef>, FunctionId>,
-    structs: LocationIntener<ItemLoc<ast::StructDef>, StructId>,
-    enums: LocationIntener<ItemLoc<ast::EnumDef>, EnumId>,
-    consts: LocationIntener<ItemLoc<ast::ConstDef>, ConstId>,
-    statics: LocationIntener<ItemLoc<ast::StaticDef>, StaticId>,
-    traits: LocationIntener<ItemLoc<ast::TraitDef>, TraitId>,
-    types: LocationIntener<ItemLoc<ast::TypeAliasDef>, TypeId>,
+    macros: LocationInterner<MacroCallLoc, MacroCallId>,
+    fns: LocationInterner<ItemLoc<ast::FnDef>, FunctionId>,
+    structs: LocationInterner<ItemLoc<ast::StructDef>, StructId>,
+    enums: LocationInterner<ItemLoc<ast::EnumDef>, EnumId>,
+    consts: LocationInterner<ItemLoc<ast::ConstDef>, ConstId>,
+    statics: LocationInterner<ItemLoc<ast::StaticDef>, StaticId>,
+    traits: LocationInterner<ItemLoc<ast::TraitDef>, TraitId>,
+    types: LocationInterner<ItemLoc<ast::TypeAliasDef>, TypeId>,
 }
 
 impl HirInterner {
@@ -204,7 +204,7 @@ impl<'a, DB: PersistentHirDatabase> LocationCtx<&'a DB> {
 }
 
 pub(crate) trait AstItemDef<N: AstNode>: ArenaId + Clone {
-    fn interner(interner: &HirInterner) -> &LocationIntener<ItemLoc<N>, Self>;
+    fn interner(interner: &HirInterner) -> &LocationInterner<ItemLoc<N>, Self>;
     fn from_ast(ctx: LocationCtx<&impl PersistentHirDatabase>, ast: &N) -> Self {
         let items = ctx.db.file_items(ctx.file_id);
         let item_id = items.id_of(ctx.file_id, ast.syntax());
@@ -238,7 +238,7 @@ pub(crate) trait AstItemDef<N: AstNode>: ArenaId + Clone {
 pub struct FunctionId(RawId);
 impl_arena_id!(FunctionId);
 impl AstItemDef<ast::FnDef> for FunctionId {
-    fn interner(interner: &HirInterner) -> &LocationIntener<ItemLoc<ast::FnDef>, Self> {
+    fn interner(interner: &HirInterner) -> &LocationInterner<ItemLoc<ast::FnDef>, Self> {
         &interner.fns
     }
 }
@@ -247,7 +247,7 @@ impl AstItemDef<ast::FnDef> for FunctionId {
 pub struct StructId(RawId);
 impl_arena_id!(StructId);
 impl AstItemDef<ast::StructDef> for StructId {
-    fn interner(interner: &HirInterner) -> &LocationIntener<ItemLoc<ast::StructDef>, Self> {
+    fn interner(interner: &HirInterner) -> &LocationInterner<ItemLoc<ast::StructDef>, Self> {
         &interner.structs
     }
 }
@@ -256,7 +256,7 @@ impl AstItemDef<ast::StructDef> for StructId {
 pub struct EnumId(RawId);
 impl_arena_id!(EnumId);
 impl AstItemDef<ast::EnumDef> for EnumId {
-    fn interner(interner: &HirInterner) -> &LocationIntener<ItemLoc<ast::EnumDef>, Self> {
+    fn interner(interner: &HirInterner) -> &LocationInterner<ItemLoc<ast::EnumDef>, Self> {
         &interner.enums
     }
 }
@@ -265,7 +265,7 @@ impl AstItemDef<ast::EnumDef> for EnumId {
 pub struct ConstId(RawId);
 impl_arena_id!(ConstId);
 impl AstItemDef<ast::ConstDef> for ConstId {
-    fn interner(interner: &HirInterner) -> &LocationIntener<ItemLoc<ast::ConstDef>, Self> {
+    fn interner(interner: &HirInterner) -> &LocationInterner<ItemLoc<ast::ConstDef>, Self> {
         &interner.consts
     }
 }
@@ -274,7 +274,7 @@ impl AstItemDef<ast::ConstDef> for ConstId {
 pub struct StaticId(RawId);
 impl_arena_id!(StaticId);
 impl AstItemDef<ast::StaticDef> for StaticId {
-    fn interner(interner: &HirInterner) -> &LocationIntener<ItemLoc<ast::StaticDef>, Self> {
+    fn interner(interner: &HirInterner) -> &LocationInterner<ItemLoc<ast::StaticDef>, Self> {
         &interner.statics
     }
 }
@@ -283,7 +283,7 @@ impl AstItemDef<ast::StaticDef> for StaticId {
 pub struct TraitId(RawId);
 impl_arena_id!(TraitId);
 impl AstItemDef<ast::TraitDef> for TraitId {
-    fn interner(interner: &HirInterner) -> &LocationIntener<ItemLoc<ast::TraitDef>, Self> {
+    fn interner(interner: &HirInterner) -> &LocationInterner<ItemLoc<ast::TraitDef>, Self> {
         &interner.traits
     }
 }
@@ -292,7 +292,7 @@ impl AstItemDef<ast::TraitDef> for TraitId {
 pub struct TypeId(RawId);
 impl_arena_id!(TypeId);
 impl AstItemDef<ast::TypeAliasDef> for TypeId {
-    fn interner(interner: &HirInterner) -> &LocationIntener<ItemLoc<ast::TypeAliasDef>, Self> {
+    fn interner(interner: &HirInterner) -> &LocationInterner<ItemLoc<ast::TypeAliasDef>, Self> {
         &interner.types
     }
 }
diff --git a/crates/ra_hir/src/name.rs b/crates/ra_hir/src/name.rs
index 06bafa6f0..677d18efc 100644
--- a/crates/ra_hir/src/name.rs
+++ b/crates/ra_hir/src/name.rs
@@ -23,7 +23,10 @@ impl fmt::Debug for Name {
 }
 
 impl Name {
-    pub(crate) fn new(text: SmolStr) -> Name {
+    /// Note: this is private to make creating name from random string hard.
+    /// Hopefully, this should allow us to integrate hygiene cleaner in the
+    /// future, and to switch to interned representation of names.
+    fn new(text: SmolStr) -> Name {
         Name { text }
     }
 
diff --git a/crates/ra_hir/src/nameres/collector.rs b/crates/ra_hir/src/nameres/collector.rs
index 12ed49a0a..3ea8d592c 100644
--- a/crates/ra_hir/src/nameres/collector.rs
+++ b/crates/ra_hir/src/nameres/collector.rs
@@ -124,7 +124,7 @@ where
     }
 
     fn resolve_import(
-        &mut self,
+        &self,
         module_id: CrateModuleId,
         import: &raw::ImportData,
     ) -> (PerNs<ModuleDef>, ReachedFixedPoint) {
diff --git a/crates/ra_hir/src/ty/lower.rs b/crates/ra_hir/src/ty/lower.rs
index 278f592d3..389a2fc68 100644
--- a/crates/ra_hir/src/ty/lower.rs
+++ b/crates/ra_hir/src/ty/lower.rs
@@ -63,9 +63,9 @@ impl Ty {
     pub(crate) fn from_hir_path(db: &impl HirDatabase, resolver: &Resolver, path: &Path) -> Self {
         if let Some(name) = path.as_ident() {
             // TODO handle primitive type names in resolver as well?
-            if let Some(int_ty) = primitive::UncertainIntTy::from_name(name) {
+            if let Some(int_ty) = primitive::UncertainIntTy::from_type_name(name) {
                 return Ty::Int(int_ty);
-            } else if let Some(float_ty) = primitive::UncertainFloatTy::from_name(name) {
+            } else if let Some(float_ty) = primitive::UncertainFloatTy::from_type_name(name) {
                 return Ty::Float(float_ty);
             } else if let Some(known) = name.as_known_name() {
                 match known {
diff --git a/crates/ra_hir/src/ty/primitive.rs b/crates/ra_hir/src/ty/primitive.rs
index 30aeac48e..421f7e980 100644
--- a/crates/ra_hir/src/ty/primitive.rs
+++ b/crates/ra_hir/src/ty/primitive.rs
@@ -10,10 +10,20 @@ pub enum UncertainIntTy {
 }
 
 impl UncertainIntTy {
-    pub fn from_name(name: &Name) -> Option<UncertainIntTy> {
-        if let Some(ty) = IntTy::from_name(name) {
+    pub(crate) fn from_type_name(name: &Name) -> Option<UncertainIntTy> {
+        if let Some(ty) = IntTy::from_type_name(name) {
             Some(UncertainIntTy::Signed(ty))
-        } else if let Some(ty) = UintTy::from_name(name) {
+        } else if let Some(ty) = UintTy::from_type_name(name) {
+            Some(UncertainIntTy::Unsigned(ty))
+        } else {
+            None
+        }
+    }
+
+    pub(crate) fn from_suffix(suffix: &str) -> Option<UncertainIntTy> {
+        if let Some(ty) = IntTy::from_suffix(suffix) {
+            Some(UncertainIntTy::Signed(ty))
+        } else if let Some(ty) = UintTy::from_suffix(suffix) {
             Some(UncertainIntTy::Unsigned(ty))
         } else {
             None
@@ -38,12 +48,12 @@ pub enum UncertainFloatTy {
 }
 
 impl UncertainFloatTy {
-    pub fn from_name(name: &Name) -> Option<UncertainFloatTy> {
-        if let Some(ty) = FloatTy::from_name(name) {
-            Some(UncertainFloatTy::Known(ty))
-        } else {
-            None
-        }
+    pub(crate) fn from_type_name(name: &Name) -> Option<UncertainFloatTy> {
+        FloatTy::from_type_name(name).map(UncertainFloatTy::Known)
+    }
+
+    pub(crate) fn from_suffix(suffix: &str) -> Option<UncertainFloatTy> {
+        FloatTy::from_suffix(suffix).map(UncertainFloatTy::Known)
     }
 }
 
@@ -87,7 +97,7 @@ impl fmt::Display for IntTy {
 }
 
 impl IntTy {
-    pub fn from_name(name: &Name) -> Option<IntTy> {
+    fn from_type_name(name: &Name) -> Option<IntTy> {
         match name.as_known_name()? {
             KnownName::Isize => Some(IntTy::Isize),
             KnownName::I8 => Some(IntTy::I8),
@@ -98,6 +108,18 @@ impl IntTy {
             _ => None,
         }
     }
+
+    fn from_suffix(suffix: &str) -> Option<IntTy> {
+        match suffix {
+            "isize" => Some(IntTy::Isize),
+            "i8" => Some(IntTy::I8),
+            "i16" => Some(IntTy::I16),
+            "i32" => Some(IntTy::I32),
+            "i64" => Some(IntTy::I64),
+            "i128" => Some(IntTy::I128),
+            _ => None,
+        }
+    }
 }
 
 #[derive(Clone, PartialEq, Eq, PartialOrd, Ord, Hash, Copy)]
@@ -125,7 +147,7 @@ impl fmt::Display for UintTy {
 }
 
 impl UintTy {
-    pub fn from_name(name: &Name) -> Option<UintTy> {
+    fn from_type_name(name: &Name) -> Option<UintTy> {
         match name.as_known_name()? {
             KnownName::Usize => Some(UintTy::Usize),
             KnownName::U8 => Some(UintTy::U8),
@@ -136,6 +158,18 @@ impl UintTy {
             _ => None,
         }
     }
+
+    fn from_suffix(suffix: &str) -> Option<UintTy> {
+        match suffix {
+            "usize" => Some(UintTy::Usize),
+            "u8" => Some(UintTy::U8),
+            "u16" => Some(UintTy::U16),
+            "u32" => Some(UintTy::U32),
+            "u64" => Some(UintTy::U64),
+            "u128" => Some(UintTy::U128),
+            _ => None,
+        }
+    }
 }
 
 impl fmt::Debug for UintTy {
@@ -170,11 +204,19 @@ impl FloatTy {
         }
     }
 
-    pub fn from_name(name: &Name) -> Option<FloatTy> {
+    fn from_type_name(name: &Name) -> Option<FloatTy> {
         match name.as_known_name()? {
             KnownName::F32 => Some(FloatTy::F32),
             KnownName::F64 => Some(FloatTy::F64),
             _ => None,
         }
     }
+
+    fn from_suffix(suffix: &str) -> Option<FloatTy> {
+        match suffix {
+            "f32" => Some(FloatTy::F32),
+            "f64" => Some(FloatTy::F64),
+            _ => None,
+        }
+    }
 }
diff --git a/crates/ra_ide_api/src/extend_selection.rs b/crates/ra_ide_api/src/extend_selection.rs
index d23290b74..63879a0b5 100644
--- a/crates/ra_ide_api/src/extend_selection.rs
+++ b/crates/ra_ide_api/src/extend_selection.rs
@@ -1,13 +1,378 @@
 use ra_db::SourceDatabase;
-use ra_syntax::AstNode;
-
-use crate::{
-    TextRange, FileRange,
-    db::RootDatabase,
+use ra_syntax::{
+    Direction, SyntaxNode, TextRange, TextUnit, AstNode,
+    algo::{find_covering_node, find_leaf_at_offset, LeafAtOffset},
+    SyntaxKind::*,
 };
 
+use crate::{FileRange, db::RootDatabase};
+
 // FIXME: restore macro support
 pub(crate) fn extend_selection(db: &RootDatabase, frange: FileRange) -> TextRange {
     let source_file = db.parse(frange.file_id);
-    ra_ide_api_light::extend_selection(source_file.syntax(), frange.range).unwrap_or(frange.range)
+    try_extend_selection(source_file.syntax(), frange.range).unwrap_or(frange.range)
+}
+
+fn try_extend_selection(root: &SyntaxNode, range: TextRange) -> Option<TextRange> {
+    let string_kinds = [COMMENT, STRING, RAW_STRING, BYTE_STRING, RAW_BYTE_STRING];
+    let list_kinds = [
+        FIELD_PAT_LIST,
+        MATCH_ARM_LIST,
+        NAMED_FIELD_DEF_LIST,
+        POS_FIELD_DEF_LIST,
+        NAMED_FIELD_LIST,
+        ENUM_VARIANT_LIST,
+        USE_TREE_LIST,
+        TYPE_PARAM_LIST,
+        TYPE_ARG_LIST,
+        PARAM_LIST,
+        ARG_LIST,
+        ARRAY_EXPR,
+    ];
+
+    if range.is_empty() {
+        let offset = range.start();
+        let mut leaves = find_leaf_at_offset(root, offset);
+        if leaves.clone().all(|it| it.kind() == WHITESPACE) {
+            return Some(extend_ws(root, leaves.next()?, offset));
+        }
+        let leaf_range = match leaves {
+            LeafAtOffset::None => return None,
+            LeafAtOffset::Single(l) => {
+                if string_kinds.contains(&l.kind()) {
+                    extend_single_word_in_comment_or_string(l, offset).unwrap_or_else(|| l.range())
+                } else {
+                    l.range()
+                }
+            }
+            LeafAtOffset::Between(l, r) => pick_best(l, r).range(),
+        };
+        return Some(leaf_range);
+    };
+    let node = find_covering_node(root, range);
+
+    // Using shallowest node with same range allows us to traverse siblings.
+    let node = node.ancestors().take_while(|n| n.range() == node.range()).last().unwrap();
+
+    if range == node.range() {
+        if string_kinds.contains(&node.kind()) {
+            if let Some(range) = extend_comments(node) {
+                return Some(range);
+            }
+        }
+
+        if node.parent().map(|n| list_kinds.contains(&n.kind())) == Some(true) {
+            if let Some(range) = extend_list_item(node) {
+                return Some(range);
+            }
+        }
+    }
+
+    match node.ancestors().skip_while(|n| n.range() == range).next() {
+        None => None,
+        Some(parent) => Some(parent.range()),
+    }
+}
+
+fn extend_single_word_in_comment_or_string(
+    leaf: &SyntaxNode,
+    offset: TextUnit,
+) -> Option<TextRange> {
+    let text: &str = leaf.leaf_text()?;
+    let cursor_position: u32 = (offset - leaf.range().start()).into();
+
+    let (before, after) = text.split_at(cursor_position as usize);
+
+    fn non_word_char(c: char) -> bool {
+        !(c.is_alphanumeric() || c == '_')
+    }
+
+    let start_idx = before.rfind(non_word_char)? as u32;
+    let end_idx = after.find(non_word_char).unwrap_or(after.len()) as u32;
+
+    let from: TextUnit = (start_idx + 1).into();
+    let to: TextUnit = (cursor_position + end_idx).into();
+
+    let range = TextRange::from_to(from, to);
+    if range.is_empty() {
+        None
+    } else {
+        Some(range + leaf.range().start())
+    }
+}
+
+fn extend_ws(root: &SyntaxNode, ws: &SyntaxNode, offset: TextUnit) -> TextRange {
+    let ws_text = ws.leaf_text().unwrap();
+    let suffix = TextRange::from_to(offset, ws.range().end()) - ws.range().start();
+    let prefix = TextRange::from_to(ws.range().start(), offset) - ws.range().start();
+    let ws_suffix = &ws_text.as_str()[suffix];
+    let ws_prefix = &ws_text.as_str()[prefix];
+    if ws_text.contains('\n') && !ws_suffix.contains('\n') {
+        if let Some(node) = ws.next_sibling() {
+            let start = match ws_prefix.rfind('\n') {
+                Some(idx) => ws.range().start() + TextUnit::from((idx + 1) as u32),
+                None => node.range().start(),
+            };
+            let end = if root.text().char_at(node.range().end()) == Some('\n') {
+                node.range().end() + TextUnit::of_char('\n')
+            } else {
+                node.range().end()
+            };
+            return TextRange::from_to(start, end);
+        }
+    }
+    ws.range()
+}
+
+fn pick_best<'a>(l: &'a SyntaxNode, r: &'a SyntaxNode) -> &'a SyntaxNode {
+    return if priority(r) > priority(l) { r } else { l };
+    fn priority(n: &SyntaxNode) -> usize {
+        match n.kind() {
+            WHITESPACE => 0,
+            IDENT | SELF_KW | SUPER_KW | CRATE_KW | LIFETIME => 2,
+            _ => 1,
+        }
+    }
+}
+
+/// Extend list item selection to include nearby comma and whitespace.
+fn extend_list_item(node: &SyntaxNode) -> Option<TextRange> {
+    fn is_single_line_ws(node: &SyntaxNode) -> bool {
+        node.kind() == WHITESPACE && !node.leaf_text().unwrap().contains('\n')
+    }
+
+    fn nearby_comma(node: &SyntaxNode, dir: Direction) -> Option<&SyntaxNode> {
+        node.siblings(dir)
+            .skip(1)
+            .skip_while(|node| is_single_line_ws(node))
+            .next()
+            .filter(|node| node.kind() == COMMA)
+    }
+
+    if let Some(comma_node) = nearby_comma(node, Direction::Prev) {
+        return Some(TextRange::from_to(comma_node.range().start(), node.range().end()));
+    }
+
+    if let Some(comma_node) = nearby_comma(node, Direction::Next) {
+        // Include any following whitespace when comma if after list item.
+        let final_node = comma_node
+            .siblings(Direction::Next)
+            .skip(1)
+            .next()
+            .filter(|node| is_single_line_ws(node))
+            .unwrap_or(comma_node);
+
+        return Some(TextRange::from_to(node.range().start(), final_node.range().end()));
+    }
+
+    return None;
+}
+
+fn extend_comments(node: &SyntaxNode) -> Option<TextRange> {
+    let prev = adj_comments(node, Direction::Prev);
+    let next = adj_comments(node, Direction::Next);
+    if prev != next {
+        Some(TextRange::from_to(prev.range().start(), next.range().end()))
+    } else {
+        None
+    }
+}
+
+fn adj_comments(node: &SyntaxNode, dir: Direction) -> &SyntaxNode {
+    let mut res = node;
+    for node in node.siblings(dir) {
+        match node.kind() {
+            COMMENT => res = node,
+            WHITESPACE if !node.leaf_text().unwrap().as_str().contains("\n\n") => (),
+            _ => break,
+        }
+    }
+    res
+}
+
+#[cfg(test)]
+mod tests {
+    use ra_syntax::{SourceFile, AstNode};
+    use test_utils::extract_offset;
+
+    use super::*;
+
+    fn do_check(before: &str, afters: &[&str]) {
+        let (cursor, before) = extract_offset(before);
+        let file = SourceFile::parse(&before);
+        let mut range = TextRange::offset_len(cursor, 0.into());
+        for &after in afters {
+            range = try_extend_selection(file.syntax(), range).unwrap();
+            let actual = &before[range];
+            assert_eq!(after, actual);
+        }
+    }
+
+    #[test]
+    fn test_extend_selection_arith() {
+        do_check(r#"fn foo() { <|>1 + 1 }"#, &["1", "1 + 1", "{ 1 + 1 }"]);
+    }
+
+    #[test]
+    fn test_extend_selection_list() {
+        do_check(r#"fn foo(<|>x: i32) {}"#, &["x", "x: i32"]);
+        do_check(r#"fn foo(<|>x: i32, y: i32) {}"#, &["x", "x: i32", "x: i32, "]);
+        do_check(r#"fn foo(<|>x: i32,y: i32) {}"#, &["x", "x: i32", "x: i32,"]);
+        do_check(r#"fn foo(x: i32, <|>y: i32) {}"#, &["y", "y: i32", ", y: i32"]);
+        do_check(r#"fn foo(x: i32, <|>y: i32, ) {}"#, &["y", "y: i32", ", y: i32"]);
+        do_check(r#"fn foo(x: i32,<|>y: i32) {}"#, &["y", "y: i32", ",y: i32"]);
+
+        do_check(r#"const FOO: [usize; 2] = [ 22<|> , 33];"#, &["22", "22 , "]);
+        do_check(r#"const FOO: [usize; 2] = [ 22 , 33<|>];"#, &["33", ", 33"]);
+        do_check(r#"const FOO: [usize; 2] = [ 22 , 33<|> ,];"#, &["33", ", 33"]);
+
+        do_check(
+            r#"
+const FOO: [usize; 2] = [
+    22,
+    <|>33,
+]"#,
+            &["33", "33,"],
+        );
+
+        do_check(
+            r#"
+const FOO: [usize; 2] = [
+    22
+    , 33<|>,
+]"#,
+            &["33", ", 33"],
+        );
+    }
+
+    #[test]
+    fn test_extend_selection_start_of_the_line() {
+        do_check(
+            r#"
+impl S {
+<|>    fn foo() {
+
+    }
+}"#,
+            &["    fn foo() {\n\n    }\n"],
+        );
+    }
+
+    #[test]
+    fn test_extend_selection_doc_comments() {
+        do_check(
+            r#"
+struct A;
+
+/// bla
+/// bla
+struct B {
+    <|>
+}
+            "#,
+            &["\n    \n", "{\n    \n}", "/// bla\n/// bla\nstruct B {\n    \n}"],
+        )
+    }
+
+    #[test]
+    fn test_extend_selection_comments() {
+        do_check(
+            r#"
+fn bar(){}
+
+// fn foo() {
+// 1 + <|>1
+// }
+
+// fn foo(){}
+    "#,
+            &["1", "// 1 + 1", "// fn foo() {\n// 1 + 1\n// }"],
+        );
+
+        do_check(
+            r#"
+// #[derive(Debug, Clone, Copy, PartialEq, Eq)]
+// pub enum Direction {
+//  <|>   Next,
+//     Prev
+// }
+"#,
+            &[
+                "//     Next,",
+                "// #[derive(Debug, Clone, Copy, PartialEq, Eq)]\n// pub enum Direction {\n//     Next,\n//     Prev\n// }",
+            ],
+        );
+
+        do_check(
+            r#"
+/*
+foo
+_bar1<|>*/
+    "#,
+            &["_bar1", "/*\nfoo\n_bar1*/"],
+        );
+
+        do_check(
+            r#"
+//!<|>foo_2 bar
+    "#,
+            &["foo_2", "//!foo_2 bar"],
+        );
+
+        do_check(
+            r#"
+/<|>/foo bar
+    "#,
+            &["//foo bar"],
+        );
+    }
+
+    #[test]
+    fn test_extend_selection_prefer_idents() {
+        do_check(
+            r#"
+fn main() { foo<|>+bar;}
+    "#,
+            &["foo", "foo+bar"],
+        );
+        do_check(
+            r#"
+fn main() { foo+<|>bar;}
+    "#,
+            &["bar", "foo+bar"],
+        );
+    }
+
+    #[test]
+    fn test_extend_selection_prefer_lifetimes() {
+        do_check(r#"fn foo<<|>'a>() {}"#, &["'a", "<'a>"]);
+        do_check(r#"fn foo<'a<|>>() {}"#, &["'a", "<'a>"]);
+    }
+
+    #[test]
+    fn test_extend_selection_select_first_word() {
+        do_check(r#"// foo bar b<|>az quxx"#, &["baz", "// foo bar baz quxx"]);
+        do_check(
+            r#"
+impl S {
+    fn foo() {
+        // hel<|>lo world
+    }
+}
+        "#,
+            &["hello", "// hello world"],
+        );
+    }
+
+    #[test]
+    fn test_extend_selection_string() {
+        do_check(
+            r#"
+fn bar(){}
+
+" fn f<|>oo() {"
+    "#,
+            &["foo", "\" fn foo() {\""],
+        );
+    }
 }
diff --git a/crates/ra_ide_api/src/lib.rs b/crates/ra_ide_api/src/lib.rs
index b8a4adbce..81ca57035 100644
--- a/crates/ra_ide_api/src/lib.rs
+++ b/crates/ra_ide_api/src/lib.rs
@@ -211,6 +211,23 @@ pub struct Analysis {
 // API, the API should in theory be usable as a library, or via a different
 // protocol.
 impl Analysis {
+    // Creates an analysis instance for a single file, without any extenal
+    // dependencies, stdlib support or ability to apply changes. See
+    // `AnalysisHost` for creating a fully-featured analysis.
+    pub fn from_single_file(text: String) -> (Analysis, FileId) {
+        let mut host = AnalysisHost::default();
+        let source_root = SourceRootId(0);
+        let mut change = AnalysisChange::new();
+        change.add_root(source_root, true);
+        let mut crate_graph = CrateGraph::default();
+        let file_id = FileId(0);
+        crate_graph.add_crate_root(file_id, Edition::Edition2018);
+        change.add_file(source_root, file_id, "main.rs".into(), Arc::new(text));
+        change.set_crate_graph(crate_graph);
+        host.apply_change(change);
+        (host.analysis(), file_id)
+    }
+
     /// Debug info about the current state of the analysis
     pub fn status(&self) -> String {
         status::status(&*self.db)
diff --git a/crates/ra_ide_api_light/src/extend_selection.rs b/crates/ra_ide_api_light/src/extend_selection.rs
deleted file mode 100644
index 28d62f290..000000000
--- a/crates/ra_ide_api_light/src/extend_selection.rs
+++ /dev/null
@@ -1,369 +0,0 @@
-use ra_syntax::{
-    Direction, SyntaxNode, TextRange, TextUnit,
-    algo::{find_covering_node, find_leaf_at_offset, LeafAtOffset},
-    SyntaxKind::*,
-};
-
-pub fn extend_selection(root: &SyntaxNode, range: TextRange) -> Option<TextRange> {
-    let string_kinds = [COMMENT, STRING, RAW_STRING, BYTE_STRING, RAW_BYTE_STRING];
-    let list_kinds = [
-        FIELD_PAT_LIST,
-        MATCH_ARM_LIST,
-        NAMED_FIELD_DEF_LIST,
-        POS_FIELD_DEF_LIST,
-        NAMED_FIELD_LIST,
-        ENUM_VARIANT_LIST,
-        USE_TREE_LIST,
-        TYPE_PARAM_LIST,
-        TYPE_ARG_LIST,
-        PARAM_LIST,
-        ARG_LIST,
-        ARRAY_EXPR,
-    ];
-
-    if range.is_empty() {
-        let offset = range.start();
-        let mut leaves = find_leaf_at_offset(root, offset);
-        if leaves.clone().all(|it| it.kind() == WHITESPACE) {
-            return Some(extend_ws(root, leaves.next()?, offset));
-        }
-        let leaf_range = match leaves {
-            LeafAtOffset::None => return None,
-            LeafAtOffset::Single(l) => {
-                if string_kinds.contains(&l.kind()) {
-                    extend_single_word_in_comment_or_string(l, offset).unwrap_or_else(|| l.range())
-                } else {
-                    l.range()
-                }
-            }
-            LeafAtOffset::Between(l, r) => pick_best(l, r).range(),
-        };
-        return Some(leaf_range);
-    };
-    let node = find_covering_node(root, range);
-
-    // Using shallowest node with same range allows us to traverse siblings.
-    let node = node.ancestors().take_while(|n| n.range() == node.range()).last().unwrap();
-
-    if range == node.range() {
-        if string_kinds.contains(&node.kind()) {
-            if let Some(range) = extend_comments(node) {
-                return Some(range);
-            }
-        }
-
-        if node.parent().map(|n| list_kinds.contains(&n.kind())) == Some(true) {
-            if let Some(range) = extend_list_item(node) {
-                return Some(range);
-            }
-        }
-    }
-
-    match node.ancestors().skip_while(|n| n.range() == range).next() {
-        None => None,
-        Some(parent) => Some(parent.range()),
-    }
-}
-
-fn extend_single_word_in_comment_or_string(
-    leaf: &SyntaxNode,
-    offset: TextUnit,
-) -> Option<TextRange> {
-    let text: &str = leaf.leaf_text()?;
-    let cursor_position: u32 = (offset - leaf.range().start()).into();
-
-    let (before, after) = text.split_at(cursor_position as usize);
-
-    fn non_word_char(c: char) -> bool {
-        !(c.is_alphanumeric() || c == '_')
-    }
-
-    let start_idx = before.rfind(non_word_char)? as u32;
-    let end_idx = after.find(non_word_char).unwrap_or(after.len()) as u32;
-
-    let from: TextUnit = (start_idx + 1).into();
-    let to: TextUnit = (cursor_position + end_idx).into();
-
-    let range = TextRange::from_to(from, to);
-    if range.is_empty() {
-        None
-    } else {
-        Some(range + leaf.range().start())
-    }
-}
-
-fn extend_ws(root: &SyntaxNode, ws: &SyntaxNode, offset: TextUnit) -> TextRange {
-    let ws_text = ws.leaf_text().unwrap();
-    let suffix = TextRange::from_to(offset, ws.range().end()) - ws.range().start();
-    let prefix = TextRange::from_to(ws.range().start(), offset) - ws.range().start();
-    let ws_suffix = &ws_text.as_str()[suffix];
-    let ws_prefix = &ws_text.as_str()[prefix];
-    if ws_text.contains('\n') && !ws_suffix.contains('\n') {
-        if let Some(node) = ws.next_sibling() {
-            let start = match ws_prefix.rfind('\n') {
-                Some(idx) => ws.range().start() + TextUnit::from((idx + 1) as u32),
-                None => node.range().start(),
-            };
-            let end = if root.text().char_at(node.range().end()) == Some('\n') {
-                node.range().end() + TextUnit::of_char('\n')
-            } else {
-                node.range().end()
-            };
-            return TextRange::from_to(start, end);
-        }
-    }
-    ws.range()
-}
-
-fn pick_best<'a>(l: &'a SyntaxNode, r: &'a SyntaxNode) -> &'a SyntaxNode {
-    return if priority(r) > priority(l) { r } else { l };
-    fn priority(n: &SyntaxNode) -> usize {
-        match n.kind() {
-            WHITESPACE => 0,
-            IDENT | SELF_KW | SUPER_KW | CRATE_KW | LIFETIME => 2,
-            _ => 1,
-        }
-    }
-}
-
-/// Extend list item selection to include nearby comma and whitespace.
-fn extend_list_item(node: &SyntaxNode) -> Option<TextRange> {
-    fn is_single_line_ws(node: &SyntaxNode) -> bool {
-        node.kind() == WHITESPACE && !node.leaf_text().unwrap().contains('\n')
-    }
-
-    fn nearby_comma(node: &SyntaxNode, dir: Direction) -> Option<&SyntaxNode> {
-        node.siblings(dir)
-            .skip(1)
-            .skip_while(|node| is_single_line_ws(node))
-            .next()
-            .filter(|node| node.kind() == COMMA)
-    }
-
-    if let Some(comma_node) = nearby_comma(node, Direction::Prev) {
-        return Some(TextRange::from_to(comma_node.range().start(), node.range().end()));
-    }
-
-    if let Some(comma_node) = nearby_comma(node, Direction::Next) {
-        // Include any following whitespace when comma if after list item.
-        let final_node = comma_node
-            .siblings(Direction::Next)
-            .skip(1)
-            .next()
-            .filter(|node| is_single_line_ws(node))
-            .unwrap_or(comma_node);
-
-        return Some(TextRange::from_to(node.range().start(), final_node.range().end()));
-    }
-
-    return None;
-}
-
-fn extend_comments(node: &SyntaxNode) -> Option<TextRange> {
-    let prev = adj_comments(node, Direction::Prev);
-    let next = adj_comments(node, Direction::Next);
-    if prev != next {
-        Some(TextRange::from_to(prev.range().start(), next.range().end()))
-    } else {
-        None
-    }
-}
-
-fn adj_comments(node: &SyntaxNode, dir: Direction) -> &SyntaxNode {
-    let mut res = node;
-    for node in node.siblings(dir) {
-        match node.kind() {
-            COMMENT => res = node,
-            WHITESPACE if !node.leaf_text().unwrap().as_str().contains("\n\n") => (),
-            _ => break,
-        }
-    }
-    res
-}
-
-#[cfg(test)]
-mod tests {
-    use ra_syntax::{SourceFile, AstNode};
-    use test_utils::extract_offset;
-
-    use super::*;
-
-    fn do_check(before: &str, afters: &[&str]) {
-        let (cursor, before) = extract_offset(before);
-        let file = SourceFile::parse(&before);
-        let mut range = TextRange::offset_len(cursor, 0.into());
-        for &after in afters {
-            range = extend_selection(file.syntax(), range).unwrap();
-            let actual = &before[range];
-            assert_eq!(after, actual);
-        }
-    }
-
-    #[test]
-    fn test_extend_selection_arith() {
-        do_check(r#"fn foo() { <|>1 + 1 }"#, &["1", "1 + 1", "{ 1 + 1 }"]);
-    }
-
-    #[test]
-    fn test_extend_selection_list() {
-        do_check(r#"fn foo(<|>x: i32) {}"#, &["x", "x: i32"]);
-        do_check(r#"fn foo(<|>x: i32, y: i32) {}"#, &["x", "x: i32", "x: i32, "]);
-        do_check(r#"fn foo(<|>x: i32,y: i32) {}"#, &["x", "x: i32", "x: i32,"]);
-        do_check(r#"fn foo(x: i32, <|>y: i32) {}"#, &["y", "y: i32", ", y: i32"]);
-        do_check(r#"fn foo(x: i32, <|>y: i32, ) {}"#, &["y", "y: i32", ", y: i32"]);
-        do_check(r#"fn foo(x: i32,<|>y: i32) {}"#, &["y", "y: i32", ",y: i32"]);
-
-        do_check(r#"const FOO: [usize; 2] = [ 22<|> , 33];"#, &["22", "22 , "]);
-        do_check(r#"const FOO: [usize; 2] = [ 22 , 33<|>];"#, &["33", ", 33"]);
-        do_check(r#"const FOO: [usize; 2] = [ 22 , 33<|> ,];"#, &["33", ", 33"]);
-
-        do_check(
-            r#"
-const FOO: [usize; 2] = [
-    22,
-    <|>33,
-]"#,
-            &["33", "33,"],
-        );
-
-        do_check(
-            r#"
-const FOO: [usize; 2] = [
-    22
-    , 33<|>,
-]"#,
-            &["33", ", 33"],
-        );
-    }
-
-    #[test]
-    fn test_extend_selection_start_of_the_line() {
-        do_check(
-            r#"
-impl S {
-<|>    fn foo() {
-
-    }
-}"#,
-            &["    fn foo() {\n\n    }\n"],
-        );
-    }
-
-    #[test]
-    fn test_extend_selection_doc_comments() {
-        do_check(
-            r#"
-struct A;
-
-/// bla
-/// bla
-struct B {
-    <|>
-}
-            "#,
-            &["\n    \n", "{\n    \n}", "/// bla\n/// bla\nstruct B {\n    \n}"],
-        )
-    }
-
-    #[test]
-    fn test_extend_selection_comments() {
-        do_check(
-            r#"
-fn bar(){}
-
-// fn foo() {
-// 1 + <|>1
-// }
-
-// fn foo(){}
-    "#,
-            &["1", "// 1 + 1", "// fn foo() {\n// 1 + 1\n// }"],
-        );
-
-        do_check(
-            r#"
-// #[derive(Debug, Clone, Copy, PartialEq, Eq)]
-// pub enum Direction {
-//  <|>   Next,
-//     Prev
-// }
-"#,
-            &[
-                "//     Next,",
-                "// #[derive(Debug, Clone, Copy, PartialEq, Eq)]\n// pub enum Direction {\n//     Next,\n//     Prev\n// }",
-            ],
-        );
-
-        do_check(
-            r#"
-/*
-foo
-_bar1<|>*/
-    "#,
-            &["_bar1", "/*\nfoo\n_bar1*/"],
-        );
-
-        do_check(
-            r#"
-//!<|>foo_2 bar
-    "#,
-            &["foo_2", "//!foo_2 bar"],
-        );
-
-        do_check(
-            r#"
-/<|>/foo bar
-    "#,
-            &["//foo bar"],
-        );
-    }
-
-    #[test]
-    fn test_extend_selection_prefer_idents() {
-        do_check(
-            r#"
-fn main() { foo<|>+bar;}
-    "#,
-            &["foo", "foo+bar"],
-        );
-        do_check(
-            r#"
-fn main() { foo+<|>bar;}
-    "#,
-            &["bar", "foo+bar"],
-        );
-    }
-
-    #[test]
-    fn test_extend_selection_prefer_lifetimes() {
-        do_check(r#"fn foo<<|>'a>() {}"#, &["'a", "<'a>"]);
-        do_check(r#"fn foo<'a<|>>() {}"#, &["'a", "<'a>"]);
-    }
-
-    #[test]
-    fn test_extend_selection_select_first_word() {
-        do_check(r#"// foo bar b<|>az quxx"#, &["baz", "// foo bar baz quxx"]);
-        do_check(
-            r#"
-impl S {
-    fn foo() {
-        // hel<|>lo world
-    }
-}
-        "#,
-            &["hello", "// hello world"],
-        );
-    }
-
-    #[test]
-    fn test_extend_selection_string() {
-        do_check(
-            r#"
-fn bar(){}
-
-" fn f<|>oo() {"
-    "#,
-            &["foo", "\" fn foo() {\""],
-        );
-    }
-}
diff --git a/crates/ra_ide_api_light/src/lib.rs b/crates/ra_ide_api_light/src/lib.rs
index 43cdd6ea4..ca13eb018 100644
--- a/crates/ra_ide_api_light/src/lib.rs
+++ b/crates/ra_ide_api_light/src/lib.rs
@@ -3,7 +3,6 @@
 //! This usually means functions which take syntax tree as an input and produce
 //! an edit or some auxiliary info.
 
-mod extend_selection;
 mod folding_ranges;
 mod line_index;
 mod line_index_utils;
@@ -14,15 +13,16 @@ mod join_lines;
 mod typing;
 mod diagnostics;
 
-#[derive(Debug)]
-pub struct LocalEdit {
-    pub label: String,
-    pub edit: ra_text_edit::TextEdit,
-    pub cursor_position: Option<TextUnit>,
-}
+use rustc_hash::FxHashSet;
+use ra_text_edit::TextEditBuilder;
+use ra_syntax::{
+    SourceFile, SyntaxNode, TextRange, TextUnit, Direction,
+    algo::find_leaf_at_offset,
+    SyntaxKind::{self, *},
+    ast::{self, AstNode},
+};
 
-pub use self::{
-    extend_selection::extend_selection,
+pub use crate::{
     folding_ranges::{folding_ranges, Fold, FoldKind},
     line_index::{LineCol, LineIndex},
     line_index_utils::translate_offset_with_edit,
@@ -30,16 +30,14 @@ pub use self::{
     diagnostics::diagnostics,
     join_lines::join_lines,
     typing::{on_enter, on_dot_typed, on_eq_typed},
-
 };
-use ra_text_edit::TextEditBuilder;
-use ra_syntax::{
-    SourceFile, SyntaxNode, TextRange, TextUnit, Direction,
-    SyntaxKind::{self, *},
-    ast::{self, AstNode},
-    algo::find_leaf_at_offset,
-};
-use rustc_hash::FxHashSet;
+
+#[derive(Debug)]
+pub struct LocalEdit {
+    pub label: String,
+    pub edit: ra_text_edit::TextEdit,
+    pub cursor_position: Option<TextUnit>,
+}
 
 #[derive(Debug)]
 pub struct HighlightedRange {
diff --git a/crates/ra_parser/src/event.rs b/crates/ra_parser/src/event.rs
index 6361d5d86..c1773e8e0 100644
--- a/crates/ra_parser/src/event.rs
+++ b/crates/ra_parser/src/event.rs
@@ -105,7 +105,9 @@ pub(super) fn process(sink: &mut dyn TreeSink, mut events: Vec<Event>) {
                     // append `A`'s forward_parent `B`
                     fp = match mem::replace(&mut events[idx], Event::tombstone()) {
                         Event::Start { kind, forward_parent } => {
-                            forward_parents.push(kind);
+                            if kind != TOMBSTONE {
+                                forward_parents.push(kind);
+                            }
                             forward_parent
                         }
                         _ => unreachable!(),
diff --git a/crates/ra_parser/src/grammar/expressions.rs b/crates/ra_parser/src/grammar/expressions.rs
index 83812e938..73e1acd5a 100644
--- a/crates/ra_parser/src/grammar/expressions.rs
+++ b/crates/ra_parser/src/grammar/expressions.rs
@@ -8,10 +8,10 @@ const EXPR_FIRST: TokenSet = LHS_FIRST;
 
 pub(super) fn expr(p: &mut Parser) -> BlockLike {
     let r = Restrictions { forbid_structs: false, prefer_stmt: false };
-    expr_bp(p, r, 1)
+    expr_bp(p, r, 1).1
 }
 
-pub(super) fn expr_stmt(p: &mut Parser) -> BlockLike {
+pub(super) fn expr_stmt(p: &mut Parser) -> (Option<CompletedMarker>, BlockLike) {
     let r = Restrictions { forbid_structs: false, prefer_stmt: true };
     expr_bp(p, r, 1)
 }
@@ -38,6 +38,13 @@ pub(crate) fn block(p: &mut Parser) {
     m.complete(p, BLOCK);
 }
 
+fn is_expr_stmt_attr_allowed(kind: SyntaxKind) -> bool {
+    match kind {
+        BIN_EXPR | RANGE_EXPR | IF_EXPR => false,
+        _ => true,
+    }
+}
+
 pub(crate) fn expr_block_contents(p: &mut Parser) {
     // This is checked by a validator
     attributes::inner_attributes(p);
@@ -55,6 +62,13 @@ pub(crate) fn expr_block_contents(p: &mut Parser) {
         // test block_items
         // fn a() { fn b() {} }
         let m = p.start();
+        // test attr_on_expr_stmt
+        // fn foo() {
+        //     #[A] foo();
+        //     #[B] bar!{}
+        //     #[C] #[D] {}
+        //     #[D] return ();
+        // }
         let has_attrs = p.at(POUND);
         attributes::outer_attributes(p);
         if p.at(LET_KW) {
@@ -67,35 +81,51 @@ pub(crate) fn expr_block_contents(p: &mut Parser) {
             Err(m) => m,
         };
 
-        if has_attrs {
-            m.abandon(p);
-            p.error("expected a let statement or an item after attributes in block");
-        } else {
-            let is_blocklike = expressions::expr_stmt(p) == BlockLike::Block;
-            if p.at(R_CURLY) {
+        let (cm, blocklike) = expr_stmt(p);
+        let kind = cm.as_ref().map(|cm| cm.kind()).unwrap_or(ERROR);
+
+        if has_attrs && !is_expr_stmt_attr_allowed(kind) {
+            // test_err attr_on_expr_not_allowed
+            // fn foo() {
+            //    #[A] 1 + 2;
+            //    #[B] if true {};
+            // }
+            p.error(format!("attributes are not allowed on {:?}", kind));
+        }
+
+        if p.at(R_CURLY) {
+            // test attr_on_last_expr_in_block
+            // fn foo() {
+            //     { #[A] bar!()? }
+            //     #[B] &()
+            // }
+            if let Some(cm) = cm {
+                cm.undo_completion(p).abandon(p);
+                m.complete(p, kind);
+            } else {
                 m.abandon(p);
+            }
+        } else {
+            // test no_semi_after_block
+            // fn foo() {
+            //     if true {}
+            //     loop {}
+            //     match () {}
+            //     while true {}
+            //     for _ in () {}
+            //     {}
+            //     {}
+            //     macro_rules! test {
+            //          () => {}
+            //     }
+            //     test!{}
+            // }
+            if blocklike.is_block() {
+                p.eat(SEMI);
             } else {
-                // test no_semi_after_block
-                // fn foo() {
-                //     if true {}
-                //     loop {}
-                //     match () {}
-                //     while true {}
-                //     for _ in () {}
-                //     {}
-                //     {}
-                //     macro_rules! test {
-                //          () => {}
-                //     }
-                //     test!{}
-                // }
-                if is_blocklike {
-                    p.eat(SEMI);
-                } else {
-                    p.expect(SEMI);
-                }
-                m.complete(p, EXPR_STMT);
+                p.expect(SEMI);
             }
+            m.complete(p, EXPR_STMT);
         }
     }
 
@@ -176,7 +206,7 @@ fn current_op(p: &Parser) -> (u8, Op) {
 }
 
 // Parses expression with binding power of at least bp.
-fn expr_bp(p: &mut Parser, r: Restrictions, bp: u8) -> BlockLike {
+fn expr_bp(p: &mut Parser, r: Restrictions, bp: u8) -> (Option<CompletedMarker>, BlockLike) {
     let mut lhs = match lhs(p, r) {
         Some((lhs, blocklike)) => {
             // test stmt_bin_expr_ambiguity
@@ -185,11 +215,11 @@ fn expr_bp(p: &mut Parser, r: Restrictions, bp: u8) -> BlockLike {
             //     {1} &2;
             // }
             if r.prefer_stmt && blocklike.is_block() {
-                return BlockLike::Block;
+                return (Some(lhs), BlockLike::Block);
             }
             lhs
         }
-        None => return BlockLike::NotBlock,
+        None => return (None, BlockLike::NotBlock),
     };
 
     loop {
@@ -208,7 +238,7 @@ fn expr_bp(p: &mut Parser, r: Restrictions, bp: u8) -> BlockLike {
         expr_bp(p, r, op_bp + 1);
         lhs = m.complete(p, if is_range { RANGE_EXPR } else { BIN_EXPR });
     }
-    BlockLike::NotBlock
+    (Some(lhs), BlockLike::NotBlock)
 }
 
 const LHS_FIRST: TokenSet =
diff --git a/crates/ra_parser/src/grammar/expressions/atom.rs b/crates/ra_parser/src/grammar/expressions/atom.rs
index d933288cd..a23977bfb 100644
--- a/crates/ra_parser/src/grammar/expressions/atom.rs
+++ b/crates/ra_parser/src/grammar/expressions/atom.rs
@@ -392,9 +392,9 @@ fn match_arm(p: &mut Parser) -> BlockLike {
         match_guard(p);
     }
     p.expect(FAT_ARROW);
-    let ret = expr_stmt(p);
+    let blocklike = expr_stmt(p).1;
     m.complete(p, MATCH_ARM);
-    ret
+    blocklike
 }
 
 // test match_guard
diff --git a/crates/ra_parser/src/parser.rs b/crates/ra_parser/src/parser.rs
index a18458148..3c326452b 100644
--- a/crates/ra_parser/src/parser.rs
+++ b/crates/ra_parser/src/parser.rs
@@ -212,8 +212,9 @@ impl Marker {
             }
             _ => unreachable!(),
         }
+        let finish_pos = p.events.len() as u32;
         p.push_event(Event::Finish);
-        CompletedMarker::new(self.pos, kind)
+        CompletedMarker::new(self.pos, finish_pos, kind)
     }
 
     /// Abandons the syntax tree node. All its children
@@ -230,11 +231,15 @@ impl Marker {
     }
 }
 
-pub(crate) struct CompletedMarker(u32, SyntaxKind);
+pub(crate) struct CompletedMarker {
+    start_pos: u32,
+    finish_pos: u32,
+    kind: SyntaxKind,
+}
 
 impl CompletedMarker {
-    fn new(pos: u32, kind: SyntaxKind) -> Self {
-        CompletedMarker(pos, kind)
+    fn new(start_pos: u32, finish_pos: u32, kind: SyntaxKind) -> Self {
+        CompletedMarker { start_pos, finish_pos, kind }
     }
 
     /// This method allows to create a new node which starts
@@ -251,17 +256,32 @@ impl CompletedMarker {
     /// distance to `NEWSTART` into forward_parent(=2 in this case);
     pub(crate) fn precede(self, p: &mut Parser) -> Marker {
         let new_pos = p.start();
-        let idx = self.0 as usize;
+        let idx = self.start_pos as usize;
         match p.events[idx] {
             Event::Start { ref mut forward_parent, .. } => {
-                *forward_parent = Some(new_pos.pos - self.0);
+                *forward_parent = Some(new_pos.pos - self.start_pos);
             }
             _ => unreachable!(),
         }
         new_pos
     }
 
+    /// Undo this completion and turns into a `Marker`
+    pub(crate) fn undo_completion(self, p: &mut Parser) -> Marker {
+        let start_idx = self.start_pos as usize;
+        let finish_idx = self.finish_pos as usize;
+        match p.events[start_idx] {
+            Event::Start { ref mut kind, forward_parent: None } => *kind = TOMBSTONE,
+            _ => unreachable!(),
+        }
+        match p.events[finish_idx] {
+            ref mut slot @ Event::Finish => *slot = Event::tombstone(),
+            _ => unreachable!(),
+        }
+        Marker::new(self.start_pos)
+    }
+
     pub(crate) fn kind(&self) -> SyntaxKind {
-        self.1
+        self.kind
     }
 }
diff --git a/crates/ra_syntax/tests/data/parser/inline/err/0009_attr_on_expr_not_allowed.rs b/crates/ra_syntax/tests/data/parser/inline/err/0009_attr_on_expr_not_allowed.rs
new file mode 100644
index 000000000..d725a07ce
--- /dev/null
+++ b/crates/ra_syntax/tests/data/parser/inline/err/0009_attr_on_expr_not_allowed.rs
@@ -0,0 +1,4 @@
+fn foo() {
+   #[A] 1 + 2;
+   #[B] if true {};
+}
diff --git a/crates/ra_syntax/tests/data/parser/inline/err/0009_attr_on_expr_not_allowed.txt b/crates/ra_syntax/tests/data/parser/inline/err/0009_attr_on_expr_not_allowed.txt
new file mode 100644
index 000000000..fdea1ec1e
--- /dev/null
+++ b/crates/ra_syntax/tests/data/parser/inline/err/0009_attr_on_expr_not_allowed.txt
@@ -0,0 +1,55 @@
+SOURCE_FILE@[0; 48)
+  FN_DEF@[0; 47)
+    FN_KW@[0; 2)
+    WHITESPACE@[2; 3)
+    NAME@[3; 6)
+      IDENT@[3; 6) "foo"
+    PARAM_LIST@[6; 8)
+      L_PAREN@[6; 7)
+      R_PAREN@[7; 8)
+    WHITESPACE@[8; 9)
+    BLOCK@[9; 47)
+      L_CURLY@[9; 10)
+      WHITESPACE@[10; 14)
+      EXPR_STMT@[14; 25)
+        ATTR@[14; 18)
+          POUND@[14; 15)
+          TOKEN_TREE@[15; 18)
+            L_BRACK@[15; 16)
+            IDENT@[16; 17) "A"
+            R_BRACK@[17; 18)
+        WHITESPACE@[18; 19)
+        BIN_EXPR@[19; 24)
+          LITERAL@[19; 20)
+            INT_NUMBER@[19; 20) "1"
+          WHITESPACE@[20; 21)
+          PLUS@[21; 22)
+          WHITESPACE@[22; 23)
+          LITERAL@[23; 24)
+            INT_NUMBER@[23; 24) "2"
+            err: `attributes are not allowed on BIN_EXPR`
+        SEMI@[24; 25)
+      WHITESPACE@[25; 29)
+      EXPR_STMT@[29; 45)
+        ATTR@[29; 33)
+          POUND@[29; 30)
+          TOKEN_TREE@[30; 33)
+            L_BRACK@[30; 31)
+            IDENT@[31; 32) "B"
+            R_BRACK@[32; 33)
+        WHITESPACE@[33; 34)
+        IF_EXPR@[34; 44)
+          IF_KW@[34; 36)
+          WHITESPACE@[36; 37)
+          CONDITION@[37; 41)
+            LITERAL@[37; 41)
+              TRUE_KW@[37; 41)
+          WHITESPACE@[41; 42)
+          BLOCK@[42; 44)
+            L_CURLY@[42; 43)
+            R_CURLY@[43; 44)
+            err: `attributes are not allowed on IF_EXPR`
+        SEMI@[44; 45)
+      WHITESPACE@[45; 46)
+      R_CURLY@[46; 47)
+  WHITESPACE@[47; 48)
diff --git a/crates/ra_syntax/tests/data/parser/inline/ok/0126_attr_on_expr_stmt.rs b/crates/ra_syntax/tests/data/parser/inline/ok/0126_attr_on_expr_stmt.rs
new file mode 100644
index 000000000..b28c078f9
--- /dev/null
+++ b/crates/ra_syntax/tests/data/parser/inline/ok/0126_attr_on_expr_stmt.rs
@@ -0,0 +1,6 @@
+fn foo() {
+    #[A] foo();
+    #[B] bar!{}
+    #[C] #[D] {}
+    #[D] return ();
+}
diff --git a/crates/ra_syntax/tests/data/parser/inline/ok/0126_attr_on_expr_stmt.txt b/crates/ra_syntax/tests/data/parser/inline/ok/0126_attr_on_expr_stmt.txt
new file mode 100644
index 000000000..7cd525cc7
--- /dev/null
+++ b/crates/ra_syntax/tests/data/parser/inline/ok/0126_attr_on_expr_stmt.txt
@@ -0,0 +1,88 @@
+SOURCE_FILE@[0; 82)
+  FN_DEF@[0; 81)
+    FN_KW@[0; 2)
+    WHITESPACE@[2; 3)
+    NAME@[3; 6)
+      IDENT@[3; 6) "foo"
+    PARAM_LIST@[6; 8)
+      L_PAREN@[6; 7)
+      R_PAREN@[7; 8)
+    WHITESPACE@[8; 9)
+    BLOCK@[9; 81)
+      L_CURLY@[9; 10)
+      WHITESPACE@[10; 15)
+      EXPR_STMT@[15; 26)
+        ATTR@[15; 19)
+          POUND@[15; 16)
+          TOKEN_TREE@[16; 19)
+            L_BRACK@[16; 17)
+            IDENT@[17; 18) "A"
+            R_BRACK@[18; 19)
+        WHITESPACE@[19; 20)
+        CALL_EXPR@[20; 25)
+          PATH_EXPR@[20; 23)
+            PATH@[20; 23)
+              PATH_SEGMENT@[20; 23)
+                NAME_REF@[20; 23)
+                  IDENT@[20; 23) "foo"
+          ARG_LIST@[23; 25)
+            L_PAREN@[23; 24)
+            R_PAREN@[24; 25)
+        SEMI@[25; 26)
+      WHITESPACE@[26; 31)
+      EXPR_STMT@[31; 42)
+        ATTR@[31; 35)
+          POUND@[31; 32)
+          TOKEN_TREE@[32; 35)
+            L_BRACK@[32; 33)
+            IDENT@[33; 34) "B"
+            R_BRACK@[34; 35)
+        WHITESPACE@[35; 36)
+        MACRO_CALL@[36; 42)
+          PATH@[36; 39)
+            PATH_SEGMENT@[36; 39)
+              NAME_REF@[36; 39)
+                IDENT@[36; 39) "bar"
+          EXCL@[39; 40)
+          TOKEN_TREE@[40; 42)
+            L_CURLY@[40; 41)
+            R_CURLY@[41; 42)
+      WHITESPACE@[42; 47)
+      EXPR_STMT@[47; 59)
+        ATTR@[47; 51)
+          POUND@[47; 48)
+          TOKEN_TREE@[48; 51)
+            L_BRACK@[48; 49)
+            IDENT@[49; 50) "C"
+            R_BRACK@[50; 51)
+        WHITESPACE@[51; 52)
+        ATTR@[52; 56)
+          POUND@[52; 53)
+          TOKEN_TREE@[53; 56)
+            L_BRACK@[53; 54)
+            IDENT@[54; 55) "D"
+            R_BRACK@[55; 56)
+        WHITESPACE@[56; 57)
+        BLOCK_EXPR@[57; 59)
+          BLOCK@[57; 59)
+            L_CURLY@[57; 58)
+            R_CURLY@[58; 59)
+      WHITESPACE@[59; 64)
+      EXPR_STMT@[64; 79)
+        ATTR@[64; 68)
+          POUND@[64; 65)
+          TOKEN_TREE@[65; 68)
+            L_BRACK@[65; 66)
+            IDENT@[66; 67) "D"
+            R_BRACK@[67; 68)
+        WHITESPACE@[68; 69)
+        RETURN_EXPR@[69; 78)
+          RETURN_KW@[69; 75)
+          WHITESPACE@[75; 76)
+          TUPLE_EXPR@[76; 78)
+            L_PAREN@[76; 77)
+            R_PAREN@[77; 78)
+        SEMI@[78; 79)
+      WHITESPACE@[79; 80)
+      R_CURLY@[80; 81)
+  WHITESPACE@[81; 82)
diff --git a/crates/ra_syntax/tests/data/parser/inline/ok/0127_attr_on_last_expr_in_block.rs b/crates/ra_syntax/tests/data/parser/inline/ok/0127_attr_on_last_expr_in_block.rs
new file mode 100644
index 000000000..9c5c8eb36
--- /dev/null
+++ b/crates/ra_syntax/tests/data/parser/inline/ok/0127_attr_on_last_expr_in_block.rs
@@ -0,0 +1,4 @@
+fn foo() {
+    { #[A] bar!()? }
+    #[B] &()
+}
diff --git a/crates/ra_syntax/tests/data/parser/inline/ok/0127_attr_on_last_expr_in_block.txt b/crates/ra_syntax/tests/data/parser/inline/ok/0127_attr_on_last_expr_in_block.txt
new file mode 100644
index 000000000..4af64559c
--- /dev/null
+++ b/crates/ra_syntax/tests/data/parser/inline/ok/0127_attr_on_last_expr_in_block.txt
@@ -0,0 +1,54 @@
+SOURCE_FILE@[0; 47)
+  FN_DEF@[0; 46)
+    FN_KW@[0; 2)
+    WHITESPACE@[2; 3)
+    NAME@[3; 6)
+      IDENT@[3; 6) "foo"
+    PARAM_LIST@[6; 8)
+      L_PAREN@[6; 7)
+      R_PAREN@[7; 8)
+    WHITESPACE@[8; 9)
+    BLOCK@[9; 46)
+      L_CURLY@[9; 10)
+      WHITESPACE@[10; 15)
+      EXPR_STMT@[15; 31)
+        BLOCK_EXPR@[15; 31)
+          BLOCK@[15; 31)
+            L_CURLY@[15; 16)
+            WHITESPACE@[16; 17)
+            TRY_EXPR@[17; 29)
+              ATTR@[17; 21)
+                POUND@[17; 18)
+                TOKEN_TREE@[18; 21)
+                  L_BRACK@[18; 19)
+                  IDENT@[19; 20) "A"
+                  R_BRACK@[20; 21)
+              WHITESPACE@[21; 22)
+              MACRO_CALL@[22; 28)
+                PATH@[22; 25)
+                  PATH_SEGMENT@[22; 25)
+                    NAME_REF@[22; 25)
+                      IDENT@[22; 25) "bar"
+                EXCL@[25; 26)
+                TOKEN_TREE@[26; 28)
+                  L_PAREN@[26; 27)
+                  R_PAREN@[27; 28)
+              QUESTION@[28; 29)
+            WHITESPACE@[29; 30)
+            R_CURLY@[30; 31)
+      WHITESPACE@[31; 36)
+      REF_EXPR@[36; 44)
+        ATTR@[36; 40)
+          POUND@[36; 37)
+          TOKEN_TREE@[37; 40)
+            L_BRACK@[37; 38)
+            IDENT@[38; 39) "B"
+            R_BRACK@[39; 40)
+        WHITESPACE@[40; 41)
+        AMP@[41; 42)
+        TUPLE_EXPR@[42; 44)
+          L_PAREN@[42; 43)
+          R_PAREN@[43; 44)
+      WHITESPACE@[44; 45)
+      R_CURLY@[45; 46)
+  WHITESPACE@[46; 47)
diff --git a/docs/dev/README.md b/docs/dev/README.md
new file mode 100644
index 000000000..ac7f4fd71
--- /dev/null
+++ b/docs/dev/README.md
@@ -0,0 +1,124 @@
+# Contributing Quick Start
+
+Rust Analyzer is just a usual rust project, which is organized as a Cargo
+workspace, builds on stable and doesn't depend on C libraries. So, just
+
+```
+$ cargo test
+```
+
+should be enough to get you started!
+
+To learn more about how rust-analyzer works, see
+[./architecture.md](./architecture.md) document.
+
+Various organizational and process issues are discussed here.
+
+# Getting in Touch
+
+Rust Analyzer is a part of [RLS-2.0 working
+group](https://github.com/rust-lang/compiler-team/tree/6a769c13656c0a6959ebc09e7b1f7c09b86fb9c0/working-groups/rls-2.0).
+Discussion happens in this Zulip stream:
+
+https://rust-lang.zulipchat.com/#narrow/stream/185405-t-compiler.2Fwg-rls-2.2E0
+
+# Issue Labels
+
+* [good-first-issue](https://github.com/rust-analyzer/rust-analyzer/labels/good%20first%20issue)
+  are good issues to get into the project.
+* [E-mentor](https://github.com/rust-analyzer/rust-analyzer/issues?q=is%3Aopen+is%3Aissue+label%3AE-mentor)
+  issues have links to the code in question and tests.
+* [E-easy](https://github.com/rust-analyzer/rust-analyzer/issues?q=is%3Aopen+is%3Aissue+label%3AE-easy),
+  [E-medium](https://github.com/rust-analyzer/rust-analyzer/issues?q=is%3Aopen+is%3Aissue+label%3AE-medium),
+  [E-hard](https://github.com/rust-analyzer/rust-analyzer/issues?q=is%3Aopen+is%3Aissue+label%3AE-hard),
+  labels are *estimates* for how hard would be to write a fix.
+* [E-fun](https://github.com/rust-analyzer/rust-analyzer/issues?q=is%3Aopen+is%3Aissue+label%3AE-fun)
+  is for cool, but probably hard stuff.
+
+# CI
+
+We use Travis for CI. Most of the things, including formatting, are checked by
+`cargo test` so, if `cargo test` passes locally, that's a good sign that CI will
+be green as well. We use bors-ng to enforce the [not rocket
+science](https://graydon2.dreamwidth.org/1597.html) rule.
+
+You can run `cargo format-hook` to install git-hook to run rustfmt on commit.
+
+# Code organization
+
+All Rust code lives in the `crates` top-level directory, and is organized as a
+single Cargo workspace. The `editors` top-level directory contains code for
+integrating with editors. Currently, it contains plugins for VS Code (in
+typescript) and Emacs (in elisp). The `docs` top-level directory contains both
+developer and user documentation.
+
+We have some automation infra in Rust in the `crates/tool` package. It contains
+stuff like formatting checking, code generation and powers `cargo install-code`.
+The latter syntax is achieved with the help of cargo aliases (see `.cargo`
+directory).
+
+# Launching rust-analyzer
+
+Debugging language server can be tricky: LSP is rather chatty, so driving it
+from the command line is not really feasible, driving it via VS Code requires
+interacting with two processes.
+
+For this reason, the best way to see how rust-analyzer works is to find a
+relevant test and execute it (VS Code includes an action for running a single
+test).
+
+However, launching a VS Code instance with locally build language server is
+possible. There's even a VS Code task for this, so just <kbd>F5</kbd> should
+work (thanks, [@andrew-w-ross](https://github.com/andrew-w-ross)!).
+
+I often just install development version with `cargo jinstall-lsp` and
+restart the host VS Code.
+
+See [./debugging.md](./debugging.md) for how to attach to rust-analyzer with
+debugger, and don't forget that rust-analyzer has useful `pd` snippet and `dbg`
+postfix completion for printf debugging :-)
+
+# Working With VS Code Extension
+
+To work on the VS Code extension, launch code inside `editors/code` and use `F5`
+to launch/debug. To automatically apply formatter and linter suggestions, use
+`npm run fix`.
+
+# Logging
+
+Logging is done by both rust-analyzer and VS Code, so it might be tricky to
+figure out where logs go.
+
+Inside rust-analyzer, we use the standard `log` crate for logging, and
+`flexi_logger` for logging frotend. By default, log goes to stderr (the same as
+with `env_logger`), but the stderr itself is processed by VS Code. To mirror
+logs to a `./log` directory, set `RA_INTERNAL_MODE=1` environmental variable.
+
+To see stderr in the running VS Code instance, go to the "Output" tab of the
+panel and select `rust-analyzer`. This shows `eprintln!` as well. Note that
+`stdout` is used for the actual protocol, so `println!` will break things.
+
+To log all communication between the server and the client, there are two choices:
+
+* you can log on the server side, by running something like
+  ```
+  env RUST_LOG=gen_lsp_server=trace code .
+  ```
+
+* you can log on the client side, by enabling `"rust-analyzer.trace.server":
+  "verbose"` workspace setting. These logs are shown in a separate tab in the
+  output and could be used with LSP inspector. Kudos to
+  [@DJMcNab](https://github.com/DJMcNab) for setting this awesome infra up!
+
+
+There's also two VS Code commands which might be of interest:
+
+* `Rust Analyzer: Status` shows some memory-usage statistics. To take full
+  advantage of it, you need to compile rust-analyzer with jemalloc support:
+  ```
+  $ cargo install --path crates/ra_lsp_server --force --features jemalloc
+  ```
+
+  There's an alias for this: `cargo jinstall-lsp`.
+
+* `Rust Analyzer: Syntax Tree` shows syntax tree of the current file/selection.
diff --git a/ARCHITECTURE.md b/docs/dev/architecture.md
index 57f76ebae..f990d5bf0 100644
--- a/ARCHITECTURE.md
+++ b/docs/dev/architecture.md
@@ -7,8 +7,10 @@ in the right place!
 See also the [guide](./guide.md), which walks through a particular snapshot of
 rust-analyzer code base.
 
-For syntax-trees specifically, there's a [video walk
-through](https://youtu.be/DGAuLWdCCAI) as well.
+Yet another resource is this playlist with videos about various parts of the
+analyzer:
+
+https://www.youtube.com/playlist?list=PL85XCvVPmGQho7MZkdW-wtPtuJcFpzycE
 
 ## The Big Picture
 
@@ -61,7 +63,7 @@ processes. These are outlined below:
 
 ## Code Walk-Through
 
-### `crates/ra_syntax`
+### `crates/ra_syntax`, `crates/ra_parser`
 
 Rust syntax tree structure and parser. See
 [RFC](https://github.com/rust-lang/rfcs/pull/2256) for some design notes.
@@ -145,12 +147,14 @@ throughout its modules.
 
 An LSP implementation which wraps `ra_ide_api` into a langauge server protocol.
 
-### `crates/ra_vfs`
+### `ra_vfs`
 
 Although `hir` and `ra_ide_api` don't do any IO, we need to be able to read
 files from disk at the end of the day. This is what `ra_vfs` does. It also
 manages overlays: "dirty" files in the editor, whose "true" contents is
-different from data on disk.
+different from data on disk. This is more or less the single really
+platform-dependent component, so it lives in a separate repository and has an
+extensive cross-platform CI testing.
 
 ### `crates/gen_lsp_server`
 
@@ -164,37 +168,32 @@ Run with `RUST_LOG=sync_lsp_server=debug` to see all the messages.
 
 A CLI interface to rust-analyzer.
 
-### `crate/tools`
-
-Custom Cargo tasks used to develop rust-analyzer:
-
-- `cargo gen-syntax` -- generate `ast` and `syntax_kinds`
-- `cargo gen-tests` -- collect inline tests from grammar
-- `cargo install-code` -- build and install VS Code extension and server
-
-### `editors/code`
-
-VS Code plugin
 
+## Testing Infrastructure
 
-## Common workflows
+Rust Analyzer has three interesting [systems
+boundaries](https://www.tedinski.com/2018/04/10/making-tests-a-positive-influence-on-design.html)
+to concentrate tests on.
 
-To try out VS Code extensions, run `cargo install-code`.  This installs both the
-`ra_lsp_server` binary and the VS Code extension. To install only the binary, use
-`cargo install-lsp` (shorthand for `cargo install --path crates/ra_lsp_server --force`)
+The outermost boundary is the `ra_lsp_server` crate, which defines an LSP
+interface in terms of stdio. We do integration testing of this component, by
+feeding it with a stream of LSP requests and checking responses. These tests are
+known as "heavy", because they interact with Cargo and read real files from
+disk. For this reason, we try to avoid writing too many tests on this boundary:
+in a statically typed language, it's hard to make an error in the protocol
+itself if messages are themselves typed.
 
-To see logs from the language server, set `RUST_LOG=info` env variable. To see
-all communication between the server and the client, use
-`RUST_LOG=gen_lsp_server=debug` (this will print quite a bit of stuff).
+The middle, and most important, boundary is `ra_ide_api`. Unlike
+`ra_lsp_server`, which exposes API, `ide_api` uses Rust API and is intended to
+use by various tools. Typical test creates an `AnalysisHost`, calls some
+`Analysis` functions and compares the results against expectation.
 
-There's `rust-analyzer: status` command which prints common high-level debug
-info. In particular, it prints info about memory usage of various data
-structures, and, if compiled with jemalloc support (`cargo jinstall-lsp` or 
-`cargo install --path crates/ra_lsp_server --force --features jemalloc`), includes
- statistic about the heap.
+The innermost and most elaborate boundary is `hir`. It has a much richer
+vocabulary of types than `ide_api`, but the basic testing setup is the same: we
+create a database, run some queries, assert result.
 
-To run tests, just `cargo test`.
+For comparisons, we use [insta](https://github.com/mitsuhiko/insta/) library for
+snapshot testing.
 
-To work on the VS Code extension, launch code inside `editors/code` and use `F5` to
-launch/debug. To automatically apply formatter and linter suggestions, use `npm
-run fix`.
+To test various analysis corner cases and avoid forgetting about old tests, we
+use so-called marks. See the `marks` module in the `test_utils` crate for more.
diff --git a/DEBUGGING.md b/docs/dev/debugging.md
index f868e6998..f868e6998 100644
--- a/DEBUGGING.md
+++ b/docs/dev/debugging.md
diff --git a/guide.md b/docs/dev/guide.md
index abbe4c154..abbe4c154 100644
--- a/guide.md
+++ b/docs/dev/guide.md
diff --git a/docs/dev/lsp-features.md b/docs/dev/lsp-features.md
new file mode 100644
index 000000000..212d132ee
--- /dev/null
+++ b/docs/dev/lsp-features.md
@@ -0,0 +1,74 @@
+# Supported LSP features
+
+This list documents LSP features, supported by rust-analyzer.
+
+## General
+- [x] [initialize](https://microsoft.github.io/language-server-protocol/specification#initialize)
+- [x] [initialized](https://microsoft.github.io/language-server-protocol/specification#initialized)
+- [x] [shutdown](https://microsoft.github.io/language-server-protocol/specification#shutdown)
+- [ ] [exit](https://microsoft.github.io/language-server-protocol/specification#exit)
+- [x] [$/cancelRequest](https://microsoft.github.io/language-server-protocol/specification#cancelRequest)
+
+## Workspace
+- [ ] [workspace/workspaceFolders](https://microsoft.github.io/language-server-protocol/specification#workspace_workspaceFolders)
+- [ ] [workspace/didChangeWorkspaceFolders](https://microsoft.github.io/language-server-protocol/specification#workspace_didChangeWorkspaceFolders)
+- [x] [workspace/didChangeConfiguration](https://microsoft.github.io/language-server-protocol/specification#workspace_didChangeConfiguration)
+- [ ] [workspace/configuration](https://microsoft.github.io/language-server-protocol/specification#workspace_configuration)
+- [x] [workspace/didChangeWatchedFiles](https://microsoft.github.io/language-server-protocol/specification#workspace_didChangeWatchedFiles)
+- [x] [workspace/symbol](https://microsoft.github.io/language-server-protocol/specification#workspace_symbol)
+- [x] [workspace/executeCommand](https://microsoft.github.io/language-server-protocol/specification#workspace_executeCommand)
+ - `apply_code_action`
+- [ ] [workspace/applyEdit](https://microsoft.github.io/language-server-protocol/specification#workspace_applyEdit)
+
+## Text Synchronization
+- [x] [textDocument/didOpen](https://microsoft.github.io/language-server-protocol/specification#textDocument_didOpen)
+- [x] [textDocument/didChange](https://microsoft.github.io/language-server-protocol/specification#textDocument_didChange)
+- [ ] [textDocument/willSave](https://microsoft.github.io/language-server-protocol/specification#textDocument_willSave)
+- [ ] [textDocument/willSaveWaitUntil](https://microsoft.github.io/language-server-protocol/specification#textDocument_willSaveWaitUntil)
+- [x] [textDocument/didSave](https://microsoft.github.io/language-server-protocol/specification#textDocument_didSave)
+- [x] [textDocument/didClose](https://microsoft.github.io/language-server-protocol/specification#textDocument_didClose)
+
+## Diagnostics
+- [x] [textDocument/publishDiagnostics](https://microsoft.github.io/language-server-protocol/specification#textDocument_publishDiagnostics)
+
+## Lanuguage Features
+- [x] [textDocument/completion](https://microsoft.github.io/language-server-protocol/specification#textDocument_completion)
+ - open close: false
+ - change: Full
+ - will save: false
+ - will save wait until: false
+ - save: false
+- [x] [completionItem/resolve](https://microsoft.github.io/language-server-protocol/specification#completionItem_resolve)
+ - resolve provider: none
+ - trigger characters: `:`, `.`
+- [x] [textDocument/hover](https://microsoft.github.io/language-server-protocol/specification#textDocument_hover)
+- [x] [textDocument/signatureHelp](https://microsoft.github.io/language-server-protocol/specification#textDocument_signatureHelp)
+ - trigger characters: `(`,  `,`,  `)`
+- [ ] [textDocument/declaration](https://microsoft.github.io/language-server-protocol/specification#textDocument_declaration)
+- [x] [textDocument/definition](https://microsoft.github.io/language-server-protocol/specification#textDocument_definition)
+- [ ] [textDocument/typeDefinition](https://microsoft.github.io/language-server-protocol/specification#textDocument_typeDefinition)
+- [x] [textDocument/implementation](https://microsoft.github.io/language-server-protocol/specification#textDocument_implementation)
+- [x] [textDocument/references](https://microsoft.github.io/language-server-protocol/specification#textDocument_references)
+- [x] [textDocument/documentHighlight](https://microsoft.github.io/language-server-protocol/specification#textDocument_documentHighlight)
+- [x] [textDocument/documentSymbol](https://microsoft.github.io/language-server-protocol/specification#textDocument_documentSymbol)
+- [x] [textDocument/codeAction](https://microsoft.github.io/language-server-protocol/specification#textDocument_codeAction)
+ - rust-analyzer.syntaxTree
+ - rust-analyzer.extendSelection
+ - rust-analyzer.matchingBrace
+ - rust-analyzer.parentModule
+ - rust-analyzer.joinLines
+ - rust-analyzer.run
+ - rust-analyzer.analyzerStatus
+- [x] [textDocument/codeLens](https://microsoft.github.io/language-server-protocol/specification#textDocument_codeLens)
+- [ ] [textDocument/documentLink](https://microsoft.github.io/language-server-protocol/specification#codeLens_resolve)
+- [ ] [documentLink/resolve](https://microsoft.github.io/language-server-protocol/specification#documentLink_resolve)
+- [ ] [textDocument/documentColor](https://microsoft.github.io/language-server-protocol/specification#textDocument_documentColor)
+- [ ] [textDocument/colorPresentation](https://microsoft.github.io/language-server-protocol/specification#textDocument_colorPresentation)
+- [x] [textDocument/formatting](https://microsoft.github.io/language-server-protocol/specification#textDocument_formatting)
+- [ ] [textDocument/rangeFormatting](https://microsoft.github.io/language-server-protocol/specification#textDocument_rangeFormatting)
+- [x] [textDocument/onTypeFormatting](https://microsoft.github.io/language-server-protocol/specification#textDocument_onTypeFormatting)
+ - first trigger character: `=`
+ - more trigger character `.`
+- [x] [textDocument/rename](https://microsoft.github.io/language-server-protocol/specification#textDocument_rename)
+- [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)
diff --git a/docs/user/README.md b/docs/user/README.md
new file mode 100644
index 000000000..439c4e6ae
--- /dev/null
+++ b/docs/user/README.md
@@ -0,0 +1,77 @@
+The main interface to rust-analyzer is the
+[LSP](https://microsoft.github.io/language-server-protocol/) implementation. To
+install lsp server, use `cargo install-lsp`, which is a shorthand for `cargo
+install --package ra_lsp_server`. The binary is named `ra_lsp_server`, you
+should be able to use it with any LSP-compatible editor. We use custom
+extensions to LSP, so special client-side support is required to take full
+advantage of rust-analyzer. This repository contains support code for VS Code
+and Emacs.
+
+Rust Analyzer needs sources of rust standard library to work, so you might need
+to execute
+
+```
+$ rustup component add rust-src
+```
+
+See [./features.md](./features.md) document for a list of features that are available.
+
+## VS Code
+
+Prerequisites:
+
+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:
+
+```
+$ git clone https://github.com/rust-analyzer/rust-analyzer.git --depth 1
+$ cd rust-analyzer
+$ cargo install-code
+```
+
+This will run `cargo install --package ra_lsp_server` to install the server
+binary into `~/.cargo/bin`, and then will build and install plugin from
+`editors/code`. See
+[this](https://github.com/rust-analyzer/rust-analyzer/blob/69ee5c9c5ef212f7911028c9ddf581559e6565c3/crates/tools/src/main.rs#L37-L56)
+for details. The installation is expected to *just work*, if it doesn't, report
+bugs!
+
+It's better to remove existing Rust plugins to avoid interference.
+
+Beyond basic LSP features, there are some extension commands which you can
+invoke via <kbd>Ctrl+Shift+P</kbd> or bind to a shortcut. See [./features.md](./features.md)
+for details.
+
+### Settings
+
+* `rust-analyzer.highlightingOn`: enables experimental syntax highlighting
+* `rust-analyzer.showWorkspaceLoadedNotification`: to ease troubleshooting, a
+  notification is shown by default when a workspace is loaded
+* `rust-analyzer.enableEnhancedTyping`: by default, rust-analyzer intercepts
+  `Enter` key to make it easier to continue comments
+* `rust-analyzer.raLspServerPath`: path to `ra_lsp_server` executable
+* `rust-analyzer.enableCargoWatchOnStartup`: prompt to install & enable `cargo
+  watch` for live error highlighting (note, this **does not** use rust-analyzer)
+* `rust-analyzer.trace.server`: enables internal logging
+
+
+## Emacs
+
+Prerequisites:
+
+`emacs-lsp`, `dash` and `ht` packages.
+
+Installation:
+
+* add
+[ra-emacs-lsp.el](https://github.com/rust-analyzer/rust-analyzer/blob/69ee5c9c5ef212f7911028c9ddf581559e6565c3/editors/emacs/ra-emacs-lsp.el)
+to load path and require it in `init.el`
+* run `lsp` in a rust buffer
+* (Optionally) bind commands like `rust-analyzer-join-lines` or `rust-analyzer-extend-selection` to keys
diff --git a/docs/user/features.md b/docs/user/features.md
new file mode 100644
index 000000000..b9d2aa84f
--- /dev/null
+++ b/docs/user/features.md
@@ -0,0 +1,359 @@
+This documents is an index of features that rust-analyzer language server
+provides. Shortcuts are for the default VS Code layout. If there's no shortcut,
+you can use <kbd>Ctrl+Shift+P</kbd> to search for the corresponding action.
+
+### Workspace Symbol <kbd>ctrl+t</kbd>
+
+Uses fuzzy-search to find types, modules and function by name across your
+project and dependencies. This **the** most useful feature, which improves code
+navigation tremendously. It mostly works on top of the built-in LSP
+functionality, however `#` and `*` symbols can be used to narrow down the
+search. Specifically,
+
+- `Foo` searches for `Foo` type in the current workspace
+- `foo#` searches for `foo` function in the current workspace
+- `Foo*` searches for `Foo` type among dependencies, excluding `stdlib`
+- `foo#*` searches for `foo` function among dependencies.
+
+That is, `#` switches from "types" to all symbols, `*` switches from the current
+workspace to dependencies.
+
+### Document Symbol <kbd>ctrl+shift+o</kbd>
+
+Provides a tree of the symbols defined in the file. Can be used to
+
+* fuzzy search symbol in a file (super useful)
+* draw breadcrumbs to describe the context around the cursor
+* draw outline of the file
+
+### On Typing Assists
+
+Some features trigger on typing certain characters:
+
+- typing `let =` tries to smartly add `;` if `=` is followed by an existing expression.
+- Enter inside comments automatically inserts `///`
+- typing `.` in a chain method call auto-indents
+
+### Commands <kbd>ctrl+shift+p</kbd>
+
+#### Extend Selection
+
+Extends the current selection to the encompassing syntactic construct
+(expression, statement, item, module, etc). It works with multiple cursors. Do
+bind this command to a key, it's super-useful! Expected to be upstreamed to LSP
+soonish: https://github.com/Microsoft/language-server-protocol/issues/613
+
+#### Run
+
+Shows popup suggesting to run a test/benchmark/binary **at the current cursor
+location**. Super useful for repeatedly running just a single test. Do bind this
+to a shortcut!
+
+#### Parent Module
+
+Navigates to the parent module of the current module.
+
+#### Matching Brace
+
+If the cursor is on any brace (`<>(){}[]`) which is a part of a brace-pair,
+moves cursor to the matching brace. It uses the actual parser to determine
+braces, so it won't confuse generics with comparisons.
+
+#### Join Lines
+
+Join selected lines into one, smartly fixing up whitespace and trailing commas.
+
+#### Show Syntax Tree
+
+Shows the parse tree of the current file. It exists mostly for debugging
+rust-analyzer itself.
+
+#### Status
+
+Shows internal statistic about memory usage of rust-analyzer
+
+#### Run garbage collection
+
+Manually triggers GC
+
+### Code Actions (Assists)
+
+These are triggered in a particular context via light bulb. We use custom code on
+the VS Code side to be able to position cursor. `<|>` signifies cursor
+
+- Add `#[derive]`
+
+```rust
+// before:
+struct Foo {
+    <|>x: i32
+}
+// after:
+#[derive(<|>)]
+struct Foo {
+    x: i32
+}
+```
+
+- Add `impl`
+
+```rust
+// before:
+struct Foo<'a, T: Debug> {
+    <|>t: T
+}
+// after:
+struct Foo<'a, T: Debug> {
+    t: T
+}
+
+impl<'a, T: Debug> Foo<'a, T> {
+    <|>
+}
+```
+
+- Add missing `impl` members
+
+```rust
+// before:
+trait Foo {
+    fn foo(&self);
+    fn bar(&self);
+    fn baz(&self);
+}
+
+struct S;
+
+impl Foo for S {
+    fn bar(&self) {}
+    <|>
+}
+
+// after:
+trait Foo {
+    fn foo(&self);
+    fn bar(&self);
+    fn baz(&self);
+}
+
+struct S;
+
+impl Foo for S {
+    fn bar(&self) {}
+    fn foo(&self) { unimplemented!() }
+    fn baz(&self) { unimplemented!() }<|>
+}
+```
+
+- Import path
+
+```rust
+// before:
+impl std::fmt::Debug<|> for Foo {
+}
+
+// after:
+use std::fmt::Debug;
+
+impl Debug<|> for Foo {
+}
+```
+
+- Change Visibility
+
+```rust
+// before:
+<|>fn foo() {}
+
+// after:
+<|>pub(crate) fn foo() {}
+
+// after:
+<|>pub fn foo() {}
+```
+
+- Fill match arms
+
+```rust
+// before:
+enum A {
+    As,
+    Bs,
+    Cs(String),
+    Ds(String, String),
+    Es{x: usize, y: usize}
+}
+
+fn main() {
+    let a = A::As;
+    match a<|> {}
+}
+
+// after:
+enum A {
+    As,
+    Bs,
+    Cs(String),
+    Ds(String, String),
+    Es{x: usize, y: usize}
+}
+
+fn main() {
+    let a = A::As;
+    match <|>a {
+        A::As => (),
+        A::Bs => (),
+        A::Cs(_) => (),
+        A::Ds(_, _) => (),
+        A::Es{x, y} => (),
+    }
+}
+```
+
+-- Fill struct fields
+
+```rust
+// before:
+struct S<'a, D> {
+    a: u32,
+    b: String,
+    c: (i32, i32),
+    d: D,
+    r: &'a str,
+}
+
+fn main() {
+    let s = S<|> {}
+}
+
+// after:
+struct S<'a, D> {
+    a: u32,
+    b: String,
+    c: (i32, i32),
+    d: D,
+    r: &'a str,
+}
+
+fn main() {
+    let s = <|>S {
+        a: (),
+        b: (),
+        c: (),
+        d: (),
+        r: (),
+    }
+}
+```
+
+- Flip `,`
+
+```rust
+// before:
+fn foo(x: usize,<|> dim: (usize, usize)) {}
+// after:
+fn foo(dim: (usize, usize), x: usize) {}
+```
+
+- Introduce variable:
+
+```rust
+// before:
+fn foo() {
+    foo(<|>1 + 1<|>);
+}
+
+// after:
+fn foo() {
+    let var_name = 1 + 1;
+    foo(var_name);
+}
+```
+
+-- Remove `dbg!`
+
+```rust
+// before:
+fn foo(n: usize) {
+    if let Some(_) = dbg!(n.<|>checked_sub(4)) {
+        // ...
+    }
+}
+
+// after:
+fn foo(n: usize) {
+    if let Some(_) = n.<|>checked_sub(4) {
+        // ...
+    }
+}
+```
+
+- Replace if-let with match:
+
+```rust
+// before:
+impl VariantData {
+    pub fn is_struct(&self) -> bool {
+        if <|>let VariantData::Struct(..) = *self {
+            true
+        } else {
+            false
+        }
+    }
+}
+
+// after:
+impl VariantData {
+    pub fn is_struct(&self) -> bool {
+        <|>match *self {
+            VariantData::Struct(..) => true,
+            _ => false,
+        }
+    }
+}
+```
+
+- Split import
+
+```rust
+// before:
+use algo:<|>:visitor::{Visitor, visit};
+//after:
+use algo::{<|>visitor::{Visitor, visit}};
+```
+
+### Magic Completions
+
+In addition to usual reference completion, rust-analyzer provides some ✨magic✨
+completions as well:
+
+Keywords like `if`, `else` `while`, `loop` are completed with braces, and cursor
+is placed at the appropriate position. Even though `if` is easy to type, you
+still want to complete it, to get ` { }` for free! `return` is inserted with a
+space or `;` depending on the return type of the function.
+
+When completing a function call, `()` are automatically inserted. If function
+takes arguments, cursor is positioned inside the parenthesis.
+
+There are postifx completions, which can be triggerd by typing something like
+`foo().if`. The word after `.` determines postifx completion, possible variants are:
+
+- `expr.if` -> `if expr {}`
+- `expr.match` -> `match expr {}`
+- `expr.while` -> `while expr {}`
+- `expr.ref` -> `&expr`
+- `expr.refm` -> `&mut expr`
+- `expr.not` -> `!expr`
+- `expr.dbg` -> `dbg!(expr)`
+
+There also snippet completions:
+
+#### Inside Expressions
+
+- `pd` -> `println!("{:?}")`
+- `ppd` -> `println!("{:#?}")`
+
+#### Inside Modules
+
+- `tfn` -> `#[test] fn f(){}`
+
diff --git a/editors/README.md b/editors/README.md
deleted file mode 100644
index ddc6ee048..000000000
--- a/editors/README.md
+++ /dev/null
@@ -1,241 +0,0 @@
-
-Prerequisites:
-
-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:
-
-```
-$ git clone https://github.com/rust-analyzer/rust-analyzer.git --depth 1
-$ cd rust-analyzer
-$ cargo install-code
-
-# for stdlib support
-$ rustup component add rust-src
-```
-
-This will run `cargo install --package ra_lsp_server` to install the server
-binary into `~/.cargo/bin`, and then will build and install plugin from
-`editors/code`. See
-[this](https://github.com/rust-analyzer/rust-analyzer/blob/0199572a3d06ff66eeae85a2d2c9762996f0d2d8/crates/tools/src/main.rs#L150)
-for details. The installation is expected to *just work*, if it doesn't, report
-bugs!
-
-It's better to remove existing Rust plugins to avoid interference.
-
-## Rust Analyzer Specific Features
-
-These features are implemented as extensions to the language server protocol.
-They are more experimental in nature and work only with VS Code.
-
-### Syntax highlighting
-
-It overrides built-in highlighting, and works only with a specific theme
-(zenburn). `rust-analyzer.highlightingOn` setting can be used to disable it.
-
-### Go to symbol in workspace <kbd>ctrl+t</kbd>
-
-It mostly works on top of the built-in LSP functionality, however `#` and `*`
-symbols can be used to narrow down the search. Specifically,
-
-- `#Foo` searches for `Foo` type in the current workspace
-- `#foo#` searches for `foo` function in the current workspace
-- `#Foo*` searches for `Foo` type among dependencies, excluding `stdlib`
-- `#foo#*` searches for `foo` function among dependencies.
-
-That is, `#` switches from "types" to all symbols, `*` switches from the current
-workspace to dependencies.
-
-### Commands <kbd>ctrl+shift+p</kbd>
-
-#### Show Rust Syntax Tree
-
-Shows the parse tree of the current file. It exists mostly for debugging
-rust-analyzer itself.
-
-#### Extend Selection
-
-Extends the current selection to the encompassing syntactic construct
-(expression, statement, item, module, etc). It works with multiple cursors. Do
-bind this command to a key, its super-useful! Expected to be upstreamed to LSP soonish:
-https://github.com/Microsoft/language-server-protocol/issues/613
-
-#### Matching Brace
-
-If the cursor is on any brace (`<>(){}[]`) which is a part of a brace-pair,
-moves cursor to the matching brace. It uses the actual parser to determine
-braces, so it won't confuse generics with comparisons.
-
-#### Parent Module
-
-Navigates to the parent module of the current module.
-
-#### Join Lines
-
-Join selected lines into one, smartly fixing up whitespace and trailing commas.
-
-#### Run
-
-Shows popup suggesting to run a test/benchmark/binary **at the current cursor
-location**. Super useful for repeatedly running just a single test. Do bind this
-to a shortcut!
-
-
-### On Typing Assists
-
-Some features trigger on typing certain characters:
-
-- typing `let =` tries to smartly add `;` if `=` is followed by an existing expression.
-- Enter inside comments automatically inserts `///`
-- typing `.` in a chain method call auto-indents
-
-
-### Code Actions (Assists)
-
-These are triggered in a particular context via light bulb. We use custom code on
-the VS Code side to be able to position cursor.
-
-
-- Flip `,`
-
-```rust
-// before:
-fn foo(x: usize,<|> dim: (usize, usize))
-// after:
-fn foo(dim: (usize, usize), x: usize)
-```
-
-- Add `#[derive]`
-
-```rust
-// before:
-struct Foo {
-    <|>x: i32
-}
-// after:
-#[derive(<|>)]
-struct Foo {
-    x: i32
-}
-```
-
-- Add `impl`
-
-```rust
-// before:
-struct Foo<'a, T: Debug> {
-    <|>t: T
-}
-// after:
-struct Foo<'a, T: Debug> {
-    t: T
-}
-
-impl<'a, T: Debug> Foo<'a, T> {
-    <|>
-}
-```
-
-- Change visibility
-
-```rust
-// before:
-fn<|> foo() {}
-
-// after
-pub(crate) fn foo() {}
-```
-
-- Introduce variable:
-
-```rust
-// before:
-fn foo() {
-    foo(<|>1 + 1<|>);
-}
-
-// after:
-fn foo() {
-    let var_name = 1 + 1;
-    foo(var_name);
-}
-```
-
-- Replace if-let with match:
-
-```rust
-// before:
-impl VariantData {
-    pub fn is_struct(&self) -> bool {
-        if <|>let VariantData::Struct(..) = *self {
-            true
-        } else {
-            false
-        }
-    }
-}
-
-// after:
-impl VariantData {
-    pub fn is_struct(&self) -> bool {
-        <|>match *self {
-            VariantData::Struct(..) => true,
-            _ => false,
-        }
-    }
-}
-```
-
-- Split import
-
-```rust
-// before:
-use algo:<|>:visitor::{Visitor, visit};
-//after:
-use algo::{<|>visitor::{Visitor, visit}};
-```
-
-## LSP features
-
-* **Go to definition**: works correctly for local variables and some paths,
-  falls back to heuristic name matching for other things for the time being.
-
-* **Completion**: completes paths, including dependencies and standard library.
-  Does not handle glob imports and macros. Completes fields and inherent
-  methods.
-
-* **Outline** <kbd>alt+shift+o</kbd>
-
-* **Signature Info**
-
-* **Format document**. Formats the current file with rustfmt. Rustfmt must be
-  installed separately with `rustup component add rustfmt`.
-
-* **Hover** shows types of expressions and docstings
-
-* **Rename** works for local variables
-
-* **Code Lens** for running tests
-
-* **Folding**
-
-* **Diagnostics**
-  - missing module for `mod foo;` with a fix to create `foo.rs`.
-  - struct field shorthand
-  - unnecessary braces in use item
-
-
-## Performance
-
-Rust Analyzer is expected to be pretty fast. Specifically, the initial analysis
-of the project (i.e, when you first invoke completion or symbols) typically
-takes dozen of seconds at most. After that, everything is supposed to be more or
-less instant. However currently all analysis results are kept in memory, so
-memory usage is pretty high. Working with `rust-lang/rust` repo, for example,
-needs about 5 gigabytes of ram.