3 files changed, 386 insertions, 114 deletions

diff --git a/docs/dev/README.md b/docs/dev/README.md
index 65cc9fc12..3af01cd6b 100644
--- a/docs/dev/README.md
+++ b/docs/dev/README.md
@@ -1,6 +1,6 @@
 # Contributing Quick Start
 
-Rust Analyzer is just a usual rust project, which is organized as a Cargo
+Rust Analyzer is an ordinary Rust project, which is organized as a Cargo
 workspace, builds on stable and doesn't depend on C libraries. So, just
 
 ```
@@ -30,7 +30,7 @@ https://rust-lang.zulipchat.com/#narrow/stream/185405-t-compiler.2Fwg-rls-2.2E0
 
 * [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)
+* [E-has-instructions](https://github.com/rust-analyzer/rust-analyzer/issues?q=is%3Aopen+is%3Aissue+label%3AE-has-instructions)
   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),
@@ -55,7 +55,7 @@ You can run `cargo xtask install-pre-commit-hook` to install git-hook to run rus
 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 the plugin for VS Code (in
-typescript). The `docs` top-level directory contains both developer and user
+TypeScript). The `docs` top-level directory contains both developer and user
 documentation.
 
 We have some automation infra in Rust in the `xtask` package. It contains
@@ -65,7 +65,7 @@ directory).
 
 # Launching rust-analyzer
 
-Debugging language server can be tricky: LSP is rather chatty, so driving it
+Debugging the 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.
 
@@ -73,14 +73,14 @@ 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
+However, launching a VS Code instance with a locally built language server is
 possible. There's **"Run Extension (Debug Build)"** launch configuration for this.
 
 In general, I use one of the following workflows for fixing bugs and
 implementing features.
 
-If the problem concerns only internal parts of rust-analyzer (ie, I don't need
-to touch `rust-analyzer` crate or typescript code), there is a unit-test for it.
+If the problem concerns only internal parts of rust-analyzer (i.e. I don't need
+to touch the `rust-analyzer` crate or TypeScript code), there is a unit-test for it.
 So, I use **Rust Analyzer: Run** action in VS Code to run this single test, and
 then just do printf-driven development/debugging. As a sanity check after I'm
 done, I use `cargo xtask install --server` and **Reload Window** action in VS
@@ -88,8 +88,8 @@ Code to sanity check that the thing works as I expect.
 
 If the problem concerns only the VS Code extension, I use **Run Installed Extension**
 launch configuration from `launch.json`. Notably, this uses the usual
-`rust-analyzer` binary from `PATH`. For this it is important to have the following
-in `setting.json` file:
+`rust-analyzer` binary from `PATH`. For this, it is important to have the following
+in your `settings.json` file:
 ```json
 {
     "rust-analyzer.serverPath": "rust-analyzer"
@@ -107,7 +107,7 @@ things up, sometimes I open a temporary hello-world project which has
 `"rust-analyzer.withSysroot": false` in `.code/settings.json`. This flag causes
 rust-analyzer to skip loading the sysroot, which greatly reduces the amount of
 things rust-analyzer needs to do, and makes printf's more useful. Note that you
-should only use `eprint!` family of macros for debugging: stdout is used for LSP
+should only use the `eprint!` family of macros for debugging: stdout is used for LSP
 communication, and `print!` would break it.
 
 If I need to fix something simultaneously in the server and in the client, I
@@ -117,6 +117,258 @@ Additionally, I use `cargo run --release -p rust-analyzer -- analysis-stats
 path/to/some/rust/crate` to run a batch analysis. This is primarily useful for
 performance optimizations, or for bug minimization.
 
+# Code Style & Review Process
+
+Our approach to "clean code" is two-fold:
+
+* We generally don't block PRs on style changes.
+* At the same time, all code in rust-analyzer is constantly refactored.
+
+It is explicitly OK for a reviewer to flag only some nits in the PR, and then send a follow-up cleanup PR for things which are easier to explain by example, cc-ing the original author.
+Sending small cleanup PRs (like renaming a single local variable) is encouraged.
+
+## Scale of Changes
+
+Everyone knows that it's better to send small & focused pull requests.
+The problem is, sometimes you *have* to, eg, rewrite the whole compiler, and that just doesn't fit into a set of isolated PRs.
+
+The main things to keep an eye on are the boundaries between various components.
+There are three kinds of changes:
+
+1. Internals of a single component are changed.
+   Specifically, you don't change any `pub` items.
+   A good example here would be an addition of a new assist.
+
+2. API of a component is expanded.
+   Specifically, you add a new `pub` function which wasn't there before.
+   A good example here would be expansion of assist API, for example, to implement lazy assists or assists groups.
+
+3. A new dependency between components is introduced.
+   Specifically, you add a `pub use` reexport from another crate or you add a new line to the `[dependencies]` section of `Cargo.toml`.
+   A good example here would be adding reference search capability to the assists crates.
+
+For the first group, the change is generally merged as long as:
+
+* it works for the happy case,
+* it has tests,
+* it doesn't panic for the unhappy case.
+
+For the second group, the change would be subjected to quite a bit of scrutiny and iteration.
+The new API needs to be right (or at least easy to change later).
+The actual implementation doesn't matter that much.
+It's very important to minimize the amount of changed lines of code for changes of the second kind.
+Often, you start doing a change of the first kind, only to realise that you need to elevate to a change of the second kind.
+In this case, we'll probably ask you to split API changes into a separate PR.
+
+Changes of the third group should be pretty rare, so we don't specify any specific process for them.
+That said, adding an innocent-looking `pub use` is a very simple way to break encapsulation, keep an eye on it!
+
+Note: if you enjoyed this abstract hand-waving about boundaries, you might appreciate
+https://www.tedinski.com/2018/02/06/system-boundaries.html
+
+## Minimal Tests
+
+Most tests in rust-analyzer start with a snippet of Rust code.
+This snippets should be minimal -- if you copy-paste a snippet of real code into the tests, make sure to remove everything which could be removed.
+There are many benefits to this:
+
+* less to read or to scroll past
+* easier to understand what exactly is tested
+* less stuff printed during printf-debugging
+* less time to run test
+
+It also makes sense to format snippets more compactly (for example, by placing enum defitions like `enum E { Foo, Bar }` on a single line),
+as long as they are still readable.
+
+## Order of Imports
+
+We separate import groups with blank lines
+
+```rust
+mod x;
+mod y;
+
+use std::{ ... }
+
+use crate_foo::{ ... }
+use crate_bar::{ ... }
+
+use crate::{}
+
+use super::{} // but prefer `use crate::`
+```
+
+## Import Style
+
+Items from `hir` and `ast` should be used qualified:
+
+```rust
+// Good
+use ra_syntax::ast;
+
+fn frobnicate(func: hir::Function, strukt: ast::StructDef) {}
+
+// Not as good
+use hir::Function;
+use ra_syntax::ast::StructDef;
+
+fn frobnicate(func: Function, strukt: StructDef) {}
+```
+
+Avoid local `use MyEnum::*` imports.
+
+Prefer `use crate::foo::bar` to `use super::bar`.
+
+## Order of Items
+
+Optimize for the reader who sees the file for the first time, and wants to get the general idea about what's going on.
+People read things from top to bottom, so place most important things first.
+
+Specifically, if all items except one are private, always put the non-private item on top.
+
+Put `struct`s and `enum`s first, functions and impls last.
+
+Do
+
+```rust
+// Good
+struct Foo {
+    bars: Vec<Bar>
+}
+
+struct Bar;
+```
+
+rather than
+
+```rust
+// Not as good
+struct Bar;
+
+struct Foo {
+    bars: Vec<Bar>
+}
+```
+
+## Variable Naming
+
+We generally use boring and long names for local variables ([yay code completion](https://github.com/rust-analyzer/rust-analyzer/pull/4162#discussion_r417130973)).
+The default name is a lowercased name of the type: `global_state: GlobalState`.
+Avoid ad-hoc acronyms and contractions, but use the ones that exist consistently (`db`, `ctx`, `acc`).
+The default name for "result of the function" local variable is `res`.
+
+## Collection types
+
+We prefer `rustc_hash::FxHashMap` and `rustc_hash::FxHashSet` instead of the ones in `std::collections`.
+They use a hasher that's slightly faster and using them consistently will reduce code size by some small amount.
+
+## Preconditions
+
+Function preconditions should generally be expressed in types and provided by the caller (rather than checked by callee):
+
+```rust
+// Good
+fn frbonicate(walrus: Walrus) {
+    ...
+}
+
+// Not as good
+fn frobnicate(walrus: Option<Walrus>) {
+    let walrus = match walrus {
+        Some(it) => it,
+        None => return,
+    };
+    ...
+}
+```
+
+## Premature Pessimization
+
+While we don't specifically optimize code yet, avoid writing code which is slower than it needs to be.
+Don't allocate a `Vec` where an iterator would do, don't allocate strings needlessly.
+
+```rust
+// Good
+use itertools::Itertools;
+
+let (first_word, second_word) = match text.split_ascii_whitespace().collect_tuple() {
+    Some(it) => it,
+    None => return,
+}
+
+// Not as good
+let words = text.split_ascii_whitespace().collect::<Vec<_>>();
+if words.len() != 2 {
+    return
+}
+```
+
+## Documentation
+
+For `.md` and `.adoc` files, prefer a sentence-per-line format, don't wrap lines.
+If the line is too long, you want to split the sentence in two :-)
+
+## Commit Style
+
+We don't have specific rules around git history hygiene.
+Maintaining clean git history is encouraged, but not enforced.
+We use rebase workflow, it's OK to rewrite history during PR review process.
+
+Avoid @mentioning people in commit messages and pull request descriptions (they are added to commit message by bors), as such messages create a lot of duplicate notification traffic during rebases.
+
+# Architecture Invariants
+
+This section tries to document high-level design constraints, which are not
+always obvious from the low-level code.
+
+## Incomplete syntax trees
+
+Syntax trees are by design incomplete and do not enforce well-formedness.
+If an AST method returns an `Option`, it *can* be `None` at runtime, even if this is forbidden by the grammar.
+
+## LSP independence
+
+rust-analyzer is independent from LSP.
+It provides features for a hypothetical perfect Rust-specific IDE client.
+Internal representations are lowered to LSP in the `rust-analyzer` crate (the only crate which is allowed to use LSP types).
+
+## IDE/Compiler split
+
+There's a semi-hard split between "compiler" and "IDE", at the `ra_hir` crate.
+Compiler derives new facts about source code.
+It explicitly acknowledges that not all info is available (i.e. you can't look at types during name resolution).
+
+IDE assumes that all information is available at all times.
+
+IDE should use only types from `ra_hir`, and should not depend on the underling compiler types.
+`ra_hir` is a facade.
+
+## IDE API
+
+The main IDE crate (`ra_ide`) uses "Plain Old Data" for the API.
+Rather than talking in definitions and references, it talks in Strings and textual offsets.
+In general, API is centered around UI concerns -- the result of the call is what the user sees in the editor, and not what the compiler sees underneath.
+The results are 100% Rust specific though.
+
+## Parser Tests
+
+Tests for the parser (`ra_parser`) live in the `ra_syntax` crate (see `test_data` directory).
+There are two kinds of tests:
+
+* Manually written test cases in `parser/ok` and `parser/err`
+* "Inline" tests in `parser/inline` (these are generated) from comments in `ra_parser` crate.
+
+The purpose of inline tests is not to achieve full coverage by test cases, but to explain to the reader of the code what each particular `if` and `match` is responsible for.
+If you are tempted to add a large inline test, it might be a good idea to leave only the simplest example in place, and move the test to a manual `parser/ok` test.
+
+To update test data, run with `UPDATE_EXPECT` variable:
+
+```bash
+env UPDATE_EXPECT=1 cargo qt
+```
+
+After adding a new inline test you need to run `cargo xtest codegen` and also update the test data as described above.
+
 # Logging
 
 Logging is done by both rust-analyzer and VS Code, so it might be tricky to
@@ -143,7 +395,7 @@ To log all communication between the server and the client, there are two choice
   [@DJMcNab](https://github.com/DJMcNab) for setting this awesome infra up!
 
 
-There's also two VS Code commands which might be of interest:
+There are 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:
@@ -159,8 +411,8 @@ There's also two VS Code commands which might be of interest:
   rust code that it refers to and the rust editor will also highlight the proper
   text range.
 
-  If you press <kbd>Ctrl</kbd> (i.e. trigger goto definition) in the inspected
-  Rust source file the syntax tree read-only editor should scroll to and select the
+  If you trigger Go to Definition in the inspected Rust source file,
+  the syntax tree read-only editor should scroll to and select the
   appropriate syntax node token.
 
   ![demo](https://user-images.githubusercontent.com/36276403/78225773-6636a480-74d3-11ea-9d9f-1c9d42da03b0.png)
diff --git a/docs/dev/lsp-extensions.md b/docs/dev/lsp-extensions.md
index dbc95be38..6d6bbac7c 100644
--- a/docs/dev/lsp-extensions.md
+++ b/docs/dev/lsp-extensions.md
@@ -7,6 +7,16 @@ All capabilities are enabled via `experimental` field of `ClientCapabilities` or
 Requests which we hope to upstream live under `experimental/` namespace.
 Requests, which are likely to always remain specific to `rust-analyzer` are under `rust-analyzer/` namespace.
 
+If you want to be notified about the changes to this document, subscribe to [#4604](https://github.com/rust-analyzer/rust-analyzer/issues/4604).
+
+## `initializationOptions`
+
+As `initializationOptions`, `rust-analyzer` expects `"rust-analyzer"` section of the configuration.
+That is, `rust-analyzer` usually sends `"workspace/configuration"` request with `{ "items": ["rust-analyzer"] }` payload.
+`initializationOptions` should contain the same data that would be in the first item of the result.
+It's OK to not send anything, then all the settings would take their default values.
+However, some settings can not be changed after startup at the moment.
+
 ## Snippet `TextEdit`
 
 **Issue:** https://github.com/microsoft/language-server-protocol/issues/724
@@ -87,6 +97,30 @@ Invoking code action at this position will yield two code actions for importing
 * Is a fixed two-level structure enough?
 * Should we devise a general way to encode custom interaction protocols for GUI refactorings?
 
+## Lazy assists with `ResolveCodeAction`
+
+**Issue:** https://github.com/microsoft/language-server-protocol/issues/787
+
+**Client Capability** `{ "resolveCodeAction": boolean }`
+
+If this capability is set, the assists will be computed lazily. Thus `CodeAction` returned from the server will only contain `id` but not `edit` or `command` fields. The only exclusion from the rule is the diagnostic edits.
+
+After the client got the id, it should then call `experimental/resolveCodeAction` command on the server and provide the following payload:
+
+```typescript
+interface ResolveCodeActionParams {
+    id: string;
+    codeActionParams: lc.CodeActionParams;
+}
+```
+
+As a result of the command call the client will get the respective workspace edit (`lc.WorkspaceEdit`).
+
+### Unresolved Questions
+
+* Apply smarter filtering for ids?
+* Upon `resolveCodeAction` command only call the assits which should be resolved and not all of them?
+
 ## Parent Module
 
 **Issue:** https://github.com/microsoft/language-server-protocol/issues/1002
@@ -301,6 +335,50 @@ Moreover, it would be cool if editors didn't need to implement even basic langua
   This is how `SelectionRange` request works.
 * Alternatively, should we perhaps flag certain `SelectionRange`s as being brace pairs?
 
+## Runnables
+
+**Issue:** https://github.com/microsoft/language-server-protocol/issues/944
+
+**Server Capability:** `{ "runnables": { "kinds": string[] } }`
+
+This request is send from client to server to get the list of things that can be run (tests, binaries, `cargo check -p`).
+
+**Method:** `experimental/runnables`
+
+**Request:**
+
+```typescript
+interface RunnablesParams {
+    textDocument: TextDocumentIdentifier;
+    /// If null, compute runnables for the whole file.
+    position?: Position;
+}
+```
+
+**Response:** `Runnable[]`
+
+```typescript
+interface Runnable {
+    label: string;
+    /// If this Runnable is associated with a specific function/module, etc, the location of this item
+    location?: LocationLink;
+    /// Running things is necessary technology specific, `kind` needs to be advertised via server capabilities,
+    // the type of `args` is specific to `kind`. The actual running is handled by the client.
+    kind: string;
+    args: any;
+}
+```
+
+rust-analyzer supports only one `kind`, `"cargo"`. The `args` for `"cargo"` look like this:
+
+```typescript
+{
+    workspaceRoot?: string;
+    cargoArgs: string[];
+    executableArgs: string[];
+}
+```
+
 ## Analyzer Status
 
 **Method:** `rust-analyzer/analyzerStatus`
@@ -311,15 +389,27 @@ Moreover, it would be cool if editors didn't need to implement even basic langua
 
 Returns internal status message, mostly for debugging purposes.
 
-## Collect Garbage
+## Reload Workspace
 
-**Method:** `rust-analyzer/collectGarbage`
+**Method:** `rust-analyzer/reloadWorkspace`
 
 **Request:** `null`
 
 **Response:** `null`
 
-Frees some caches. For internal use, and is mostly broken at the moment.
+Reloads project information (that is, re-executes `cargo metadata`).
+
+## Status Notification
+
+**Client Capability:** `{ "statusNotification": boolean }`
+
+**Method:** `rust-analyzer/status`
+
+**Notification:** `"loading" | "ready" | "invalid" | "needsReload"`
+
+This notification is sent from server to client.
+The client can use it to display persistent status to the user (in modline).
+For `needsReload` state, the client can provide a context-menu action to run `rust-analyzer/reloadWorkspace` request.
 
 ## Syntax Tree
 
@@ -390,38 +480,40 @@ interface InlayHint {
 }
 ```
 
-## Runnables
-
-**Method:** `rust-analyzer/runnables`
+## Hover Actions
 
-This request is send from client to server to get the list of things that can be run (tests, binaries, `cargo check -p`).
-Note that we plan to move this request to `experimental/runnables`, as it is not really Rust-specific, but the current API is not necessary the right one.
-Upstream issue: https://github.com/microsoft/language-server-protocol/issues/944
+**Client Capability:** `{ "hoverActions": boolean }`
 
-**Request:**
+If this capability is set, `Hover` request returned from the server might contain an additional field, `actions`:
 
 ```typescript
-interface RunnablesParams {
-    textDocument: TextDocumentIdentifier;
-    /// If null, compute runnables for the whole file.
-    position?: Position;
+interface Hover {
+    ...
+    actions?: CommandLinkGroup[];
 }
-```
 
-**Response:** `Runnable[]`
+interface CommandLink extends Command {
+    /**
+     * A tooltip for the command, when represented in the UI.
+     */
+    tooltip?: string;
+}
 
-```typescript
-interface Runnable {
-    /// The range this runnable is applicable for.
-    range: lc.Range;
-    /// The label to show in the UI.
-    label: string;
-    /// The following fields describe a process to spawn.
-    bin: string;
-    args: string[];
-    /// Args for cargo after `--`.
-    extraArgs: string[];
-    env: { [key: string]: string };
-    cwd: string | null;
+interface CommandLinkGroup {
+    title?: string;
+    commands: CommandLink[];
 }
 ```
+
+Such actions on the client side are appended to a hover bottom as command links:
+```
+  +-----------------------------+
+  | Hover content               |
+  |                             |
+  +-----------------------------+
+  | _Action1_ | _Action2_       |  <- first group, no TITLE
+  +-----------------------------+
+  | TITLE _Action1_ | _Action2_ |  <- second group
+  +-----------------------------+
+  ...
+```
diff --git a/docs/dev/lsp-features.md b/docs/dev/lsp-features.md
deleted file mode 100644
index 00b0867d7..000000000
--- a/docs/dev/lsp-features.md
+++ /dev/null
@@ -1,72 +0,0 @@
-# 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)
-- [ ] [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)
-- [x] [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)
-- [x] [textDocument/selectionRange](https://github.com/Microsoft/language-server-protocol/issues/613)
- - rust-analyzer.syntaxTree
- - 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)
-- [x] [codeLens/resolve](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)