3 files changed, 60 insertions, 1 deletions

diff --git a/docs/dev/README.md b/docs/dev/README.md
index 36edddc70..90e74f226 100644
--- a/docs/dev/README.md
+++ b/docs/dev/README.md
@@ -35,7 +35,12 @@ https://rust-lang.zulipchat.com/#narrow/stream/185405-t-compiler.2Fwg-rls-2.2E0
 * [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-unknown](https://github.com/rust-analyzer/rust-analyzer/issues?q=is%3Aopen+is%3Aissue+label%3AE-unknown),
+  labels are *estimates* for how hard would be to write a fix. Each triaged issue should have one of these labels.
+* [S-actionable](https://github.com/rust-analyzer/rust-analyzer/issues?q=is%3Aopen+is%3Aissue+label%3AS-actionable) and
+  [S-unactionable](https://github.com/rust-analyzer/rust-analyzer/issues?q=is%3Aopen+is%3Aissue+label%3AS-unactionable)
+  specify if there are concrete steps to resolve or advance an issue. Roughly, actionable issues need only work to be fixed,
+  while unactionable ones are effectively wont-fix. Each triaged issue should have one of these labels.
 * [fun](https://github.com/rust-analyzer/rust-analyzer/issues?q=is%3Aopen+is%3Aissue+label%3Afun)
   is for cool, but probably hard stuff.
 
diff --git a/docs/dev/lsp-extensions.md b/docs/dev/lsp-extensions.md
index 3f861f3e0..43a69d6ce 100644
--- a/docs/dev/lsp-extensions.md
+++ b/docs/dev/lsp-extensions.md
@@ -1,3 +1,13 @@
+<!---
+lsp_ext.rs hash: 286f8bbac885531a
+
+If you need to change the above hash to make the test pass, please check if you
+need to adjust this doc as well and ping this issue:
+
+  https://github.com/rust-analyzer/rust-analyzer/issues/4604
+
+--->
+
 # LSP Extensions
 
 This document describes LSP extensions used by rust-analyzer.
diff --git a/docs/dev/style.md b/docs/dev/style.md
index 59067d234..883a6845d 100644
--- a/docs/dev/style.md
+++ b/docs/dev/style.md
@@ -186,6 +186,31 @@ impl Person {
 }
 ```
 
+## Constructors
+
+Prefer `Default` to zero-argument `new` function
+
+```rust
+// Good
+#[derive(Default)]
+struct Foo {
+    bar: Option<Bar>
+}
+
+// Not as good
+struct Foo {
+    bar: Option<Bar>
+}
+
+impl Foo {
+    fn new() -> Foo {
+        Foo { bar: None }
+    }
+}
+```
+
+Prefer `Default` even it has to be implemented manually.
+
 ## Avoid Monomorphization
 
 Rust uses monomorphization to compile generic code, meaning that for each instantiation of a generic functions with concrete types, the function is compiled afresh, *per crate*.
@@ -223,6 +248,8 @@ fn frbonicate(f: impl AsRef<Path>) {
 
 # Premature Pessimization
 
+## Avoid Allocations
+
 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.
 
@@ -242,6 +269,8 @@ if words.len() != 2 {
 }
 ```
 
+## Push Allocations to the Call Site
+
 If allocation is inevitable, let the caller allocate the resource:
 
 ```rust
@@ -257,6 +286,9 @@ fn frobnicate(s: &str) {
 }
 ```
 
+This is better because it reveals the costs.
+It is also more efficient when the caller already owns the allocation.
+
 ## Collection types
 
 Prefer `rustc_hash::FxHashMap` and `rustc_hash::FxHashSet` instead of the ones in `std::collections`.
@@ -371,6 +403,18 @@ Default names:
 * `n_foo` -- number of foos
 * `foo_idx` -- index of `foo`
 
+Many names in rust-analyzer conflict with keywords.
+We use mangled names instead of `r#ident` syntax:
+
+```
+struct -> strukt
+crate  -> krate
+impl   -> imp
+trait  -> trait_
+fn     -> func
+enum   -> enum_
+mod    -> module
+```
 
 ## Early Returns