mention the hair

2020-04-04 12:50:27 -05:00 · 2020-04-04 12:50:27 -05:00 · d5d65558c5
commit d5d65558c5
parent 2fb3d1c2d6
1 changed files with 3 additions and 0 deletions
--- a/src/doc/rustc-dev-guide/src/overview.md
+++ b/src/doc/rustc-dev-guide/src/overview.md
@ -40,6 +40,9 @@ we'll talk about that later.
 - **TODO: Maybe some other things are done here? I think initial type checking
  happens here? And trait solving?**
 - The HIR is then [lowered to Mid-Level Intermediate Representation (MIR)][mir].
+  - Along the way, we construct the HAIR, which is an even more desugared HIR.
+    HAIR is used for pattern and exhaustiveness checking. It is also more
+    convenient to convert into MIR than HIR is.
 - The MIR is used for [borrow checking].
 - **TODO: const eval fits in somewhere here I think**
 - We (want to) do [many optimizations on the MIR][mir-opt] because it is still