This PR renames `Substring` to `Substring.Raw`.
This is to signify its status as a second-class citizen (not deprecated,
but no real plans for verification, like `String.Pos.Raw`) and to free
up the name `Substring` for a possible future type `String.Substring :
String -> Type` so that `s.Substring` is the type of substrings of `s`.
The functions `String.toSubstring` and `String.toSubstring'` will remain
for now for bootstrapping reasons.
This PR moves many operations involving `String.Pos.Raw` to a the
`String.Pos.Raw` namespace with the eventual aim of freeing up the
`String` namespace to contain operations using `String.ValidPos` (to be
renamed to `String.Pos`) instead.
This PR adds the `String.ValidPos.set` and `String.ValidPos.modify`
functions.
After this PR, `String.pos_lt_eq` is no longer a `simp` lemma. Add
`String.Pos.Raw.lt_iff` as a `simp` lemma if your proofs break.
This PR allows the interpreter to jump to native code of `[export]`
declarations, which can increase performance as well as the
effectiveness of `interpreter.prefer_native=true` during bootstrapping.
This PR consolidates common attribute-related error messages into
reusable functions and updates the wording and formatting of relevant
error messages.
This PR adds documentation to builtin attributes like `@[refl]` or
`@[implemented_by]`.
Closes#8432
---------
Co-authored-by: David Thrane Christiansen <david@davidchristiansen.dk>
Co-authored-by: David Thrane Christiansen <david@lean-fro.org>
