This PR enforces rules around arithmetic of `String.Pos.Raw`.
Specifically, it adopts the following conventions:
- Byte indices ("ordinals") in strings should be represented using
`String.Pos.Raw`
- Amounts of bytes ("cardinals") in strings should be represented using
`Nat`.
For example, `String.Slice.utf8ByteSize` now returns `Nat` instead of
`String.Pos.Raw`, and there is a new function `String.Slice.rawEndPos`.
Finally, the `HAdd` and `HSub` instances for `String.Pos.Raw` are
reorganized. This is a **breaking change**.
The `HAdd/HSub String.Pos.Raw String.Pos.Raw String.Pos.Raw` instances
have been removed. For the use case of tracking positions relative to
some other position, we instead provide `offsetBy` and `unoffsetBy`
functions. For the use case of advancing/unadvancing a position by an
arbitrary number of bytes, we instead provide `increaseBy` and
`decreaseBy` functions. For
offsetting/unoffsetting/advancing/unadvancing a position `p` by the size
of a string `s` (resp. character `c`), use `s + p`/`p - s`/`p + s`/`p -
s` (resp. `c + p`/`p - c`/`p + c`/`p - c`).
This PR adjusts the import graph, primarily of `Lean`, such that the
worst case rebuild time of core (`lean` only) is below 3 minutes on the
speedcenter machine (not captured by benchmark yet).
This PR migrates usages of `Std.Range` to the new polymorphic ranges.
This PR unfortunately increases the transitive imports for
frequently-used parts of `Init` because the ranges now rely on iterators
in order to provide their functionality for types other than `Nat`.
However, iteration over ranges in compiled code is as efficient as
before in the examples I checked. This is because of a special
`IteratorLoop` implementation provided in the PR for this purpose.
There were two issues that were uncovered during migration:
* In `IndPredBelow.lean`, migrating the last remaining range causes
`compilerTest1.lean` to break. I have minimized the issue and came to
the conclusion it's a compiler bug. Therefore, I have not replaced said
old range usage yet (see #9186).
* In `BRecOn.lean`, we are publicly importing the ranges. Making this
import private should theoretically work, but there seems to be a
problem with the module system, causing the build to panic later in
`Init.Data.Grind.Poly` (see #9185).
* In `FuzzyMatching.lean`, inlining fails with the new ranges, which
would have led to significant slowdown. Therefore, I have not migrated
this file either.
This PR implements signature help support. When typing a function
application, editors with support for signature help will now display a
popup that designates the current (remaining) function type. This
removes the need to remember the function signature while typing the
function application, or having to constantly cycle between hovering
over the function identifier and typing the application. In VS Code, the
signature help can be triggered manually using `Ctrl+Shift+Space`.
### Other changes
- In order to support signature help for the partial syntax `f a <|` or
`f a $`, these notations now elaborate as `f a`, not `f a .missing`.
- The logic in `delabConstWithSignature` that delaborates parameters is
factored out into a function `delabForallParamsWithSignature` so that it
can be used for arbitrary `forall`s, not just constants.
- The `InfoTree` formatter is adjusted to produce output where it is
easier to identify the kind of `Info` in the `InfoTree`.
- A bug in `InfoTree.smallestInfo?` is fixed so that it doesn't panic
anymore when its predicate `p` does not ensure that both `pos?` and
`tailPos?` of the `Info` are present.
