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 modifies dot identifier notation so that `(.a : T)` resolves
`T.a` with respect to the root namespace, like for generalized field
notation. This lets the notation refer to private names, follow aliases,
and also use open namespaces. The LSP completions are improved to follow
how dot ident notation is resolved, but it doesn't yet take into account
aliases or open namespaces.
Closes#9629
This PR consolidates common attribute-related error messages into
reusable functions and updates the wording and formatting of relevant
error messages.
This PR removes uses of `Lean.RBMap` in Lean itself.
Furthermore some massaging of the import graph is done in order to avoid
having `Std.Data.TreeMap.AdditionalOperations` (which is quite
expensive) be the critical path for a large chunk of Lean. In particular
we can build `Lean.Meta.Simp` and `Lean.Meta.Grind` without it thanks to
these changes.
We did previously not conduct this change as `Std.TreeMap` was not
outperforming `Lean.RBMap` yet, however this has changed with the new
code generator.
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 fixes a bug where the unknown identifier code actions wouldn't
work correctly for some unknown identifier error spans and adjusts
several unknown identifier spans to actually end on the identifier in
question.
The following additional adjustments are made:
- The fallback mechanism of the unknown identifier code actions is
removed, since it could produce severely incorrect suggestions for
unknown identifier errors on fields.
- A performance bug when using the code action to import all unknown
identifiers is fixed.
- A bug that occurs when the elaborator produces multiple overlapping
completion infos is fixed.
- A bug in the snapshot selection that could cause it to wait for
snapshots in snapshots with non-canonical syntax is fixed.
- Some invariants of the snapshot tree are documented.
- The snapshot tree formatting is adjusted to display the final info
tree again.
This PR adds support for code actions that resolve 'unknown identifier'
errors by either importing the missing declaration or by changing the
identifier to one from the environment.
<details>
<summary>Demo (Click to open)</summary>

</details>
Specifically, the following kinds of code actions are added by this PR,
all of which are triggered on 'unknown identifier' errors:
- A code action to import the module containing the identifier at the
text cursor position.
- A code action to change the identifier at the text cursor position to
one from the environment.
- A source action to import the modules for all unambiguous identifiers
in the file.
### Details
When clicking on an identifier with an 'unknown identifier' diagnostic,
after a debounce delay of 1000ms, the language server looks up the
(potentially partial) identifier at the position of the cursor in the
global reference data structure by fuzzy-matching against all
identifiers and collects the 10 closest matching entries. This search
accounts for open namespaces at the position of the cursor, including
the namespace of the type / expected type when using dot notation. The
10 closest matching entries are then offered to the user as code
actions:
- If the suggested identifier is not contained in the environment, a
code action that imports the module that the identifier is contained in
and changes the identifier to the suggested one is offered. The
suggestion is inserted in a "minimal" manner, i.e. by accounting for
open namespaces.
- If the suggested identifier is contained in the environment, a code
action that only changes the identifier to the suggested one is offered.
- If the suggested identifier is not contained in the environment and
the suggested identifier is a perfectly unambiguous match, a source
action to import all unambiguous in the file is offered.
The source action to import all unambiguous identifiers can also always
be triggered by right-clicking in the document and selecting the 'Source
Action...' entry.
At the moment, for large projects, the search for closely matching
identifiers in the global reference data structure is still a bit slow.
I hope to optimize it next quarter.
### Implementation notes
- Since the global reference data structure is in the watchdog process,
whereas the elaboration information is in the file worker process, this
PR implements support for file worker -> watchdog requests, including a
new `$/lean/queryModule` request that can be used by the file worker to
request global identifier information.
- To identify 'unknown identifier' errors, several 'unknown identifier'
errors in the elaborator are tagged with a new tag.
- The debounce delay of 1000ms is necessary because VS Code will
re-request code actions while editing an unknown identifier and also
while hovering over the identifier.
- We also implement cancellation for these 'unknown identifier' code
actions. Once the file worker responds to the request as having been
cancelled, the watchdog cancels its computation of all corresponding
file worker -> watchdog requests, too.
- Aliases (i.e. `export`) are currently not accounted for. I've found
that we currently don't handle them correctly in auto-completion, too,
so we will likely add support for this later when fixing the
corresponding auto-completion issue.
- The new code actions added by this request support incrementality.
This PR adds language server support for request cancellation to the
following expensive requests: Code actions, auto-completion, document
symbols, folding ranges and semantic highlighting. This means that when
the client informs the language server that a request is stale (e.g.
because it belongs to a previous state of the document), the language
server will now prematurely cancel the computation of the response in
order to reduce the CPU load for requests that will be discarded by the
client anyways.
- Add support for reserved declaration names. We use them for theorems
generated on demand.
- Equation theorems are not private declarations anymore.
- Generate equation theorems on demand when resolving symbols.
- Prevent users from creating declarations using reserved names. Users
can bypass it using meta-programming.
See next test for examples.