This PR replaces three independent name demangling implementations
(Lean, C++, Python) with a single source of truth in
`Lean.Compiler.NameDemangling`. The new module handles the full
pipeline: prefix parsing (`l_`, `lp_`, `_init_`, `initialize_`,
`lean_apply_N`, `_lean_main`), postprocessing (suffix flags, private
name stripping, hygienic suffix stripping, specialization contexts),
backtrace line parsing, and C exports via `@[export]`.
The C++ runtime backtrace handler now calls the Lean-exported functions
instead of its own 792-line reimplementation. This is safe because
`print_backtrace` is only called from `lean_panic_impl` (soft panics),
not `lean_internal_panic`.
The Python profiler demangler (`script/profiler/lean_demangle.py`) is
replaced with a thin subprocess wrapper around a Lean CLI tool,
preserving the `demangle_lean_name` API so downstream scripts work
unchanged.
**New files:**
- `src/Lean/Compiler/NameDemangling.lean` — single source of truth (483
lines)
- `tests/lean/run/demangling.lean` — comprehensive tests (281 lines)
- `script/profiler/lean_demangle_cli.lean` — `c++filt`-style CLI tool
**Deleted files:**
- `src/runtime/demangle.cpp` (792 lines)
- `src/runtime/demangle.h` (26 lines)
- `script/profiler/test_demangle.py` (670 lines)
Net: −1,381 lines of duplicated C++/Python code.
🤖 Prepared with Claude Code
---------
Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>
This PR cuts some edges from the import graph.
Specifically:
- `TreeMap` and `HashMap` no longer depend on `String`, so now the
expensive things are all in parallel instead of partially in sequence
- `Omega` no longer relies on `List` lemmas
- The section of the import graph between `Init.Omega` and
`Init.Data.Bitvec.Lemmas` is cleaned up a bit
This PR reworks the `simp` set around the `Id` monad, to not elide or
unfold `pure` and `Id.run`
In particular, it stops encoding the "defeq abuse" of `Id X = X` in the
statements of theorems, instead using `Id.run` and `pure` to pass back
and forth between these two spellings. Often when writing these with
`pure`, they generalize to other lawful monads; though such changes were
split off to other PRs.
This fixes the problem with the current simp set where `Id.run (pure x)`
is simplified to `Id.run x`, instead of the desirable `x`.
This is particularly bad because the` x` is sometimes inferred with type
`Id X` instead of `X`, which prevents other `simp` lemmas about `X` from
firing.
Making `Id` reducible instead is not an option, as then the `Monad`
instances would have nothing to key on.
---------
Co-authored-by: Sebastian Graf <sg@lean-fro.org>
Co-authored-by: Kim Morrison <kim@tqft.net>
Co-authored-by: Paul Reichert <6992158+datokrat@users.noreply.github.com>
This PR adds basic auto-completion support for imports. Since it still
lacks Lake support for accurate completion suggestions (cc @tydeu - we
already know what needs to be done), it falls back to traversing the
`LEAN_SRC_PATH` for available imports.
Three kinds of import completion requests are supported:
- Completion of the full `import` command. Triggered when requesting
completions in an empty space within the header.
- Known issue: It is possible to trigger this completion within a
comment in the header. Fixing this would require architecture for
parsing some kind of sub-syntax between individual commands.
- Completion of the full module name after an incomplete `import`
command.
- Completion of a partial module name with a trailing dot.
Since the set of imports is potentially expensive to compute, they are
cached for 10 seconds after the last import auto-completion request.
Closes#2655.
### Changes
This PR also makes the following changes:
- To support completions on the trailing dot, the `import` syntax was
adjusted to provide partial syntax when a trailing dot is used.
- `FileWorker.lean` was refactored lightly with some larger definitions
being broken apart.
- The `WorkerState` gained two new fields:
- `currHeaderStx` tracks the current header syntax, as opposed to
tracking only the initial header syntax in `initHeaderStx`. When the
header syntax changes, a task is launched that restarts the file worker
after a certain delay to avoid constant restarts while editing the
header. During this time period, we may still want to serve import
auto-completion requests, so we need to know the up-to-date header
syntax.
- `importCachingTask?` contains a task that computes the set of
available imports.
- `determineLakePath` has moved to a new file `Lean/Util/LakePath.lean`
as it is now needed both in `ImportCompletion.lean` and
`FileWorker.lean`.
- `forEachModuleIn` from `Lake/Config/Blob.lean` has moved to
`Lean/Util/Path.lean` as it is a generally useful utility function that
was useful for traversing the `LEAN_SRC_PATH` as well.
### Tests
Unfortunately, this PR lacks tests since the set of imports available in
`tests/lean/interactive` will not be stable. In the future, I will add
support for testing LSP requests in full project setups, which is when
tests for import auto-completion will be added as well.
