Continuation of #3958. To ensure that lean code is able to uphold the
invariant that `String`s are valid UTF-8 (which is assumed by the lean
model), we have to make sure that no lean objects are created with
invalid UTF-8. #3958 covers the case of lean code creating strings via
`fromUTF8Unchecked`, but there are still many cases where C++ code
constructs strings from a `const char *` or `std::string` with unclear
UTF-8 status.
To address this and minimize accidental missed validation, the
`(lean_)mk_string` function is modified to validate UTF-8. The original
function is renamed to `mk_string_unchecked`, with several other
variants depending on whether we know the string is UTF-8 or ASCII and
whether we have the length and/or utf8 char count on hand. I reviewed
every function which leads to `mk_string` or its variants in the C code,
and used the appropriate validation function, defaulting to `mk_string`
if the provenance is unclear.
This PR adds no new error handling paths, meaning that incorrect UTF-8
will still produce incorrect results in e.g. IO functions, they are just
not causing unsound behavior anymore. A subsequent PR will handle adding
better error reporting for bad UTF-8.
Extends Lean's incremental reporting and reuse between commands into
various steps inside declarations:
* headers and bodies of each (mutual) definition/theorem
* `theorem ... := by` for each contained tactic step, including
recursively inside supported combinators currently consisting of
* `·` (cdot), `case`, `next`
* `induction`, `cases`
* macros such as `next` unfolding to the above

*Incremental reuse* means not recomputing any such steps if they are not
affected by a document change. *Incremental reporting* includes the
parts seen in the recording above: the progress bar and messages. Other
language server features such as hover etc. are *not yet* supported
incrementally, i.e. they are shown only when the declaration has been
fully processed as before.
---------
Co-authored-by: Scott Morrison <scott.morrison@gmail.com>
Adds `IO.getTaskState` which returns the state of a `Task` in the Lean
runtime's task manager. The `TaskState` inductive has 3 constructors:
`waiting`, `running`, and `finished`. The `waiting` constructor
encompasses the waiting and queued states within the C task object
documentation, because the task object does not provide a low cost way
to distinguish these different forms of waiting. Furthermore, it seems
unlikely for consumers to wish to distinguish between these internal
states. The `running` constructor encompasses both the running and
promised states in C docs. While not ideal, the C implementation does
not provide a way to distinguish between a running `Task` and a waiting
`Promise.result` (they both have null closures).
Adds `IO.FS.Handle.isTty` to check whether a handle is a Windows console
or Unix terminal. Also adds an `isTty` field to `IO.FS.Stream`, so that
this can be checked on, e.g., `stdout`.
In the new snapshot design, we have a tree of `Task`s that represents
the asynchronously processed document structure. When transforming this
tree in response to a user edit, we want to quickly run through
reusable, already computed nodes of the tree synchronously and then
spawn new tasks for the new parts. The new flag allows us to do such
mixed sync/async tree transformations uniformly. This flag exists as
e.g.
[`ExecuteSynchronously`](https://learn.microsoft.com/en-us/dotnet/api/system.threading.tasks.taskcontinuationoptions?view=net-8.0)
in other runtimes.
else I see
```
[ 69%] Building CXX object runtime/CMakeFiles/leanrt.dir/platform.cpp.o
/home/jojo/build/lean/lean4/src/runtime/io.cpp:509:75: warning: 'static_assert' with no message is a C++17 extension [-Wc++17-extensions]
static_assert(sizeof(std::chrono::milliseconds::rep) <= sizeof(uint64));
^
, ""
/home/jojo/build/lean/lean4/src/runtime/io.cpp:517:74: warning: 'static_assert' with no message is a C++17 extension [-Wc++17-extensions]
static_assert(sizeof(std::chrono::nanoseconds::rep) <= sizeof(uint64));
^
, ""
2 warnings generated.
```
when building
We got an assertion violation yesterday at `leanpkg` at
```cpp
case EEXIST: case EINPROGRESS: case EISCONN:
lean_assert(fname == nullptr); // <<<<<<< HERE
return lean_mk_io_error_already_exists(errnum, details);
```
Make EOF handling in IO.FS.Handle consistent with EOF handling in
IO.FS.Handle.getLine. Previously returned error at EOF which ended up
causing segmentation fault. Remove the declaration of g_io_error_eof,
since it becomes redundant.
Closes#349