When the Python iterator backing `PyIterator` has a `__length_hint__` special
method, we can use this as a lower bound for Rust's `Iterator::size_hint` to
e.g. support pre-allocation of collections.
This is implemented using `PyObject_LengthHint` which is not available in the
stable ABI and hence so is `Iterator::size_hint`. This should be fine since this
is an optimization in any case and the stable ABI is expected to have slightly
worse performance overall.
3203: support ordering magic methods for `#[pyclass]` r=adamreichold a=davidhewitt
Closes#2089
This adds `__lt__`, `__le__`, `__eq__`, `__ne__`, `__gt__`, and `__ge__` as per the Python implementations of what we call `__richcmp__`.
There's a UI test confirming that the user cannot implement split forms and `__richcmp__` simultaneously.
There's also a benchmark comparing implementing these split methods against using `__richcmp__`. I couldn't see a meaningful performance difference, so I'm tempted to deprecate `__richcmp__`, given that's not a magic method which exists in Python. Potentially we can provide options such as the opt-in `#[pyclass(eq, ord)]` to avoid boilerplate for people who don't want to implement six different methods.
Co-authored-by: David Hewitt <1939362+davidhewitt@users.noreply.github.com>
3029: use dynamic trampoline for all getters and setters r=adamreichold a=davidhewitt
This is an extension to the "trampoline" changes made in #2705 to re-use a single trampoline for all `#[getter]`s (and similar for all `#[setters]`). It works by setting the currently-unused `closure` member of the `ffi::PyGetSetDef` structure to point at a new `struct GetSetDefClosure` which contains function pointers to the `getter` / `setter` implementations.
A universal trampoline for all `getter`, for example, then works by reading the actual getter implementation out of the `GetSetDefClosure`.
Advantages of doing this:
- Very minimal simplification to the macro code / generated code size. It made a 4.4% reduction to `test_getter_setter` generated size, which is an exaggerated result as most code will probably have lots of bulk that isn't just the macro code.
Disadvantages:
- Additional level of complexity in the `getter` and `setter` trampolines and accompanying code.
- To keep the `GetSetDefClosure` objects alive, I've added them to the static `LazyTypeObject` inner.
- Very slight performance overhead at runtime (shouldn't be more than an additional pointer read). It's so slight I couldn't measure it.
Overall I'm happy to either merge or close this based on what reviewers think!
Co-authored-by: David Hewitt <1939362+davidhewitt@users.noreply.github.com>
2980: support `text_signature` on `#[new]` r=adamreichold a=davidhewitt
Closes#2866
This is a breaking change for 0.19.0, because it starts autogenerating `text_signature` for `#[new]`. This could affect runtime behaviour if the user is relying on the class docs at runtime for some reason.
Guide & tests all updated accordingly.
`#[pyclass(text_signature = "...")]` is deprecated by this PR, however if it's set, it will be used in preference to `#[new]`.
(The signature / `text_signature` from `#[new]` will simply be ignored in this case. I figure that when users fix their deprecation warnings by removing `#[pyclass(text_signature = "...")]` then the `#[new]` signatures will start flowing properly, and this is good enough.)
Co-authored-by: David Hewitt <1939362+davidhewitt@users.noreply.github.com>
Co-authored-by: Adam Reichold <adam.reichold@t-online.de>
2975: RFC: Add GILProtected synchronization primitive and use it for LazyTypeObjectInner. r=davidhewitt a=adamreichold
I would also like to use that type in rust-numpy and it seems we can avoid ~~both a manual unsafe impl and~~ a full blown mutex if we apply it to `LazyTypeObjectInner`.
One downside might be that it ties us closer to the GIL when we want to enable nogil experimentation, but on the other hand, it may also help by reifying the GIL usage. (This is currently limited to comments in unsafe code in rust-numpy for example.)
3022: Fix function name shadowing r=davidhewitt a=mejrs
Fixes https://github.com/PyO3/pyo3/issues/3017
3023: Emit a better error for bad argument names r=davidhewitt a=mejrs
This will emit a better error for code like
```rust
#[pyfunction]
fn output([a,b,c]: [u8;3]) {}
```
Co-authored-by: Adam Reichold <adam.reichold@t-online.de>
Co-authored-by: mejrs <59372212+mejrs@users.noreply.github.com>
David Hewitt