This is a continuation of the idea from #174091 to add `match` support
for MLIR containers. In this PR the `OpAttributeMap` container is
registered as a `Mapping`, so be mapped as a "dictionary" in `match`
statements.
For this to work the `get(key, default=None)` method had to be
implemented. Those are pretty much copys of `dunderGetItemNamed` and
`dunderGetItemIndexed` with an added argument and `nb::object` as return
type, because they can now return other types than just `PyAttribute`.
Was unsure if I should refactor this to make `dunderGetItem...` use the
new `getWithDefault...` or if a separate method is preferred. Kept it as
a copy for simplicitys sake for now.
Even though the `OpAttributeMap` supports indexing by `int` and `str`,
Python does not allow to register it as a `Sequence` and a `Mapping` at
the same time. If it is registered as a Sequence it only returns the
attribute names as string, not as `NamedAttribute`. It is technically
possible to also use integer keys for the `dict`-like match, but it
doesn't provide any constraints on the number of attributes, etc., so
probably not recommended.
<details><summary>Example</summary>
```python
from mlir.ir import Context, Module, OpAttributeMap
from collections.abc import Sequence
ctx = Context()
ctx.allow_unregistered_dialects = True
module = Module.parse(
r"""
"some.op"() { some.attribute = 1 : i8,
other.attribute = 3.0,
dependent = "text" } : () -> ()
""",
ctx,
)
op = module.body.operations[0]
def test(attr):
match attr:
case [*args]:
print("matched a Sequence", args)
case _:
print("Didn't match as Sequence")
match attr:
case {"some.attribute": a, "other.attribute": b, "dependent": c}:
print("Matched as Mapping individually", a, b, c)
case _:
print("Didn't match a Mapping")
match attr:
case {0: a, 1: b}:
print("Matched as Mapping with 2 int keys", a, b)
case _:
print("Didn't match as Mapping with 2 int keys")
print("Registered as Mapping only:")
test(op.attributes)
print("\nAfter additonally registering as Sequence:")
Sequence.register(OpAttributeMap)
test(op.attributes)
```
Output:
```
Registered as Mapping only:
Didn't match as Sequence
Matched as Mapping individually 1 : i8 3.000000e+00 : f64 "text"
Matched as Mapping with 2 int keys NamedAttribute(dependent="text") NamedAttribute(other.attribute=3.000000e+00 : f64)
After additonally registering as Sequence:
matched a Sequence ['dependent', 'other.attribute', 'some.attribute']
Didn't match a Mapping
Didn't match as Mapping with 2 int keys
```
</details>
makslevental Would be great if you could take a look again ❤️
---------
Co-authored-by: Maksim Levental <maksim.levental@gmail.com>
524fde8a4d