id,node_id,number,title,user,state,locked,assignee,milestone,comments,created_at,updated_at,closed_at,author_association,active_lock_reason,draft,pull_request,body,reactions,performed_via_github_app,state_reason,repo,type
1943539215,PR_kwDOAMm_X85c0AkW,8309,Move variable typed ops to NamedArray,43316012,open,0,,,1,2023-10-14T20:22:07Z,2023-10-26T21:55:01Z,,COLLABORATOR,,1,pydata/xarray/pulls/8309,"<!-- Feel free to remove check-list items aren't relevant to your change -->

- xref https://github.com/pydata/xarray/issues/8238

This is highly WIP and probably everything is broken right now...
Just creating this now, so other people don't work on the same :)
Feel free to continue here with me.

@pydata/xarray 
1. what do we do with commonly used functions, is it ok to copy them?
2. Moving the typed ops requires a lot of functions to be added to NamedArray, is there a consensus of what we want to move? Is it basically everything?
3. Slowly the utils module is becomming a graveyard of stuff we dont want to put elsewhere, maybe we should at least move the typing stuff over to a types module.","{""url"": ""https://api.github.com/repos/pydata/xarray/issues/8309/reactions"", ""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",,,13221727,pull
1275747776,I_kwDOAMm_X85MCl3A,6703,"Add coarsen, rolling and weighted to generate_reductions",43316012,open,0,,,1,2022-06-18T09:49:22Z,2022-06-18T16:04:15Z,,COLLABORATOR,,,,"### Is your feature request related to a problem?

Coarsen reductions are currently added dynamically which is not very useful for typing.
This is a follow-up to @Illviljan in https://github.com/pydata/xarray/pull/6702#discussion_r900700532_

Same goes for Weighted.
And similar for Rolling (not sure if it is exactly the same though?)

### Describe the solution you'd like

Extend the generate_reductions script to include `DataArrayCoarsen` and `DatasetCoarsen`.
Once finished: use type checking in all test_coarsen tests.","{""url"": ""https://api.github.com/repos/pydata/xarray/issues/6703/reactions"", ""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",,,13221727,issue
1150618439,I_kwDOAMm_X85ElQtH,6306,Assigning to dataset with missing dim raises ValueError,43316012,open,0,,,1,2022-02-25T16:08:04Z,2022-05-21T20:35:52Z,,COLLABORATOR,,,,"### What happened?

I tried to assign values to a dataset with a selector-dict where a variable is missing the dim from the selector-dict.
This raises a ValueError.

### What did you expect to happen?

I expect that assigning works the same as selecting and it will ignore the missing dims.

### Minimal Complete Verifiable Example

```Python
import xarray as xr

ds = xr.Dataset({""a"": (""x"", [1, 2, 3]), ""b"": (""y"", [4, 5])})

ds[{""x"": 1}]
# this works and returns:
# <xarray.Dataset>
# Dimensions:  (y: 2)
# Dimensions without coordinates: y
# Data variables:
#     a        int64 2
#     b        (y) int64 4 5

ds[{""x"": 1}] = 1
# this fails and raises a ValueError
# ValueError: Variable 'b': indexer {'x': 1} not available
```


### Relevant log output

```Python
Traceback (most recent call last):
  File ""xarray/core/dataset.py"", line 1591, in _setitem_check
    var_k = var[key]
  File ""xarray/core/dataarray.py"", line 740, in __getitem__
    return self.isel(indexers=self._item_key_to_dict(key))
  File ""xarray/core/dataarray.py"", line 1204, in isel
    variable = self._variable.isel(indexers, missing_dims=missing_dims)
  File ""xarray/core/variable.py"", line 1181, in isel
    indexers = drop_dims_from_indexers(indexers, self.dims, missing_dims)
  File ""xarray/core/utils.py"", line 834, in drop_dims_from_indexers
    raise ValueError(
ValueError: Dimensions {'x'} do not exist. Expected one or more of ('y',)

The above exception was the direct cause of the following exception:

Traceback (most recent call last):
  File ""<stdin>"", line 1, in <module>
  File ""xarray/core/dataset.py"", line 1521, in __setitem__
    value = self._setitem_check(key, value)
  File ""xarray/core/dataset.py"", line 1593, in _setitem_check
    raise ValueError(
ValueError: Variable 'b': indexer {'x': 1} not available
```


### Anything else we need to know?

_No response_

### Environment

INSTALLED VERSIONS
------------------
commit: None
python: 3.9.1 (default, Jan 13 2021, 15:21:08) 
[GCC 4.8.5 20150623 (Red Hat 4.8.5-44)]
python-bits: 64
OS: Linux
OS-release: 3.10.0-1160.49.1.el7.x86_64
machine: x86_64
processor: x86_64
byteorder: little
LC_ALL: None
LANG: en_US.UTF-8
LOCALE: ('en_US', 'UTF-8')
libhdf5: 1.12.0
libnetcdf: 4.7.4

xarray: 0.21.1
pandas: 1.4.0
numpy: 1.21.5
scipy: 1.7.3
netCDF4: 1.5.8
pydap: None
h5netcdf: None
h5py: None
Nio: None
zarr: None
cftime: 1.5.1.1
nc_time_axis: None
PseudoNetCDF: None
rasterio: None
cfgrib: None
iris: None
bottleneck: None
dask: None
distributed: None
matplotlib: 3.5.1
cartopy: None
seaborn: None
numbagg: None
fsspec: None
cupy: None
pint: None
sparse: None
setuptools: 49.2.1
pip: 22.0.3
conda: None
pytest: 6.2.5
IPython: 8.0.0
sphinx: None","{""url"": ""https://api.github.com/repos/pydata/xarray/issues/6306/reactions"", ""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",,,13221727,issue