[WIP] feat: add dask windows

[gerrymanoim]

Previously dask supported "noop" windows. This PR adds some limited window functionality. Draft to see how far I can reasonably get while keeping this a reasonable size.

Notes:

• dask only supports single value sorts, so any window with grouping and sorting is not supported
• I'm trying to keep the structure quite close the pandas backend, which will make some eventual consolidation and refactoring much easier to do. However, the pandas windowing code definitely needs some broad refactoring so things look a bit messy.

[codecov[bot]]

Codecov Report

Merging #4157 (0ed1e89) into master (0393891) will increase coverage by 0.00%. The diff coverage is 93.75%.

@@           Coverage Diff           @@
##           master    #4157   +/-   ##
=======================================
  Coverage   92.98%   92.98%           
=======================================
  Files         158      158           
  Lines       18298    18373   +75     
  Branches     2663     2675   +12     
=======================================
+ Hits        17014    17085   +71     
- Misses        963      965    +2     
- Partials      321      323    +2     

Flag	Coverage Δ
Linux	92.88% <93.75%> (+<0.01%)	:arrow_up:
Windows	72.13% <93.75%> (+0.10%)	:arrow_up:
backend	89.89% <93.75%> (+0.01%)	:arrow_up:
clickhouse	49.91% <0.00%> (-0.21%)	:arrow_down:
core	52.42% <0.00%> (-0.09%)	:arrow_down:
dask	52.23% <93.75%> (+0.41%)	:arrow_up:
datafusion	43.89% <0.00%> (-0.18%)	:arrow_down:
duckdb	49.67% <0.00%> (-0.21%)	:arrow_down:
impala	55.23% <0.00%> (-0.24%)	:arrow_down:
mysql	47.48% <0.00%> (-0.20%)	:arrow_down:
pandas	49.28% <0.00%> (-0.21%)	:arrow_down:
postgres	51.52% <0.00%> (-0.22%)	:arrow_down:
pyspark	52.75% <0.00%> (-0.22%)	:arrow_down:
python-3.10.5	86.89% <93.75%> (+0.04%)	:arrow_up:
python-3.8.10	72.13% <93.75%> (+0.10%)	:arrow_up:
python-3.8.13	92.89% <93.75%> (+<0.01%)	:arrow_up:
python-3.9.13	52.28% <0.00%> (-9.29%)	:arrow_down:
sqlite	48.95% <0.00%> (-0.21%)	:arrow_down:
tpc	35.17% <0.00%> (-0.15%)	:arrow_down:
tpch	35.17% <0.00%> (-0.15%)	:arrow_down:

Flags with carried forward coverage won't be shown. Click here to find out more.

Impacted Files	Coverage Δ
ibis/backends/dask/execution/util.py	89.62% <83.33%> (+1.56%)	:arrow_up:
ibis/backends/dask/execution/window.py	95.68% <94.38%> (-4.32%)	:arrow_down:
ibis/backends/dask/execution/selection.py	87.23% <100.00%> (ø)
ibis/backends/impala/client.py	87.17% <0.00%> (-0.66%)	:arrow_down:
ibis/backends/dask/execution/arrays.py	100.00% <0.00%> (+4.76%)	:arrow_up:

[github-actions[bot]]

Unit Test Results

       35 files         35 suites   1h 7m 54s :stopwatch:   8 662 tests   6 760 :heavy_check_mark: 1 665 :zzz: 0 :x: 237 :fire: 31 827 runs  25 235 :heavy_check_mark: 6 355 :zzz: 0 :x: 237 :fire:

For more details on these errors, see this check.

Results for commit 0ed1e894.

:recycle: This comment has been updated with latest results.

[cpcloud]

@gerrymanoim We're planning on a 3.2.0 release around the beginning of September. Do you think you'll be able to finish this up by then?

[cpcloud]

@gerrymanoim Are you still working on this?

[gerrymanoim]

Hey - apologies I missed your first message.

Yes - this is still on our list of things we want to do - I don't have an ETA unfortunately for when I'll next carve out time to work on this. You can close this if you'd like.

[cpcloud]

Closing. Please reopen if you get a chance to work on it later!