improve to native types

[goodwanghan]

No description provided.

[codecov-commenter]

Codecov Report

Merging #7 (2ba386b) into master (381a973) will not change coverage.
The diff coverage is 100.00%.

@@            Coverage Diff             @@
##            master        #7    +/-   ##
==========================================
  Coverage   100.00%   100.00%            
==========================================
  Files            5         9     +4     
  Lines          667      1282   +615     
==========================================
+ Hits           667      1282   +615     

Impacted Files	Coverage Δ
slide/_type_utils.py	100.00% <100.00%> (ø)
slide/operators/execution_plan.py	100.00% <100.00%> (ø)
slide/operators/graph.py	100.00% <100.00%> (ø)
slide/utils.py	100.00% <100.00%> (ø)
slide_dask/utils.py	100.00% <100.00%> (ø)
slide_pandas/__init__.py	100.00% <100.00%> (ø)
slide_pandas/utils.py	100.00% <100.00%> (ø)

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