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Confusing error using primitive as Dict key

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Assessment

Difficulty
3/5
Estimated time
1-2 days
Newbie friendliness
30/100
Issue type
Bug
Clarity
Needs clarification
Activity status
Stale
Tech stack
python
Domain
backend

Research direction

Reproduce the supplied Python snippet using static and inspect the CheckedDict[int64, bool] getitem path that produces the reported TypeError. Confirm whether primitive keys are supported and establish the expected behavior and diagnostic before changing the runtime handling.

Written by the indexing model from the issue text.

Description

Are primitives like int64 allowed as Dict keys?

I guess not because they can't be sent as function arguments and this program gives a runtime error:

from __static__ import int64, Array, CheckedList, CheckedDict

def create(n: int):
    d = CheckedDict[int64, bool]()
    nn = int64(n)
    if not d[nn]:
      d[nn] = True
    return

create(4)

But the error message is very confusing:

  ....
  File "test.py", line 6, in create
    if not d[nn]:
TypeError: chkdict[int64, bool].__getitem__()() argument 1 expected int64

Argument 1 is an int64 ... right?!

Dominant language
Python
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