List & Dict can't accept `array.dtype` as argument.

Reporting a bug

• I have tried using the latest released version of Numba (most recent is visible in the change log (https://github.com/numba/numba/blob/main/CHANGE_LOG).
• I have included a self contained code sample to reproduce the problem. i.e. it’s possible to run as ‘python bug.py’.

As title.

import numpy as np
from numba import njit
from numba.typed.typedlist import List
from numba.typed.typeddict import Dict


@njit
def example_list(a):
    ls = List.empty_list(a.dtype)
    ls.append(a[0])
    return ls


example_list(np.zeros(1))

- Resolution failure for literal arguments:
No implementation of function Function(<function impl_append at 0x7fc16b232af0>) found for signature:
 >>> impl_append(ListType[dtype(float64)], float64)
There are 2 candidate implementations:
    - Of which 2 did not match due to:
    Overload in function 'impl_append': File: numba/typed/listobject.py: Line 592.
      With argument(s): '(ListType[dtype(float64)], float64)':
     Rejected as the implementation raised a specific error:
       NumbaNotImplementedError: Failed in nopython mode pipeline (step: native lowering)
     Cannot cast float64 to dtype(float64): double %"arg.item"
     During: lowering "casteditem = call $2load_global.0(item, $6load_deref.2, func=$2load_global.0, args=[Var(item, listobject.py:600), Var($6load_deref.2, listobject.py:600)], kws=(), vararg=None, varkwarg=None, target=None)" at /home/auderson/miniconda3/lib/python3.8/site-packages/numba/typed/listobject.py (600)
  raised from /home/auderson/miniconda3/lib/python3.8/site-packages/numba/core/base.py:704
- Resolution failure for non-literal arguments:
None
During: resolving callee type: BoundFunction((<class 'numba.core.types.containers.ListType'>, 'append') for ListType[dtype(float64)])
During: typing of call at <ipython-input-12-6baf440651d6> (10)
File "<ipython-input-12-6baf440651d6>", line 10:
def example_list(a):
    <source elided>
    ls = List.empty_list(a.dtype)
    ls.append(a[0])
    ^

@njit
def example_dict(a):
    d = Dict.empty(a.dtype, a.dtype)
    d[a[0]] = a[0]
    return d


example_dict(np.zeros(1))

No implementation of function Function(<built-in function setitem>) found for signature:
 
 >>> setitem(DictType[dtype(float64),dtype(float64)]<iv=None>, float64, float64)
 
There are 16 candidate implementations:
  - Of which 14 did not match due to:
  Overload of function 'setitem': File: <numerous>: Line N/A.
    With argument(s): '(DictType[dtype(float64),dtype(float64)]<iv=None>, float64, float64)':
   No match.
  - Of which 2 did not match due to:
  Overload in function 'impl_setitem': File: numba/typed/dictobject.py: Line 695.
    With argument(s): '(DictType[dtype(float64),dtype(float64)]<iv=None>, float64, float64)':
   Rejected as the implementation raised a specific error:
     TypingError: Failed in nopython mode pipeline (step: nopython frontend)
   No implementation of function Function(<built-in function hash>) found for signature:
    
    >>> hash(dtype(float64))
    
   There are 4 candidate implementations:
         - Of which 2 did not match due to:
         Overload of function 'hash': File: numba/experimental/jitclass/overloads.py: Line 0.
           With argument(s): '(dtype(float64))':
          No match.
         - Of which 2 did not match due to:
         Overload in function 'hash_overload': File: numba/cpython/hashing.py: Line 48.
           With argument(s): '(dtype(float64))':
          Rejected as the implementation raised a specific error:
            TypingError: Failed in nopython mode pipeline (step: nopython frontend)
          Unknown attribute '__hash__' of type dtype(float64)
          
          File "../miniconda3/lib/python3.8/site-packages/numba/cpython/hashing.py", line 51:
              def impl(obj):
                  return obj.__hash__()
                  ^
          
          During: typing of get attribute at /home/auderson/miniconda3/lib/python3.8/site-packages/numba/cpython/hashing.py (51)
          
          File "../miniconda3/lib/python3.8/site-packages/numba/cpython/hashing.py", line 51:
              def impl(obj):
                  return obj.__hash__()
                  ^
   
     raised from /home/auderson/miniconda3/lib/python3.8/site-packages/numba/core/typeinfer.py:1086
   
   During: resolving callee type: Function(<built-in function hash>)
   During: typing of call at /home/auderson/miniconda3/lib/python3.8/site-packages/numba/typed/dictobject.py (706)
   
   
   File "../miniconda3/lib/python3.8/site-packages/numba/typed/dictobject.py", line 706:
       def impl(d, key, value):
           <source elided>
           castedval = _cast(value, valty)
           status = _dict_insert(d, castedkey, hash(castedkey), castedval)
           ^
  raised from /home/auderson/miniconda3/lib/python3.8/site-packages/numba/core/typeinfer.py:1086
During: typing of setitem at <ipython-input-3-3aa1714a8578> (4)
File "<ipython-input-3-3aa1714a8578>", line 4:
def example_dict(a):
    <source elided>
    d = Dict.empty(a.dtype, a.dtype)
    d[a[0]] = a[0]
    ^

[auderson]

@esc Thanks! This works.

[stuartarchibald]

@stuartarchibald Many thanks for this detailed reply. Actually I’ve tried ls = typed.List.empty_list(a.dtype.dtype) becasue I found DType has a dtype propertyjoy.

No problem. Glad you’ve found something that works. Am going to close this as resolved and have opened #8372 to track the issue with typed.List.append not validating types correctly.