def from_dtype(dtype):
"""
Return a Numba Type instance corresponding to the given Numpy *dtype*.
NotImplementedError is raised on unsupported Numpy dtypes.
"""
if type(dtype) == type and issubclass(dtype, np.generic):
dtype = np.dtype(dtype)
elif getattr(dtype, "fields", None) is not None:
return from_struct_dtype(dtype)
try:
return FROM_DTYPE[dtype]
except KeyError:
pass
try:
char = dtype.char
except AttributeError:
pass
else:
if char in 'SU':
return _from_str_dtype(dtype)
if char in 'mM':
return _from_datetime_dtype(dtype)
if char in 'V' and dtype.subdtype is not None:
subtype = from_dtype(dtype.subdtype[0])
return types.NestedArray(subtype, dtype.shape)
raise errors.NumbaNotImplementedError(dtype)
def as_dtype(nbtype):
"""
Return a numpy dtype instance corresponding to the given Numba type.
NotImplementedError is if no correspondence is known.
"""
nbtype = types.unliteral(nbtype)
if isinstance(nbtype, (types.Complex, types.Integer, types.Float)):
return np.dtype(str(nbtype))
if nbtype is types.bool_:
return np.dtype('?')
if isinstance(nbtype, (types.NPDatetime, types.NPTimedelta)):
letter = _as_dtype_letters[type(nbtype)]
if nbtype.unit:
return np.dtype('%s[%s]' % (letter, nbtype.unit))
else:
return np.dtype(letter)
if isinstance(nbtype, (types.CharSeq, types.UnicodeCharSeq)):
letter = _as_dtype_letters[type(nbtype)]
return np.dtype('%s%d' % (letter, nbtype.count))
if isinstance(nbtype, types.Record):
return as_struct_dtype(nbtype)
if isinstance(nbtype, types.EnumMember):
return as_dtype(nbtype.dtype)
if isinstance(nbtype, types.npytypes.DType):
return as_dtype(nbtype.dtype)
if isinstance(nbtype, types.NumberClass):
return as_dtype(nbtype.dtype)
if isinstance(nbtype, types.NestedArray):
spec = (as_dtype(nbtype.dtype), tuple(nbtype.shape))
return np.dtype(spec)
if isinstance(nbtype, types.PyObject):
return np.dtype(object)
msg = f"{nbtype} cannot be represented as a NumPy dtype"
raise errors.NumbaNotImplementedError(msg)
def cast(self, builder, val, fromty, toty):
"""
Cast a value of type *fromty* to type *toty*.
This implements implicit conversions as can happen due to the
granularity of the Numba type system, or lax Python semantics.
"""
if fromty == toty or toty == types.Any:
return val
try:
impl = self._casts.find((fromty, toty))
return impl(self, builder, fromty, toty, val)
except errors.NumbaNotImplementedError:
raise errors.NumbaNotImplementedError(
"Cannot cast %s to %s: %s" % (fromty, toty, val))
def _find(self, sig):
candidates = self._select_compatible(sig)
if candidates:
return candidates[self._best_signature(candidates)]
else:
raise errors.NumbaNotImplementedError(f'{self}, {sig}')