Class PyScalarDTypeMeta
- Namespace
- NumSharp
- Assembly
- NumSharp.dll
NumPy's abstract DType classes for Python scalars — numpy.dtypes._PyLongDType,
_PyFloatDType, _PyComplexDType (abstractdtypes.c). They are how NEP 50 "weak" promotion
works: a literal contributes only its abstract CLASS to result_type (no descriptor, so no value or
width), and the class's CommonDType(DTypeMeta) lets the other operand's dtype win within its kind
(int8 + 300 → int8, float32 + 1e300 → float32) while still lifting across kinds
(int8 + 1.5 → float64). A literal that survives alone falls back to the class default
(int64 / float64 / complex128).
public sealed class PyScalarDTypeMeta : DTypeMeta- Inheritance
-
PyScalarDTypeMeta
- Inherited Members
Remarks
C# has no Python-literal/NumPy-scalar split, so the mapping is by TYPE (the house NEP 50 rule): the integer
primitives, float/double and Complex are weak; bool, char, Half,
decimal and every NDArray (0-d included) are strong.
Properties
PyKind
Which literal category this class stands for.
public PyScalarKind PyKind { get; }Property Value
Methods
CommonDType(DTypeMeta)
Ports of int_common_dtype / float_common_dtype / complex_common_dtype. The builtin
classes handle most pairs themselves (their common_dtype is asked FIRST and answers for a literal of
their own or a lower kind); these implement the remaining directions: a weak int with bool is the
default integer, a weak float or complex with an integer or bool class is float64 /
complex128, and two abstract classes resolve to the higher category. The NumSharp-only storage
classes (Decimal, Char) are treated as the numeric builtins they masquerade as — Char is an unsigned
integer here, so result_type(char_array, 1.5) is float64 exactly like uint16 — rather
than through NumPy's opaque-user-dtype fallback; a genuinely foreign legacy class still takes that
fallback (promote with the smallest concrete type of the literal's category and let it decide).
public override DTypeMeta CommonDType(DTypeMeta other)Parameters
otherDTypeMeta
Returns
DefaultDescr()
The default descriptor a lone literal resolves to: int64 (NumPy's intp), float64, complex128.
public override DType DefaultDescr()Returns
IsKnownScalarType(Type)
Weak literals map onto the C# primitives of their category.
public override bool IsKnownScalarType(Type type)Parameters
typeType