TType
Abstract base class for types that are used in a type system.
Inheritance
| Level | Ancestor | Description |
|---|---|---|
| 1 | TObject | Ultimate ancestor in a class hierarchy |
| 2 | TBaseObject | A base class for objects that can be used instead of TObject. |
| 3 | TReferenceCountedObject | Object that keeps track of the number of times it is referenced from other objects |
| 4 | TValue | Base class for an immutable object that stores a value of a certain TType. |
| 5 | TType |
Source
Type_.pas (30)
Description
Models a type as used in a formal type system. In this sense a type represents a (possibly infinite) set of possible values. This set is called the value set of a type. Using the set theoretic approach ensures a very sound type system where type relations are clear and correct. The subtype relation for types for instance cleanly maps onto the subset relation for sets. That is, type A is a subtype of type B when the value set of type A is a subset of the value set of type B.
Methods
| Scope | Visibility | Result | Name | Description |
|---|---|---|---|---|
| Instance | protected | TBoolean | IsValueSubtype(Type_: TType) | |
| Instance | public | TStorageType | GetStorageType() | |
| Instance | public | TType | GetDecoratedType() | |
| Instance | public | TDocumentNode | GetCaption() | |
| Instance | public | TBoolean | IsNullable() | |
| Instance | public | TBoolean | IsNumeric() | |
| Instance | public | TBoolean | CheckValue(Messages: TList<TDocumentNode>; Value: TValue) | |
| Instance | public | TBoolean | IsValidValue(Messages: TList<TDocumentNode>; Value: TValue) | |
| Instance | public | TBoolean | IsValidValue(Value: TValue) | |
| Instance | public | TComparator<TValue> | GetValueComparator() | |
| Instance | public | TBoolean | IsEquivalentTo(OtherType: TType) | |
| Instance | public | TBoolean | IsSupertypeOf(OtherType: TType) | |
| Instance | public | TBoolean | OverlapsWith(OtherType: TType) | |
| Instance | public | TType | CommonType(OtherType: TType) | |
| Instance | public | TBoolean | SharesTypePath(OtherType: TType) | |
| Instance | public | TBoolean | IsProperSupertypeOf(OtherType: TType) | |
| Instance | public | TBoolean | IsSubtypeOf(OtherType: TType) | |
| Instance | public | TBoolean | IsProperSubtypeOf(OtherType: TType) | |
| Instance | public | TType | Optional() |