Syntax
{ ALPHA ( numcst ) } |
|
{ NUM_E ( numcst1 , numcst2 ) } |
|
{ NUM_P ( numcst1 , numcst2 ) } |
|
{ BOOL } |
|
{ DATE } |
|
{ TIME } |
|
{ TIMESTAMP } |
|
{ NUM_BIN_2 } |
|
{ NUM_BIN_4 } |
|
{ NUM_BIN_8 } |
|
{ VariableId } |
This syntax can be used to refer to the specified user variable's Adelia definition. |
{ AdeliaClassName } |
Cast of a class instance. |
Description
Cast can be used in the context of graphical object-type variables or class instance-type variables.
Context: graphical object-type variables
It is possible to provide read/write access to a Mixed (and as such non-defined) property by using special syntax:
<Cast> <object:MixedProperty>
(The cast instruction that forces the type always precedes the mixed property).
All 4GL instructions that can have a variable as a parameter can also have a mixed property with a cast type.
Whenever a property with an unspecified type (e.g. VALUE property for a GRAPHIC_OBJECT variable) is used, it must be preceded by a cast instruction.
Context: class instance-type variables
Used to assign, in a given class instance variable, the reference contained in a class instance variable which encompasses the given class.
DestClassiVariable = { DestClassName } OrigClassiVariable
where DestClassiVariable is declared as CLASS_REF(DestClassName)
where OrigClassiVariable is declared as CLASS_REF(*OBJECT)
Examples
Context: variables of graphic object type
GRAPHIC_OBJECT (INPUT_FIELD) MyGraphicObject
NUM_BIN_4 Result
Result = { NUM_BIN_4 } MyGraphicObject:VALUE
Result = { Result } MyGraphicObject:VALUE
Context: variables of class instance type
REF_CLASS(*OBJECT) iObject
REF_CLASS(PERSON) iPerson
...
IF iObject PERSON_INSTANCE
iPerson = { PERSON } iObject
END
Back to the description of the GRAPHIC_OBJECT instruction
Back to the description of the assignment operator