Compiler Functions

Size = SizeOf(Type)

SizeOf can be used to find out the size of any complex Structure (it does not work on the simple built-in types such as word and float), Interface or even variables. This can be useful in many areas such as calculating memory requirements for operations, using API commands, etc.

Note: In unicode mode one character uses 2 bytes. In Ascii mode one character uses 1 byte. Sizeof(Character) allows to return the size (in bytes), which is taken by one character according to the active mode.

Example:

  Structure Person
    Name.s
    ForName.s 
    Age.w 
  EndStructure
  
  Debug "The size of my friend is "+Str(Sizeof(Person))+" bytes" ; will be 10 (4+4+2)
  
  John.Person\Name = "John"
  
  Debug SizeOf(John) ; will be also 10 

Note: if a variable and a structure have the same name, the structure will have the priority over the variable.

Index = OffsetOf(Structure\Field)
Index = OffsetOf(Interface\Function())

OffsetOf can be used to find out the index of a Structure field or the index of an Interface function. When used with an Interface, the function index is the memory offset, so it will be IndexOfTheFunction*4.

Example:

  Structure Person
    Name.s
    ForName.s 
    Age.w 
  EndStructure
  
  Debug OffsetOf(Person\Age) ; will be 8 as a string is 4 byte in memory
  
  
  Interface ITest
    Create()
    Destroy(Flags) 
  EndInterface
  
  Debug OffsetOf(ITest\Destroy()) ; will be 4

Result = Subsystem(<constant string expression>)

Subsystem can be used to find out if a subsystem is in use for the program being compiled. The name of the subsystem is not case sensitive.

Example:

  CompilerIf Subsystem("OpenGL")
    Debug "Compiling with the OpenGL subsystem"
  CompilerEndIf

Result = Defined(Name, Type)

Defined checks if a particular object of a code source like structure, interface, variables etc. is already defined or not. The 'Name' parameter has to be specified without any extra decoration (ie: without the '#' for a constant, without '()' for an array or a linkedlist).

The 'Type' parameter can be one of the following values:

  #PB_Constant
  #PB_Variable
  #PB_Array
  #PB_LinkedList
  #PB_Structure
  #PB_Interface

Example:

  #PureConstant = 10
  
  CompilerIf Defined(PureConstant, #PB_Constant)
    Debug "Constant 'PureConstant' is already declared"
  CompilerEndIf
  
  Test = 25
  
  CompilerIf Defined(Test, #PB_Variable)
    Debug "Variable 'Test' is already declared"
  CompilerEndIf