Pointers and Structures in BASIC+
DLL functions often pass parameters by reference and therefore require pointers to BASIC+ variable data.
| Pointer/Structure | Description |
|---|---|
| Blank_Struct() | Builds a blank structure to pass to a DLL which will then fill in the structure's elements. |
| Build_Struct() | Assembles a binary structure out of BASIC+ variables. |
| Declare_FCNS routine | Compiles a .DLL definition record into BASIC+ callable functions. |
| Define_Struct routine | Starts the Structure Designer tool. |
| GetPointer() | Returns a pointer to the actual data of a BASIC+ variable. Refer to LockVariable, below. |
| GetValue() | De-references a pointer and copies the data to a BASIC+ variable of a specified type. |
| LockVariable statement | Locks a variable so its data does not move in memory. |
| Parse_Struct subroutine | Extracts elements from a structure into BASIC+ variables. |
| Struct_Flush subroutine | Flushes any cached structure definitions. |
| Struct_Len() | Returns the length in bytes of a structure based on the structure's definition. |
| Struct_To_Var() | Converts a binary structure to a dynamic array, placing each element from the structure into the corresponding field. |
| UnlockVariable statement | Unlocks a BASIC+ variable locked by LockVariable. |
| Var_To_Struct() | Converts an @fm-delimited variable into a structure placing, obtaining each structure element from the corresponding field in the variable. |
For more information on DLLs, refer to Chapter 7: Calling DLLs from BASIC+.