Adding Functions

Once you have initialized the MyBASIC2 environment you can create and open an interpreter and start adding your script functions.

Opening the Interpreter

int mb_open( mb_interpreter_t** s );

This function opens an interpreter structure to get ready for parsing and running.

Closing the Interpreter

int mb_close(mb_interpreter_t** s);

This function closes an interpreter structure when it is no longer used. mb_open and mb_close must be matched in pair.

Adding Functions

int mb_register_func( mb_interpreter_t* s, const char* n, mb_func_t f );

This function registers a function pointer into an interpreter structure using a given name. The function to be registered must be a pointer as int (*mb_func_t)( struct mb_interpreter_t*, void** ). A registered function can be called in script.

int mb_remove_func( mb_interpreter_t* s, const char* n );

This function removes a registered function out of an interpreter structure by a given name.

Example

/////////////////////////////////////////////////////////////////////////////

// Forward Declare our callback functions

int _hello_func( mb_interpreter_t* s, void** l );

int _bye_func( mb_interpreter_t* s, void** l );

.

.

// Initialize MyBASIC2

mb_init();

// Create and Open an interpreter

mb_interpreter_t* bas = NULL;

mb_open( &bas );

// Register our functions

mb_register_func( bas, "HELLO", _hello_func );

mb_register_func( bas, "BYE", _bye_func );

// Load and run the script

if ( mb_load_file( bas, "MY_SCRIPT.BAS" ) == MB_FUNC_OK )

{

  // Note, mb_run will return MB_FUNC_END when normal termination

  if ( mb_run( bas ) != MB_FUNC_END )

  {

     printf( "Error Running Script File MY_SCRIPT.BAS\n" );

  }

}

else

{

  printf( "Error Loading Script File MY_SCRIPT.BAS\n" );

}

// Remove functions and close interpreter

mb_remove_func( "HELLO" );

mb_remove_func( "BYE );

mb_close( &bas );

// Terminate MyBASIC2

mb_exit();

.

.

/////////////////////////////////////////////////////////////////////////////

//

int _hello_func( mb_interpreter_t* s, void** l )

{

  // Parse Empty Parameters

  BEGIN_PARSE( s, l )

  END_PARSE

  // Create output String

  COPY_STRING( pHello, "HELLO" );

  // Return the string "HELLO"

  RETURN_STRING( pHello );

}

/////////////////////////////////////////////////////////////////////////////

//

int _bye_func( mb_interpreter_t* s, void** l )

{

  // Parse Empty Parameters

  BEGIN_PARSE( s, l )

  END_PARSE

  // Terminate Interpreter

  RETURN_INT_BYE( 1 );

}