BASICCompiling programsCompiler directives

Compiler directives

Compiler directives control how a program is compiled. D3 supports a number of compiler directives to affect how a program is compiled.

Any line that begins with a dollar sign character ($) is considered to be a compiler directive.

The BASIC compiler stores the object code for a BASIC program in the dictionary of the same file as the source code, using the same item-ID.

Remarks

Remarks or comments can be embedded anywhere in the program without affecting program execution. These remarks can be used to document or explain the logic of the program.

Remark statements are specified by the letters REM, or an asterisk (*), or an exclamation point (!) at the beginning of a program statement. Any characters that follow (up to the end of the line) are ignored by the compiler. Note that the compiler comments out the whole attribute and does not honor semicolons (;). An example of remark statements is as follows:
REM THESE BASIC STATEMENTS
! DO NOT AFFECT
* PROGRAM EXECUTION

Refer to the following sections for details regarding available directives:

  • $* directive
    The $* (asterisk) directive allows a comment to be embedded directly into the program’s object code at compilation.
  • $chain directive
    The $chain directive continues FlashBASIC or BASIC compilation in a different source item.
  • $DEFINE directive
    The $DEFINE directive supplies replacement text for a symbol and defines a symbol used to control the compilation of the program.
  • $IFDEF directive
    The $IFDEF directive tests for the definition of an identifier in the compiler symbol table.
  • $IFNDEF directive
    The $IFNDEF directive tests for the absence of a definition for an identifier in the compiler symbol table.
  • $include directive
    The $include directive inserts FlashBASIC or BASIC code from a separate item (known as an include item) to be compiled as part of the object module of the current program or subroutine. The original source program is not altered.
  • $options directive
    The $options directive sets compatibility options for the FlashBASIC or BASIC compiler.
  • $UNDEFINE directive
    The $UNDEFINE directive deletes a specified identifier from the symbol table. The identifier must have previously been defined by a $DEFINE directive.

Related topics
Compiling programs
FlashBASIC and BASIC differences
Error logging
Performance
BASIC symbolic debugger