test_example.lst

' ================================================================
! GFA BASIC 3.6 Enhanced Syntax Highlighting Test File
! Purpose: Demonstrate comprehensive syntax highlighting features
! ================================================================

! Variable type demonstrations
DIM screen_buffer|(32000)    ! 8-bit integer array for screen buffer
DIM palette&(16)             ! 16-bit integer array for color palette
DIM counters|(8)             ! 8-bit integer array for counters
DIM flags!(10)               ! Boolean array for flags
DIM messages$(20)            ! String array for messages
DIM coordinates(100)         ! Float array for coordinates

! System memory addresses (hexadecimal)
screen_base% = &HFFFF8200    ! Screen base address
palette_reg% = &HFFFF8240    ! Palette register base
video_mode& = &HFFFF8260     ! Video mode register

! Binary constants for bit manipulation
mask_bits| = &X11110000      ! Binary mask
flag_bits| = &X00001111      ! Binary flags

! String and numeric variables
title$ = "GFA BASIC 3.6 Demo"
version$ = "Enhanced v2.0"
max_objects& = 100
animation_speed! = TRUE
pi = 3.14159265

! ================================================================
! MAIN PROGRAM
! ================================================================

! Initialize system
CALL initialize_system%
CALL setup_graphics%

! Main program loop
REPEAT
  @handle_input
  GOSUB update_animation
  GOSUB draw_graphics
  VSYNC                      ! Wait for vertical sync
UNTIL quit!

! Cleanup and exit
CALL cleanup_system%
END

! ================================================================
! PROCEDURES AND FUNCTIONS
! ================================================================

! Initialize system procedure
PROCEDURE initialize_system
  ! Set video mode
  old_rez& = XBIOS(4)        ! Get current resolution
  ~XBIOS(5,L:-1,L:-1,W:1)        ! Set medium resolution
  
  ! Initialize variables
  quit! = FALSE
  frame_count& = 0
  
  ! Setup color palette
  FOR i| = 0 TO 15
    palette&(i|) = RAND(4096) ! Random color values
    SETCOLOR i|, palette&(i|)
  NEXT i|
  
  PRINT "System initialized successfully!"
RETURN

! Graphics setup function
FUNCTION setup_graphics
  LOCAL result!
  
  ! Clear screen
  CLS
  
  ' Set drawing parameters
  DEFFILL 1, 2, 8           ! Fill style, color, pattern
  DEFLINE 1, 1, &HAAAA      ! Line style, color, pattern
  DEFMARK 1, 2, 10          ! Marker style, color, size
  
  ' Draw title
  LOCATE 10, 2
  PRINT title$; " - "; version$
  
  result! = TRUE
  RETURN result!
ENDFUNC

! Input handling subroutine
handle_input:
  key$ = INKEY$
  
  SELECT key$
  CASE CHR$(27)              ! ESC key
    quit! = TRUE
  CASE "s", "S"              ! Save screenshot
    GOSUB save_screen
  CASE "p", "P"              ! Pause animation
    animation_speed! = NOT animation_speed!
  CASE " "                   ! Space - step frame
    IF NOT animation_speed!
      GOSUB update_animation
    ENDIF
  DEFAULT
    ' Do nothing for other keys
  ENDSELECT
RETURN

! Animation update subroutine
update_animation:
  IF animation_speed!
    INC frame_count&
    
    ' Update object positions
    FOR i& = 0 TO max_objects& - 1
      coordinates(i& * 2) = 160 + SIN(frame_count& + i&) * 100
      coordinates(i& * 2 + 1) = 100 + COS(frame_count& + i&) * 50
    NEXT i&
  ENDIF
RETURN

! Graphics drawing subroutine
draw_graphics:
  ! Clear previous frame
  PBOX 0, 50, 319, 199      ! Clear drawing area
  
  ! Draw animated objects
  FOR i& = 0 TO max_objects& - 1
    x& = coordinates(i& * 2)
    y& = coordinates(i& * 2 + 1)
    color| = i& MOD 16
    
    ! Draw different shapes based on object index
    SELECT i& MOD 4
    CASE 0
      PSET x&, y&, color|    ! Draw pixel
    CASE 1
      CIRCLE x&, y&, 5      ! Draw circle
    CASE 2
      BOX x& - 3, y& - 3, x& + 3, y& + 3  ! Draw box
    CASE 3
      LINE x& - 5, y&, x& + 5, y&         ! Draw line
    ENDSELECT
  NEXT i&
  
  ' Draw status information
  LOCATE 1,24
  PRINT "Frame: "; frame_count&; " Objects: "; max_objects&
  PRINT "Speed: "; 
  IF animation_speed!
    PRINT "ON "
  ELSE
    PRINT "OFF"
  ENDIF
RETURN

! Screen save subroutine
save_screen:
  filename$ = "SCREEN" + STR$(frame_count&) + ".PI1"
  
  ' Save screen to file (simplified)
  OPEN "O", #1, filename$
  FOR addr% = screen_base% TO screen_base% + 32000
    PUT #1, PEEK(addr%)
  NEXT addr%
  CLOSE #1
  
  PRINT "Screen saved as: "; filename$
RETURN

! Cleanup procedure
PROCEDURE cleanup_system
  ! Restore original resolution
  ~XBIOS(5,L:-1,L:-1,W:-1)
  
  ! Clear screen
  CLS
  
  ! Display exit message
  PRINT "Thanks for using GFA BASIC 3.6!"
  PRINT "Extension by Hylst - Enhanced Syntax Highlighting"
  
  ! Wait for keypress
  PRINT "Press any key to exit..."
  REPEAT
  UNTIL INKEY$ <> ""
RETURN

! ================================================================
! MATHEMATICAL FUNCTIONS
! ================================================================

! Fast sine calculation using lookup table
FUNCTION fast_sin(angle)
  LOCAL result
  
  ' Normalize angle to 0-359 degrees
  WHILE angle >= 360
    angle = angle - 360
  WEND
  WHILE angle < 0
    angle = angle + 360
  WEND
  
  ' Use built-in SIN function (in radians)
  result = SIN(angle * pi / 180)
  
  RETURN result
ENDFUNC

! Bit manipulation demonstration
FUNCTION manipulate_bits(value&)
  LOCAL result&
  
  ' Demonstrate various bit operations
  result& = value&
  result& = SHL(result&, 1)   ! Shift left
  result& = result& OR mask_bits|
  result& = result& XOR flag_bits|
  result& = SHR(result&, 1)   ! Shift right
  
  RETURN result&
ENDFUNC

! String processing function
FUNCTION process_string$(input$)
  LOCAL output$, i&, char|
  
  output$ = ""
  
  FOR i& = 1 TO LEN(input$)
    char| = ASC(MID$(input$, i&, 1))
    
    ' Convert to uppercase if lowercase
    IF char| >= 97 AND char| <= 122
      char| = char| - 32
    ENDIF
    
    output$ = output$ + CHR$(char|)
  NEXT i&
  
  RETURN output$
ENDFUNC

! ================================================================
! DATA SECTION
! ================================================================

! Sample data for demonstration
data_start:
DATA "GFA BASIC", "Atari ST", "Retro Programming"
DATA 1985, 1986, 1987, 1988, 1989
DATA 3.14159, 2.71828, 1.41421, 1.73205
DATA TRUE, FALSE, TRUE, TRUE, FALSE

! ================================================================
! MEMORY AND SYSTEM OPERATIONS
! ================================================================

! Direct memory access demonstration
PROCEDURE memory_demo
  LOCAL test_addr%, test_value&
  
  ' Allocate memory
  test_addr% = MALLOC(1000)
  
  IF test_addr% <> 0
    ' Write test pattern to memory
    FOR i& = 0 TO 999
      POKE test_addr% + i&, i& MOD 256
    NEXT i&
    
    ' Read back and verify
    FOR i& = 0 TO 999
      test_value& = PEEK(test_addr% + i&)
      IF test_value& <> (i& MOD 256)
        PRINT "Memory test failed at offset "; i&
        EXIT FOR
      ENDIF
    NEXT i&
    
    ' Free allocated memory
    ~MFREE(test_addr%)
    PRINT "Memory test completed successfully"
  ELSE
    PRINT "Memory allocation failed"
  ENDIF
RETURN

! ================================================================
! END OF PROGRAM
! ================================================================

! This file demonstrates:
! - All variable types with proper suffixes
! - Comprehensive instruction usage
! - Control structures (FOR, WHILE, IF, SELECT, REPEAT)
! - Procedures and functions
! - Graphics operations
! - System calls (XBIOS)
! - Memory operations (PEEK, POKE, MALLOC, MFREE)
! - String manipulation
! - Mathematical operations
! - Bit manipulation
! - Data statements
! - Comments using ! syntax
! - Number formats (decimal, hexadecimal, binary)
! - Proper indentation and code structure