c65gm/examples/switch_demo/switch_demo.c65

//-----------------------------------------------------------
// SWITCH/CASE Statement Demo
// Demonstrates the SWITCH/CASE control flow statement
// with implicit breaks and long jump pragma support
//-----------------------------------------------------------

#INCLUDE <c64start.c65>
#INCLUDE <c64defs.c65>
#INCLUDE <cbmiolib.c65>

#PRAGMA _P_USE_CBM_STRINGS 1

GOTO start

WORD result
BYTE test_var

BYTE CONST TEST_VAL1 = 10
BYTE CONST TEST_VAL2 = 20
BYTE CONST TEST_VAL3 = 30
BYTE CONST OFFSET = 5

//-----------------------------------------------------------
// Test 1: Basic SWITCH with DEFAULT
//-----------------------------------------------------------
FUNC test_basic_switch
  LET test_var = 2

  SWITCH test_var
    CASE 1
      LET result = $0A
    CASE 2
      LET result = $14
    CASE 3
      LET result = $1E
    DEFAULT
      LET result = $63
  ENDSWITCH

  lib_cbmio_print("1.basic: ")
  lib_cbmio_hexoutw(result)
  lib_cbmio_printlf(" (exp 0014)")
FEND

//-----------------------------------------------------------
// Test 2: SWITCH without DEFAULT
//-----------------------------------------------------------
FUNC test_no_default
  LET test_var = 5
  LET result = 0

  SWITCH test_var
    CASE 1
      LET result = $64
    CASE 5
      LET result = $01F4
    CASE 10
      LET result = $03E8
  ENDSWITCH

  lib_cbmio_print("2.no default: ")
  lib_cbmio_hexoutw(result)
  lib_cbmio_printlf(" (exp 01f4)")
FEND

//-----------------------------------------------------------
// Test 3: Nested SWITCH statements
//-----------------------------------------------------------
FUNC test_nested_switch
  BYTE outer
  BYTE inner

  LET outer = 2
  LET inner = 3
  LET result = 0

  SWITCH outer
    CASE 1
      LET result = $01
    CASE 2
      SWITCH inner
        CASE 2
          LET result = $16
        CASE 3
          LET result = $17
        DEFAULT
          LET result = $14
      ENDSWITCH
    CASE 3
      LET result = $03
  ENDSWITCH

  lib_cbmio_print("3.nested: ")
  lib_cbmio_hexoutw(result)
  lib_cbmio_printlf(" (exp 0017)")
FEND

//-----------------------------------------------------------
// Test 4: SWITCH with long jump pragma
// (for cases where branches are far apart)
//-----------------------------------------------------------
FUNC test_long_jump
  #PRAGMA _P_USE_LONG_JUMP 1

  LET test_var = 3

  SWITCH test_var
    CASE 1
      LET result = $0B
    CASE 2
      LET result = $16
    CASE 3
      LET result = $21
    CASE 4
      LET result = $2C
    DEFAULT
      LET result = $00
  ENDSWITCH

  #PRAGMA _P_USE_LONG_JUMP 0

  lib_cbmio_print("4.long jump: ")
  lib_cbmio_hexoutw(result)
  lib_cbmio_printlf(" (exp 0021)")
FEND

//-----------------------------------------------------------
// Test 5: SWITCH with WORD values
//-----------------------------------------------------------
FUNC test_word_switch
  WORD big_value

  LET big_value = 1000
  LET result = 0

  SWITCH big_value
    CASE 100
      LET result = $0001
    CASE 1000
      LET result = $0002
    CASE 10000
      LET result = $0003
    DEFAULT
      LET result = $0063
  ENDSWITCH

  lib_cbmio_print("5.word: ")
  lib_cbmio_hexoutw(result)
  lib_cbmio_printlf(" (exp 0002)")
FEND

//-----------------------------------------------------------
// Test 6: SWITCH with constants and compile-time evaluation
//-----------------------------------------------------------
FUNC test_constants
  LET test_var = 25
  LET result = 0

  SWITCH test_var
    CASE TEST_VAL1
      LET result = $01
    CASE TEST_VAL2
      LET result = $02
    CASE TEST_VAL2+OFFSET
      LET result = $03
    CASE TEST_VAL3
      LET result = $04
    DEFAULT
      LET result = $63
  ENDSWITCH

  lib_cbmio_print("6.constants: ")
  lib_cbmio_hexoutw(result)
  lib_cbmio_printlf(" (exp 0003)")
FEND

//-----------------------------------------------------------
// Test 7: SWITCH with variable cases (not just literals)
//-----------------------------------------------------------
FUNC test_variables
  BYTE match_val1
  BYTE match_val2
  WORD match_val3

  LET match_val1 = 15
  LET match_val2 = 42
  LET match_val3 = 1000

  LET test_var = 42
  LET result = 0

  SWITCH test_var
    CASE match_val1
      LET result = $01
    CASE match_val2
      LET result = $02
    CASE match_val3
      LET result = $03
    DEFAULT
      LET result = $63
  ENDSWITCH

  lib_cbmio_print("7.variables: ")
  lib_cbmio_hexoutw(result)
  lib_cbmio_printlf(" (exp 0002)")
FEND

//-----------------------------------------------------------
// Test 8: SWITCH that actually executes DEFAULT
//-----------------------------------------------------------
FUNC test_default_execution
  LET test_var = 99
  LET result = 0

  SWITCH test_var
    CASE 1
      LET result = $0A
    CASE 2
      LET result = $14
    CASE 3
      LET result = $1E
    DEFAULT
      LET result = $03E7
  ENDSWITCH

  lib_cbmio_print("8.default exec: ")
  lib_cbmio_hexoutw(result)
  lib_cbmio_printlf(" (exp 03e7)")
FEND

//-----------------------------------------------------------
// Main program
//-----------------------------------------------------------
FUNC main
  lib_cbmio_cls()

  lib_cbmio_printlf("switch/case demo")
  lib_cbmio_lf()

  test_basic_switch()
  test_no_default()
  test_nested_switch()
  test_long_jump()
  test_word_switch()
  test_constants()
  test_variables()
  test_default_execution()

  lib_cbmio_lf()
  lib_cbmio_printlf("all tests complete!")

FEND

LABEL start
  main()
  SUBEND