module tokenizer_mod
    implicit none

    type token
        character(:), allocatable :: type
        character(:), allocatable :: value
        integer :: index
    end type token

contains

    type(token) function init_token(type, value, index) result(this)
        character(:), allocatable :: type
        character(:), allocatable :: value
        integer :: index

        this%type = type
        this%value = value
        this%index = index
    end function

    function tokenize(code) result(tokens)
        character(:), allocatable :: code
        type(token), dimension(:), allocatable :: tokens
        integer :: pos1 = 1, pos2
    
        do
            pos2 = scan(code(pos1:), " \n\t\v\f\r")
            if (pos2 == 0) then
                tokens = [tokens, token("expression", code(pos1:), pos1)]
                return
            end if

            tokens = [tokens, token("expression", code(pos1:pos1+pos2-2), pos1)]
            pos1 = pos2+pos1
        end do

    end function tokenize

    pure logical function isAlpha(c)
        character, intent(in) :: c
        isAlpha = (c .ge. 'a' .and. c .le. 'z') .or. (c .ge. 'A' .and. c .le. 'Z') .or. c .eq. '_' .or. c .eq. "'" .or. c .eq. '?'
    end function isAlpha

    pure logical function isDigit(c)
        character, intent(in) :: c
        isDigit = (c .ge. '0' .and. c .le. '9') .or. c .eq. '-'
    end function isDigit

end module tokenizer_mod

module parser_mod
    implicit none
    
contains
    
end module parser_mod

module opcodes_mod
    implicit none 
       character, parameter :: UNREACHABLE          = achar(0)  
       character, parameter :: NOP                  = achar(1)  
       character, parameter :: BLOCK                = achar(2)  
       character, parameter :: LOOP                 = achar(3)  
       character, parameter :: IF                   = achar(4)  
       character, parameter :: ELSE                 = achar(5)  
       character, parameter :: TRY                  = achar(6)  ! PROPOSED
       character, parameter :: CATCH                = achar(7)  ! PROPOSED
       character, parameter :: THROW                = achar(8)  ! PROPOSED
       character, parameter :: RETHROW              = achar(9)  ! PROPOSED
       character, parameter :: BR_ON_EXN            = achar(10) ! PROPOSED
       character, parameter :: END                  = achar(11)
       character, parameter :: BR                   = achar(12)
       character, parameter :: BR_IF                = achar(13)
       character, parameter :: BR_TABLE             = achar(14)
       character, parameter :: RETURN               = achar(15)
       character, parameter :: CALL                 = achar(16)
       character, parameter :: CALL_INDIRECT        = achar(17)
       character, parameter :: RETURN_CALL          = achar(18) ! PROPOSED
       character, parameter :: RETURN_CALL_INDIRECT = achar(19) ! PROPOSED
       character, parameter :: DROP                 = achar(26)
       character, parameter :: SELECT               = achar(27)
       character, parameter :: SELECT_T             = achar(28) ! PROPOSED
       character, parameter :: LOCAL_GET            = achar(32)
       character, parameter :: LOCAL_SET            = achar(33)
       character, parameter :: LOCAL_TEE            = achar(34)
       character, parameter :: GLOBAL_GET           = achar(35)
       character, parameter :: GLOBAL_SET           = achar(36)
       character, parameter :: TABLE_GET            = achar(37) ! PROPOSED
       character, parameter :: TABLE_SET            = achar(38) ! PROPOSED
       character, parameter :: I32_LOAD             = achar(40)
       character, parameter :: I64_LOAD             = achar(41)
       character, parameter :: F32_LOAD             = achar(42)
       character, parameter :: F64_LOAD             = achar(43)
       character, parameter :: I32_LOAD8_S          = achar(44)
       character, parameter :: I32_LOAD8_U          = achar(45)
       character, parameter :: I32_LOAD16_S         = achar(46)
       character, parameter :: I32_LOAD16_U         = achar(47)
       character, parameter :: I64_LOAD8_S          = achar(48)
       character, parameter :: I64_LOAD8_U          = achar(49)
       character, parameter :: I64_LOAD16_S         = achar(50)
       character, parameter :: I64_LOAD16_U         = achar(51)
       character, parameter :: I64_LOAD32_S         = achar(52)
       character, parameter :: I64_LOAD32_U         = achar(53)
       character, parameter :: I32_STORE            = achar(54)
       character, parameter :: I64_STORE            = achar(55)
       character, parameter :: F32_STORE            = achar(56)
       character, parameter :: F64_STORE            = achar(57)
       character, parameter :: I32_STORE8           = achar(58)
       character, parameter :: I32_STORE16          = achar(59)
       character, parameter :: I64_STORE8           = achar(60)
       character, parameter :: I64_STORE16          = achar(61)
       character, parameter :: I64_STORE32          = achar(62)
       character, parameter :: MEMORY_SIZE          = achar(63)
       character, parameter :: MEMORY_GROW          = achar(64)
       character, parameter :: I32_CONST            = achar(65)
       character, parameter :: I64_CONST            = achar(66)
       character, parameter :: F32_CONST            = achar(67)
       character, parameter :: F64_CONST            = achar(68)
       character, parameter :: I32_EQZ              = achar(69)
       character, parameter :: I32_EQ               = achar(70)
       character, parameter :: I32_NE               = achar(71)
       character, parameter :: I32_LT_S             = achar(72)
       character, parameter :: I32_LT_U             = achar(73)
       character, parameter :: I32_GT_S             = achar(74)
       character, parameter :: I32_GT_U             = achar(75)
       character, parameter :: I32_LE_S             = achar(76)
       character, parameter :: I32_LE_U             = achar(77)
       character, parameter :: I32_GE_S             = achar(78)
       character, parameter :: I32_GE_U             = achar(79)
       character, parameter :: I64_EQZ              = achar(80)
       character, parameter :: I64_EQ               = achar(81)
       character, parameter :: I64_NE               = achar(82)
       character, parameter :: I64_LT_S             = achar(83)
       character, parameter :: I64_LT_U             = achar(84)
       character, parameter :: I64_GT_S             = achar(85)
       character, parameter :: I64_GT_U             = achar(86)
       character, parameter :: I64_LE_S             = achar(87)
       character, parameter :: I64_LE_U             = achar(88)
       character, parameter :: I64_GE_S             = achar(89)
       character, parameter :: I64_GE_U             = achar(90)
       character, parameter :: F32_EQ               = achar(91)
       character, parameter :: F32_NE               = achar(92)
       character, parameter :: F32_LT               = achar(93)
       character, parameter :: F32_GT               = achar(94)
       character, parameter :: F32_LE               = achar(95)
       character, parameter :: F32_GE               = achar(96)
       character, parameter :: F64_EQ               = achar(97)
       character, parameter :: F64_NE               = achar(98)
       character, parameter :: F64_LT               = achar(99)
       character, parameter :: F64_GT               = achar(100)
       character, parameter :: F64_LE               = achar(101)
       character, parameter :: F64_GE               = achar(102)
       character, parameter :: I32_CLZ              = achar(103)
       character, parameter :: I32_CTZ              = achar(104)
       character, parameter :: I32_POPCNT           = achar(105)
       character, parameter :: I32_ADD              = achar(106)
       character, parameter :: I32_SUB              = achar(107)
       character, parameter :: I32_MUL              = achar(108)
       character, parameter :: I32_DIV_S            = achar(109)
       character, parameter :: I32_DIV_U            = achar(110)
       character, parameter :: I32_REM_S            = achar(111)
       character, parameter :: I32_REM_U            = achar(112)
       character, parameter :: I32_AND              = achar(113)
       character, parameter :: I32_OR               = achar(114)
       character, parameter :: I32_XOR              = achar(115)
       character, parameter :: I32_SHL              = achar(116)
       character, parameter :: I32_SHR_S            = achar(117)
       character, parameter :: I32_SHR_U            = achar(118)
       character, parameter :: I32_ROTL             = achar(119)
       character, parameter :: I32_ROTR             = achar(120)
       character, parameter :: I64_CLZ              = achar(121)
       character, parameter :: I64_CTZ              = achar(122)
       character, parameter :: I64_POPCNT           = achar(123)
       character, parameter :: I64_ADD              = achar(124)
       character, parameter :: I64_SUB              = achar(125)
       character, parameter :: I64_MUL              = achar(126)
       character, parameter :: I64_DIV_S            = achar(127)
       character, parameter :: I64_DIV_U            = achar(128)
       character, parameter :: I64_REM_S            = achar(129)
       character, parameter :: I64_REM_U            = achar(130)
       character, parameter :: I64_AND              = achar(131)
       character, parameter :: I64_OR               = achar(132)
       character, parameter :: I64_XOR              = achar(133)
       character, parameter :: I64_SHL              = achar(134)
       character, parameter :: I64_SHR_S            = achar(135)
       character, parameter :: I64_SHR_U            = achar(136)
       character, parameter :: I64_ROTL             = achar(137)
       character, parameter :: I64_ROTR             = achar(138)
       character, parameter :: F32_ABS              = achar(139)
       character, parameter :: F32_NEG              = achar(140)
       character, parameter :: F32_CEIL             = achar(141)
       character, parameter :: F32_FLOOR            = achar(142)
       character, parameter :: F32_TRUNC            = achar(143)
       character, parameter :: F32_NEAREST          = achar(144)
       character, parameter :: F32_SQRT             = achar(145)
       character, parameter :: F32_ADD              = achar(146)
       character, parameter :: F32_SUB              = achar(147)
       character, parameter :: F32_MUL              = achar(148)
       character, parameter :: F32_DIV              = achar(149)
       character, parameter :: F32_MIN              = achar(150)
       character, parameter :: F32_MAX              = achar(151)
       character, parameter :: F32_COPYSIGN         = achar(152)
       character, parameter :: F64_ABS              = achar(153)
       character, parameter :: F64_NEG              = achar(154)
       character, parameter :: F64_CEIL             = achar(155)
       character, parameter :: F64_FLOOR            = achar(156)
       character, parameter :: F64_TRUNC            = achar(157)
       character, parameter :: F64_NEAREST          = achar(158)
       character, parameter :: F64_SQRT             = achar(159)
       character, parameter :: F64_ADD              = achar(160)
       character, parameter :: F64_SUB              = achar(161)
       character, parameter :: F64_MUL              = achar(162)
       character, parameter :: F64_DIV              = achar(163)
       character, parameter :: F64_MIN              = achar(164)
       character, parameter :: F64_MAX              = achar(165)
       character, parameter :: F64_COPYSIGN         = achar(166)
       character, parameter :: I32_WRAP_I64         = achar(167)
       character, parameter :: I32_TRUNC_F32_S      = achar(168)
       character, parameter :: I32_TRUNC_F32_U      = achar(169)
       character, parameter :: I32_TRUNC_F64_S      = achar(170)
       character, parameter :: I32_TRUNC_F64_U      = achar(171)
       character, parameter :: I64_EXTEND_I32_S     = achar(172)
       character, parameter :: I64_EXTEND_I32_U     = achar(173)
       character, parameter :: I64_TRUNC_F32_S      = achar(174)
       character, parameter :: I64_TRUNC_F32_U      = achar(175)
       character, parameter :: I64_TRUNC_F64_S      = achar(176)
       character, parameter :: I64_TRUNC_F64_U      = achar(177)
       character, parameter :: F32_CONVERT_I32_S    = achar(178)
       character, parameter :: F32_CONVERT_I32_U    = achar(179)
       character, parameter :: F32_CONVERT_I64_S    = achar(180)
       character, parameter :: F32_CONVERT_I64_U    = achar(181)
       character, parameter :: F32_DEMOTE_F64       = achar(182)
       character, parameter :: F64_CONVERT_I32_S    = achar(183)
       character, parameter :: F64_CONVERT_I32_U    = achar(184)
       character, parameter :: F64_CONVERT_I64_S    = achar(185)
       character, parameter :: F64_CONVERT_I64_U    = achar(186)
       character, parameter :: F64_PROMOTE_F32      = achar(187)
       character, parameter :: I32_REINTERPRET_F32  = achar(188)
       character, parameter :: I64_REINTERPRET_F64  = achar(189)
       character, parameter :: F32_REINTERPRET_I32  = achar(190)
       character, parameter :: F64_REINTERPRET_I64  = achar(191)
end module opcodes_mod
    
module types_mod
    implicit none
    ! https://webassembly.github.io/spec/core/binary/types.html
    character, parameter :: i32 = achar(127)
    character, parameter :: i64 = achar(126)
    character, parameter :: f32 = achar(125)
    character, parameter :: f64 = achar(124)

    ! http://webassembly.github.io/spec/core/binary/types.html#function-types
    character, parameter :: type_function = achar(96)

    character, parameter :: type_empty_array = achar(0)

    ! http://webassembly.github.io/spec/core/binary/modules.html#export-section
    character, parameter :: export_func     = achar(0)
    character, parameter :: export_table    = achar(1)
    character, parameter :: export_mem      = achar(2)
    character, parameter :: export_global   = achar(3)

    ! https://webassembly.github.io/spec/core/binary/modules.html#sections
    character, parameter :: section_custom  = achar(0)
    character, parameter :: section_type    = achar(1)
    character, parameter :: section_import  = achar(2)
    character, parameter :: section_func    = achar(3)
    character, parameter :: section_table   = achar(4)
    character, parameter :: section_memory  = achar(5)
    character, parameter :: section_global  = achar(6)
    character, parameter :: section_export  = achar(7)
    character, parameter :: section_start   = achar(8)
    character, parameter :: section_element = achar(9)
    character, parameter :: section_code    = achar(10)
    character, parameter :: section_data    = achar(11)
end module types_mod