Grammer2/src/io/getKeyTok.z80

getKeyTok:
;converts a key press to a token
;Takes key value in A
;returns DE as token, c flag set if not a valid key else nc.

;Check mod tokens
;Check [2nd]
    cp 54 \ jr nz,+_
    ;If previous state was [2nd], set normal, else set [2nd]
    ld a,(keyflags+flags)
    res shift,(iy+keyflags)
    res alpha,(iy+keyflags)
    and 3
    dec a
    scf
    ret z
    set shift,(iy+keyflags)
    ret
_:

;Check [Alpha]
    cp 48 \ jp z,mod_alpha

;Any other keys bigger should return c
    ccf
    ret c

;Check for no key pressed, or arrows
    sub 9
    ret c

;If [ALPHA] or [alpha] mode, check those LUTs
    bit alpha,(iy+keyflags)
    jr nz,chkalphakey_tok

;Else we have normal or [shift] mode
;Check if shift or normal, reset either way
    bit shift,(iy+keyflags)
    res shift,(iy+keyflags)

;get the LUT pointer for the mode
    ld hl,shiftkeytokLUT
    jr nz,+_
    ld hl,regkeytokLUT
_:

;Now get the offset into the LUT
    add a,a
    add a,l
    ld l,a
    jr nc,+_
    inc h
_:

;Load the value into DE
    ld e,(hl)
    inc hl
    ld d,(hl)

;Return c if output is null
    ld a,d
    or e
    sub 1
    ret

chkalphakey_tok:
;either uppercase or lowercase
    call toAlpha_tok
    ld e,a
    ld d,0
    ret c
;Get [ALPHA] or [alpha] mode
    bit shift,(iy+keyflags)

;Do mod_reset. If [ALPHA], no need to modify further so exit
    jp z,mod_reset
    call mod_reset


    cp 'Z'+1
    ret nc
    cp 2Ah \ jr nz,+_ \ ld e,$AE \ ret    ;Quote --> apostrophe
_:
    cp $AF \ jr nz,+_ \ ld e,$2D \ ret    ;? --> !
_:
    cp $3E \ jr nz,+_ \ ld de,$BBD6 \ ret    ;: --> ;
_:
    cp $29 \ jr nz,+_ \ ld de,$BBD9 \ ret    ;space --> underscore
_:
    cp 'A'
    ccf
    ret nc
    ld d,$BB
    cp 'L'
    ccf
    adc a,$B0-'A'
    ld e,a
    ret
toAlpha_tok:
  or a
  jr nz,+_
  ld a,$3F  ;newline
  ret
_:
  cp 1
  jr nz,+_
  ld a,2Ah    ;Quote
  ret
_:
;38 -> 0   30->1   22->2
;37 -> 5   29->6   21->7
;36 -> 10
;35 -> 15
;34 -> 20
;33 -> 25
;32 -> 30
;y=5*((-x-1)&7)-(x>>3) - 1
; =5*((~x)&7)-(x>>3) - 1
  ld c,a
  cpl
  and 7
  ld b,a
  add a,a
  add a,a
  add a,b
  srl c
  srl c
  srl c
  sub c
  dec a
  cp 3
  jr c,+_
  sub 2
_:
    cp 27
    jr nc,+_
    add a,'A'
    ret
_:
    sub 29
    jr nz,+_
    ld a,29h    ;space token
    ret
_:
    dec a
    jr nz,+_
    ld a,$3E    ;Colon token
    ret
_:
    ld a,$AF
    ret

regKeyTokLUT:
;.dw 0,0,0,0,0,0,0,0               ;down,left,right,up
.dw $3F,$70,$71,$82,$83,$F0,0,0   ;Enter,+-*/^
.dw $B0,$33,$36,$39,$11,$C6,0,0   ;neg369)
.dw $3A,$32,$35,$38,$10,$C4,0,0   ;.258(
.dw $30,$31,$34,$37,$2B,$C2,0,0   ;0147,
.dw $00,$04,$BE,$C0,$0D,$0C,0,0   ;sto

shiftKeyTokLUT:
;.dw 0,0,0,0,0,0,0,0                    ;down,left,right,up
.dw $00,$00,$07,$06,$BB31,$AC,0,0       ;Enter,+-*/^
.dw $72,$5D02,$5D05,$5E82,$09,$C7,0,0   ;neg369)
.dw $2C,$5D01,$5D04,$5E81,$08,$C5,0,0   ;.258(
.dw $00,$5D00,$5D03,$5E80,$3B,$C3,0,0   ;0147,
.dw $00,$00,$BF,$C1,$BC,$00,0,0         ;sto