Mega CD-ROM 1/megacd_rom_1.zip/megacd_rom_1/FREEMACS/EMAC16AS.ZIP/MARKS.ASM

Assembly Source File | 1989-12-19 | 14KB | 622 lines

;History:576,1
;02-21-88 00:09:37 use the form pointer in get_syntax:
;07-06-87 06:53:58 Use botbot for end, rather than LINENEW
    .xlist
    page    ,132

    include    memory.def
    include    mint.def
    include    mintform.def

formSeg    segment    public
    extrn    syntax_table: word
formSeg    ends

data    segment    byte public
    extrn    syntax_seg: word
    extrn    textseg: word

;Marks are referred to by a single ASCII character.  If the mark is a digit,
;  it is a user-defined mark.
mark_first_temp    equ    '0'    ;first temp mark
mark_last_temp    equ    '9'    ;last temp mark
mark_first_perm    equ    '@'    ;first permanent mark.
mark_last_perm    equ    'Z'    ;last permanent mark.
mark_split    equ    '*'    ;split mark

;If the mark is one of the following characters, it is a system-defined mark.
mark_list    label    byte
    db    '>'        ;character to the right of the point
    dw    mark_right
    db    '<'        ;character to the left of the point.
    dw    mark_left
    db    '['        ;first character in the file.
    dw    mark_top
    db    ']'        ;last character in the file.
    dw    mark_bot
    db    '^'        ;beginning of this line.
    dw    mark_begin
    db    '$'        ;end of this line.
    dw    mark_end
    db    '-'        ;blanks to the left.
    dw    mark_lblanks
    db    '+'        ;blanks to the right.
    dw    mark_rblanks
    db    '}'        ;word to the right of this one.
    dw    mark_word_right
    db    '{'        ;word to the left of this one.
    dw    mark_word_left
    db    '.'        ;point or anything else no in the list.
    dw    mark_point
mark_list_size    equ    ($-mark_list)/3


data    ends


bufseg    segment    public

byte_ptr    label    byte

    extrn    toptop: word
    extrn    topbot: word
    extrn    bottop: word
    extrn    botbot: word

comment /*******************************************************************
    marks contains the marks, which is a count of characters from the
beginning of the file.  There are permanent (global) marks and temporary
(local) marks.  The permanent marks are accessible at all times, while the
temporary marks are accessible only while they are on the top of the stack.
There are a These marks are defined below.  The actual number of temporary
marks is given by the value of [temp_mark_count]-[temp_mark_base].  As you can
see, this is initially zero.  The number of marks is adjusted by calling
stack_marks.
****************************************************************************/

MAX_MARKS    equ    50
temp_mark_base    db    ?        ;first temporary mark
temp_mark_count    db    ?        ;total number of temporary marks
perm_mark_count    db    ?        ;number of permanent marks
    public    split_mark
split_mark    dw    ?        ;mark used for split screen.
mark_offset    dw    max_marks dup(?)
marks_sp    dw    ?
    db    max_marks dup(?)

wdummy    struc
w    dw    ?
wdummy    ends

bdummy    struc
b    db    ?
bdummy    ends

bufseg    ends


code    segment    byte public
    assume    cs:code, ds:data, es:data

    public    set_mark
set_mark:
    push    ds
    mov    ds,textseg
    call    set_mark$
    pop    ds
    ret


    public    stack_marks
stack_marks:
    push    ds
    mov    ds,textseg
    call    stack_marks$
    pop    ds
    ret

code    ends

code    segment    byte public
    assume    cs:code, ds:bufseg, es:data

    public    init_marks
    public    set_mark_si
    public    get_mark
    public    adjust_marks_del
    public    adjust_marks_ins


init_marks:
    mov    temp_mark_base,1
    mov    temp_mark_count,1
    mov    perm_mark_count,1
    mov    bx,offset marks_sp+2
    mov    byte ptr [bx],0        ;initial stack frame is empty.
    mov    marks_sp,bx
    mov    mark_offset[0],0    ;init the only mark.
    mov    split_mark,0        ;set the mark to the beginning.
    ret


user_mark:
;enter with al=mark.
;if user mark, exit with bx->proper marks array entry, nc.
;if sytem mark, exit with cy.
    cmp    al,mark_first_perm    ;permanent user mark?
    jb    user_mark_3
    cmp    al,mark_last_perm
    ja    user_mark_3
    mov    bl,al
    sub    bl,mark_first_perm
    cmp    bl,perm_mark_count
    jae    user_mark_1        ;too bit, can't be user mark.
    jmp    short user_mark_2
user_mark_3:
    cmp    al,mark_first_temp
    jb    user_mark_1
    cmp    al,mark_last_temp
    ja    user_mark_1
    mov    bl,al
    sub    bl,mark_first_temp
    mov    bh,temp_mark_count    ;compute the number of temporary marks.
    sub    bh,temp_mark_base
    cmp    bl,bh
    jae    user_mark_1        ;too big, can't be user mark.
    add    bl,temp_mark_base
user_mark_2:
    add    bl,bl
    mov    bh,0
    lea    bx,mark_offset[bx]
    ret                ;cy was cleared by previous operation
user_mark_1:
    cmp    al,mark_split        ;split is a settable mark.
    jne    user_mark_4
    mov    bx,offset split_mark
    ret
user_mark_4:
    stc
    ret


stack_marks$:
;enter with ax>0=number of temporary marks to stack or
;  ax<0=number of permanent marks to create (temporary marks are destroyed) or
;  ax=0 to unstack.
;exit with cy if overflow/underflow.
    cmp    ax,0
    jg    stack_marks_1    ;stack
    jl    stack_marks_4    ;create perms.
    mov    bx,marks_sp
    mov    al,[bx]        ;get the current frame size
    or    al,al
    je    stack_marks_2    ;nothing to unstack.
    sub    temp_mark_count,al    ;reduce count by this frame size
    dec    bx
    mov    al,[bx]        ;get the previous frame size
    sub    temp_mark_base,al
    mov    marks_sp,bx
    clc
    ret
stack_marks_4:
    neg    ax
    cmp    al,MAX_MARKS        ;stack overflow?
    jae    stack_marks_2        ;  yes.
    mov    temp_mark_base,al
    mov    temp_mark_count,al
    mov    perm_mark_count,al
    mov    bx,offset marks_sp    ;find the new tos.
    add    bx,ax
    mov    byte ptr [bx],0        ;initial stack frame is empty.
    mov    marks_sp,bx
    mov    ax,'.'*256+mark_first_perm
    mov    cl,perm_mark_count
    mov    ch,0
    jmp    short stack_marks_3
stack_marks_1:
    mov    ah,temp_mark_count    ;get number of marks.
    add    ah,al            ;add desired number
    cmp    ah,MAX_MARKS        ;stack overflow?
    jae    stack_marks_2        ;  yes.
    mov    bx,marks_sp
    inc    bx            ;bump stack pointer
    mov    [bx],al            ;save the frame size
    mov    marks_sp,bx
    mov    al,temp_mark_count
    mov    temp_mark_base,al    ;new base is old max.
    mov    temp_mark_count,ah    ;new max is old+count of new marks
;set all the new temp marks to the point.
    sub    ah,al            ;ah=temp_mark_count-temp_mark_base
    mov    cl,ah
    mov    ch,0
    mov    ax,'.'*256+mark_first_temp
stack_marks_3:
    push    ax
    push    cx
    call    set_mark$
    pop    cx
    pop    ax
    inc    al
    loop    stack_marks_3
    clc
    ret
stack_marks_2:
    stc
    ret


set_mark_si:
;enter with al=number of dest mark, si->text.
;note that system marks cannot be set.
    call    user_mark
    jc    set_mark_si_1    ;not a user mark.
    cmp    si,topbot    ;is new mark above point?
    jb    set_mark_si_2    ;no, make it relative to toptop
    sub    si,bottop
    add    si,topbot
    sub    si,toptop
    jmp    short set_mark_si_3
set_mark_si_2:
    sub    si,toptop
set_mark_si_3:
    mov    [bx],si
set_mark_si_1:
    ret


set_mark$:
;enter with al=dest mark, ah=source mark.
    push    ax
    mov    al,ah
    call    get_mark_count
    pop    ax
    call    user_mark
    jc    set_mark_1
    mov    [bx],cx        ;store the mark.
set_mark_1:
    ret


    assume    es:nothing, ss:data

get_mark_count:
;enter with al=number of mark to get.
;exit with cx=number of characters before the mark.
    call    user_mark
    jc    get_mark_count_1    ;anything larger (or negative)
    mov    cx,[bx]
    ret
get_mark_count_1:
    mov    bx,offset mark_list-3    ;get the mark list.
    mov    cx,mark_list_size
get_mark_count_2:            ;scan the list for the mark.
    add    bx,3            ;preincrement
    cmp    al,ss:[bx]        ;is it this one?
    loopne    get_mark_count_2    ;continue if not.
    jmp    word ptr ss:[bx+1]    ;go to the correct mark.


mark_right:
    mov    cx,botbot    ;compute the number of characters after the
    sub    cx,bottop    ;  point.
    je    mark_bot    ;  return the mark at the end of the file.
    mov    cx,topbot    ;compute the number of characters before the
    sub    cx,toptop    ;  point.
    inc    cx        ;because we want the character to the right.
    mov    bx,bottop    ;check for breaking up a NEWLINE
    cmp    [bx].w,LINENEW
    jne    mark_right_1    ;not NEWLINE.
    inc    cx        ;because we don't want to split a newline.
mark_right_1:
    ret


mark_left:
    mov    cx,topbot
    sub    cx,toptop
    jz    mark_left_1    ;if no characters, mark is at beginning of file.
    dec    cx        ;because we want the character to the left.
    mov    bx,topbot
    cmp    [bx-2].w,LINENEW
    jne    mark_left_1
    dec    cx        ;because we don't want to split a newline.
mark_left_1:
    ret


mark_top:
    mov    cx,0        ;zero characters before beginning of file.
    ret


mark_bot:
    mov    cx,topbot    ;size of text before point +
    sub    cx,toptop
    add    cx,botbot    ;size of text after point.
    sub    cx,bottop
    ret


mark_point:
    mov    cx,topbot    ;size of text before point.
    sub    cx,toptop
    ret


mark_begin:
    mov    cx,topbot
    mov    bx,cx
    sub    cx,toptop
mark_begin_1:
    cmp    [bx-2].w,LINENEW    ;at beginning?
    je    mark_begin_2        ;yes.
    dec    bx
    dec    cx
    jmp    mark_begin_1
mark_begin_2:
    ret


mark_end:
    mov    cx,topbot        ;start at point
    sub    cx,toptop
    mov    bx,bottop
mark_end_1:
    cmp    bx,botbot        ;at end?
    je    mark_end_2    ;yes.
    cmp    [bx].w,LINENEW    ;at end?
    je    mark_end_2    ;yes.
    inc    bx
    inc    cx
    jmp    mark_end_1
mark_end_2:
    ret


mark_word_right:
    mov    cx,topbot        ;start at point
    sub    cx,toptop
    mov    bx,bottop
mark_word_right_1:
    cmp    bx,botbot        ;end of buffer is end of word.
    je    mark_word_right_2
    mov    al,[bx]            ;is this character a blank?
    call    get_syntax
    test    al,1
    je    mark_word_right_2    ;yes - we're done.
    inc    bx
    inc    cx
    jmp    mark_word_right_1
mark_word_right_2:
    ret


mark_word_left:
    mov    cx,topbot        ;start at point
    mov    bx,cx
    sub    cx,toptop
    jcxz    mark_word_left_1    ;if nothing to the left, leave.
    dec    bx
mark_word_left_2:
    mov    al,[bx]            ;is this character a blank?
    call    get_syntax
    test    al,1
    je    mark_word_left_1    ;yes - exit now.
    dec    bx
    dec    cx
    jne    mark_word_left_2
mark_word_left_1:
    ret


mark_lblanks:
    mov    cx,topbot        ;start at point
    mov    bx,cx
    sub    cx,toptop
    jcxz    mark_lblanks_1        ;if nothing to left, leave.
    dec    bx
    cmp    [bx-1].w,LINENEW    ;starting at newline?
    jne    mark_lblanks_2        ;no.
    sub    cx,2            ;yes - move back over it.
    sub    bx,2
    jcxz    mark_lblanks_1        ;if nothing more to left, leave.
mark_lblanks_2:
    mov    al,[bx]            ;is this char a blank?
    call    get_syntax
    test    al,3            ;non-blank or line break?
    jne    mark_lblanks_1    ;yes - exit now.
    dec    bx
    dec    cx
    jne    mark_lblanks_2
mark_lblanks_1:
    ret


mark_rblanks:
    mov    cx,topbot        ;start at point
    sub    cx,toptop
    mov    bx,bottop
    cmp    bx,botbot        ;starting at end of buffer?
    je    mark_rblanks_2        ;yes - end.
    cmp    [bx].w,LINENEW        ;starting at newline?
    jne    mark_rblanks_1        ;no.
    add    bx,2            ;start by skipping the newline.
    add    cx,2
mark_rblanks_1:
    cmp    bx,botbot        ;end of buffer is end of word.
    je    mark_rblanks_2        ;yes - end.
    mov    al,[bx]
    call    get_syntax
    test    al,3            ;non-blank or line break?
    jne    mark_rblanks_2        ;yes - exit now.
    inc    bx
    inc    cx
    jmp    mark_rblanks_1
mark_rblanks_2:
    ret


    public    split_at_point
split_at_point:
;return cy if the split mark is at or after the point.
    mov    cx,split_mark
    mov    ax,topbot
    sub    ax,toptop
    cmp    split_mark,ax        ;is the split mark at or after the point?
    jae    split_at_point_1    ;yes - return cy.
    clc
    ret
split_at_point_1:
    stc
    ret


    public    get_split_mark
get_split_mark:
;same as get_mark('*'), only faster.
    mov    cx,split_mark
    jmp    short compute_mark
get_mark:
;enter with al=number of mark to get.
    call    get_mark_count
compute_mark:
;enter with cx=the number of characters before the point.
;exit with cx=count of chars between the mark and the point, si->text at mark,
;cy=1 if mark is after the point.
    mov    si,topbot
    sub    si,toptop
    sub    cx,si
    jb    compute_mark_1
    mov    si,bottop    ;make si->bottom
    add    si,cx        ;make si->text.
    stc
    ret
compute_mark_1:
    mov    si,topbot    ;Compute pointer to text.
    add    si,cx        ;  cx is difference between topbot and mark,
    neg    cx        ;  which is negative.  make it positive.
    clc
    ret


    assume    es:data


adjust_marks_ins:
;enter with ax=number of characters inserted
;exit with all marks adjusted accordingly.
;if a mark is at or after the point, move it up or down.
;if a mark is before the point, leave it alone.
    mov    cl,temp_mark_count
    mov    ch,0
    inc    cx
    mov    bx,offset mark_offset-2
    mov    dx,topbot
    sub    dx,toptop
adjust_marks_ins_1:
    mov    si,[bx]            ;get a mark
    cmp    si,dx            ;is it before the point?
    jb    adjust_marks_ins_2    ;yes.
adjust_marks_ins_3:
    add    si,ax            ;no - adjust it and store it back.
    mov    [bx],si
adjust_marks_ins_2:
    add    bx,2            ;go to the next mark.
    loop    adjust_marks_ins_1
    ret


adjust_marks_del:
;enter with ax=number of characters deleted.
;exit with all marks adjusted accordingly.
;if a mark is after the point, move it up or down.
;if a mark is at or before the point, leave it alone.
;Adjusting for deletion is more complex than adjusting for insertion,
;  because we have to adjust all the marks that fall in the range of
;  the characters deleted.
    mov    cl,temp_mark_count
    mov    ch,0
    inc    cx
    mov    bx,offset mark_offset-2
    mov    dx,topbot
    sub    dx,toptop        ;make dx -> before first mark to adjust
    mov    di,dx
    add    di,ax            ;make di -> last mark to adjust.
adjust_marks_del_1:
    mov    si,[bx]            ;get a mark
    cmp    si,dx            ;is it at or before the point?
    jbe    adjust_marks_del_2    ;yes.
    cmp    si,di            ;does it mark a deleted character?
    ja    adjust_marks_del_3    ;no - adjust it down.
    mov    [bx],dx            ;all deleted marks will mark the point.
    jmp    short adjust_marks_del_2
adjust_marks_del_3:
    sub    si,ax            ;no - adjust it and store it back.
    mov    [bx],si
adjust_marks_del_2:
    add    bx,2            ;go to the next mark.
    loop    adjust_marks_del_1
    ret

    assume    es:nothing

    public    get_syntax
get_syntax:
;enter with al=character.
;don't change any other registers.
;exit with al=syntax of that character.
    push    ds
    push    bx
    mov    ds,ss:syntax_seg
    assume    ds:formSeg
    mov    bx,formSeg:syntax_table
    cmp    bx,NIL
    je    get_syntax_3
    push    ax
    mov    ax,formSeg:[bx].name_length
    add    ax,formSeg:[bx].form_pointer
    add    bx,(size form_struc)    ;make bx->name.
    add    bx,ax            ;make bx->data.
    pop    ax
    xlat    formSeg:byte_ptr
    pop    bx
    pop    ds
    ret
get_syntax_3:
    pop    bx
    pop    ds
    assume    ds:nothing
    cmp    al,'_'
    je    get_syntax_1
    cmp    al,cr
    je    get_syntax_2
    cmp    al,lf
    je    get_syntax_2
    cmp    al,'0'
    jb    get_syntax_0
    cmp    al,'9'
    jbe    get_syntax_1
    cmp    al,'A'
    jb    get_syntax_0
    cmp    al,'Z'
    jbe    get_syntax_1
    cmp    al,'a'
    jb    get_syntax_0
    cmp    al,'z'
    jbe    get_syntax_1
get_syntax_0:
    mov    al,0
    ret
get_syntax_1:
    mov    al,1
    ret
get_syntax_2:
    mov    al,2
    ret


code    ends

    end