Category : Word Processors
Archive   : BESIDES.ZIP
Filename : SEQREAD1.SEQ

\ SEQREAD1.SEQ Sequential read by Tom Zimmer

\ Link this file into the FILELIST chain.

FILES DEFINITIONS

VARIABLE SEQREAD1.SEQ

FORTH DEFINITIONS

DECIMAL

\ Read sequential lines from a file, delimited by CRLF.

32767 ( 16383) VALUE IBLEN1 \ input buffer length


\ The value of OBLEN can be reduced to 64 if you want to read lines from
\ normal Forth BLOCK files. You should use BLKTOSEQ.SEQ for this though.

255 VALUE OBLEN1 \ output buffer length

0 VALUE INSTART1
0 VALUE INLENGTH1
0 VALUE INBSEG1 \ the input buffer
CREATE OUTBUF1 oblen1 1+ ALLOT \ the line output buffer

VARIABLE FILEPOINTER1 2 allot \ most recent read

HANDLE INFILE1

: .INFILE1 ( --- )
INFILE1 count type ;



: SAVEPOINTER1 ( --- )
INFILE1 curpointer inlength1 0 d- FILEPOINTER1 2! ;

CODE GET_ALINE1 ( --- a1 )
push es \ Save ES for later restoral
mov di, ' instart1 >body \ Searching from instart1
mov ax, # $0A \ Searching for a Linefeed char
mov cx, ' inlength1 >body \ for inlength1 clipped to oblen1
cmp cx, ' oblen1 >body \ if inlength1 > oblen1
> if mov cx, ' oblen1 >body \ clip search length to oblen1
then mov dx, cx \ save search length in DX
cx<>0 if mov es, ' inbseg1 >body \ searching inbseg1 segment
repnz scasb \ Scan for Linefeed char
then sub dx, cx \ DX = length of line
sub ' inlength1 >body dx \ subtract line from remaining
mov outbuf1 dl byte \ set the length of outbuf1
mov bx, si \ save IP for later restoral
mov si, ' instart1 >body \ moving from instart1
add ' instart1 >body dx \ set start to after line
mov cx, dx \ cx = length to move
mov di, # outbuf1 1+ \ moving to outbuf1
mov ds, ' inbseg1 >body \ from inbseg1 segment
mov ax, cs mov es, ax \ to CODE segment
cx<>0 if repnz movsb \ move the line to outbuf1
then
mov ax, cs mov ds, ax \ restore DS
mov si, bx \ restore IP
pop es \ restore ES
mov ax, # outbuf1 \ return address of buffer
1push end-code

: FILLBUFF1 ( --- ) \ Refill the input buffer.
inbseg1 instart1 over 0 inlength1 cmovel
%off> instart1
inlength1 iblen1 inlength1 -
INFILE1 inbseg1 exhread %+!> inlength1
SAVEPOINTER1 ;

CODE ?FILLBUFF1 ( --- ) \ refill INBUF if needed
cmp ' inlength1 >body # oblen1 1+ word
u>= if mov bx, # FILEPOINTER1 \ Set BX to point to FILEPOINTER1
sub cx, cx \ clear CX
mov cl, outbuf1 \ read byte length of outbuf1
add 2 [bx], cx \ Add to 32bit contents
adc 0 [bx], # 0
next
then \ If we got here, then
mov ax, # ' FILLBUFF1 \ go and re-fill the buffer
jmp ax
end-code

: LINEREAD1 ( --- a1 ) \ read a line delimited by CRLF
?FILLBUFF1 \ re-fill buffer if needed.
GET_ALINE1 ; \ returns line including CRLF



: IBRESET1 ( --- )
%off> instart1
%off> inlength1 ;

\ : $HOPEN ( A1 --- F1 ) \ Returns a boolean for open successful
\ INFILE1 hclose drop
\ INFILE1 $>handle
\ INFILE1 hopen
\ ibreset1 ;


: SEEK1 ( d1 --- ) \ Move the FILEPOINTER1 in INFILE1 to the
INFILE1 movepointer ; \ specified by d1.
: SEQINIT1 iblen1 paragraph alloc 8 = memchk nip %!> inbseg1 ;

SEQINIT1