mirror of
https://github.com/hsoft/collapseos.git
synced 2024-11-06 02:20:58 +11:00
79 lines
2.0 KiB
Forth
79 lines
2.0 KiB
Forth
|
( requires core, parse )
|
||
|
|
|
||
|
|
( Managing variables in a core module is tricky. Sure, we
|
||
|
|
have (sysv), but here we need to allocate a big buffer, and
|
||
|
|
that cannot be done through (sysv). What we do is that we
|
||
|
|
allocate that buffer at runtime and use (sysv) to point to
|
||
|
|
it, a pointer that is set during the initialization
|
||
|
|
routine. )
|
||
|
|
|
||
|
|
64 CONSTANT INBUFSZ
|
||
|
|
( points to INBUF )
|
||
|
|
(sysv) IN(
|
||
|
|
( points to INBUF's end )
|
||
|
|
(sysv) IN)
|
||
|
|
( current position in INBUF )
|
||
|
|
(sysv) IN>
|
||
|
|
|
||
|
|
( flush input buffer )
|
||
|
|
( set IN> to IN( and set IN> @ to null )
|
||
|
|
: (infl) 0 IN( @ DUP IN> ! ! ;
|
||
|
|
|
||
|
|
( Initializes the readln subsystem )
|
||
|
|
: (c<$)
|
||
|
|
HERE @ IN( !
|
||
|
|
INBUFSZ ALLOT
|
||
|
|
HERE @ IN) !
|
||
|
|
(infl)
|
||
|
|
;
|
||
|
|
|
||
|
|
( handle backspace: go back one char in IN>, if possible, then
|
||
|
|
emit SPC + BS )
|
||
|
|
: (inbs)
|
||
|
|
( already at IN( ? )
|
||
|
|
IN> @ IN( @ = IF EXIT THEN
|
||
|
|
IN> @ 1 - IN> !
|
||
|
|
SPC BS
|
||
|
|
;
|
||
|
|
|
||
|
|
( read one char into input buffer and returns whether we
|
||
|
|
should continue, that is, whether newline was not met. )
|
||
|
|
: (rdlnc) ( -- f )
|
||
|
|
( buffer overflow? stop now )
|
||
|
|
IN> @ IN) @ = IF 0 EXIT THEN
|
||
|
|
( get and echo back )
|
||
|
|
KEY DUP ( c c )
|
||
|
|
( del? same as backspace )
|
||
|
|
DUP 0x7f = IF DROP DROP 0x8 DUP THEN
|
||
|
|
EMIT ( c )
|
||
|
|
( bacspace? handle and exit )
|
||
|
|
DUP 0x8 = IF (inbs) EXIT THEN
|
||
|
|
( write and advance )
|
||
|
|
DUP ( keep as result ) ( c c )
|
||
|
|
IN> @ ! 1 IN> +! ( c )
|
||
|
|
( not newline? exit now )
|
||
|
|
DUP 0xa = NOT IF EXIT THEN ( c )
|
||
|
|
( newline? make our result 0 and write it to indicate
|
||
|
|
EOL )
|
||
|
|
DROP 0
|
||
|
|
DUP IN> @ ! ( c )
|
||
|
|
;
|
||
|
|
|
||
|
|
( Read one line in input buffer and make IN> point to it )
|
||
|
|
: (rdln)
|
||
|
|
( TODO: don't emit prompt in middle of defs and comments )
|
||
|
|
LF '>' EMIT SPC
|
||
|
|
(infl)
|
||
|
|
BEGIN (rdlnc) NOT UNTIL
|
||
|
|
IN( @ IN> !
|
||
|
|
;
|
||
|
|
|
||
|
|
( And finally, implement a replacement for the C< routine )
|
||
|
|
: C<
|
||
|
|
IN> @ C@ ( c )
|
||
|
|
( not EOL? good, inc and return )
|
||
|
|
DUP IF 1 IN> +! EXIT THEN ( c )
|
||
|
|
( EOL ? readline. we still return typed char though )
|
||
|
|
(rdln) ( c )
|
||
|
|
;
|