collapseos/forth/core.fs
2020-03-27 15:25:20 -04:00

107 lines
2.8 KiB
Forth

: H@ HERE @ ;
: -^ SWAP - ;
: [ INTERPRET 1 FLAGS ! ; IMMEDIATE
: ] R> DROP ;
: LIT [ ROUTINE S LITN ] , ;
: LITS LIT SCPY ;
: LIT< WORD LITS ; IMMEDIATE
: _err LIT< word-not-found (print) ABORT ;
: ' WORD (find) SKIP? _err ;
: ['] WORD (find) SKIP? _err LITN ; IMMEDIATE
: COMPILE ' LITN ['] , , ; IMMEDIATE
: [COMPILE] ' , ; IMMEDIATE
: BEGIN H@ ; IMMEDIATE
: AGAIN COMPILE (bbr) H@ -^ C, ; IMMEDIATE
: UNTIL COMPILE SKIP? COMPILE (bbr) H@ -^ C, ; IMMEDIATE
: ( BEGIN LIT< ) WORD SCMP NOT UNTIL ; IMMEDIATE
( Hello, hello, krkrkrkr... do you hear me?
Ah, voice at last! Some lines above need comments
BTW: Forth lines limited to 64 cols because of default
input buffer size in Collapse OS
"_": words starting with "_" are meant to be "private",
that is, only used by their immediate surrondings.
COMPILE: Tough one. Get addr of caller word (example above
(bbr)) and then call LITN on it. )
: +! SWAP OVER @ + SWAP ! ;
: ALLOT HERE +! ;
: IF ( -- a | a: br cell addr )
COMPILE SKIP? ( if true, don't branch )
COMPILE (fbr)
H@ ( push a )
1 ALLOT ( br cell allot )
; IMMEDIATE
: THEN ( a -- | a: br cell addr )
DUP H@ -^ SWAP ( a-H a )
C!
; IMMEDIATE
: ELSE ( a1 -- a2 | a1: IF cell a2: ELSE cell )
COMPILE (fbr)
1 ALLOT
DUP H@ -^ SWAP ( a-H a )
C!
H@ 1 - ( push a. -1 for allot offset )
; IMMEDIATE
: CREATE
(entry) ( empty header with name )
[ ROUTINE C LITN ] ( push cellWord addr )
, ( write it )
;
: VARIABLE CREATE 2 ALLOT ;
: CONSTANT CREATE H@ ! DOES> @ ;
: = CMP NOT ;
: < CMP 0 1 - = ;
: > CMP 1 = ;
: / /MOD SWAP DROP ;
: MOD /MOD DROP ;
( In addition to pushing H@ this compiles 2 >R so that loop
variables are sent to PS at runtime )
: DO
COMPILE SWAP COMPILE >R COMPILE >R
H@
; IMMEDIATE
( One could think that we should have a sub word to avoid all
these COMPILE, but we can't because otherwise it messes with
the RS )
: LOOP
COMPILE R> 1 LITN COMPILE + COMPILE DUP COMPILE >R
COMPILE I' COMPILE = COMPILE SKIP? COMPILE (bbr)
H@ -^ C,
COMPILE R> COMPILE DROP COMPILE R> COMPILE DROP
; IMMEDIATE
( WARNING: there are no limit checks. We must be cautious, in
core code, not to create more than SYSV_BUFSIZE/2 sys vars.
Also: SYSV shouldn't be used during runtime: SYSVNXT won't
point at the right place. It should only be used during
stage1 compilation. This is why this word is not documented
in dictionary.txt )
: (sysv)
(entry)
[ ROUTINE Y LITN ] ,
SYSVNXT @ ,
2 SYSVNXT +!
;
: ."
LIT
BEGIN
C< DUP ( c c )
( 34 is ASCII for " )
DUP 34 = IF DROP DROP 0 0 THEN
C,
0 = UNTIL
COMPILE (print)
; IMMEDIATE
: ABORT" [COMPILE] ." COMPILE ABORT ; IMMEDIATE