mirror of
https://github.com/hsoft/collapseos.git
synced 2024-12-25 04:38:05 +11:00
forth: implement readline in Forth
The commit ended up being much bigger than anticipated. This was a long thread of underlying complexities. This lead to the creation of interesting concepts such as (sysv).
This commit is contained in:
Virgil Dupras
parent
2feb246334
commit
c1ece95089
@ -7,7 +7,7 @@ AVRABIN = zasm/avra
|
||||
SHELLAPPS = zasm ed
|
||||
SHELLTGTS = ${SHELLAPPS:%=cfsin/%}
|
||||
# Those Forth source files are in a particular order
|
||||
FORTHSRCS = core.fs str.fs parse.fs fmt.fs
|
||||
FORTHSRCS = core.fs str.fs parse.fs readln.fs fmt.fs
|
||||
FORTHSRC_PATHS = ${FORTHSRCS:%=../forth/%}
|
||||
CFSIN_CONTENTS = $(SHELLTGTS) cfsin/user.h
|
||||
OBJS = emul.o libz80/libz80.o
|
||||
|
||||
@ -1,23 +1,20 @@
|
||||
: H HERE @ ;
|
||||
: -^ SWAP - ;
|
||||
: +! SWAP OVER @ + SWAP ! ;
|
||||
: ALLOT HERE +! ;
|
||||
: C, H C! 1 ALLOT ;
|
||||
: COMPILE ' LITN ['] , , ; IMMEDIATE
|
||||
: BEGIN H ; IMMEDIATE
|
||||
: AGAIN COMPILE (bbr) H -^ C, ; IMMEDIATE
|
||||
: UNTIL COMPILE SKIP? COMPILE (bbr) H -^ C, ; IMMEDIATE
|
||||
: NOT 1 SWAP SKIP? EXIT 0 * ;
|
||||
: ( BEGIN LITS ) 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
|
||||
|
||||
COMPILE; Tough one. Get addr of caller word (example above
|
||||
(bbr)) and then call LITN on it.
|
||||
COMPILE: Tough one. Get addr of caller word (example above
|
||||
(bbr)) and then call LITN on it. )
|
||||
|
||||
NOT: a bit convulted because we don't have IF yet )
|
||||
: +! SWAP OVER @ + SWAP ! ;
|
||||
: ALLOT HERE +! ;
|
||||
|
||||
: IF ( -- a | a: br cell addr )
|
||||
COMPILE SKIP? ( if true, don't branch )
|
||||
|
||||
@ -32,7 +32,7 @@ directly, but as part of another word.
|
||||
"*I*" in description indicates an IMMEDIATE word.
|
||||
|
||||
*** Defining words ***
|
||||
(find) x -- a f Read word x and find it in dict. If found, f=1 and
|
||||
(find) a -- a f Read at a and find it in dict. If found, f=1 and
|
||||
a = wordref. If not found, f=0 and a = string addr.
|
||||
: x ... -- Define a new word
|
||||
; R:I -- Exit a colon definition
|
||||
@ -186,6 +186,7 @@ core.
|
||||
." xxx" -- *I* Compiles string literal xxx followed by a call
|
||||
to (print)
|
||||
are never considered negative. "-1 .X -> ffff"
|
||||
C< -- c Read one char from buffered input.
|
||||
EMIT c -- Spit char c to output stream
|
||||
IN> -- a Address of variable containing current pos in input
|
||||
buffer.
|
||||
@ -195,6 +196,8 @@ PC@ a -- c Fetch c from port a
|
||||
WORD -- a Read one word from buffered input and push its addr
|
||||
|
||||
There are also ascii const emitters:
|
||||
BS
|
||||
CR
|
||||
LF
|
||||
SPC
|
||||
|
||||
|
||||
613
forth/forth.asm
613
forth/forth.asm
@ -35,12 +35,11 @@
|
||||
.equ NAMELEN 7
|
||||
; Offset of the code link relative to the beginning of the word
|
||||
.equ CODELINK_OFFSET NAMELEN+3
|
||||
; Size of the readline buffer. If a typed line reaches this size, the line is
|
||||
; flushed immediately (same as pressing return).
|
||||
.equ INPT_BUFSIZE 0x40
|
||||
; Buffer where WORD copies its read word to. It's significantly larger than
|
||||
; NAMELEN, but who knows, in a comment, we might have a very long word...
|
||||
.equ WORD_BUFSIZE 0x20
|
||||
; Allocated space for sysvars (see comment above SYSVCNT)
|
||||
.equ SYSV_BUFSIZE 0x10
|
||||
|
||||
; Flags for the "flag field" of the word structure
|
||||
; IMMEDIATE word
|
||||
@ -54,16 +53,25 @@
|
||||
.equ HERE @+2
|
||||
; Interpreter pointer. See Execution model comment below.
|
||||
.equ IP @+2
|
||||
; Pointer to where we currently are in the interpretation of the current line.
|
||||
.equ INPUTPOS @+2
|
||||
; Pointer to the system's number parsing function. It points to then entry that
|
||||
; had the "(parse)" name at startup. During stage0, it's out builtin PARSE,
|
||||
; but at stage1, it becomes "(parse)" from core.fs. It can also be changed at
|
||||
; runtime.
|
||||
.equ PARSEPTR @+2
|
||||
.equ INPTBUF @+2
|
||||
.equ WORDBUF @+INPT_BUFSIZE
|
||||
.equ RAMEND @+WORD_BUFSIZE
|
||||
; Pointer to the word executed by "C<". During stage0, this points to KEY.
|
||||
; However, KEY ain't very interactive. This is why we implement a readline
|
||||
; interface in Forth, which we plug in during init. If "(c<)" exists in the
|
||||
; dict, CINPTR is set to it. Otherwise, we set KEY
|
||||
.equ CINPTR @+2
|
||||
.equ WORDBUF @+2
|
||||
; Sys Vars are variables with their value living in the system RAM segment. We
|
||||
; need this mechanisms for core Forth source needing variables. Because core
|
||||
; Forth source is pre-compiled, it needs to be able to live in ROM, which means
|
||||
; that we can't compile a regular variable in it. SYSVNXT points to the next
|
||||
; free space in SYSVBUF. Then, at the word level, it's a regular sysvarWord.
|
||||
.equ SYSVNXT @+WORD_BUFSIZE
|
||||
.equ SYSVBUF @+2
|
||||
.equ RAMEND @+SYSV_BUFSIZE
|
||||
|
||||
; (HERE) usually starts at RAMEND, but in certain situations, such as in stage0,
|
||||
; (HERE) will begin at a strategic place.
|
||||
@ -107,6 +115,7 @@ forthMain:
|
||||
; we check for stack underflow.
|
||||
push af \ push af \ push af
|
||||
ld (INITIAL_SP), sp
|
||||
ld ix, RS_ADDR
|
||||
; LATEST is a *indirect* label to the latest entry of the dict. See
|
||||
; default at the bottom of dict.asm. This indirection allows us to
|
||||
; override latest to a value set in a binary dict compiled separately,
|
||||
@ -116,53 +125,61 @@ forthMain:
|
||||
ld (CURRENT), hl
|
||||
ld hl, HERE_INITIAL
|
||||
ld (HERE), hl
|
||||
; Set (INPUTPOS) to somewhere where there's a NULL so we consider
|
||||
; ourselves EOL.
|
||||
ld (INPUTPOS), hl
|
||||
xor a
|
||||
ld (hl), a
|
||||
; Set up PARSEPTR
|
||||
ld hl, PARSE-CODELINK_OFFSET
|
||||
call find
|
||||
ld (PARSEPTR), de
|
||||
forthRdLine:
|
||||
ld hl, msgOk
|
||||
call printstr
|
||||
forthRdLineNoOk:
|
||||
; Setup return stack. After INTERPRET, we run forthExecLine
|
||||
ld ix, RS_ADDR
|
||||
ld hl, MAINLOOP
|
||||
; Set up CINPTR
|
||||
; do we have a C< impl?
|
||||
ld hl, .cinName
|
||||
call find
|
||||
jr z, .skip
|
||||
; no? then use KEY
|
||||
ld de, KEY
|
||||
.skip:
|
||||
ld (CINPTR), de
|
||||
; Set up SYSVNXT
|
||||
ld hl, SYSVBUF
|
||||
ld (SYSVNXT), hl
|
||||
ld hl, BEGIN
|
||||
push hl
|
||||
jp EXECUTE+2
|
||||
|
||||
.cinName:
|
||||
.db "C<", 0
|
||||
|
||||
forthLoop:
|
||||
ld hl, INTERPRET
|
||||
push hl
|
||||
jp EXECUTE+2
|
||||
|
||||
BEGIN:
|
||||
.dw compiledWord
|
||||
.dw LIT
|
||||
.db "(c<$)", 0
|
||||
.dw FIND_
|
||||
.dw NOT
|
||||
.dw CSKIP
|
||||
.dw EXECUTE
|
||||
.dw INTERPRET
|
||||
|
||||
INTERPRET:
|
||||
.dw compiledWord
|
||||
; BBR mark
|
||||
.dw WORD
|
||||
.dw FIND_
|
||||
.dw CSKIP
|
||||
.dw .maybeNum
|
||||
.dw FBR
|
||||
.db 6
|
||||
; It's a word, execute it
|
||||
.dw EXECUTE
|
||||
.dw EXIT
|
||||
|
||||
.maybeNum:
|
||||
.dw compiledWord
|
||||
.dw BBR
|
||||
.db 13
|
||||
; FBR mark, try number
|
||||
.dw PARSEI
|
||||
.dw R2P ; exit INTERPRET
|
||||
.dw DROP
|
||||
.dw EXIT
|
||||
|
||||
MAINLOOP:
|
||||
.dw compiledWord
|
||||
.dw INTERPRET
|
||||
.dw INP
|
||||
.dw FETCH
|
||||
.dw CFETCH
|
||||
.dw CSKIP
|
||||
.dw QUIT
|
||||
.dw MAINLOOP
|
||||
|
||||
msgOk:
|
||||
.db " ok", 0
|
||||
.dw BBR
|
||||
.db 18
|
||||
; infinite loop
|
||||
|
||||
; *** Collapse OS lib copy ***
|
||||
; In the process of Forth-ifying Collapse OS, apps will be slowly rewritten to
|
||||
@ -172,105 +189,6 @@ msgOk:
|
||||
; give us an idea of Forth's compactness.
|
||||
; These routines below are copy/paste from apps/lib and stdio.
|
||||
|
||||
; print null-terminated string pointed to by HL
|
||||
printstr:
|
||||
push af
|
||||
push hl
|
||||
|
||||
.loop:
|
||||
ld a, (hl) ; load character to send
|
||||
or a ; is it zero?
|
||||
jr z, .end ; if yes, we're finished
|
||||
call PUTC
|
||||
inc hl
|
||||
jr .loop
|
||||
|
||||
.end:
|
||||
pop hl
|
||||
pop af
|
||||
ret
|
||||
|
||||
; Prints a line terminator. This routine is a bit of a misnomer because it's
|
||||
; designed to be overridable to, for example, printlf, but we'll live with it
|
||||
; for now...
|
||||
printcrlf:
|
||||
push af
|
||||
ld a, CR
|
||||
call PUTC
|
||||
ld a, LF
|
||||
call PUTC
|
||||
pop af
|
||||
ret
|
||||
|
||||
; Repeatedly calls stdioGetC until a whole line was read, that is, when CR or
|
||||
; LF is read or if the buffer is full. Sets HL to the beginning of the read
|
||||
; line, which is null-terminated.
|
||||
;
|
||||
; This routine also takes care of echoing received characters back to the TTY.
|
||||
; It also manages backspaces properly.
|
||||
readline:
|
||||
call printcrlf
|
||||
ld hl, INPTBUF
|
||||
ld b, INPT_BUFSIZE-1
|
||||
.loop:
|
||||
; Let's wait until something is typed.
|
||||
call GETC
|
||||
; got it. Now, is it a CR or LF?
|
||||
cp CR
|
||||
jr z, .complete ; char is CR? buffer complete!
|
||||
cp LF
|
||||
jr z, .complete
|
||||
cp DEL
|
||||
jr z, .delchr
|
||||
cp BS
|
||||
jr z, .delchr
|
||||
|
||||
; Echo the received character right away so that we see what we type
|
||||
call PUTC
|
||||
|
||||
; Ok, gotta add it do the buffer
|
||||
ld (hl), a
|
||||
inc hl
|
||||
djnz .loop
|
||||
; buffer overflow, complete line
|
||||
.complete:
|
||||
; The line in our buffer is complete.
|
||||
; Let's null-terminate it and return.
|
||||
xor a
|
||||
ld (hl), a
|
||||
ld hl, INPTBUF
|
||||
ld (INPUTPOS), hl
|
||||
ret
|
||||
|
||||
.delchr:
|
||||
; Deleting is a tricky business. We have to decrease HL and increase B
|
||||
; so that everything stays consistent. We also have to make sure that
|
||||
; We don't do buffer underflows.
|
||||
ld a, b
|
||||
cp INPT_BUFSIZE-1
|
||||
jr z, .loop ; beginning of line, nothing to delete
|
||||
dec hl
|
||||
inc b
|
||||
; Char deleted in buffer, now send BS + space + BS for the terminal
|
||||
; to clear its previous char
|
||||
ld a, BS
|
||||
call PUTC
|
||||
ld a, ' '
|
||||
call PUTC
|
||||
ld a, BS
|
||||
call PUTC
|
||||
jr .loop
|
||||
|
||||
; Ensures that Z is unset (more complicated than it sounds...)
|
||||
; There are often better inline alternatives, either replacing rets with
|
||||
; appropriate jmps, or if an 8 bit register is known to not be 0, an inc
|
||||
; then a dec. If a is nonzero, 'or a' is optimal.
|
||||
unsetZ:
|
||||
or a ;if a nonzero, Z reset
|
||||
ret nz
|
||||
cp 1 ;if a is zero, Z reset
|
||||
ret
|
||||
|
||||
; copy (HL) into DE, then exchange the two, utilising the optimised HL instructions.
|
||||
; ld must be done little endian, so least significant byte first.
|
||||
intoHL:
|
||||
@ -484,26 +402,6 @@ parseDecimal:
|
||||
ret
|
||||
|
||||
; *** Support routines ***
|
||||
; Advance (INPUTPOS) until a non-whitespace is met. If needed,
|
||||
; call readline.
|
||||
; Set HL to newly set (INPUTPOS)
|
||||
toword:
|
||||
ld hl, (INPUTPOS)
|
||||
; skip leading whitespace
|
||||
dec hl ; offset leading "inc hl"
|
||||
.loop:
|
||||
inc hl
|
||||
ld a, (hl)
|
||||
or a
|
||||
; When at EOL, fetch a new line directly
|
||||
jr z, .empty
|
||||
cp ' '+1
|
||||
jr c, .loop
|
||||
ret
|
||||
.empty:
|
||||
call readline
|
||||
jr toword
|
||||
|
||||
; Sets Z if (HL) == E and (HL+1) == D
|
||||
HLPointsDE:
|
||||
ld a, (hl)
|
||||
@ -555,24 +453,6 @@ find:
|
||||
; Z will be set if DE is zero
|
||||
ret
|
||||
|
||||
; Spit name (in (HL)) + prev in (HERE) and adjust (HERE) and (CURRENT)
|
||||
; HL points to new (HERE)
|
||||
entryhead:
|
||||
ld de, (HERE)
|
||||
call strcpy
|
||||
ex de, hl ; (HERE) now in HL
|
||||
ld de, (CURRENT)
|
||||
ld a, NAMELEN
|
||||
call addHL
|
||||
call DEinHL
|
||||
; Set word flags: not IMMED, so it's 0
|
||||
xor a
|
||||
ld (hl), a
|
||||
inc hl
|
||||
ld (CURRENT), hl
|
||||
ld (HERE), hl
|
||||
ret
|
||||
|
||||
; Checks flags Z and S and sets BC to 0 if Z, 1 if C and -1 otherwise
|
||||
flagsToBC:
|
||||
ld bc, 0
|
||||
@ -782,7 +662,8 @@ EXIT:
|
||||
.db 0
|
||||
QUIT:
|
||||
.dw nativeWord
|
||||
jp forthRdLine
|
||||
ld ix, RS_ADDR
|
||||
jp forthLoop
|
||||
|
||||
.db "ABORT"
|
||||
.fill 2
|
||||
@ -790,25 +671,20 @@ QUIT:
|
||||
.db 0
|
||||
ABORT:
|
||||
.dw nativeWord
|
||||
abort:
|
||||
; flush rest of input
|
||||
ld hl, (INPUTPOS)
|
||||
xor a
|
||||
ld (hl), a
|
||||
; Reinitialize PS (RS is reinitialized in forthInterpret)
|
||||
; Reinitialize PS
|
||||
ld sp, (INITIAL_SP)
|
||||
jp forthRdLineNoOk
|
||||
|
||||
; prints msg in (HL) then aborts
|
||||
abortMsg:
|
||||
call printstr
|
||||
jr abort
|
||||
jp QUIT+2
|
||||
|
||||
abortUnderflow:
|
||||
ld hl, .msg
|
||||
jr abortMsg
|
||||
.msg:
|
||||
ld hl, .word
|
||||
push hl
|
||||
jp EXECUTE+2
|
||||
.word:
|
||||
.dw compiledWord
|
||||
.dw LIT
|
||||
.db "stack underflow", 0
|
||||
.dw PRINT
|
||||
.dw ABORT
|
||||
|
||||
.db "ABORT", '"'
|
||||
.fill 1
|
||||
@ -817,17 +693,11 @@ abortUnderflow:
|
||||
ABORTI:
|
||||
.dw compiledWord
|
||||
.dw PRINTI
|
||||
.dw .private
|
||||
.dw NUMBER
|
||||
.dw ABORT
|
||||
.dw WR
|
||||
.dw EXIT
|
||||
|
||||
.private:
|
||||
.dw nativeWord
|
||||
ld hl, (HERE)
|
||||
ld de, ABORT
|
||||
call DEinHL
|
||||
ld (HERE), hl
|
||||
jp next
|
||||
|
||||
.db "BYE"
|
||||
.fill 4
|
||||
.dw ABORTI
|
||||
@ -862,8 +732,13 @@ PRINT:
|
||||
.dw nativeWord
|
||||
pop hl
|
||||
call chkPS
|
||||
call printstr
|
||||
jp next
|
||||
.loop:
|
||||
ld a, (hl) ; load character to send
|
||||
or a ; is it zero?
|
||||
jp z, next ; if yes, we're finished
|
||||
call PUTC
|
||||
inc hl
|
||||
jr .loop
|
||||
|
||||
|
||||
.db '.', '"'
|
||||
@ -871,34 +746,31 @@ PRINT:
|
||||
.dw PRINT
|
||||
.db 1 ; IMMEDIATE
|
||||
PRINTI:
|
||||
.dw nativeWord
|
||||
ld hl, (HERE)
|
||||
ld de, LIT
|
||||
call DEinHL
|
||||
ex de, hl ; (HERE) now in DE
|
||||
ld hl, (INPUTPOS)
|
||||
.loop:
|
||||
ld a, (hl)
|
||||
or a ; null? not cool
|
||||
jp z, abort
|
||||
cp '"'
|
||||
jr z, .loopend
|
||||
ld (de), a
|
||||
inc hl
|
||||
inc de
|
||||
jr .loop
|
||||
.loopend:
|
||||
inc hl ; inputpos to char afterwards
|
||||
ld (INPUTPOS), hl
|
||||
; null-terminate LIT
|
||||
inc de
|
||||
xor a
|
||||
ld (de), a
|
||||
ex de, hl ; (HERE) in HL
|
||||
ld de, PRINT
|
||||
call DEinHL
|
||||
ld (HERE), hl
|
||||
jp next
|
||||
.dw compiledWord
|
||||
.dw NUMBER
|
||||
.dw LIT
|
||||
.dw WR
|
||||
; BBR mark
|
||||
.dw CIN
|
||||
.dw DUP
|
||||
.dw NUMBER
|
||||
.dw '"'
|
||||
.dw CMP
|
||||
.dw CSKIP
|
||||
.dw FBR
|
||||
.db 6
|
||||
.dw CWR
|
||||
.dw BBR
|
||||
.db 19
|
||||
; FBR mark
|
||||
; null terminate string
|
||||
.dw NUMBER
|
||||
.dw 0
|
||||
.dw CWR
|
||||
.dw NUMBER
|
||||
.dw PRINT
|
||||
.dw WR
|
||||
.dw EXIT
|
||||
|
||||
; ( c port -- )
|
||||
.db "PC!"
|
||||
@ -927,9 +799,24 @@ PFETCH:
|
||||
push hl
|
||||
jp next
|
||||
|
||||
.db "C,"
|
||||
.fill 5
|
||||
.dw PFETCH
|
||||
.db 0
|
||||
CWR:
|
||||
.dw nativeWord
|
||||
pop de
|
||||
call chkPS
|
||||
ld hl, (HERE)
|
||||
ld (hl), e
|
||||
inc hl
|
||||
ld (HERE), hl
|
||||
jp next
|
||||
|
||||
|
||||
.db ","
|
||||
.fill 6
|
||||
.dw PFETCH
|
||||
.dw CWR
|
||||
.db 0
|
||||
WR:
|
||||
.dw nativeWord
|
||||
@ -963,6 +850,7 @@ EXECUTE:
|
||||
.db 1 ; IMMEDIATE
|
||||
COMPILE:
|
||||
.dw compiledWord
|
||||
.dw WORD
|
||||
.dw FIND_
|
||||
.dw CSKIP
|
||||
.dw .maybeNum
|
||||
@ -990,55 +878,37 @@ COMPILE:
|
||||
.dw EXIT
|
||||
|
||||
|
||||
.db ":"
|
||||
.db ";"
|
||||
.fill 6
|
||||
.dw COMPILE
|
||||
.db 1 ; IMMEDIATE
|
||||
ENDDEF:
|
||||
.dw compiledWord
|
||||
.dw NUMBER
|
||||
.dw EXIT
|
||||
.dw WR
|
||||
.dw R2P ; exit COMPILE
|
||||
.dw DROP
|
||||
.dw R2P ; exit DEFINE
|
||||
.dw DROP
|
||||
.dw EXIT
|
||||
|
||||
.db ":"
|
||||
.fill 6
|
||||
.dw ENDDEF
|
||||
.db 1 ; IMMEDIATE
|
||||
DEFINE:
|
||||
.dw compiledWord
|
||||
.dw WORD
|
||||
.dw .define
|
||||
.dw EXIT
|
||||
|
||||
.define:
|
||||
.dw nativeWord
|
||||
pop hl
|
||||
call entryhead
|
||||
ld de, compiledWord
|
||||
call DEinHL
|
||||
ld (HERE), hl
|
||||
.loop:
|
||||
; did we reach ";"?
|
||||
call toword
|
||||
ld a, (hl)
|
||||
cp ';'
|
||||
jr nz, .compile
|
||||
inc hl
|
||||
ld a, (hl)
|
||||
cp ' '+1
|
||||
jr c, .loopend ; whitespace, we have semicol. end
|
||||
.compile:
|
||||
ld hl, (IP)
|
||||
call pushRS
|
||||
ld hl, .retRef
|
||||
ld (IP), hl
|
||||
ld hl, COMPILE
|
||||
push hl
|
||||
jp EXECUTE+2
|
||||
.loopend:
|
||||
; Advance (INPUTPOS) to after semicol. HL is already there.
|
||||
ld (INPUTPOS), hl
|
||||
; write EXIT and return
|
||||
ld hl, (HERE)
|
||||
ld de, EXIT
|
||||
call DEinHL
|
||||
ld (HERE), hl
|
||||
jp next
|
||||
.retRef:
|
||||
.dw $+2
|
||||
.dw $+2
|
||||
call popRSIP
|
||||
jr .loop
|
||||
.dw ENTRYHEAD
|
||||
.dw NUMBER
|
||||
.dw compiledWord
|
||||
.dw WR
|
||||
; BBR branch mark
|
||||
.dw COMPILE
|
||||
.dw BBR
|
||||
.db 4
|
||||
; no need for EXIT, ENDDEF takes care of taking us out
|
||||
|
||||
|
||||
.db "DOES>"
|
||||
@ -1140,12 +1010,6 @@ LITS:
|
||||
.dw LITS
|
||||
.db 0
|
||||
FIND_:
|
||||
.dw compiledWord
|
||||
.dw WORD
|
||||
.dw .find
|
||||
.dw EXIT
|
||||
|
||||
.find:
|
||||
.dw nativeWord
|
||||
pop hl
|
||||
call find
|
||||
@ -1167,6 +1031,7 @@ FIND_:
|
||||
.db 0
|
||||
FIND:
|
||||
.dw compiledWord
|
||||
.dw WORD
|
||||
.dw FIND_
|
||||
.dw CSKIP
|
||||
.dw FINDERR
|
||||
@ -1178,6 +1043,7 @@ FIND:
|
||||
.db 0b01 ; IMMEDIATE
|
||||
FINDI:
|
||||
.dw compiledWord
|
||||
.dw WORD
|
||||
.dw FIND_
|
||||
.dw CSKIP
|
||||
.dw FINDERR
|
||||
@ -1205,18 +1071,106 @@ KEY:
|
||||
push hl
|
||||
jp next
|
||||
|
||||
; Read word from (INPUTPOS), copy to WORDBUF, null-terminate, and return, make
|
||||
; This is an indirect word that can be redirected through "CINPTR"
|
||||
; This is not a real word because it's not meant to be referred to in Forth
|
||||
; code: it is replaced in readln.fs.
|
||||
CIN:
|
||||
.dw compiledWord
|
||||
.dw NUMBER
|
||||
.dw CINPTR
|
||||
.dw FETCH
|
||||
.dw EXECUTE
|
||||
.dw EXIT
|
||||
|
||||
|
||||
; ( c -- f )
|
||||
; 33 CMP 1 + NOT
|
||||
; The NOT is to normalize the negative/positive numbers to 1 or 0.
|
||||
; Hadn't we wanted to normalize, we'd have written:
|
||||
; 32 CMP 1 -
|
||||
.db "WS?"
|
||||
.fill 4
|
||||
.dw KEY
|
||||
.db 0
|
||||
ISWS:
|
||||
.dw compiledWord
|
||||
.dw NUMBER
|
||||
.dw 33
|
||||
.dw CMP
|
||||
.dw NUMBER
|
||||
.dw 1
|
||||
.dw PLUS
|
||||
.dw NOT
|
||||
.dw EXIT
|
||||
|
||||
.db "NOT"
|
||||
.fill 4
|
||||
.dw ISWS
|
||||
.db 0
|
||||
NOT:
|
||||
.dw nativeWord
|
||||
pop hl
|
||||
call chkPS
|
||||
ld a, l
|
||||
or h
|
||||
ld hl, 0
|
||||
jr nz, .skip ; true, keep at 0
|
||||
; false, make 1
|
||||
inc hl
|
||||
.skip:
|
||||
push hl
|
||||
jp next
|
||||
|
||||
; ( -- c )
|
||||
; C< DUP 32 CMP 1 - SKIP? EXIT DROP TOWORD
|
||||
.db "TOWORD"
|
||||
.fill 1
|
||||
.dw NOT
|
||||
.db 0
|
||||
TOWORD:
|
||||
.dw compiledWord
|
||||
.dw CIN
|
||||
.dw DUP
|
||||
.dw ISWS
|
||||
.dw CSKIP
|
||||
.dw EXIT
|
||||
.dw DROP
|
||||
.dw TOWORD
|
||||
.dw EXIT
|
||||
|
||||
; Read word from C<, copy to WORDBUF, null-terminate, and return, make
|
||||
; HL point to WORDBUF.
|
||||
; Advance (INPUTPOS) to the character following the last copied character.
|
||||
; When we're at EOL, we call readline directly, so this call always returns
|
||||
; a word.
|
||||
.db "WORD"
|
||||
.fill 3
|
||||
.dw KEY
|
||||
.dw TOWORD
|
||||
.db 0
|
||||
WORD:
|
||||
.dw nativeWord
|
||||
call toword
|
||||
.dw compiledWord
|
||||
.dw WORDBUF_ ; ( a )
|
||||
.dw TOWORD ; ( a c )
|
||||
; branch mark
|
||||
.dw OVER ; ( a c a )
|
||||
.dw STORE ; ( a )
|
||||
.dw NUMBER ; ( a 1 )
|
||||
.dw 1
|
||||
.dw PLUS ; ( a+1 )
|
||||
.dw CIN ; ( a c )
|
||||
.dw DUP ; ( a c c )
|
||||
.dw ISWS ; ( a c f )
|
||||
.dw CSKIP ; ( a c )
|
||||
.dw BBR
|
||||
.db 20 ; here - mark
|
||||
; at this point, we have ( a WS )
|
||||
.dw DROP
|
||||
.dw NUMBER
|
||||
.dw 0
|
||||
.dw SWAP ; ( 0 a )
|
||||
.dw STORE ; ()
|
||||
.dw WORDBUF_
|
||||
.dw EXIT
|
||||
|
||||
.wcpy:
|
||||
.dw nativeWord
|
||||
ld de, WORDBUF
|
||||
push de ; we already have our result
|
||||
.loop:
|
||||
@ -1231,7 +1185,6 @@ WORD:
|
||||
; null-terminate the string.
|
||||
xor a
|
||||
ld (de), a
|
||||
ld (INPUTPOS), hl
|
||||
jp next
|
||||
|
||||
|
||||
@ -1284,6 +1237,27 @@ PARSEI:
|
||||
.dw EXIT
|
||||
|
||||
|
||||
; Spit name (in (HL)) + prev in (HERE) and adjust (HERE) and (CURRENT)
|
||||
; HL points to new (HERE)
|
||||
ENTRYHEAD:
|
||||
.dw nativeWord
|
||||
pop hl
|
||||
ld de, (HERE)
|
||||
call strcpy
|
||||
ex de, hl ; (HERE) now in HL
|
||||
ld de, (CURRENT)
|
||||
ld a, NAMELEN
|
||||
call addHL
|
||||
call DEinHL
|
||||
; Set word flags: not IMMED, so it's 0
|
||||
xor a
|
||||
ld (hl), a
|
||||
inc hl
|
||||
ld (CURRENT), hl
|
||||
ld (HERE), hl
|
||||
jp next
|
||||
|
||||
|
||||
.db "CREATE"
|
||||
.fill 1
|
||||
.dw PARSE
|
||||
@ -1291,21 +1265,48 @@ PARSEI:
|
||||
CREATE:
|
||||
.dw compiledWord
|
||||
.dw WORD
|
||||
.dw .create
|
||||
.dw ENTRYHEAD
|
||||
.dw NUMBER
|
||||
.dw cellWord
|
||||
.dw WR
|
||||
.dw EXIT
|
||||
|
||||
; 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
|
||||
.db "(sysv)"
|
||||
.fill 1
|
||||
.dw CREATE
|
||||
.db 0
|
||||
SYSV:
|
||||
.dw compiledWord
|
||||
.dw WORD
|
||||
.dw ENTRYHEAD
|
||||
.dw NUMBER
|
||||
.dw sysvarWord
|
||||
.dw WR
|
||||
.dw NUMBER
|
||||
.dw SYSVNXT
|
||||
.dw FETCH
|
||||
.dw WR
|
||||
; word written, now let's INC SYSVNXT
|
||||
.dw NUMBER ; a
|
||||
.dw SYSVNXT
|
||||
.dw DUP ; a a
|
||||
.dw FETCH ; a a@
|
||||
.dw NUMBER ; a a@ 2
|
||||
.dw 2
|
||||
.dw PLUS ; a a@+2
|
||||
.dw SWAP ; a@+2 a
|
||||
.dw STORE
|
||||
.dw EXIT
|
||||
|
||||
.create:
|
||||
.dw nativeWord
|
||||
pop hl
|
||||
call entryhead
|
||||
ld de, cellWord
|
||||
call DEinHL
|
||||
ld (HERE), hl
|
||||
jp next
|
||||
|
||||
.db "HERE"
|
||||
.fill 3
|
||||
.dw CREATE
|
||||
.dw SYSV
|
||||
.db 0
|
||||
HERE_: ; Caution: conflicts with actual variable name
|
||||
.dw sysvarWord
|
||||
@ -1325,18 +1326,18 @@ PARSEPTR_:
|
||||
.dw sysvarWord
|
||||
.dw PARSEPTR
|
||||
|
||||
.db "IN>"
|
||||
.fill 4
|
||||
.db "(wbuf)"
|
||||
.fill 1
|
||||
.dw PARSEPTR_
|
||||
.db 0
|
||||
INP:
|
||||
WORDBUF_:
|
||||
.dw sysvarWord
|
||||
.dw INPUTPOS
|
||||
.dw WORDBUF
|
||||
|
||||
; ( n a -- )
|
||||
.db "!"
|
||||
.fill 6
|
||||
.dw INP
|
||||
.dw WORDBUF_
|
||||
.db 0
|
||||
STORE:
|
||||
.dw nativeWord
|
||||
|
||||
78
forth/readln.fs
Normal file
78
forth/readln.fs
Normal file
@ -0,0 +1,78 @@
|
||||
( 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 )
|
||||
;
|
||||
@ -6,5 +6,7 @@
|
||||
AGAIN
|
||||
;
|
||||
|
||||
: BS 8 EMIT ;
|
||||
: LF 10 EMIT ;
|
||||
: CR 13 EMIT ;
|
||||
: SPC 32 EMIT ;
|
||||
|
||||
Loading…
Reference in New Issue
Block a user