mirror of
https://github.com/hsoft/collapseos.git
synced 2024-11-02 10:30:55 +11:00
Compare commits
3 Commits
94166186eb
...
7befe56597
Author | SHA1 | Date | |
---|---|---|---|
|
7befe56597 | ||
|
e1f815baeb | ||
|
764b2222c7 |
@ -4,20 +4,24 @@
|
||||
: ALLOT HERE +! ;
|
||||
: , H ! 2 ALLOT ;
|
||||
: C, H C! 1 ALLOT ;
|
||||
: IF ['] (fbr?) , H 1 ALLOT ; IMMEDIATE
|
||||
: THEN DUP H -^ SWAP C! ; IMMEDIATE
|
||||
: ELSE ['] (fbr) , 1 ALLOT DUP H -^ SWAP C! H 1 - ; IMMEDIATE
|
||||
: NOT 1 SWAP SKIP? EXIT 0 * ;
|
||||
: RECURSE R> R> 2 - >R >R EXIT ;
|
||||
: ( LIT@ ) WORD SCMP IF RECURSE THEN ; IMMEDIATE
|
||||
( Hello, hello, krkrkrkr... do you hear me? )
|
||||
( Ah, voice at last! Some lines above need comments )
|
||||
( IF: write (fbr?) addr, push HERE, create cell )
|
||||
( THEN: Subtract TOS from H to get offset to write to cell )
|
||||
( in that same TOS's addr )
|
||||
( ELSE: write (fbr) addr, allot, then same as THEN )
|
||||
( RECURSE: RS TOS is for RECURSE itself, then we have to dig )
|
||||
( one more level to get to RECURSE's parent's caller. )
|
||||
: NOT IF 0 ELSE 1 THEN ;
|
||||
: ( LIT@ ) WORD SCMP NOT SKIP? RECURSE ; 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
|
||||
NOT: a bit convulted because we don't have IF yet
|
||||
RECURSE: RS TOS is for RECURSE itself, then we have to dig
|
||||
one more level to get to RECURSE's parent's caller.
|
||||
IF true, skip following (fbr). Also, push br cell ref H,
|
||||
to PS )
|
||||
: IF ['] SKIP? , ['] (fbr) , H 1 ALLOT ; IMMEDIATE
|
||||
( Subtract TOS from H to get offset to write to IF or ELSE's
|
||||
br cell )
|
||||
: THEN DUP H -^ SWAP C! ; IMMEDIATE
|
||||
( write (fbr) addr, allot, then same as THEN )
|
||||
: ELSE ['] (fbr) , 1 ALLOT DUP H -^ SWAP C! H 1 - ; IMMEDIATE
|
||||
: ? @ . ;
|
||||
: VARIABLE CREATE 2 ALLOT ;
|
||||
: CONSTANT CREATE H ! DOES> @ ;
|
||||
|
@ -206,7 +206,6 @@ PFETCH:
|
||||
EXECUTE:
|
||||
.dw nativeWord
|
||||
pop iy ; is a wordref
|
||||
executeCodeLink:
|
||||
ld l, (iy)
|
||||
ld h, (iy+1)
|
||||
; HL points to code pointer
|
||||
@ -216,9 +215,68 @@ executeCodeLink:
|
||||
jp (hl) ; go!
|
||||
|
||||
|
||||
.db "COMPILE"
|
||||
.dw EXECUTE
|
||||
.db 1 ; IMMEDIATE
|
||||
COMPILE:
|
||||
.dw nativeWord
|
||||
pop hl ; word addr
|
||||
call find
|
||||
jr nz, .maybeNum
|
||||
ex de, hl
|
||||
call HLisIMMED
|
||||
jr z, .immed
|
||||
ex de, hl
|
||||
call .writeDE
|
||||
jp next
|
||||
.maybeNum:
|
||||
push hl ; --> lvl 1. save string addr
|
||||
call parseLiteral
|
||||
pop hl ; <-- lvl 1
|
||||
jr nz, .undef
|
||||
; a valid number in DE!
|
||||
ex de, hl
|
||||
ld de, NUMBER
|
||||
call .writeDE
|
||||
ex de, hl ; number in DE
|
||||
call .writeDE
|
||||
jp next
|
||||
.undef:
|
||||
; When encountering an undefined word during compilation, we spit a
|
||||
; reference to litWord, followed by the null-terminated word.
|
||||
; This way, if a preceding word expect a string literal, it will read it
|
||||
; by calling readLIT, and if it doesn't, the routine will be
|
||||
; called, triggering an abort.
|
||||
ld de, LIT
|
||||
call .writeDE
|
||||
ld de, (HERE)
|
||||
call strcpyM
|
||||
ld (HERE), de
|
||||
jp next
|
||||
.immed:
|
||||
; For this IMMEDIATE word to be compatible with regular execution model,
|
||||
; it needs to be compiled as an atom somewhere in memory.
|
||||
; For example, RECURSE backtracks in RS and steps back 2 bytes. This
|
||||
; can only work with our compiled atom being next to an EXIT atom.
|
||||
ex de, hl ; atom to write in DE
|
||||
ld hl, (OLDHERE)
|
||||
push hl \ pop iy
|
||||
call DEinHL
|
||||
ld de, EXIT
|
||||
call DEinHL
|
||||
jp compiledWord
|
||||
.writeDE:
|
||||
push hl
|
||||
ld hl, (HERE)
|
||||
call DEinHL
|
||||
ld (HERE), hl
|
||||
pop hl
|
||||
ret
|
||||
|
||||
|
||||
.db ";"
|
||||
.fill 6
|
||||
.dw EXECUTE
|
||||
.dw COMPILE
|
||||
.db 0
|
||||
ENDDEF:
|
||||
.dw nativeWord
|
||||
@ -377,7 +435,6 @@ KEY:
|
||||
WORD:
|
||||
.dw nativeWord
|
||||
call readword
|
||||
jp nz, abort
|
||||
push hl
|
||||
jp next
|
||||
|
||||
@ -411,10 +468,18 @@ CURRENT_:
|
||||
.dw sysvarWord
|
||||
.dw CURRENT
|
||||
|
||||
.db "IN>"
|
||||
.fill 4
|
||||
.dw CURRENT_
|
||||
.db 0
|
||||
INP:
|
||||
.dw sysvarWord
|
||||
.dw INPUTPOS
|
||||
|
||||
; ( n -- )
|
||||
.db "."
|
||||
.fill 6
|
||||
.dw CURRENT_
|
||||
.dw INP
|
||||
.db 0
|
||||
DOT:
|
||||
.dw nativeWord
|
||||
@ -487,10 +552,20 @@ LITFETCH:
|
||||
push hl
|
||||
jp next
|
||||
|
||||
; ( a -- )
|
||||
.db "DROP"
|
||||
.fill 3
|
||||
.dw LITFETCH
|
||||
.db 0
|
||||
DROP:
|
||||
.dw nativeWord
|
||||
pop hl
|
||||
jp next
|
||||
|
||||
; ( a b -- b a )
|
||||
.db "SWAP"
|
||||
.fill 3
|
||||
.dw LITFETCH
|
||||
.dw DROP
|
||||
.db 0
|
||||
SWAP:
|
||||
.dw nativeWord
|
||||
@ -711,12 +786,27 @@ CMP:
|
||||
push bc
|
||||
jp next
|
||||
|
||||
.db "SKIP?"
|
||||
.fill 2
|
||||
.dw CMP
|
||||
.db 0
|
||||
CSKIP:
|
||||
.dw nativeWord
|
||||
pop hl
|
||||
ld a, h
|
||||
or l
|
||||
jp z, next ; False, do nothing.
|
||||
ld hl, (IP)
|
||||
call compSkip
|
||||
ld (IP), hl
|
||||
jp next
|
||||
|
||||
; This word's atom is followed by 1b *relative* offset (to the cell's addr) to
|
||||
; where to branch to. For example, The branching cell of "IF THEN" would
|
||||
; contain 3. Add this value to RS.
|
||||
.db "(fbr)"
|
||||
.fill 2
|
||||
.dw CMP
|
||||
.dw CSKIP
|
||||
.db 0
|
||||
FBR:
|
||||
.dw nativeWord
|
||||
@ -728,23 +818,6 @@ FBR:
|
||||
pop de
|
||||
jp next
|
||||
|
||||
; Conditional branch, only branch if TOS is zero
|
||||
.db "(fbr?)"
|
||||
.fill 1
|
||||
.dw FBR
|
||||
.db 0
|
||||
FBRC:
|
||||
.dw nativeWord
|
||||
pop hl
|
||||
ld a, h
|
||||
or l
|
||||
jr z, FBR+2
|
||||
; skip next byte in RS
|
||||
ld hl, (IP)
|
||||
inc hl
|
||||
ld (IP), hl
|
||||
jp next
|
||||
|
||||
LATEST:
|
||||
.dw FBRC
|
||||
.dw FBR
|
||||
|
||||
|
@ -49,10 +49,9 @@ LITERAL n -- *I* Inserts number from TOS as a literal
|
||||
VARIABLE c -- Creates cell x with 2 bytes allocation.
|
||||
|
||||
*** Flow ***
|
||||
(fbr?) f -- Conditionally branches forward by the number
|
||||
specified in its atom's cell.
|
||||
(fbr) -- Branches forward by the number specified in its
|
||||
atom's cell.
|
||||
COMPILE a -- Compile string word at addr a and spit it to HERE.
|
||||
ELSE I:a -- *I* Compiles a (fbr) and set branching cell at a.
|
||||
EXECUTE a -- Execute wordref at addr a
|
||||
IF -- I:a *I* Compiles a (fbr?) and pushes its cell's addr
|
||||
@ -60,9 +59,13 @@ INTERPRET -- Get a line from stdin, compile it in tmp memory,
|
||||
then execute the compiled contents.
|
||||
QUIT R:drop -- Return to interpreter promp immediately
|
||||
RECURSE R:I -- R:I-2 Run the current word again.
|
||||
SKIP? f -- If f is true, skip the execution of the next atom.
|
||||
Use this right before ";" and you're gonna have a
|
||||
bad time.
|
||||
THEN I:a -- *I* Set branching cell at a.
|
||||
|
||||
*** Parameter Stack ***
|
||||
DROP a --
|
||||
DUP a -- a a
|
||||
OVER a b -- a b a
|
||||
SWAP a b -- b a
|
||||
@ -109,10 +112,21 @@ LIT@ x -- a Read following LIT and push its addr to a
|
||||
SCMP a1 a2 -- n Compare strings a1 and a2. See CMP
|
||||
|
||||
*** I/O ***
|
||||
|
||||
A little word about inputs. There are two kind of inputs: direct and buffered.
|
||||
As a general rule, we read line in a buffer, then feed words in it to the
|
||||
interpreter. That's what "WORD" does. If it's at the End Of Line, it blocks and
|
||||
wait until another line is entered.
|
||||
|
||||
KEY input, however, is direct. Regardless of the input buffer's state, KEY will
|
||||
return the next typed key.
|
||||
|
||||
. n -- Print n in its decimal form
|
||||
EMIT c -- Spit char c to stdout
|
||||
KEY -- c Get char c from stdin
|
||||
EMIT c -- Spit char c to output stream
|
||||
IN> -- a Address of variable containing current pos in input
|
||||
buffer.
|
||||
KEY -- c Get char c from direct input
|
||||
PC! c a -- Spit c to port a
|
||||
PC@ a -- c Fetch c from port a
|
||||
WORD -- a Read one word from stdin and push its addr
|
||||
WORD -- a Read one word from buffered input and push its addr
|
||||
|
||||
|
@ -69,7 +69,7 @@
|
||||
; EXECUTING A WORD
|
||||
;
|
||||
; At it's core, executing a word is having the wordref in IY and call
|
||||
; executeCodeLink. Then, we let the word do its things. Some words are special,
|
||||
; EXECUTE. Then, we let the word do its things. Some words are special,
|
||||
; but most of them are of the compiledWord type, and that's their execution that
|
||||
; we describe here.
|
||||
;
|
||||
@ -102,16 +102,16 @@ 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
|
||||
forthRdLine:
|
||||
ld hl, msgOk
|
||||
call printstr
|
||||
forthRdLineNoOk:
|
||||
call printcrlf
|
||||
call stdioReadLine
|
||||
ld (INPUTPOS), hl
|
||||
; Setup return stack. As a safety net, we set its bottom to ABORTREF.
|
||||
ld hl, ABORTREF
|
||||
ld (RS_ADDR), hl
|
||||
; Setup return stack. After INTERPRET, we run forthExecLine
|
||||
ld ix, RS_ADDR
|
||||
; We're about to compile the line and possibly execute IMMEDIATE words.
|
||||
; Let's save current (HERE) and temporarily set it to COMPBUF.
|
||||
@ -119,61 +119,24 @@ forthRdLineNoOk:
|
||||
ld (OLDHERE), hl
|
||||
ld hl, COMPBUF
|
||||
ld (HERE), hl
|
||||
forthInterpret:
|
||||
call readword
|
||||
jr nz, .execute
|
||||
call find
|
||||
jr nz, .maybeNum
|
||||
ex de, hl
|
||||
call HLisIMMED
|
||||
jr z, .immed
|
||||
ex de, hl
|
||||
call .writeDE
|
||||
jr forthInterpret
|
||||
.maybeNum:
|
||||
push hl ; --> lvl 1. save string addr
|
||||
call parseLiteral
|
||||
pop hl ; <-- lvl 1
|
||||
jr nz, .undef
|
||||
; a valid number in DE!
|
||||
ex de, hl
|
||||
ld de, NUMBER
|
||||
call .writeDE
|
||||
ex de, hl ; number in DE
|
||||
call .writeDE
|
||||
jr forthInterpret
|
||||
.undef:
|
||||
; When encountering an undefined word during compilation, we spit a
|
||||
; reference to litWord, followed by the null-terminated word.
|
||||
; This way, if a preceding word expect a string literal, it will read it
|
||||
; by calling readLIT, and if it doesn't, the routine will be
|
||||
; called, triggering an abort.
|
||||
ld de, LIT
|
||||
call .writeDE
|
||||
ld de, (HERE)
|
||||
call strcpyM
|
||||
ld (HERE), de
|
||||
jr forthInterpret
|
||||
.immed:
|
||||
; For this IMMEDIATE word to be compatible with regular execution model,
|
||||
; it needs to be compiled as an atom list. We need a temporary space for
|
||||
; this, let's use (OLDHERE) while it isn't used.
|
||||
ex de, hl ; atom to write in DE
|
||||
ld hl, (OLDHERE)
|
||||
call DEinHL
|
||||
; Now, let's write the .retRef
|
||||
ld de, .retRef
|
||||
call DEinHL
|
||||
ld iy, (OLDHERE)
|
||||
jr .execIY
|
||||
.execute:
|
||||
ld hl, .retRef
|
||||
ld (IP), hl
|
||||
ld hl, INTERPRET
|
||||
push hl
|
||||
jp EXECUTE+2
|
||||
.retRef:
|
||||
.dw $+2
|
||||
.dw forthExecLine
|
||||
|
||||
forthExecLine:
|
||||
ld de, QUIT
|
||||
call .writeDE
|
||||
ld hl, (HERE)
|
||||
call DEinHL
|
||||
ld (HERE), hl
|
||||
; Compilation done, let's restore (HERE) and execute!
|
||||
ld hl, (OLDHERE)
|
||||
ld (HERE), hl
|
||||
ld iy, COMPBUF
|
||||
.execIY:
|
||||
; before we execute, let's play with our RS a bit: compiledWord is
|
||||
; going to push (IP) on the RS, but we don't expect our compiled words
|
||||
; to ever return: it ends with QUIT. Let's set (IP) to ABORTREF and
|
||||
@ -182,16 +145,22 @@ forthInterpret:
|
||||
ld (IP), hl
|
||||
ld ix, RS_ADDR-2
|
||||
jp compiledWord
|
||||
.writeDE:
|
||||
push hl
|
||||
ld hl, (HERE)
|
||||
call DEinHL
|
||||
ld (HERE), hl
|
||||
pop hl
|
||||
ret
|
||||
|
||||
.retRef:
|
||||
.dw forthInterpret
|
||||
; (we don't have RECURSE here. Calling interpret makes us needlessly use our
|
||||
; RS stack, but it can take it, can't it? )
|
||||
; WORD COMPILE IN> @ C@ (to check if null) SKIP? (skip if not null) EXIT INTERPRET
|
||||
.db 0b10 ; UNWORD
|
||||
INTERPRET:
|
||||
.dw compiledWord
|
||||
.dw WORD
|
||||
.dw COMPILE
|
||||
.dw INP
|
||||
.dw FETCH
|
||||
.dw CFETCH
|
||||
.dw CSKIP
|
||||
.dw EXIT
|
||||
.dw INTERPRET
|
||||
.dw EXIT
|
||||
|
||||
msgOk:
|
||||
.db " ok", 0
|
||||
|
@ -7,7 +7,8 @@ pad:
|
||||
; Read word from (INPUTPOS) and return, in HL, a null-terminated word.
|
||||
; Advance (INPUTPOS) to the character following the whitespace ending the
|
||||
; word.
|
||||
; Z set of word was read, unset if end of line.
|
||||
; When we're at EOL, we call fetchline directly, so this call always returns
|
||||
; a word.
|
||||
readword:
|
||||
ld hl, (INPUTPOS)
|
||||
; skip leading whitespace
|
||||
@ -16,6 +17,7 @@ readword:
|
||||
inc hl
|
||||
ld a, (hl)
|
||||
or a
|
||||
; When at EOL, fetch a new line directly
|
||||
jr z, .empty
|
||||
cp ' '+1
|
||||
jr c, .loop1
|
||||
@ -39,9 +41,8 @@ readword:
|
||||
pop hl ; <-- lvl 1. our result
|
||||
ret ; Z set from XOR A
|
||||
.empty:
|
||||
ld (hl), a
|
||||
inc a ; unset Z
|
||||
ret
|
||||
call fetchline
|
||||
jr readword
|
||||
|
||||
; Sets Z if (HL) == E and (HL+1) == D
|
||||
HLPointsDE:
|
||||
@ -73,10 +74,6 @@ HLPointsBR:
|
||||
push de
|
||||
ld de, FBR
|
||||
call HLPointsDE
|
||||
jr z, .end
|
||||
ld de, FBRC
|
||||
call HLPointsDE
|
||||
.end:
|
||||
pop de
|
||||
ret
|
||||
|
||||
@ -340,3 +337,10 @@ DEinHL:
|
||||
ld (hl), d
|
||||
inc hl
|
||||
ret
|
||||
|
||||
fetchline:
|
||||
call printcrlf
|
||||
call stdioReadLine
|
||||
ld (INPUTPOS), hl
|
||||
ret
|
||||
|
||||
|
Loading…
Reference in New Issue
Block a user