mirror of
https://github.com/hsoft/collapseos.git
synced 2024-11-08 15:38:06 +11:00
123 lines
2.3 KiB
NASM
123 lines
2.3 KiB
NASM
; A dictionary entry has this structure:
|
|
; - 8b name (zero-padded)
|
|
; - 2b prev pointer
|
|
; - 2b code pointer
|
|
; - Parameter field area (PFA)
|
|
;
|
|
; The code pointer point to "word routines". These routines expect to be called
|
|
; with IY pointing to the PFA. They themselves are expected to end by jumping
|
|
; to the address at the top of the Return Stack. They will usually do so with
|
|
; "jp exit".
|
|
|
|
; Execute a word containing native code at its PFA
|
|
nativeWord:
|
|
jp (iy)
|
|
|
|
; Execute a compiled word containing a list of references to other words,
|
|
; usually ended by a reference to EXIT.
|
|
; A reference to a word in a compiledWord section is *not* a direct reference,
|
|
; but a word+CODELINK_OFFSET reference. Therefore, for a code link "link",
|
|
; (link) is the routine to call.
|
|
compiledWord:
|
|
push iy \ pop hl
|
|
inc hl
|
|
inc hl
|
|
; HL points to next Interpreter pointer.
|
|
call pushRS
|
|
ld l, (iy)
|
|
ld h, (iy+1)
|
|
push hl \ pop iy
|
|
; IY points to code link
|
|
jp executeCodeLink
|
|
|
|
; ( R:I -- )
|
|
EXIT:
|
|
.db "EXIT", 0, 0, 0, 0
|
|
.dw 0
|
|
.dw nativeWord
|
|
; When we call the EXIT word, we have to do a "double exit" because our current
|
|
; Interpreter pointer is pointing to the word *next* to our EXIT reference when,
|
|
; in fact, we want to continue processing the one above it.
|
|
call popRS
|
|
exit:
|
|
call popRS
|
|
; We have a pointer to a word
|
|
push hl \ pop iy
|
|
jp compiledWord
|
|
|
|
; ( c -- )
|
|
EMIT:
|
|
.db "EMIT", 0, 0, 0, 0
|
|
.dw EXIT
|
|
.dw nativeWord
|
|
pop hl
|
|
ld a, l
|
|
call stdioPutC
|
|
jp exit
|
|
|
|
; ( addr -- )
|
|
EXECUTE:
|
|
.db "EXECUTE", 0
|
|
.dw EMIT
|
|
.dw nativeWord
|
|
pop iy ; Points to word_offset
|
|
ld de, CODELINK_OFFSET
|
|
add iy, de
|
|
executeCodeLink:
|
|
ld l, (iy)
|
|
ld h, (iy+1)
|
|
; HL points to code pointer
|
|
inc iy
|
|
inc iy
|
|
; IY points to PFA
|
|
jp (hl) ; go!
|
|
|
|
; ( -- c )
|
|
KEY:
|
|
.db "KEY", 0, 0, 0, 0, 0
|
|
.dw EXECUTE
|
|
.dw nativeWord
|
|
call stdioGetC
|
|
ld h, 0
|
|
ld l, a
|
|
push hl
|
|
jp exit
|
|
|
|
INTERPRET:
|
|
.db "INTERPRE"
|
|
.dw KEY
|
|
.dw nativeWord
|
|
call pad
|
|
push hl \ pop iy
|
|
call stdioReadLine
|
|
ld (INPUTPOS), hl
|
|
.loop:
|
|
call readword
|
|
jp nz, .loopend
|
|
call compile
|
|
jr nz, .notfound
|
|
jr .loop
|
|
.loopend:
|
|
call compileExit
|
|
call pad
|
|
push hl \ pop iy
|
|
jp compiledWord
|
|
.notfound:
|
|
ld hl, .msg
|
|
call printstr
|
|
jp exit
|
|
.msg:
|
|
.db "not found", 0
|
|
|
|
; ( n -- )
|
|
DOT:
|
|
.db "."
|
|
.fill 7
|
|
.dw INTERPRET
|
|
.dw nativeWord
|
|
pop de
|
|
call pad
|
|
call fmtDecimalS
|
|
call printstr
|
|
jp exit
|