mirror of
https://github.com/hsoft/collapseos.git
synced 2024-12-25 05:08:05 +11:00
forth: Make (parse) indirect and Forth-ify (parsec)
This commit is contained in:
parent
4212d5161f
commit
9451c599e0
@ -49,6 +49,24 @@
|
||||
: / /MOD SWAP DROP ;
|
||||
: MOD /MOD DROP ;
|
||||
|
||||
( Parse numbers )
|
||||
: (parsec) ( a -- n f )
|
||||
( apostrophe is ASCII 39 )
|
||||
DUP C@ 39 = NOT IF 0 EXIT THEN ( -- a 0 )
|
||||
DUP 2 + C@ 39 = NOT IF 0 EXIT THEN ( -- a 0 )
|
||||
( surrounded by apos, good, return )
|
||||
1 + C@ 1 ( -- n 1 )
|
||||
;
|
||||
|
||||
: (parse) ( a -- n )
|
||||
(parsec) NOT SKIP? EXIT
|
||||
(parsed) NOT SKIP? EXIT
|
||||
( nothing works )
|
||||
ABORT" unknown word! "
|
||||
;
|
||||
|
||||
' (parse) (parse*) !
|
||||
|
||||
( Format numbers )
|
||||
( TODO FORGET this word )
|
||||
: PUSHDGTS
|
||||
|
@ -339,7 +339,7 @@ COMPILE:
|
||||
.db 0b10 ; UNWORD
|
||||
.maybeNum:
|
||||
.dw compiledWord
|
||||
.dw PARSE
|
||||
.dw PARSEI
|
||||
.dw LITN
|
||||
.dw R2P ; exit COMPILE
|
||||
.dw DROP
|
||||
@ -554,10 +554,6 @@ PARSED:
|
||||
.dw nativeWord
|
||||
pop hl
|
||||
call chkPS
|
||||
; temporary: run parseCharLit in here until it's implemented in Forth
|
||||
; core.fs needs char literal parsing.
|
||||
call parseCharLit
|
||||
jr z, .success
|
||||
call parseDecimal
|
||||
jr z, .success
|
||||
; error
|
||||
@ -573,7 +569,7 @@ PARSED:
|
||||
|
||||
|
||||
.db "(parse)"
|
||||
.dw WORD
|
||||
.dw PARSED
|
||||
.db 0
|
||||
PARSE:
|
||||
.dw compiledWord
|
||||
@ -592,6 +588,16 @@ PARSE:
|
||||
.dw ABORT
|
||||
|
||||
|
||||
; Indirect parse caller. Reads PARSEPTR and calls
|
||||
.db 0b10 ; UNWORD
|
||||
PARSEI:
|
||||
.dw compiledWord
|
||||
.dw PARSEPTR_
|
||||
.dw FETCH
|
||||
.dw EXECUTE
|
||||
.dw EXIT
|
||||
|
||||
|
||||
.db "CREATE"
|
||||
.fill 1
|
||||
.dw PARSE
|
||||
@ -622,9 +628,16 @@ CURRENT_:
|
||||
.dw sysvarWord
|
||||
.dw CURRENT
|
||||
|
||||
.db "(parse*"
|
||||
.dw CURRENT_
|
||||
.db 0
|
||||
PARSEPTR_:
|
||||
.dw sysvarWord
|
||||
.dw PARSEPTR
|
||||
|
||||
.db "IN>"
|
||||
.fill 4
|
||||
.dw CURRENT_
|
||||
.dw PARSEPTR_
|
||||
.db 0
|
||||
INP:
|
||||
.dw sysvarWord
|
||||
|
@ -176,6 +176,8 @@ core.
|
||||
Parses string at a as a number and push the result
|
||||
in n as well as whether parsing was a success in f
|
||||
(0 = failure, 1 = success)
|
||||
(parse*) -- a Variable holding the current pointer for system
|
||||
number parsing. By default, (parse).
|
||||
(print) a -- Print string at addr a.
|
||||
. n -- Print n in its decimal form
|
||||
.X n -- Print n in its hexadecimal form. In hex, numbers
|
||||
|
@ -25,7 +25,11 @@
|
||||
.equ IP @+2
|
||||
; Pointer to where we currently are in the interpretation of the current line.
|
||||
.equ INPUTPOS @+2
|
||||
; Buffer where we compile the current input line. Same size as STDIO_BUFSIZE.
|
||||
; 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 FORTH_RAMEND @+2
|
||||
|
||||
; (HERE) usually starts at RAMEND, but in certain situations, such as in stage0,
|
||||
@ -84,6 +88,10 @@ forthMain:
|
||||
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
|
||||
@ -106,7 +114,7 @@ INTERPRET:
|
||||
|
||||
.maybeNum:
|
||||
.dw compiledWord
|
||||
.dw PARSE
|
||||
.dw PARSEI
|
||||
.dw R2P ; exit INTERPRET
|
||||
.dw DROP
|
||||
.dw EXIT
|
||||
|
@ -181,24 +181,6 @@ parseDecimal:
|
||||
cp a ; ensure Z
|
||||
ret
|
||||
|
||||
parseCharLit:
|
||||
ld a, (hl)
|
||||
cp 0x27 ; apostrophe
|
||||
ret nz
|
||||
|
||||
ld d, 0 ; preset
|
||||
inc hl
|
||||
ld e, (hl) ; our result
|
||||
inc hl
|
||||
cp (hl)
|
||||
ret z
|
||||
|
||||
; Z unset and there's an error
|
||||
; In all error conditions, HL is advanced by 2. Rewind.
|
||||
dec hl \ dec hl
|
||||
; NZ already set
|
||||
ret
|
||||
|
||||
; *** Forth-specific part ***
|
||||
; Return address of scratchpad in HL
|
||||
pad:
|
||||
|
Loading…
Reference in New Issue
Block a user