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Calculate defword entry length with %strlen

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This commit is contained in:
Cesar Blum 2020-10-01 21:49:54 -07:00
parent d55d6bc190
commit e5b0b97643
1 changed files with 23 additions and 22 deletions
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45
sectorforth.asm
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@ -59,13 +59,14 @@ LENMASK equ 0x1f
%define link 0 %define link 0
; defword lays out a dictionary entry where it is expanded. ; defword lays out a dictionary entry where it is expanded.
%macro defword 3-4 0 ; name, length, label, flags %macro defword 2-3 0 ; name, label, flags
word_%3: word_%2:
dw link ; link to previous word dw link ; link to previous word
%define link word_%3 %define link word_%2
db %4+%2 ; flags+length %strlen %%len %1
db %3+%%len ; flags+length
db %1 ; name db %1 ; name
%3: ; code starts here %2: ; code starts here
%endmacro %endmacro
; NEXT advances execution to the next word. The actual code is ; NEXT advances execution to the next word. The actual code is
@ -85,25 +86,25 @@ word_%3:
; nand ( x1 x2 -- n ) NAND the two values at the top of the stack ; nand ( x1 x2 -- n ) NAND the two values at the top of the stack
; exit ( r:addr -- ) Resume execution at address at the top of ; exit ( r:addr -- ) Resume execution at address at the top of
; the return stack ; the return stack
defword "@",1,FETCH defword "@",FETCH
pop bx pop bx
push word [bx] push word [bx]
NEXT NEXT
defword "!",1,STORE defword "!",STORE
pop bx pop bx
pop word [bx] pop word [bx]
NEXT NEXT
defword "sp@",3,SPFETCH defword "sp@",SPFETCH
push sp push sp
NEXT NEXT
defword "rp@",3,RPFETCH defword "rp@",RPFETCH
push bp push bp
NEXT NEXT
defword "0=",2,ZEROEQUALS defword "0=",ZEROEQUALS
pop ax pop ax
test ax,ax test ax,ax
setnz al ; AL=0 if ZF=1, else AL=1 setnz al ; AL=0 if ZF=1, else AL=1
@ -112,14 +113,14 @@ word_%3:
push ax push ax
NEXT NEXT
defword "+",1,PLUS defword "+",PLUS
pop bx pop bx
pop ax pop ax
add ax,bx add ax,bx
push ax push ax
NEXT NEXT
defword "nand",4,NAND defword "nand",NAND
pop bx pop bx
pop ax pop ax
and ax,bx and ax,bx
@ -127,7 +128,7 @@ word_%3:
push ax push ax
NEXT NEXT
defword "exit",4,EXIT defword "exit",EXIT
xchg sp,bp ; swap SP and BP, SP controls return stack xchg sp,bp ; swap SP and BP, SP controls return stack
pop si ; pop address to next word pop si ; pop address to next word
xchg sp,bp ; restore SP and BP xchg sp,bp ; restore SP and BP
@ -139,15 +140,15 @@ word_%3:
; TIB could be left out. But it is exposed so that sectorforth ; TIB could be left out. But it is exposed so that sectorforth
; code that accesses the parse area can be written in an idiomatic ; code that accesses the parse area can be written in an idiomatic
; fashion (e.g. TIB >IN @ +). ; fashion (e.g. TIB >IN @ +).
defword "tib",3,TIBVAR defword "tib",TIBVAR
push word TIB push word TIB
NEXT NEXT
defword "state",5,STATEVAR defword "state",STATEVAR
push word STATE push word STATE
NEXT NEXT
defword ">in",3,TOINVAR defword ">in",TOINVAR
push word TOIN push word TOIN
NEXT NEXT
@ -158,12 +159,12 @@ next:
jmp ax ; jump directly to it jmp ax ; jump directly to it
; Words and data space for the HERE and LATEST variables. ; Words and data space for the HERE and LATEST variables.
defword "here",4,HEREVAR defword "here",HEREVAR
push word HERE push word HERE
NEXT NEXT
HERE: dw start_HERE HERE: dw start_HERE
defword "latest",6,LATESTVAR defword "latest",LATESTVAR
push word LATEST push word LATEST
NEXT NEXT
LATEST: dw word_SEMICOLON ; initialized to last word in dictionary LATEST: dw word_SEMICOLON ; initialized to last word in dictionary
@ -173,7 +174,7 @@ LATEST: dw word_SEMICOLON ; initialized to last word in dictionary
; ;
; KEY waits for a key press and pushes its scan code (AH) and ; KEY waits for a key press and pushes its scan code (AH) and
; ASCII character (AL) to the stack, both in a single cell. ; ASCII character (AL) to the stack, both in a single cell.
defword "key",3,KEY defword "key",KEY
mov ah,0 mov ah,0
int 0x16 int 0x16
push ax push ax
@ -181,7 +182,7 @@ LATEST: dw word_SEMICOLON ; initialized to last word in dictionary
; EMIT writes to the screen the ASCII character corresponding to ; EMIT writes to the screen the ASCII character corresponding to
; the lowest 8 bits of the value at the top of the stack. ; the lowest 8 bits of the value at the top of the stack.
defword "emit",4,EMIT defword "emit",EMIT
pop ax pop ax
call writechar call writechar
NEXT NEXT
@ -190,7 +191,7 @@ LATEST: dw word_SEMICOLON ; initialized to last word in dictionary
; creates a dictionary entry for it, writes machine code to jump ; creates a dictionary entry for it, writes machine code to jump
; to DOCOL, updates LATEST and HERE, and switches to compilation ; to DOCOL, updates LATEST and HERE, and switches to compilation
; state. ; state.
defword ":",1,COLON defword ":",COLON
call token ; parse word from input call token ; parse word from input
push si push si
mov si,di ; set parsed word as string copy source mov si,di ; set parsed word as string copy source
@ -240,7 +241,7 @@ DOCOL:
; of EXIT to the end of a new word definition, makes the word ; of EXIT to the end of a new word definition, makes the word
; visible in the dictionary, and switches back to interpretation ; visible in the dictionary, and switches back to interpretation
; state. ; state.
defword ";",1,SEMICOLON,F_IMMEDIATE defword ";",SEMICOLON,F_IMMEDIATE
mov bx,[LATEST] mov bx,[LATEST]
and byte [bx+2],~F_HIDDEN ; reveal new word and byte [bx+2],~F_HIDDEN ; reveal new word
mov byte [STATE],0 ; switch to interpretation state mov byte [STATE],0 ; switch to interpretation state