mirror of
https://github.com/hsoft/collapseos.git
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forth: put all ASM code in the same file
This commit is contained in:
Virgil Dupras
parent
f420db135d
commit
6134694513
@ -22,11 +22,7 @@
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.inc "stdio.asm"
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.equ FORTH_RAMSTART STDIO_RAMEND
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.inc "main.asm"
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.inc "util.asm"
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.inc "stack.asm"
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.inc "dict.asm"
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.inc "forth.asm"
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init:
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di
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@ -12,11 +12,7 @@
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.inc "stdio.asm"
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.equ FORTH_RAMSTART STDIO_RAMEND
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.inc "main.asm"
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.inc "util.asm"
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.inc "stack.asm"
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.inc "dict.asm"
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.inc "forth.asm"
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init:
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di
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996
forth/dict.asm
996
forth/dict.asm
@ -1,996 +0,0 @@
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; A dictionary entry has this structure:
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; - 7b name (zero-padded)
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; - 2b prev pointer
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; - 1b flags (bit 0: IMMEDIATE. bit 1: UNWORD)
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; - 2b code pointer
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; - Parameter field (PF)
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;
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; The code pointer point to "word routines". These routines expect to be called
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; with IY pointing to the PF. They themselves are expected to end by jumping
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; to the address at (IP). They will usually do so with "jp next".
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;
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; That's for "regular" words (words that are part of the dict chain). There are
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; also "special words", for example NUMBER, LIT, FBR, that have a slightly
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; different structure. They're also a pointer to an executable, but as for the
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; other fields, the only one they have is the "flags" field.
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; This routine is jumped to at the end of every word. In it, we jump to current
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; IP, but we also take care of increasing it my 2 before jumping
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next:
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; Before we continue: are stacks within bounds?
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call chkPS
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call chkRS
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ld de, (IP)
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ld h, d
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ld l, e
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inc de \ inc de
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ld (IP), de
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; HL is an atom list pointer. We need to go into it to have a wordref
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ld e, (hl)
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inc hl
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ld d, (hl)
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push de
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jp EXECUTE+2
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; Execute a word containing native code at its PF address (PFA)
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nativeWord:
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jp (iy)
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; Execute a list of atoms, which always end with EXIT.
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; IY points to that list. What do we do:
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; 1. Push current IP to RS
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; 2. Set new IP to the second atom of the list
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; 3. Execute the first atom of the list.
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compiledWord:
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ld hl, (IP)
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call pushRS
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push iy \ pop hl
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inc hl
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inc hl
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ld (IP), hl
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; IY still is our atom reference...
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ld l, (iy)
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ld h, (iy+1)
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push hl ; argument for EXECUTE
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jp EXECUTE+2
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; Pushes the PFA directly
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cellWord:
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push iy
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jp next
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; Pushes the address in the first word of the PF
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sysvarWord:
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ld l, (iy)
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ld h, (iy+1)
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push hl
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jp next
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; The word was spawned from a definition word that has a DOES>. PFA+2 (right
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; after the actual cell) is a link to the slot right after that DOES>.
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; Therefore, what we need to do push the cell addr like a regular cell, then
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; follow the link from the PFA, and then continue as a regular compiledWord.
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doesWord:
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push iy ; like a regular cell
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ld l, (iy+2)
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ld h, (iy+3)
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push hl \ pop iy
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jr compiledWord
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; This is not a word, but a number literal. This works a bit differently than
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; others: PF means nothing and the actual number is placed next to the
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; numberWord reference in the compiled word list. What we need to do to fetch
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; that number is to play with the IP.
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numberWord:
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ld hl, (IP) ; (HL) is out number
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ld e, (hl)
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inc hl
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ld d, (hl)
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inc hl
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ld (IP), hl ; advance IP by 2
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push de
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jp next
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.db 0b10 ; Flags
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NUMBER:
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.dw numberWord
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; Similarly to numberWord, this is not a real word, but a string literal.
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; Instead of being followed by a 2 bytes number, it's followed by a
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; null-terminated string. When called, puts the string's address on PS
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litWord:
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ld hl, (IP)
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push hl
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call strskip
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inc hl ; after null termination
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ld (IP), hl
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jp next
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.db 0b10 ; Flags
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LIT:
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.dw litWord
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; Pop previous IP from Return stack and execute it.
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; ( R:I -- )
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.db "EXIT"
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.fill 3
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.dw 0
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.db 0
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EXIT:
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.dw nativeWord
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call popRSIP
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jp next
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; ( R:I -- )
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.db "QUIT"
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.fill 3
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.dw EXIT
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.db 0
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QUIT:
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.dw nativeWord
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jp forthRdLine
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.db "ABORT"
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.fill 2
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.dw QUIT
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.db 0
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ABORT:
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.dw nativeWord
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abort:
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; flush rest of input
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ld hl, (INPUTPOS)
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xor a
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ld (hl), a
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; Reinitialize PS (RS is reinitialized in forthInterpret)
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ld sp, (INITIAL_SP)
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jp forthRdLineNoOk
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; prints msg in (HL) then aborts
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abortMsg:
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call printstr
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jr abort
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abortUnknownWord:
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ld hl, .msg
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jr abortMsg
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.msg:
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.db "unknown word", 0
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abortUnderflow:
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ld hl, .msg
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jr abortMsg
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.msg:
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.db "stack underflow", 0
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.db "ABORT", '"'
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.fill 1
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.dw ABORT
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.db 1 ; IMMEDIATE
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ABORTI:
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.dw compiledWord
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.dw PRINTI
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.dw .private
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.dw EXIT
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.db 0b10 ; UNWORD
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.private:
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.dw nativeWord
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ld hl, (HERE)
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ld de, ABORT
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call DEinHL
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ld (HERE), hl
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jp next
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.db "BYE"
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.fill 4
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.dw ABORTI
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.db 0
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BYE:
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.dw nativeWord
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; Goodbye Forth! Before we go, let's restore the stack
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ld sp, (INITIAL_SP)
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; unwind stack underflow buffer
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pop af \ pop af \ pop af
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; success
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xor a
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ret
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; ( c -- )
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.db "EMIT"
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.fill 3
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.dw BYE
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.db 0
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EMIT:
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.dw nativeWord
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pop hl
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call chkPS
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ld a, l
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call stdioPutC
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jp next
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.db "(print)"
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.dw EMIT
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.db 0
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PRINT:
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.dw nativeWord
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pop hl
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call chkPS
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call printstr
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jp next
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.db '.', '"'
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.fill 5
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.dw PRINT
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.db 1 ; IMMEDIATE
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PRINTI:
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.dw nativeWord
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ld hl, (HERE)
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ld de, LIT
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call DEinHL
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ex de, hl ; (HERE) now in DE
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ld hl, (INPUTPOS)
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.loop:
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ld a, (hl)
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or a ; null? not cool
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jp z, abort
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cp '"'
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jr z, .loopend
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ld (de), a
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inc hl
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inc de
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jr .loop
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.loopend:
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inc hl ; inputpos to char afterwards
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ld (INPUTPOS), hl
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; null-terminate LIT
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inc de
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xor a
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ld (de), a
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ex de, hl ; (HERE) in HL
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ld de, PRINT
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call DEinHL
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ld (HERE), hl
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jp next
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; ( c port -- )
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.db "PC!"
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.fill 4
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.dw PRINTI
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.db 0
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PSTORE:
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.dw nativeWord
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pop bc
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pop hl
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call chkPS
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out (c), l
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jp next
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; ( port -- c )
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.db "PC@"
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.fill 4
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.dw PSTORE
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.db 0
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PFETCH:
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.dw nativeWord
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pop bc
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call chkPS
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ld h, 0
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in l, (c)
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push hl
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jp next
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.db ","
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.fill 6
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.dw PFETCH
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.db 0
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WR:
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.dw nativeWord
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pop de
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call chkPS
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ld hl, (HERE)
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call DEinHL
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ld (HERE), hl
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jp next
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; ( addr -- )
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.db "EXECUTE"
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.dw WR
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.db 0
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EXECUTE:
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.dw nativeWord
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pop iy ; is a wordref
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call chkPS
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ld l, (iy)
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ld h, (iy+1)
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; HL points to code pointer
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inc iy
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inc iy
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; IY points to PFA
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jp (hl) ; go!
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.db "[COMPIL"
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.dw EXECUTE
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.db 1 ; IMMEDIATE
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COMPILE:
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.dw compiledWord
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.dw FIND_
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.dw CSKIP
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.dw .maybeNum
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.dw DUP
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.dw ISIMMED
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.dw CSKIP
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.dw .word
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; is immediate. just execute.
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.dw EXECUTE
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.dw EXIT
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.db 0b10 ; UNWORD
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.word:
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.dw compiledWord
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.dw WR
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.dw R2P ; exit COMPILE
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.dw DROP
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.dw EXIT
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.db 0b10 ; UNWORD
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.maybeNum:
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.dw compiledWord
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.dw PARSEI
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.dw LITN
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.dw R2P ; exit COMPILE
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.dw DROP
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.dw EXIT
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.db ":"
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.fill 6
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.dw COMPILE
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.db 1 ; IMMEDIATE
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DEFINE:
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.dw nativeWord
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call entryhead
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ld de, compiledWord
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call DEinHL
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ld (HERE), hl
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.loop:
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; did we reach ";"?
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call toword
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ld a, (hl)
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cp ';'
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jr nz, .compile
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inc hl
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ld a, (hl)
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cp ' '+1
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jr c, .loopend ; whitespace, we have semicol. end
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.compile:
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ld hl, (IP)
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call pushRS
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ld hl, .retRef
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ld (IP), hl
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ld hl, COMPILE
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push hl
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jp EXECUTE+2
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.loopend:
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; Advance (INPUTPOS) to after semicol. HL is already there.
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ld (INPUTPOS), hl
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; write EXIT and return
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ld hl, (HERE)
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ld de, EXIT
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call DEinHL
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ld (HERE), hl
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jp next
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.retRef:
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.dw $+2
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.dw $+2
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call popRSIP
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jr .loop
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.db "DOES>"
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.fill 2
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.dw DEFINE
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.db 0
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DOES:
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.dw nativeWord
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; We run this when we're in an entry creation context. Many things we
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; need to do.
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; 1. Change the code link to doesWord
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; 2. Leave 2 bytes for regular cell variable.
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; 3. Write down IP+2 to entry.
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; 3. exit. we're done here.
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ld hl, (CURRENT)
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ld de, doesWord
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call DEinHL
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inc hl \ inc hl ; cell variable space
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ld de, (IP)
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call DEinHL
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ld (HERE), hl
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jp EXIT+2
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.db "IMMEDIA"
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.dw DOES
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.db 0
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IMMEDIATE:
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.dw nativeWord
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ld hl, (CURRENT)
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dec hl
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set FLAG_IMMED, (hl)
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jp next
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.db "IMMED?"
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.fill 1
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.dw IMMEDIATE
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.db 0
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ISIMMED:
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.dw nativeWord
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pop hl
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call chkPS
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dec hl
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ld de, 0
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bit FLAG_IMMED, (hl)
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jr z, .notset
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inc de
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.notset:
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push de
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jp next
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; ( n -- )
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.db "LITN"
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.fill 3
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.dw ISIMMED
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.db 0
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LITN:
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.dw nativeWord
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ld hl, (HERE)
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ld de, NUMBER
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call DEinHL
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pop de ; number from stack
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call chkPS
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call DEinHL
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ld (HERE), hl
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jp next
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.db "LITS"
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.fill 3
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.dw LITN
|
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.db 1 ; IMMEDIATE
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LITS:
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.dw nativeWord
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ld hl, (HERE)
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ld de, LIT
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call DEinHL
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ex de, hl ; (HERE) in DE
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call readword
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call strcpyM
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ld (HERE), de
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jp next
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|
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.db "(find)"
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.fill 1
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.dw LITS
|
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.db 0
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FIND_:
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.dw nativeWord
|
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call readword
|
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call find
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jr z, .found
|
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; not found
|
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push hl
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ld de, 0
|
||||
push de
|
||||
jp next
|
||||
.found:
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||||
push de
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||||
ld de, 1
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push de
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||||
jp next
|
||||
|
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.db "'"
|
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.fill 6
|
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.dw FIND_
|
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.db 0
|
||||
FIND:
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.dw compiledWord
|
||||
.dw FIND_
|
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.dw CSKIP
|
||||
.dw FINDERR
|
||||
.dw EXIT
|
||||
|
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.db "[']"
|
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.fill 4
|
||||
.dw FIND
|
||||
.db 0b01 ; IMMEDIATE
|
||||
FINDI:
|
||||
.dw compiledWord
|
||||
.dw FIND_
|
||||
.dw CSKIP
|
||||
.dw FINDERR
|
||||
.dw LITN
|
||||
.dw EXIT
|
||||
|
||||
.db 0b10 ; UNWORD
|
||||
FINDERR:
|
||||
.dw compiledWord
|
||||
.dw DROP ; Drop str addr, we don't use it
|
||||
.dw LIT
|
||||
.db "word not found", 0
|
||||
.dw PRINT
|
||||
.dw ABORT
|
||||
|
||||
; ( -- c )
|
||||
.db "KEY"
|
||||
.fill 4
|
||||
.dw FINDI
|
||||
.db 0
|
||||
KEY:
|
||||
.dw nativeWord
|
||||
call stdioGetC
|
||||
ld h, 0
|
||||
ld l, a
|
||||
push hl
|
||||
jp next
|
||||
|
||||
.db "WORD"
|
||||
.fill 3
|
||||
.dw KEY
|
||||
.db 0
|
||||
WORD:
|
||||
.dw nativeWord
|
||||
call readword
|
||||
push hl
|
||||
jp next
|
||||
|
||||
|
||||
.db "(parsed"
|
||||
.dw WORD
|
||||
.db 0
|
||||
PARSED:
|
||||
.dw nativeWord
|
||||
pop hl
|
||||
call chkPS
|
||||
call parseDecimal
|
||||
jr z, .success
|
||||
; error
|
||||
ld de, 0
|
||||
push de ; dummy
|
||||
push de ; flag
|
||||
jp next
|
||||
.success:
|
||||
push de
|
||||
ld de, 1 ; flag
|
||||
push de
|
||||
jp next
|
||||
|
||||
|
||||
.db "(parse)"
|
||||
.dw PARSED
|
||||
.db 0
|
||||
PARSE:
|
||||
.dw compiledWord
|
||||
.dw PARSED
|
||||
.dw CSKIP
|
||||
.dw .error
|
||||
; success, stack is already good, we can exit
|
||||
.dw EXIT
|
||||
|
||||
.db 0b10 ; UNWORD
|
||||
.error:
|
||||
.dw compiledWord
|
||||
.dw LIT
|
||||
.db "unknown word", 0
|
||||
.dw PRINT
|
||||
.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
|
||||
.db 0
|
||||
CREATE:
|
||||
.dw nativeWord
|
||||
call entryhead
|
||||
ld de, cellWord
|
||||
ld (hl), e
|
||||
inc hl
|
||||
ld (hl), d
|
||||
inc hl
|
||||
ld (HERE), hl
|
||||
jp next
|
||||
|
||||
.db "HERE"
|
||||
.fill 3
|
||||
.dw CREATE
|
||||
.db 0
|
||||
HERE_: ; Caution: conflicts with actual variable name
|
||||
.dw sysvarWord
|
||||
.dw HERE
|
||||
|
||||
.db "CURRENT"
|
||||
.dw HERE_
|
||||
.db 0
|
||||
CURRENT_:
|
||||
.dw sysvarWord
|
||||
.dw CURRENT
|
||||
|
||||
.db "(parse*"
|
||||
.dw CURRENT_
|
||||
.db 0
|
||||
PARSEPTR_:
|
||||
.dw sysvarWord
|
||||
.dw PARSEPTR
|
||||
|
||||
.db "IN>"
|
||||
.fill 4
|
||||
.dw PARSEPTR_
|
||||
.db 0
|
||||
INP:
|
||||
.dw sysvarWord
|
||||
.dw INPUTPOS
|
||||
|
||||
; ( n a -- )
|
||||
.db "!"
|
||||
.fill 6
|
||||
.dw INP
|
||||
.db 0
|
||||
STORE:
|
||||
.dw nativeWord
|
||||
pop iy
|
||||
pop hl
|
||||
call chkPS
|
||||
ld (iy), l
|
||||
ld (iy+1), h
|
||||
jp next
|
||||
|
||||
; ( n a -- )
|
||||
.db "C!"
|
||||
.fill 5
|
||||
.dw STORE
|
||||
.db 0
|
||||
CSTORE:
|
||||
.dw nativeWord
|
||||
pop hl
|
||||
pop de
|
||||
call chkPS
|
||||
ld (hl), e
|
||||
jp next
|
||||
|
||||
; ( a -- n )
|
||||
.db "@"
|
||||
.fill 6
|
||||
.dw CSTORE
|
||||
.db 0
|
||||
FETCH:
|
||||
.dw nativeWord
|
||||
pop hl
|
||||
call chkPS
|
||||
call intoHL
|
||||
push hl
|
||||
jp next
|
||||
|
||||
; ( a -- c )
|
||||
.db "C@"
|
||||
.fill 5
|
||||
.dw FETCH
|
||||
.db 0
|
||||
CFETCH:
|
||||
.dw nativeWord
|
||||
pop hl
|
||||
call chkPS
|
||||
ld l, (hl)
|
||||
ld h, 0
|
||||
push hl
|
||||
jp next
|
||||
|
||||
; ( a -- )
|
||||
.db "DROP"
|
||||
.fill 3
|
||||
.dw CFETCH
|
||||
.db 0
|
||||
DROP:
|
||||
.dw nativeWord
|
||||
pop hl
|
||||
jp next
|
||||
|
||||
; ( a b -- b a )
|
||||
.db "SWAP"
|
||||
.fill 3
|
||||
.dw DROP
|
||||
.db 0
|
||||
SWAP:
|
||||
.dw nativeWord
|
||||
pop hl
|
||||
call chkPS
|
||||
ex (sp), hl
|
||||
push hl
|
||||
jp next
|
||||
|
||||
; ( a b c d -- c d a b )
|
||||
.db "2SWAP"
|
||||
.fill 2
|
||||
.dw SWAP
|
||||
.db 0
|
||||
SWAP2:
|
||||
.dw nativeWord
|
||||
pop de ; D
|
||||
pop hl ; C
|
||||
pop bc ; B
|
||||
call chkPS
|
||||
|
||||
ex (sp), hl ; A in HL
|
||||
push de ; D
|
||||
push hl ; A
|
||||
push bc ; B
|
||||
jp next
|
||||
|
||||
; ( a -- a a )
|
||||
.db "DUP"
|
||||
.fill 4
|
||||
.dw SWAP2
|
||||
.db 0
|
||||
DUP:
|
||||
.dw nativeWord
|
||||
pop hl
|
||||
call chkPS
|
||||
push hl
|
||||
push hl
|
||||
jp next
|
||||
|
||||
; ( a b -- a b a b )
|
||||
.db "2DUP"
|
||||
.fill 3
|
||||
.dw DUP
|
||||
.db 0
|
||||
DUP2:
|
||||
.dw nativeWord
|
||||
pop hl ; B
|
||||
pop de ; A
|
||||
call chkPS
|
||||
push de
|
||||
push hl
|
||||
push de
|
||||
push hl
|
||||
jp next
|
||||
|
||||
; ( a b -- a b a )
|
||||
.db "OVER"
|
||||
.fill 3
|
||||
.dw DUP2
|
||||
.db 0
|
||||
OVER:
|
||||
.dw nativeWord
|
||||
pop hl ; B
|
||||
pop de ; A
|
||||
call chkPS
|
||||
push de
|
||||
push hl
|
||||
push de
|
||||
jp next
|
||||
|
||||
; ( a b c d -- a b c d a b )
|
||||
.db "2OVER"
|
||||
.fill 2
|
||||
.dw OVER
|
||||
.db 0
|
||||
OVER2:
|
||||
.dw nativeWord
|
||||
pop hl ; D
|
||||
pop de ; C
|
||||
pop bc ; B
|
||||
pop iy ; A
|
||||
call chkPS
|
||||
push iy ; A
|
||||
push bc ; B
|
||||
push de ; C
|
||||
push hl ; D
|
||||
push iy ; A
|
||||
push bc ; B
|
||||
jp next
|
||||
|
||||
.db ">R"
|
||||
.fill 5
|
||||
.dw OVER2
|
||||
.db 0
|
||||
P2R:
|
||||
.dw nativeWord
|
||||
pop hl
|
||||
call chkPS
|
||||
call pushRS
|
||||
jp next
|
||||
|
||||
.db "R>"
|
||||
.fill 5
|
||||
.dw P2R
|
||||
.db 0
|
||||
R2P:
|
||||
.dw nativeWord
|
||||
call popRS
|
||||
push hl
|
||||
jp next
|
||||
|
||||
.db "I"
|
||||
.fill 6
|
||||
.dw R2P
|
||||
.db 0
|
||||
I:
|
||||
.dw nativeWord
|
||||
ld l, (ix)
|
||||
ld h, (ix+1)
|
||||
push hl
|
||||
jp next
|
||||
|
||||
.db "I'"
|
||||
.fill 5
|
||||
.dw I
|
||||
.db 0
|
||||
IPRIME:
|
||||
.dw nativeWord
|
||||
ld l, (ix-2)
|
||||
ld h, (ix-1)
|
||||
push hl
|
||||
jp next
|
||||
|
||||
.db "J"
|
||||
.fill 6
|
||||
.dw IPRIME
|
||||
.db 0
|
||||
J:
|
||||
.dw nativeWord
|
||||
ld l, (ix-4)
|
||||
ld h, (ix-3)
|
||||
push hl
|
||||
jp next
|
||||
|
||||
; ( a b -- c ) A + B
|
||||
.db "+"
|
||||
.fill 6
|
||||
.dw J
|
||||
.db 0
|
||||
PLUS:
|
||||
.dw nativeWord
|
||||
pop hl
|
||||
pop de
|
||||
call chkPS
|
||||
add hl, de
|
||||
push hl
|
||||
jp next
|
||||
|
||||
; ( a b -- c ) A - B
|
||||
.db "-"
|
||||
.fill 6
|
||||
.dw PLUS
|
||||
.db 0
|
||||
MINUS:
|
||||
.dw nativeWord
|
||||
pop de ; B
|
||||
pop hl ; A
|
||||
call chkPS
|
||||
or a ; reset carry
|
||||
sbc hl, de
|
||||
push hl
|
||||
jp next
|
||||
|
||||
; ( a b -- c ) A * B
|
||||
.db "*"
|
||||
.fill 6
|
||||
.dw MINUS
|
||||
.db 0
|
||||
MULT:
|
||||
.dw nativeWord
|
||||
pop de
|
||||
pop bc
|
||||
call chkPS
|
||||
call multDEBC
|
||||
push hl
|
||||
jp next
|
||||
|
||||
|
||||
.db "/MOD"
|
||||
.fill 3
|
||||
.dw MULT
|
||||
.db 0
|
||||
DIVMOD:
|
||||
.dw nativeWord
|
||||
pop de
|
||||
pop hl
|
||||
call chkPS
|
||||
call divide
|
||||
push hl
|
||||
push bc
|
||||
jp next
|
||||
|
||||
; ( a1 a2 -- b )
|
||||
.db "SCMP"
|
||||
.fill 3
|
||||
.dw DIVMOD
|
||||
.db 0
|
||||
SCMP:
|
||||
.dw nativeWord
|
||||
pop de
|
||||
pop hl
|
||||
call chkPS
|
||||
call strcmp
|
||||
call flagsToBC
|
||||
push bc
|
||||
jp next
|
||||
|
||||
; ( n1 n2 -- f )
|
||||
.db "CMP"
|
||||
.fill 4
|
||||
.dw SCMP
|
||||
.db 0
|
||||
CMP:
|
||||
.dw nativeWord
|
||||
pop hl
|
||||
pop de
|
||||
call chkPS
|
||||
or a ; clear carry
|
||||
sbc hl, de
|
||||
call flagsToBC
|
||||
push bc
|
||||
jp next
|
||||
|
||||
.db "SKIP?"
|
||||
.fill 2
|
||||
.dw CMP
|
||||
.db 0
|
||||
CSKIP:
|
||||
.dw nativeWord
|
||||
pop hl
|
||||
call chkPS
|
||||
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 CSKIP
|
||||
.db 0
|
||||
FBR:
|
||||
.dw nativeWord
|
||||
push de
|
||||
ld hl, (IP)
|
||||
ld a, (hl)
|
||||
call addHL
|
||||
ld (IP), hl
|
||||
pop de
|
||||
jp next
|
||||
|
||||
.db "(bbr)"
|
||||
.fill 2
|
||||
.dw FBR
|
||||
.db 0
|
||||
BBR:
|
||||
.dw nativeWord
|
||||
ld hl, (IP)
|
||||
ld d, 0
|
||||
ld e, (hl)
|
||||
or a ; clear carry
|
||||
sbc hl, de
|
||||
ld (IP), hl
|
||||
jp next
|
||||
|
||||
LATEST:
|
||||
.dw BBR
|
||||
1644
forth/forth.asm
Normal file
1644
forth/forth.asm
Normal file
File diff suppressed because it is too large
Load Diff
134
forth/main.asm
134
forth/main.asm
@ -1,134 +0,0 @@
|
||||
; *** Const ***
|
||||
; Base of the Return Stack
|
||||
.equ RS_ADDR 0xf000
|
||||
; Number of bytes we keep as a padding between HERE and the scratchpad
|
||||
.equ PADDING 0x20
|
||||
; Max length of dict entry names
|
||||
.equ NAMELEN 7
|
||||
; Offset of the code link relative to the beginning of the word
|
||||
.equ CODELINK_OFFSET NAMELEN+3
|
||||
|
||||
; Flags for the "flag field" of the word structure
|
||||
; IMMEDIATE word
|
||||
.equ FLAG_IMMED 0
|
||||
; This wordref is not a regular word (it's not preceeded by a name). It's one
|
||||
; of the NUMBER, LIT, BRANCH etc. entities.
|
||||
.equ FLAG_UNWORD 1
|
||||
|
||||
; *** Variables ***
|
||||
.equ INITIAL_SP FORTH_RAMSTART
|
||||
; wordref of the last entry of the dict.
|
||||
.equ CURRENT @+2
|
||||
; Pointer to the next free byte in dict.
|
||||
.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 FORTH_RAMEND @+2
|
||||
|
||||
; (HERE) usually starts at RAMEND, but in certain situations, such as in stage0,
|
||||
; (HERE) will begin at a strategic place.
|
||||
.equ HERE_INITIAL FORTH_RAMEND
|
||||
|
||||
; EXECUTION MODEL
|
||||
; After having read a line through stdioReadLine, we want to interpret it. As
|
||||
; a general rule, we go like this:
|
||||
;
|
||||
; 1. read single word from line
|
||||
; 2. Can we find the word in dict?
|
||||
; 3. If yes, execute that word, goto 1
|
||||
; 4. Is it a number?
|
||||
; 5. If yes, push that number to PS, goto 1
|
||||
; 6. Error: undefined word.
|
||||
;
|
||||
; EXECUTING A WORD
|
||||
;
|
||||
; At it's core, executing a word is having the wordref in IY and call
|
||||
; 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.
|
||||
;
|
||||
; First of all, at all time during execution, the Interpreter Pointer (IP)
|
||||
; points to the wordref we're executing next.
|
||||
;
|
||||
; When we execute a compiledWord, the first thing we do is push IP to the Return
|
||||
; Stack (RS). Therefore, RS' top of stack will contain a wordref to execute
|
||||
; next, after we EXIT.
|
||||
;
|
||||
; At the end of every compiledWord is an EXIT. This pops RS, sets IP to it, and
|
||||
; continues.
|
||||
|
||||
; *** Code ***
|
||||
forthMain:
|
||||
; STACK OVERFLOW PROTECTION:
|
||||
; To avoid having to check for stack underflow after each pop operation
|
||||
; (which can end up being prohibitive in terms of costs), we give
|
||||
; ourselves a nice 6 bytes buffer. 6 bytes because we seldom have words
|
||||
; requiring more than 3 items from the stack. Then, at each "exit" call
|
||||
; we check for stack underflow.
|
||||
push af \ push af \ push af
|
||||
ld (INITIAL_SP), sp
|
||||
; 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,
|
||||
; for example by the stage0 bin.
|
||||
ld hl, LATEST
|
||||
call intoHL
|
||||
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
|
||||
push hl
|
||||
jp EXECUTE+2
|
||||
|
||||
.db 0b10 ; UNWORD
|
||||
INTERPRET:
|
||||
.dw compiledWord
|
||||
.dw FIND_
|
||||
.dw CSKIP
|
||||
.dw .maybeNum
|
||||
; It's a word, execute it
|
||||
.dw EXECUTE
|
||||
.dw EXIT
|
||||
|
||||
.maybeNum:
|
||||
.dw compiledWord
|
||||
.dw PARSEI
|
||||
.dw R2P ; exit INTERPRET
|
||||
.dw DROP
|
||||
.dw EXIT
|
||||
|
||||
.db 0b10 ; UNWORD
|
||||
MAINLOOP:
|
||||
.dw compiledWord
|
||||
.dw INTERPRET
|
||||
.dw INP
|
||||
.dw FETCH
|
||||
.dw CFETCH
|
||||
.dw CSKIP
|
||||
.dw QUIT
|
||||
.dw MAINLOOP
|
||||
|
||||
msgOk:
|
||||
.db " ok", 0
|
||||
@ -1,66 +0,0 @@
|
||||
; The Parameter stack (PS) is maintained by SP and the Return stack (RS) is
|
||||
; maintained by IX. This allows us to generally use push and pop freely because
|
||||
; PS is the most frequently used. However, this causes a problem with routine
|
||||
; calls: because in Forth, the stack isn't balanced within each call, our return
|
||||
; offset, when placed by a CALL, messes everything up. This is one of the
|
||||
; reasons why we need stack management routines below. IX always points to RS'
|
||||
; Top Of Stack (TOS)
|
||||
;
|
||||
; This return stack contain "Interpreter pointers", that is a pointer to the
|
||||
; address of a word, as seen in a compiled list of words.
|
||||
|
||||
; Push value HL to RS
|
||||
pushRS:
|
||||
inc ix
|
||||
inc ix
|
||||
ld (ix), l
|
||||
ld (ix+1), h
|
||||
ret
|
||||
|
||||
; Pop RS' TOS to HL
|
||||
popRS:
|
||||
ld l, (ix)
|
||||
ld h, (ix+1)
|
||||
dec ix
|
||||
dec ix
|
||||
ret
|
||||
|
||||
popRSIP:
|
||||
call popRS
|
||||
ld (IP), hl
|
||||
ret
|
||||
|
||||
; Skip the next two bytes in RS' TOS
|
||||
skipRS:
|
||||
push hl
|
||||
ld l, (ix)
|
||||
ld h, (ix+1)
|
||||
inc hl \ inc hl
|
||||
ld (ix), l
|
||||
ld (ix+1), h
|
||||
pop hl
|
||||
ret
|
||||
|
||||
; Verifies that SP and RS are within bounds. If it's not, call ABORT
|
||||
chkRS:
|
||||
push ix \ pop hl
|
||||
push de ; --> lvl 1
|
||||
ld de, RS_ADDR
|
||||
or a ; clear carry
|
||||
sbc hl, de
|
||||
pop de ; <-- lvl 1
|
||||
jp c, abortUnderflow
|
||||
ret
|
||||
|
||||
chkPS:
|
||||
push hl
|
||||
ld hl, (INITIAL_SP)
|
||||
; We have the return address for this very call on the stack and
|
||||
; protected registers. Let's compensate
|
||||
dec hl \ dec hl
|
||||
dec hl \ dec hl
|
||||
or a ; clear carry
|
||||
sbc hl, sp
|
||||
pop hl
|
||||
ret nc ; (INITIAL_SP) >= SP? good
|
||||
jp abortUnderflow
|
||||
452
forth/util.asm
452
forth/util.asm
@ -1,452 +0,0 @@
|
||||
; *** Collapse OS lib copy ***
|
||||
; In the process of Forth-ifying Collapse OS, apps will be slowly rewritten to
|
||||
; Forth and the concept of ASM libs will become obsolete. To facilitate this
|
||||
; transition, I make, right now, a copy of the routines actually used by Forth's
|
||||
; native core. This also has the effect of reducing binary size right now and
|
||||
; give us an idea of Forth's compactness.
|
||||
; These routines below are copy/paste from apps/lib.
|
||||
|
||||
; 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:
|
||||
push de
|
||||
ld e, (hl)
|
||||
inc hl
|
||||
ld d, (hl)
|
||||
ex de, hl
|
||||
pop de
|
||||
ret
|
||||
|
||||
intoDE:
|
||||
ex de, hl
|
||||
call intoHL
|
||||
ex de, hl ; de preserved by intoHL, so no push/pop needed
|
||||
ret
|
||||
|
||||
; add the value of A into HL
|
||||
; affects carry flag according to the 16-bit addition, Z, S and P untouched.
|
||||
addHL:
|
||||
push de
|
||||
ld d, 0
|
||||
ld e, a
|
||||
add hl, de
|
||||
pop de
|
||||
ret
|
||||
|
||||
; make Z the opposite of what it is now
|
||||
toggleZ:
|
||||
jp z, unsetZ
|
||||
cp a
|
||||
ret
|
||||
|
||||
; Copy string from (HL) in (DE), that is, copy bytes until a null char is
|
||||
; encountered. The null char is also copied.
|
||||
; HL and DE point to the char right after the null char.
|
||||
strcpyM:
|
||||
ld a, (hl)
|
||||
ld (de), a
|
||||
inc hl
|
||||
inc de
|
||||
or a
|
||||
jr nz, strcpyM
|
||||
ret
|
||||
|
||||
; Like strcpyM, but preserve HL and DE
|
||||
strcpy:
|
||||
push hl
|
||||
push de
|
||||
call strcpyM
|
||||
pop de
|
||||
pop hl
|
||||
ret
|
||||
|
||||
; Compares strings pointed to by HL and DE until one of them hits its null char.
|
||||
; If equal, Z is set. If not equal, Z is reset. C is set if HL > DE
|
||||
strcmp:
|
||||
push hl
|
||||
push de
|
||||
|
||||
.loop:
|
||||
ld a, (de)
|
||||
cp (hl)
|
||||
jr nz, .end ; not equal? break early. NZ is carried out
|
||||
; to the caller
|
||||
or a ; If our chars are null, stop the cmp
|
||||
inc hl
|
||||
inc de
|
||||
jr nz, .loop ; Z is carried through
|
||||
|
||||
.end:
|
||||
pop de
|
||||
pop hl
|
||||
; Because we don't call anything else than CP that modify the Z flag,
|
||||
; our Z value will be that of the last cp (reset if we broke the loop
|
||||
; early, set otherwise)
|
||||
ret
|
||||
|
||||
; Compares strings pointed to by HL and DE up to A count of characters. If
|
||||
; equal, Z is set. If not equal, Z is reset.
|
||||
strncmp:
|
||||
push bc
|
||||
push hl
|
||||
push de
|
||||
|
||||
ld b, a
|
||||
.loop:
|
||||
ld a, (de)
|
||||
cp (hl)
|
||||
jr nz, .end ; not equal? break early. NZ is carried out
|
||||
; to the called
|
||||
cp 0 ; If our chars are null, stop the cmp
|
||||
jr z, .end ; The positive result will be carried to the
|
||||
; caller
|
||||
inc hl
|
||||
inc de
|
||||
djnz .loop
|
||||
; We went through all chars with success, but our current Z flag is
|
||||
; unset because of the cp 0. Let's do a dummy CP to set the Z flag.
|
||||
cp a
|
||||
|
||||
.end:
|
||||
pop de
|
||||
pop hl
|
||||
pop bc
|
||||
; Because we don't call anything else than CP that modify the Z flag,
|
||||
; our Z value will be that of the last cp (reset if we broke the loop
|
||||
; early, set otherwise)
|
||||
ret
|
||||
|
||||
; Given a string at (HL), move HL until it points to the end of that string.
|
||||
strskip:
|
||||
push bc
|
||||
ex af, af'
|
||||
xor a ; look for null char
|
||||
ld b, a
|
||||
ld c, a
|
||||
cpir ; advances HL regardless of comparison, so goes one too far
|
||||
dec hl
|
||||
ex af, af'
|
||||
pop bc
|
||||
ret
|
||||
|
||||
; Borrowed from Tasty Basic by Dimitri Theulings (GPL).
|
||||
; Divide HL by DE, placing the result in BC and the remainder in HL.
|
||||
divide:
|
||||
push hl ; --> lvl 1
|
||||
ld l, h ; divide h by de
|
||||
ld h, 0
|
||||
call .dv1
|
||||
ld b, c ; save result in b
|
||||
ld a, l ; (remainder + l) / de
|
||||
pop hl ; <-- lvl 1
|
||||
ld h, a
|
||||
.dv1:
|
||||
ld c, 0xff ; result in c
|
||||
.dv2:
|
||||
inc c ; dumb routine
|
||||
call .subde ; divide using subtract and count
|
||||
jr nc, .dv2
|
||||
add hl, de
|
||||
ret
|
||||
.subde:
|
||||
ld a, l
|
||||
sub e ; subtract de from hl
|
||||
ld l, a
|
||||
ld a, h
|
||||
sbc a, d
|
||||
ld h, a
|
||||
ret
|
||||
|
||||
; DE * BC -> DE (high) and HL (low)
|
||||
multDEBC:
|
||||
ld hl, 0
|
||||
ld a, 0x10
|
||||
.loop:
|
||||
add hl, hl
|
||||
rl e
|
||||
rl d
|
||||
jr nc, .noinc
|
||||
add hl, bc
|
||||
jr nc, .noinc
|
||||
inc de
|
||||
.noinc:
|
||||
dec a
|
||||
jr nz, .loop
|
||||
ret
|
||||
|
||||
; Parse string at (HL) as a decimal value and return value in DE.
|
||||
; Reads as many digits as it can and stop when:
|
||||
; 1 - A non-digit character is read
|
||||
; 2 - The number overflows from 16-bit
|
||||
; HL is advanced to the character following the last successfully read char.
|
||||
; Error conditions are:
|
||||
; 1 - There wasn't at least one character that could be read.
|
||||
; 2 - Overflow.
|
||||
; Sets Z on success, unset on error.
|
||||
|
||||
parseDecimal:
|
||||
; First char is special: it has to succeed.
|
||||
ld a, (hl)
|
||||
; Parse the decimal char at A and extract it's 0-9 numerical value. Put the
|
||||
; result in A.
|
||||
; On success, the carry flag is reset. On error, it is set.
|
||||
add a, 0xff-'9' ; maps '0'-'9' onto 0xf6-0xff
|
||||
sub 0xff-9 ; maps to 0-9 and carries if not a digit
|
||||
ret c ; Error. If it's C, it's also going to be NZ
|
||||
; During this routine, we switch between HL and its shadow. On one side,
|
||||
; we have HL the string pointer, and on the other side, we have HL the
|
||||
; numerical result. We also use EXX to preserve BC, saving us a push.
|
||||
exx ; HL as a result
|
||||
ld h, 0
|
||||
ld l, a ; load first digit in without multiplying
|
||||
|
||||
.loop:
|
||||
exx ; HL as a string pointer
|
||||
inc hl
|
||||
ld a, (hl)
|
||||
exx ; HL as a numerical result
|
||||
|
||||
; same as other above
|
||||
add a, 0xff-'9'
|
||||
sub 0xff-9
|
||||
jr c, .end
|
||||
|
||||
ld b, a ; we can now use a for overflow checking
|
||||
add hl, hl ; x2
|
||||
sbc a, a ; a=0 if no overflow, a=0xFF otherwise
|
||||
ld d, h
|
||||
ld e, l ; de is x2
|
||||
add hl, hl ; x4
|
||||
rla
|
||||
add hl, hl ; x8
|
||||
rla
|
||||
add hl, de ; x10
|
||||
rla
|
||||
ld d, a ; a is zero unless there's an overflow
|
||||
ld e, b
|
||||
add hl, de
|
||||
adc a, a ; same as rla except affects Z
|
||||
; Did we oveflow?
|
||||
jr z, .loop ; No? continue
|
||||
; error, NZ already set
|
||||
exx ; HL is now string pointer, restore BC
|
||||
; HL points to the char following the last success.
|
||||
ret
|
||||
|
||||
.end:
|
||||
push hl ; --> lvl 1, result
|
||||
exx ; HL as a string pointer, restore BC
|
||||
pop de ; <-- lvl 1, result
|
||||
cp a ; ensure Z
|
||||
ret
|
||||
|
||||
; *** Forth-specific part ***
|
||||
; Advance (INPUTPOS) until a non-whitespace is met. If needed,
|
||||
; call fetchline.
|
||||
; 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 fetchline
|
||||
jr toword
|
||||
|
||||
; Read word from (INPUTPOS) and return, in HL, a null-terminated word.
|
||||
; Advance (INPUTPOS) to the character following the whitespace ending the
|
||||
; word.
|
||||
; When we're at EOL, we call fetchline directly, so this call always returns
|
||||
; a word.
|
||||
readword:
|
||||
call toword
|
||||
push hl ; --> lvl 1. that's our result
|
||||
.loop:
|
||||
inc hl
|
||||
ld a, (hl)
|
||||
; special case: is A null? If yes, we will *not* inc A so that we don't
|
||||
; go over the bounds of our input string.
|
||||
or a
|
||||
jr z, .noinc
|
||||
cp ' '+1
|
||||
jr nc, .loop
|
||||
; we've just read a whitespace, HL is pointing to it. Let's transform
|
||||
; it into a null-termination, inc HL, then set (INPUTPOS).
|
||||
xor a
|
||||
ld (hl), a
|
||||
inc hl
|
||||
.noinc:
|
||||
ld (INPUTPOS), hl
|
||||
pop hl ; <-- lvl 1. our result
|
||||
ret ; Z set from XOR A
|
||||
|
||||
; Sets Z if (HL) == E and (HL+1) == D
|
||||
HLPointsDE:
|
||||
ld a, (hl)
|
||||
cp e
|
||||
ret nz ; no
|
||||
inc hl
|
||||
ld a, (hl)
|
||||
dec hl
|
||||
cp d ; Z has our answer
|
||||
ret
|
||||
|
||||
; Skip the compword where HL is currently pointing. If it's a regular word,
|
||||
; it's easy: we inc by 2. If it's a NUMBER, we inc by 4. If it's a LIT, we skip
|
||||
; to after null-termination.
|
||||
compSkip:
|
||||
ld de, NUMBER
|
||||
call HLPointsDE
|
||||
jr z, .isNum
|
||||
ld de, FBR
|
||||
call HLPointsDE
|
||||
jr z, .isBranch
|
||||
ld de, BBR
|
||||
call HLPointsDE
|
||||
jr z, .isBranch
|
||||
ld de, LIT
|
||||
call HLPointsDE
|
||||
jr nz, .isWord
|
||||
; We have a literal
|
||||
inc hl \ inc hl
|
||||
call strskip
|
||||
inc hl ; byte after word termination
|
||||
ret
|
||||
.isNum:
|
||||
; skip by 4
|
||||
inc hl
|
||||
; continue to isBranch
|
||||
.isBranch:
|
||||
; skip by 3
|
||||
inc hl
|
||||
; continue to isWord
|
||||
.isWord:
|
||||
; skip by 2
|
||||
inc hl \ inc hl
|
||||
ret
|
||||
|
||||
; Find the entry corresponding to word where (HL) points to and sets DE to
|
||||
; point to that entry.
|
||||
; Z if found, NZ if not.
|
||||
find:
|
||||
push hl
|
||||
push bc
|
||||
ld de, (CURRENT)
|
||||
ld bc, CODELINK_OFFSET
|
||||
.inner:
|
||||
; DE is a wordref, let's go to beginning of struct
|
||||
push de ; --> lvl 1
|
||||
or a ; clear carry
|
||||
ex de, hl
|
||||
sbc hl, bc
|
||||
ex de, hl ; We're good, DE points to word name
|
||||
ld a, NAMELEN
|
||||
call strncmp
|
||||
pop de ; <-- lvl 1, return to wordref
|
||||
jr z, .end ; found
|
||||
call .prev
|
||||
jr nz, .inner
|
||||
; Z set? end of dict unset Z
|
||||
inc a
|
||||
.end:
|
||||
pop bc
|
||||
pop hl
|
||||
ret
|
||||
|
||||
; For DE being a wordref, move DE to the previous wordref.
|
||||
; Z is set if DE point to 0 (no entry). NZ if not.
|
||||
.prev:
|
||||
dec de \ dec de \ dec de ; prev field
|
||||
call intoDE
|
||||
; DE points to prev. Is it zero?
|
||||
xor a
|
||||
or d
|
||||
or e
|
||||
; Z will be set if DE is zero
|
||||
ret
|
||||
|
||||
; Spit name + prev in (HERE) and adjust (HERE) and (CURRENT)
|
||||
; HL points to new (HERE)
|
||||
entryhead:
|
||||
call readword
|
||||
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, not UNWORD, so it's 0
|
||||
xor a
|
||||
ld (hl), a
|
||||
inc hl
|
||||
ld (CURRENT), hl
|
||||
ld (HERE), hl
|
||||
ret
|
||||
|
||||
; Sets Z if wordref at HL is of the IMMEDIATE type
|
||||
HLisIMMED:
|
||||
dec hl
|
||||
bit FLAG_IMMED, (hl)
|
||||
inc hl
|
||||
; We need an invert flag. We want to Z to be set when flag is non-zero.
|
||||
jp toggleZ
|
||||
|
||||
; Sets Z if wordref at HL is of the UNWORD type
|
||||
HLisUNWORD:
|
||||
dec hl
|
||||
bit FLAG_UNWORD, (hl)
|
||||
inc hl
|
||||
; We need an invert flag. We want to Z to be set when flag is non-zero.
|
||||
jp toggleZ
|
||||
|
||||
; Sets Z if wordref at (HL) is of the IMMEDIATE type
|
||||
HLPointsUNWORD:
|
||||
push hl
|
||||
call intoHL
|
||||
call HLisUNWORD
|
||||
pop hl
|
||||
ret
|
||||
|
||||
; Checks flags Z and S and sets BC to 0 if Z, 1 if C and -1 otherwise
|
||||
flagsToBC:
|
||||
ld bc, 0
|
||||
ret z ; equal
|
||||
inc bc
|
||||
ret m ; >
|
||||
; <
|
||||
dec bc
|
||||
dec bc
|
||||
ret
|
||||
|
||||
; Write DE in (HL), advancing HL by 2.
|
||||
DEinHL:
|
||||
ld (hl), e
|
||||
inc hl
|
||||
ld (hl), d
|
||||
inc hl
|
||||
ret
|
||||
|
||||
fetchline:
|
||||
call printcrlf
|
||||
call stdioReadLine
|
||||
ld (INPUTPOS), hl
|
||||
ret
|
||||
Loading…
Reference in New Issue
Block a user