7 size_RS = 1024 # Return stack size
8 size_PS = 1024 # Parameter stack size
9 size_TIB = 1096 # Terminal input buffer size
11 # The mem array constitutes the memory of the VM. It has the following geography:
13 # mem = +-----------------------+
14 # | Built-in Variables |
15 # +-----------------------+
17 # +-----------------------+
19 # +-----------------------+
20 # | Terminal Input Buffer |
21 # +-----------------------+
23 # +-----------------------+
25 # Note that all words (user-defined, primitive, variables, etc) are included in
28 # Simple linear addressing is used with one exception: references to primitive code
29 # blocks, which are represented as anonymous functions, appear the negative index
30 # into the primitives array which contains only these functions.
32 mem = Array{Int64,1}(size_mem)
33 primitives = Array{Function,1}()
38 RSP0 = nextVarAddr; nextVarAddr += 1
39 PSP0 = nextVarAddr; nextVarAddr += 1
40 HERE = nextVarAddr; nextVarAddr += 1
41 LATEST = nextVarAddr; nextVarAddr += 1
43 mem[RSP0] = nextVarAddr # bottom of RS
44 mem[PSP0] = mem[RSP0] + size_RS # bottom of PS
45 TIB = mem[PSP0] + size_PS # address of terminal input buffer
46 mem[HERE] = TIB + size_TIB # location of bottom of dictionary
47 mem[LATEST] = 0 # no previous definition
49 DICT = mem[HERE] # Save bottom of dictionary as constant
53 RSP::Int64 # Return stack pointer
54 PSP::Int64 # Parameter/data stack pointer
55 IP::Int64 # Instruction pointer
56 W::Int64 # Working register
57 X::Int64 # Extra register
59 reg = Reg(mem[RSP0], mem[PSP0], 0, 0, 0)
63 type StackUnderflow <: Exception end
65 getRSDepth() = reg.RSP - mem[RSP0]
66 getPSDepth() = reg.PSP - mem[PSP0]
68 function ensurePSDepth(depth::Int64)
70 throw(StackUnderflow())
74 function ensureRSDepth(depth::Int64)
76 throw(StackUnderflow())
80 function pushRS(val::Int64)
92 function pushPS(val::Int64)
93 mem[reg.PSP += 1] = val
104 # Primitive creation and calling functions
106 function createHeader(name::AbstractString, flags::Int64)
107 mem[mem[HERE]] = mem[LATEST]
108 mem[LATEST] = mem[HERE]
111 mem[mem[HERE]] = length(name) | flags; mem[HERE] += 1
112 mem[mem[HERE]:(mem[HERE]+length(name)-1)] = [Int(c) for c in name]; mem[HERE] += length(name)
115 function defPrim(name::AbstractString, f::Function; flags::Int64=0)
116 createHeader(name, flags)
118 codeWordAddr = mem[HERE]
120 mem[codeWordAddr] = -length(primitives)
126 callPrim(addr::Int64) = primitives[-addr]()
128 function defExistingVar(name::AbstractString, varAddr::Int64; flags::Int64=0)
129 defPrim(name, eval(:(() -> begin
135 function defNewVar(name::AbstractString, initial::Int64; flags::Int64=0)
136 createHeader(name, flags)
138 varAddr = mem[HERE] + 1
139 push!(primitives, eval(:(() -> begin
143 mem[mem[HERE]] = -length(primitives); mem[HERE] += 1
145 mem[mem[HERE]] = initial; mem[HERE] += 1
150 function defConst(name::AbstractString, val::Int64; flags::Int64=0)
151 defPrim(name, eval(:(() -> begin
159 function defWord(name::AbstractString, wordAddrs::Array{Int64,1}; flags::Int64=0)
160 createHeader(name, flags)
163 mem[mem[HERE]] = mem[DOCOL]
166 for wordAddr in wordAddrs
167 mem[mem[HERE]] = wordAddr
174 # Threading Primitives (inner interpreter)
176 NEXT = defPrim("NEXT", () -> begin
182 DOCOL = defPrim("DOCOL", () -> begin
188 EXIT = defPrim("EXIT", () -> begin
193 # Basic forth primitives
195 DROP = defPrim("DROP", () -> begin
200 SWAP = defPrim("SWAP", () -> begin
208 DUP = defPrim("DUP", () -> begin
213 OVER = defPrim("OVER", () -> begin
215 pushPS(mem[reg.PSP-1])
219 ROT = defPrim("ROT", () -> begin
229 NROT = defPrim("-ROT", () -> begin
239 TWODROP = defPrim("2DROP", () -> begin
245 TWODUP = defPrim("2DUP", () -> begin
254 TWOSWAP = defPrim("2SWAP", () -> begin
266 QDUP = defPrim("?DUP", () -> begin
275 INCR = defPrim("1+", () -> begin
281 DECR = defPrim("1-", () -> begin
287 INCR2 = defPrim("2+", () -> begin
293 DECR2 = defPrim("2-", () -> begin
299 ADD = defPrim("+", () -> begin
306 SUB = defPrim("-", () -> begin
313 MUL = defPrim("*", () -> begin
320 DIVMOD = defPrim("/MOD", () -> begin
329 EQU = defPrim("=", () -> begin
332 pushPS(a==b ? -1 : 0)
336 NEQU = defPrim("<>", () -> begin
339 pushPS(a!=b ? -1 : 0)
343 LT = defPrim("<", () -> begin
350 GT = defPrim(">", () -> begin
357 LE = defPrim("<=", () -> begin
360 pushPS(a<=b ? -1 : 0)
364 GE = defPrim(">=", () -> begin
367 pushPS(a>=b ? -1 : 0)
371 ZEQU = defPrim("0=", () -> begin
372 pushPS(popPS() == 0 ? -1 : 0)
376 ZNEQU = defPrim("0<>", () -> begin
377 pushPS(popPS() != 0 ? -1 : 0)
381 ZLT = defPrim("0<", () -> begin
382 pushPS(popPS() < 0 ? -1 : 0)
386 ZGT = defPrim("0>", () -> begin
387 pushPS(popPS() > 0 ? -1 : 0)
391 ZLE = defPrim("0<=", () -> begin
392 pushPS(popPS() <= 0 ? -1 : 0)
396 ZGE = defPrim("0>=", () -> begin
397 pushPS(popPS() >= 0 ? -1 : 0)
401 AND = defPrim("AND", () -> begin
408 OR = defPrim("OR", () -> begin
415 XOR = defPrim("XOR", () -> begin
422 INVERT = defPrim("INVERT", () -> begin
429 LIT = defPrim("LIT", () -> begin
437 STORE = defPrim("!", () -> begin
444 FETCH = defPrim("@", () -> begin
450 ADDSTORE = defPrim("+!", () -> begin
457 SUBSTORE = defPrim("-!", () -> begin
467 defExistingVar("HERE", HERE)
468 defExistingVar("LATEST", LATEST)
469 defExistingVar("PSP0", PSP0)
470 defExistingVar("RSP0", RSP0)
471 STATE = defNewVar("STATE", 0)
472 BASE = defNewVar("BASE", 10)
476 defConst("VERSION", 1)
477 defConst("DOCOL", DOCOL)
478 defConst("DICT", DICT)
479 F_IMMED = defConst("F_IMMED", 128)
480 F_HIDDEN = defConst("F_HIDDEN", 256)
481 F_LENMASK = defConst("F_LENMASK", 127)
485 TOR = defPrim(">R", () -> begin
490 FROMR = defPrim("R>", () -> begin
495 RSPFETCH = defPrim("RSP@", () -> begin
500 RSPSTORE = defPrim("RSP!", () -> begin
505 RDROP = defPrim("RDROP", () -> begin
512 PSPFETCH = defPrim("PSP@", () -> begin
517 PSPSTORE = defPrim("PSP!", () -> begin
525 NUMTIB = defNewVar("#TIB", 0)
526 TOIN = defNewVar(">IN", 0)
528 KEY = defPrim("KEY", () -> begin
529 if mem[TOIN] >= mem[NUMTIB]
532 mem[NUMTIB] = length(line)
533 mem[TIB:(TIB+mem[NUMTIB]-1)] = [Int64(c) for c in collect(line)]
536 pushPS(mem[TIB + mem[TOIN]])
542 EMIT = defPrim("EMIT", () -> begin
547 WORD = defPrim("WORD", () -> begin
569 if c == ' ' || c == '\t'
580 mem[wordAddr + offset] = Int64(c)
586 if c == ' ' || c == '\t' || c == '\n'
599 NUMBER = defPrim("NUMBER", () -> begin
604 s = ASCIIString([Char(c) for c in mem[wordAddr:(wordAddr+wordLen-1)]])
607 pushPS(parse(Int64, s, mem[BASE]))
610 pushPS(1) # Error indication
616 # Dictionary searches
618 FIND = defPrim("FIND", () -> begin
622 word = ASCIIString([Char(c) for c in mem[wordAddr:(wordAddr+wordLen-1)]])
627 lenAndFlags = mem[latest+1]
628 len = lenAndFlags & F_LENMASK
629 hidden = (lenAndFlags & F_HIDDEN) == F_HIDDEN
631 if hidden || len != wordLen
637 thisWord = ASCIIString([Char(c) for c in mem[thisAddr:(thisAddr+len-1)]])
649 TOCFA = defPrim(">CFA", () -> begin
652 lenAndFlags = mem[addr+1]
653 len = lenAndFlags & F_LENMASK
655 pushPS(addr + 2 + len)
660 TODFA = defWord(">DFA", [TOCFA, INCR, EXIT])
664 CREATE = defPrim("CREATE", () -> begin
668 word = ASCIIString([Char(c) for c in mem[wordAddr:(wordAddr+wordLen-1)]])
670 mem[mem[HERE]] = mem[LATEST]; mem[HERE] += 1
671 mem[LATEST] = mem[HERE]
672 mem[mem[HERE]] = wordLen; mem[HERE] += 1
674 mem[mem[HERE]:(mem[HERE]+wordLen-1)] = collect(Int64, word)
680 COMMA = defPrim(",", () -> begin
681 mem[mem[HERE]] = popPS()
687 LBRAC = defPrim("[", () -> begin
690 end, flags=F_IMMEDIATE)
692 RBRAC = defPrim("]", () -> begin
695 end, flags=F_IMMEDIATE)
697 HIDDEN = defPrim("HIDDEN", () -> begin
699 mem[addr] = mem[addr] $ F_HIDDEN
703 HIDE = defWord("HIDE",
713 LATEST, FETCH, HIDDEN,
717 SEMICOLON = defWord(";",
719 LATEST, FETCH, HIDDEN,
721 EXIT], flags=F_IMMEDIATE)
723 IMMEDIATE = defPrim("IMMEDIATE", () -> begin
724 lenAndFlagsAddr = mem[LATEST] + 1
725 mem[lenAndFlagsAddr] = mem[lenAndFlagsAddr] $ F_IMMEDIATE
727 end, flags=F_IMMEDIATE)
729 TICK = defWord("'", [WORD, FIND, TOCFA, EXIT])
733 BRANCH = defPrim("BRANCH", () -> begin
734 reg.IP += mem[reg.IP]
738 ZBRANCH = defPrim("0BRANCH", () -> begin
740 reg.IP += mem[reg.IP]
753 while (jmp = callPrim(jmp)) != 0 end
758 function dump(startAddr::Int64; count::Int64 = 100, cellsPerLine::Int64 = 10)
759 chars = Array{Char,1}(cellsPerLine)
763 if i%cellsPerLine == 0
767 print("\t$(mem[addr]) ")
769 if (mem[addr]>=32 && mem[addr]<176)
770 chars[i%cellsPerLine + 1] = Char(mem[addr])
772 chars[i%cellsPerLine + 1] = '.'
775 if i%cellsPerLine == cellsPerLine-1
776 println(string("\t", ASCIIString(chars)))
782 count = reg.PSP - mem[PSP0]
786 for i in (mem[PSP0]+1):reg.PSP
791 println("Parameter stack empty")
796 count = reg.RSP - mem[RSP0]
800 for i in (mem[RSP0]+1):reg.RSP
805 println("Return stack empty")