4 size_mem = 1000000 # 1 mega-int
7 size_RS = 1000 # Return stack size
8 size_PS = 1000 # Parameter stack size
9 size_TIB = 1000 # Terminal input buffer size
12 mem = Array{Int64,1}(size_mem)
13 primitives = Array{Function,1}()
14 primNames = Array{ASCIIString,1}()
19 H = nextVarAddr; nextVarAddr += 1
20 LATEST = nextVarAddr; nextVarAddr += 1
22 RSP0 = nextVarAddr # bottom of RS
23 PSP0 = RSP0 + size_RS # bottom of PS
24 TIB = PSP0 + size_PS # address of terminal input buffer
25 mem[H] = TIB + size_TIB # location of bottom of dictionary
26 mem[LATEST] = 0 # no previous definition
28 DICT = mem[H] # Save bottom of dictionary as constant
32 RSP::Int64 # Return stack pointer
33 PSP::Int64 # Parameter/data stack pointer
34 IP::Int64 # Instruction pointer
35 W::Int64 # Working register
37 reg = Reg(RSP0, PSP0, 0, 0)
39 # Stack manipulation functions
41 function ensurePSDepth(depth::Int64)
42 if reg.PSP - PSP0 < depth
43 error("Parameter stack underflow.")
47 function ensureRSDepth(depth::Int64)
48 if reg.RSP - RSP0 < depth
49 error("Return stack underflow.")
53 function pushRS(val::Int64)
65 function pushPS(val::Int64)
66 mem[reg.PSP += 1] = val
77 # Handy functions for adding/retrieving strings to/from memory.
79 getString(addr::Int64, len::Int64) = ASCIIString([Char(c) for c in mem[addr:(addr+len-1)]])
81 function putString(str::ASCIIString, addr::Int64)
82 mem[addr:(addr+length(str)-1)] = [Int64(c) for c in str]
85 # Primitive creation and calling functions
87 function defPrim(f::Function; name="nameless")
89 push!(primNames, replace(name, "\004", "EOF"))
91 return -length(primitives)
94 function callPrim(addr::Int64)
95 if addr >=0 || -addr>length(primitives)
96 error("Attempted to execute non-existent primitive at address $addr.")
101 getPrimName(addr::Int64) = primNames[-addr]
103 # Word creation functions
110 function createHeader(name::AbstractString, flags::Int64)
111 mem[mem[H]] = mem[LATEST]
115 mem[mem[H]] = length(name) | flags | NFA_MARK; mem[H] += 1
116 putString(name, mem[H]); mem[H] += length(name)
119 function defPrimWord(name::AbstractString, f::Function; flags::Int64=0)
120 createHeader(name, flags)
122 codeWordAddr = mem[H]
123 mem[codeWordAddr] = defPrim(f, name=name)
129 function defWord(name::AbstractString, wordAddrs::Array{Int64,1}; flags::Int64=0)
130 createHeader(name, flags)
136 for wordAddr in wordAddrs
137 mem[mem[H]] = wordAddr
144 # Variable creation functions
146 function defExistingVar(name::AbstractString, varAddr::Int64; flags::Int64=0)
148 defPrimWord(name, eval(:(() -> begin
154 function defNewVar(name::AbstractString, initial::Int64; flags::Int64=0)
155 createHeader(name, flags)
157 codeWordAddr = mem[H]
160 mem[mem[H]] = DOVAR; mem[H] += 1
161 mem[mem[H]] = initial; mem[H] += 1
163 return varAddr, codeWordAddr
166 function defConst(name::AbstractString, val::Int64; flags::Int64=0)
167 createHeader(name, flags)
169 codeWordAddr = mem[H]
171 mem[mem[H]] = DOCON; mem[H] += 1
172 mem[mem[H]] = val; mem[H] += 1
177 # Threading Primitives (inner interpreter)
179 NEXT = defPrim(() -> begin
185 DOCOL = defPrim(() -> begin
191 DOVAR = defPrim(() -> begin
196 DOCON = defPrim(() -> begin
197 pushPS(mem[reg.W + 1])
201 EXIT_CFA = defPrimWord("EXIT", () -> begin
206 # Dictionary entries for core built-in variables, constants
208 H_CFA = defExistingVar("H", H)
209 LATEST_CFA = defExistingVar("LATEST", LATEST)
211 PSP0_CFA = defConst("PSP0", PSP0)
212 RSP0_CFA = defConst("RSP0", RSP0)
214 defConst("DOCOL", DOCOL)
215 defConst("DOCON", DOCON)
216 defConst("DOVAR", DOVAR)
218 defConst("DICT", DICT)
219 defConst("MEMSIZE", size_mem)
221 F_IMMED_CFA = defConst("F_IMMED", F_IMMED)
222 F_HIDDEN_CFA = defConst("F_HIDDEN", F_HIDDEN)
223 F_LENMASK_CFA = defConst("F_LENMASK", F_LENMASK)
224 NFA_MARK_CFA = defConst("NFA_MARK", NFA_MARK)
226 # Basic forth primitives
228 DROP_CFA = defPrimWord("DROP", () -> begin
233 SWAP_CFA = defPrimWord("SWAP", () -> begin
241 DUP_CFA = defPrimWord("DUP", () -> begin
247 OVER_CFA = defPrimWord("OVER", () -> begin
249 pushPS(mem[reg.PSP-1])
253 ROT_CFA = defPrimWord("ROT", () -> begin
263 NROT_CFA = defPrimWord("-ROT", () -> begin
274 TWODROP_CFA = defPrimWord("2DROP", () -> begin
280 TWODUP_CFA = defPrimWord("2DUP", () -> begin
289 TWOSWAP_CFA = defPrimWord("2SWAP", () -> begin
301 TWOOVER_CFA = defPrimWord("2OVER", () -> begin
310 QDUP_CFA = defPrimWord("?DUP", () -> begin
319 INCR_CFA = defPrimWord("1+", () -> begin
325 DECR_CFA = defPrimWord("1-", () -> begin
331 INCR2_CFA = defPrimWord("2+", () -> begin
337 DECR2_CFA = defPrimWord("2-", () -> begin
343 ADD_CFA = defPrimWord("+", () -> begin
350 SUB_CFA = defPrimWord("-", () -> begin
357 MUL_CFA = defPrimWord("*", () -> begin
364 DIVMOD_CFA = defPrimWord("/MOD", () -> begin
373 TWOMUL_CFA = defPrimWord("2*", () -> begin
378 TWODIV_CFA = defPrimWord("2/", () -> begin
383 EQ_CFA = defPrimWord("=", () -> begin
386 pushPS(a==b ? -1 : 0)
390 NE_CFA = defPrimWord("<>", () -> begin
393 pushPS(a!=b ? -1 : 0)
397 LT_CFA = defPrimWord("<", () -> begin
404 GT_CFA = defPrimWord(">", () -> begin
411 LE_CFA = defPrimWord("<=", () -> begin
414 pushPS(a<=b ? -1 : 0)
418 GE_CFA = defPrimWord(">=", () -> begin
421 pushPS(a>=b ? -1 : 0)
425 ZE_CFA = defPrimWord("0=", () -> begin
426 pushPS(popPS() == 0 ? -1 : 0)
430 ZNE_CFA = defPrimWord("0<>", () -> begin
431 pushPS(popPS() != 0 ? -1 : 0)
435 ZLT_CFA = defPrimWord("0<", () -> begin
436 pushPS(popPS() < 0 ? -1 : 0)
440 ZGT_CFA = defPrimWord("0>", () -> begin
441 pushPS(popPS() > 0 ? -1 : 0)
445 ZLE_CFA = defPrimWord("0<=", () -> begin
446 pushPS(popPS() <= 0 ? -1 : 0)
450 ZGE_CFA = defPrimWord("0>=", () -> begin
451 pushPS(popPS() >= 0 ? -1 : 0)
455 AND_CFA = defPrimWord("AND", () -> begin
462 OR_CFA = defPrimWord("OR", () -> begin
469 XOR_CFA = defPrimWord("XOR", () -> begin
476 INVERT_CFA = defPrimWord("INVERT", () -> begin
483 LIT_CFA = defPrimWord("LIT", () -> begin
491 STORE_CFA = defPrimWord("!", () -> begin
498 FETCH_CFA = defPrimWord("@", () -> begin
504 ADDSTORE_CFA = defPrimWord("+!", () -> begin
511 SUBSTORE_CFA = defPrimWord("-!", () -> begin
521 TOR_CFA = defPrimWord(">R", () -> begin
526 FROMR_CFA = defPrimWord("R>", () -> begin
531 RFETCH_CFA = defPrimWord("R@", () -> begin
536 RSPFETCH_CFA = defPrimWord("RSP@", () -> begin
541 RSPSTORE_CFA = defPrimWord("RSP!", () -> begin
546 RDROP_CFA = defPrimWord("RDROP", () -> begin
553 PSPFETCH_CFA = defPrimWord("PSP@", () -> begin
558 PSPSTORE_CFA = defPrimWord("PSP!", () -> begin
565 WFETCH_CFA = defPrimWord("W@", () -> begin
570 WSTORE_CFA = defPrimWord("W!", () -> begin
577 sources = Array{Any,1}()
578 currentSource() = sources[length(sources)]
580 EOF_CFA = defPrimWord("\x04", () -> begin
581 if currentSource() != STDIN
589 EMIT_CFA = defPrimWord("EMIT", () -> begin
594 function raw_mode!(mode::Bool)
595 if ccall(:jl_tty_set_mode, Int32, (Ptr{Void}, Int32), STDIN.handle, mode) != 0
596 throw("FATAL: Terminal unable to enter raw mode.")
602 byte = readbytes(STDIN, 1)[1]
614 KEY_CFA = defPrimWord("KEY", () -> begin
615 pushPS(Int(getKey()))
619 function getLineFromSTDIN()
626 return ASCIIString(line)
630 return string("\x04")
635 line = line[1:length(line)-1]
640 # Strip ANSI escape sequence
641 nextKey = Char(getKey())
644 nextKey = Char(getKey())
645 if nextKey >= '@' || nextKey <= '~'
653 line = string(line, key)
658 SPAN, SPAN_CFA = defNewVar("SPAN", 0)
659 EXPECT_CFA = defPrimWord("EXPECT", () -> begin
663 if currentSource() == STDIN
664 line = getLineFromSTDIN()
666 if !eof(currentSource())
667 line = chomp(readline(currentSource()))
673 mem[SPAN] = min(length(line), maxLen)
674 putString(line[1:mem[SPAN]], addr)
679 BASE, BASE_CFA = defNewVar("BASE", 10)
680 NUMBER_CFA = defPrimWord("NUMBER", () -> begin
682 wordLen = mem[wordAddr-1]
684 s = getString(wordAddr, wordLen)
686 pushPS(parse(Int64, s, mem[BASE]))
691 # Dictionary searches
693 TOCFA_CFA = defPrimWord(">CFA", () -> begin
696 lenAndFlags = mem[addr+1]
697 len = lenAndFlags & F_LENMASK
699 pushPS(addr + 2 + len)
704 TOBODY_CFA = defWord(">BODY", [INCR_CFA, EXIT_CFA])
706 FIND_CFA = defPrimWord("FIND", () -> begin
708 countedAddr = popPS()
709 wordAddr = countedAddr + 1
710 wordLen = mem[countedAddr]
711 word = lowercase(getString(wordAddr, wordLen))
717 while (latest = mem[latest]) > 0
718 lenAndFlags = mem[latest+1]
719 len = lenAndFlags & F_LENMASK
720 hidden = (lenAndFlags & F_HIDDEN) == F_HIDDEN
722 if hidden || len != wordLen
727 thisWord = lowercase(getString(thisAddr, len))
729 if lowercase(thisWord) == lowercase(word)
736 callPrim(mem[TOCFA_CFA])
737 if (lenAndFlags & F_IMMED) == F_IMMED
753 BRANCH_CFA = defPrimWord("BRANCH", () -> begin
754 reg.IP += mem[reg.IP]
758 ZBRANCH_CFA = defPrimWord("0BRANCH", () -> begin
760 reg.IP += mem[reg.IP]
770 LITSTRING_CFA = defPrimWord("LITSTRING", () -> begin
780 TYPE_CFA = defPrimWord("TYPE", () -> begin
783 str = getString(addr, len)
788 # Interpreter/Compiler-specific I/O
790 TIB_CFA = defConst("TIB", TIB)
791 NUMTIB, NUMTIB_CFA = defNewVar("#TIB", 0)
792 TOIN, TOIN_CFA = defNewVar(">IN", 0)
794 QUERY_CFA = defWord("QUERY",
795 [TIB_CFA, LIT_CFA, 160, EXPECT_CFA,
796 SPAN_CFA, FETCH_CFA, NUMTIB_CFA, STORE_CFA,
797 LIT_CFA, 0, TOIN_CFA, STORE_CFA,
800 WORD_CFA = defPrimWord("WORD", () -> begin
803 # Chew up initial occurrences of delim
804 while (mem[TOIN]<mem[NUMTIB] && mem[TIB+mem[TOIN]] == delim)
811 # Start reading in word
813 while (mem[TOIN]<mem[NUMTIB])
814 mem[addr] = mem[TIB+mem[TOIN]]
817 if (mem[addr] == delim)
826 mem[countAddr] = count
834 STATE, STATE_CFA = defNewVar("STATE", 0)
836 COMMA_CFA = defPrimWord(",", () -> begin
837 mem[mem[H]] = popPS()
843 HERE_CFA = defWord("HERE",
844 [H_CFA, FETCH_CFA, EXIT_CFA])
846 HEADER_CFA = defPrimWord("HEADER", () -> begin
848 wordLen = mem[wordAddr-1]
849 word = getString(wordAddr, wordLen)
851 createHeader(word, 0)
856 CREATE_CFA = defWord("CREATE",
857 [LIT_CFA, 32, WORD_CFA, HEADER_CFA,
858 LIT_CFA, DOVAR, COMMA_CFA,
861 DODOES = defPrim(() -> begin
868 DOES_HELPER_CFA = defPrimWord("(DOES>)", () -> begin
871 callPrim(mem[TOCFA_CFA])
874 runtimeAddr = popPS()
876 mem[cfa] = defPrim(eval(:(() -> begin
877 pushPS($(runtimeAddr))
879 end)), name="doesPrim")
884 DOES_CFA = defWord("DOES>",
885 [LIT_CFA, LIT_CFA, COMMA_CFA, HERE_CFA, LIT_CFA, 3, ADD_CFA, COMMA_CFA,
886 LIT_CFA, DOES_HELPER_CFA, COMMA_CFA, LIT_CFA, EXIT_CFA, COMMA_CFA, EXIT_CFA],
889 LBRAC_CFA = defPrimWord("[", () -> begin
894 RBRAC_CFA = defPrimWord("]", () -> begin
899 HIDDEN_CFA = defPrimWord("HIDDEN", () -> begin
900 lenAndFlagsAddr = mem[LATEST] + 1
901 mem[lenAndFlagsAddr] = mem[lenAndFlagsAddr] $ F_HIDDEN
905 COLON_CFA = defWord(":",
906 [LIT_CFA, 32, WORD_CFA,
908 LIT_CFA, DOCOL, COMMA_CFA,
913 SEMICOLON_CFA = defWord(";",
914 [LIT_CFA, EXIT_CFA, COMMA_CFA,
917 EXIT_CFA], flags=F_IMMED)
919 IMMEDIATE_CFA = defPrimWord("IMMEDIATE", () -> begin
920 lenAndFlagsAddr = mem[LATEST] + 1
921 mem[lenAndFlagsAddr] = mem[lenAndFlagsAddr] $ F_IMMED
927 EXECUTE_CFA = defPrimWord("EXECUTE", () -> begin
932 INTERPRET_CFA = defWord("INTERPRET",
933 [LIT_CFA, 32, WORD_CFA, # Read next space-delimited word
935 DUP_CFA, FETCH_CFA, ZE_CFA, ZBRANCH_CFA, 3,
936 DROP_CFA, EXIT_CFA, # Exit if TIB is exhausted
938 STATE_CFA, FETCH_CFA, ZBRANCH_CFA, 24,
940 FIND_CFA, QDUP_CFA, ZBRANCH_CFA, 13,
943 LIT_CFA, -1, EQ_CFA, INVERT_CFA, ZBRANCH_CFA, 4,
945 # Immediate: Execute!
946 EXECUTE_CFA, BRANCH_CFA, -26,
948 # Not immediate: Compile!
949 COMMA_CFA, BRANCH_CFA, -29,
951 # No word found, parse number
952 NUMBER_CFA, LIT_CFA, LIT_CFA, COMMA_CFA, COMMA_CFA, BRANCH_CFA, -36,
955 FIND_CFA, QDUP_CFA, ZBRANCH_CFA, 5,
957 # Found word. Execute!
958 DROP_CFA, EXECUTE_CFA, BRANCH_CFA, -44,
960 # No word found, parse number and leave on stack
961 NUMBER_CFA, BRANCH_CFA, -47,
964 PROMPT_CFA = defPrimWord("PROMPT", () -> begin
965 if (mem[STATE] == 0 && currentSource() == STDIN)
972 QUIT_CFA = defWord("QUIT",
973 [LIT_CFA, 0, STATE_CFA, STORE_CFA,
974 LIT_CFA, 0, NUMTIB_CFA, STORE_CFA,
975 RSP0_CFA, RSPSTORE_CFA,
977 INTERPRET_CFA, PROMPT_CFA,
980 ABORT_CFA = defWord("ABORT",
981 [PSP0_CFA, PSPSTORE_CFA, QUIT_CFA])
983 BYE_CFA = defPrimWord("BYE", () -> begin
990 INCLUDE_CFA = defPrimWord("INCLUDE", () -> begin
992 callPrim(mem[WORD_CFA])
994 wordLen = mem[wordAddr-1]
995 word = getString(wordAddr, wordLen)
999 fname = Pkg.dir("forth","src",word)
1001 error("No file named $word found in current directory or package source directory.")
1004 push!(sources, open(fname, "r"))
1006 # Clear input buffer
1016 initFileName = nothing
1017 if isfile("lib.4th")
1018 initFileName = "lib.4th"
1019 elseif isfile(Pkg.dir("forth","src", "lib.4th"))
1020 initFileName = Pkg.dir("forth","src","lib.4th")
1023 function run(;initialize=true)
1024 # Begin with STDIN as source
1025 push!(sources, STDIN)
1027 global initialized, initFileName
1028 if !initialized && initialize
1029 if initFileName != nothing
1030 print("Including definitions from $initFileName...")
1031 push!(sources, open(initFileName, "r"))
1034 println("No library file found. Only primitive words available.")
1038 # Start with IP pointing to first instruction of outer interpreter
1039 reg.IP = QUIT_CFA + 1
1041 # Primitive processing loop.
1042 # Everyting else is simply a consequence of this loop!
1046 #println("Entering prim $(getPrimName(jmp))")
1050 showerror(STDOUT, ex)
1053 while !isempty(sources) && currentSource() != STDIN
1054 close(pop!(sources))
1058 reg.IP = ABORT_CFA + 1
1066 TRACE_CFA = defPrimWord("TRACE", () -> begin
1067 println("reg.W: $(reg.W) reg.IP: $(reg.IP)")
1068 print("PS: "); printPS()
1069 print("RS: "); printRS()
1076 function dump(startAddr::Int64; count::Int64 = 100, cellsPerLine::Int64 = 10)
1077 chars = Array{Char,1}(cellsPerLine)
1079 lineStartAddr = cellsPerLine*div((startAddr-1),cellsPerLine) + 1
1080 endAddr = startAddr + count - 1
1082 q, r = divrem((endAddr-lineStartAddr+1), cellsPerLine)
1083 numLines = q + (r > 0 ? 1 : 0)
1089 for c in 1:cellsPerLine
1090 if i >= startAddr && i <= endAddr
1092 if mem[i]>=32 && mem[i]<128
1093 chars[c] = Char(mem[i])
1105 println("\t", ASCIIString(chars))
1110 count = reg.PSP - PSP0
1114 for i in (PSP0+1):reg.PSP
1119 println("Parameter stack empty")
1124 count = reg.RSP - RSP0
1128 for i in (RSP0+1):reg.RSP
1133 println("Return stack empty")
1137 DUMP = defPrimWord("DUMP", () -> begin
1142 dump(addr, count=count)