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 # Next free memory address
20 LATEST = nextVarAddr; nextVarAddr += 1 # LFA of latest word in systetm dict
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::Array{Int64,1}; flags::Int64=0)
155 createHeader(name, flags)
157 codeWordAddr = mem[H]
160 mem[mem[H]] = DOVAR; mem[H] += 1
161 mem[mem[H]:(mem[H]+length(initial)-1)] = initial; mem[H] += length(initial)
163 return varAddr, codeWordAddr
166 defNewVar(name::AbstractString, initial::Int64; flags::Int64=0) =
167 defNewVar(name, [initial]; flags=flags)
169 function defConst(name::AbstractString, val::Int64; flags::Int64=0)
170 createHeader(name, flags)
172 codeWordAddr = mem[H]
174 mem[mem[H]] = DOCON; mem[H] += 1
175 mem[mem[H]] = val; mem[H] += 1
180 # Threading Primitives (inner interpreter)
182 NEXT = defPrim(() -> begin
188 DOCOL = defPrim(() -> begin
194 DOVAR = defPrim(() -> begin
199 DOCON = defPrim(() -> begin
200 pushPS(mem[reg.W + 1])
204 EXIT_CFA = defPrimWord("EXIT", () -> begin
209 # Dictionary entries for core built-in variables, constants
211 H_CFA = defExistingVar("H", H)
212 LATEST_CFA = defExistingVar("LATEST", LATEST)
214 PSP0_CFA = defConst("PSP0", PSP0)
215 RSP0_CFA = defConst("RSP0", RSP0)
217 defConst("DOCOL", DOCOL)
218 defConst("DOCON", DOCON)
219 defConst("DOVAR", DOVAR)
221 defConst("DICT", DICT)
222 defConst("MEMSIZE", size_mem)
224 F_IMMED_CFA = defConst("F_IMMED", F_IMMED)
225 F_HIDDEN_CFA = defConst("F_HIDDEN", F_HIDDEN)
226 F_LENMASK_CFA = defConst("F_LENMASK", F_LENMASK)
227 NFA_MARK_CFA = defConst("NFA_MARK", NFA_MARK)
229 # Basic forth primitives
231 DROP_CFA = defPrimWord("DROP", () -> begin
236 SWAP_CFA = defPrimWord("SWAP", () -> begin
244 DUP_CFA = defPrimWord("DUP", () -> begin
250 OVER_CFA = defPrimWord("OVER", () -> begin
252 pushPS(mem[reg.PSP-1])
256 ROT_CFA = defPrimWord("ROT", () -> begin
266 NROT_CFA = defPrimWord("-ROT", () -> begin
277 TWODROP_CFA = defPrimWord("2DROP", () -> begin
283 TWODUP_CFA = defPrimWord("2DUP", () -> begin
292 TWOSWAP_CFA = defPrimWord("2SWAP", () -> begin
304 TWOOVER_CFA = defPrimWord("2OVER", () -> begin
313 QDUP_CFA = defPrimWord("?DUP", () -> begin
322 INCR_CFA = defPrimWord("1+", () -> begin
328 DECR_CFA = defPrimWord("1-", () -> begin
334 INCR2_CFA = defPrimWord("2+", () -> begin
340 DECR2_CFA = defPrimWord("2-", () -> begin
346 ADD_CFA = defPrimWord("+", () -> begin
353 SUB_CFA = defPrimWord("-", () -> begin
360 MUL_CFA = defPrimWord("*", () -> begin
367 DIVMOD_CFA = defPrimWord("/MOD", () -> begin
376 TWOMUL_CFA = defPrimWord("2*", () -> begin
381 TWODIV_CFA = defPrimWord("2/", () -> begin
386 EQ_CFA = defPrimWord("=", () -> begin
389 pushPS(a==b ? -1 : 0)
393 NE_CFA = defPrimWord("<>", () -> begin
396 pushPS(a!=b ? -1 : 0)
400 LT_CFA = defPrimWord("<", () -> begin
407 GT_CFA = defPrimWord(">", () -> begin
414 LE_CFA = defPrimWord("<=", () -> begin
417 pushPS(a<=b ? -1 : 0)
421 GE_CFA = defPrimWord(">=", () -> begin
424 pushPS(a>=b ? -1 : 0)
428 ZE_CFA = defPrimWord("0=", () -> begin
429 pushPS(popPS() == 0 ? -1 : 0)
433 ZNE_CFA = defPrimWord("0<>", () -> begin
434 pushPS(popPS() != 0 ? -1 : 0)
438 ZLT_CFA = defPrimWord("0<", () -> begin
439 pushPS(popPS() < 0 ? -1 : 0)
443 ZGT_CFA = defPrimWord("0>", () -> begin
444 pushPS(popPS() > 0 ? -1 : 0)
448 ZLE_CFA = defPrimWord("0<=", () -> begin
449 pushPS(popPS() <= 0 ? -1 : 0)
453 ZGE_CFA = defPrimWord("0>=", () -> begin
454 pushPS(popPS() >= 0 ? -1 : 0)
458 AND_CFA = defPrimWord("AND", () -> begin
465 OR_CFA = defPrimWord("OR", () -> begin
472 XOR_CFA = defPrimWord("XOR", () -> begin
479 INVERT_CFA = defPrimWord("INVERT", () -> begin
486 LIT_CFA = defPrimWord("LIT", () -> begin
494 STORE_CFA = defPrimWord("!", () -> begin
501 FETCH_CFA = defPrimWord("@", () -> begin
507 ADDSTORE_CFA = defPrimWord("+!", () -> begin
514 SUBSTORE_CFA = defPrimWord("-!", () -> begin
524 TOR_CFA = defPrimWord(">R", () -> begin
529 FROMR_CFA = defPrimWord("R>", () -> begin
534 RFETCH_CFA = defPrimWord("R@", () -> begin
539 RSPFETCH_CFA = defPrimWord("RSP@", () -> begin
544 RSPSTORE_CFA = defPrimWord("RSP!", () -> begin
549 RDROP_CFA = defPrimWord("RDROP", () -> begin
556 PSPFETCH_CFA = defPrimWord("PSP@", () -> begin
561 PSPSTORE_CFA = defPrimWord("PSP!", () -> begin
568 WFETCH_CFA = defPrimWord("W@", () -> begin
573 WSTORE_CFA = defPrimWord("W!", () -> begin
580 sources = Array{Any,1}()
581 currentSource() = sources[length(sources)]
583 EOF_CFA = defPrimWord("\x04", () -> begin
584 if currentSource() != STDIN
592 EMIT_CFA = defPrimWord("EMIT", () -> begin
597 function raw_mode!(mode::Bool)
598 if ccall(:jl_tty_set_mode, Int32, (Ptr{Void}, Int32), STDIN.handle, mode) != 0
599 throw("FATAL: Terminal unable to enter raw mode.")
605 byte = readbytes(STDIN, 1)[1]
617 KEY_CFA = defPrimWord("KEY", () -> begin
618 pushPS(Int(getKey()))
622 function getLineFromSTDIN()
629 return ASCIIString(line)
633 return string("\x04")
638 line = line[1:length(line)-1]
643 # Strip ANSI escape sequence
644 nextKey = Char(getKey())
647 nextKey = Char(getKey())
648 if nextKey >= '@' || nextKey <= '~'
656 line = string(line, key)
661 SPAN, SPAN_CFA = defNewVar("SPAN", 0)
662 EXPECT_CFA = defPrimWord("EXPECT", () -> begin
666 if currentSource() == STDIN
667 line = getLineFromSTDIN()
669 if !eof(currentSource())
670 line = chomp(readline(currentSource()))
676 mem[SPAN] = min(length(line), maxLen)
677 putString(line[1:mem[SPAN]], addr)
682 BASE, BASE_CFA = defNewVar("BASE", 10)
683 NUMBER_CFA = defPrimWord("NUMBER", () -> begin
685 wordLen = mem[wordAddr-1]
687 s = getString(wordAddr, wordLen)
689 pushPS(parse(Int64, s, mem[BASE]))
694 # Dictionary searches
696 TOCFA_CFA = defPrimWord(">CFA", () -> begin
699 lenAndFlags = mem[addr+1]
700 len = lenAndFlags & F_LENMASK
702 pushPS(addr + 2 + len)
707 TOBODY_CFA = defWord(">BODY", [INCR_CFA, EXIT_CFA])
709 FIND_CFA = defPrimWord("FIND", () -> begin
711 countedAddr = popPS()
712 wordAddr = countedAddr + 1
713 wordLen = mem[countedAddr]
714 word = lowercase(getString(wordAddr, wordLen))
720 while (latest = mem[latest]) > 0
721 lenAndFlags = mem[latest+1]
722 len = lenAndFlags & F_LENMASK
723 hidden = (lenAndFlags & F_HIDDEN) == F_HIDDEN
725 if hidden || len != wordLen
730 thisWord = lowercase(getString(thisAddr, len))
732 if lowercase(thisWord) == lowercase(word)
739 callPrim(mem[TOCFA_CFA])
740 if (lenAndFlags & F_IMMED) == F_IMMED
756 BRANCH_CFA = defPrimWord("BRANCH", () -> begin
757 reg.IP += mem[reg.IP]
761 ZBRANCH_CFA = defPrimWord("0BRANCH", () -> begin
763 reg.IP += mem[reg.IP]
773 LITSTRING_CFA = defPrimWord("LITSTRING", () -> begin
783 TYPE_CFA = defPrimWord("TYPE", () -> begin
786 str = getString(addr, len)
791 # Interpreter/Compiler-specific I/O
793 TIB_CFA = defConst("TIB", TIB)
794 NUMTIB, NUMTIB_CFA = defNewVar("#TIB", 0)
795 TOIN, TOIN_CFA = defNewVar(">IN", 0)
797 QUERY_CFA = defWord("QUERY",
798 [TIB_CFA, LIT_CFA, 160, EXPECT_CFA,
799 SPAN_CFA, FETCH_CFA, NUMTIB_CFA, STORE_CFA,
800 LIT_CFA, 0, TOIN_CFA, STORE_CFA,
803 WORD_CFA = defPrimWord("WORD", () -> begin
806 # Chew up initial occurrences of delim
807 while (mem[TOIN]<mem[NUMTIB] && mem[TIB+mem[TOIN]] == delim)
814 # Start reading in word
816 while (mem[TOIN]<mem[NUMTIB])
817 mem[addr] = mem[TIB+mem[TOIN]]
820 if (mem[addr] == delim)
829 mem[countAddr] = count
837 STATE, STATE_CFA = defNewVar("STATE", 0)
839 COMMA_CFA = defPrimWord(",", () -> begin
840 mem[mem[H]] = popPS()
846 HERE_CFA = defWord("HERE",
847 [H_CFA, FETCH_CFA, EXIT_CFA])
849 HEADER_CFA = defPrimWord("HEADER", () -> begin
851 wordLen = mem[wordAddr-1]
852 word = getString(wordAddr, wordLen)
854 createHeader(word, 0)
859 CREATE_CFA = defWord("CREATE",
860 [LIT_CFA, 32, WORD_CFA, HEADER_CFA,
861 LIT_CFA, DOVAR, COMMA_CFA,
864 DODOES = defPrim(() -> begin
871 DOES_HELPER_CFA = defPrimWord("(DOES>)", () -> begin
874 callPrim(mem[TOCFA_CFA])
877 runtimeAddr = popPS()
879 mem[cfa] = defPrim(eval(:(() -> begin
880 pushPS($(runtimeAddr))
882 end)), name="doesPrim")
887 DOES_CFA = defWord("DOES>",
888 [LIT_CFA, LIT_CFA, COMMA_CFA, HERE_CFA, LIT_CFA, 3, ADD_CFA, COMMA_CFA,
889 LIT_CFA, DOES_HELPER_CFA, COMMA_CFA, LIT_CFA, EXIT_CFA, COMMA_CFA, EXIT_CFA],
892 LBRAC_CFA = defPrimWord("[", () -> begin
897 RBRAC_CFA = defPrimWord("]", () -> begin
902 HIDDEN_CFA = defPrimWord("HIDDEN", () -> begin
903 lenAndFlagsAddr = mem[LATEST] + 1
904 mem[lenAndFlagsAddr] = mem[lenAndFlagsAddr] $ F_HIDDEN
908 COLON_CFA = defWord(":",
909 [LIT_CFA, 32, WORD_CFA,
911 LIT_CFA, DOCOL, COMMA_CFA,
916 SEMICOLON_CFA = defWord(";",
917 [LIT_CFA, EXIT_CFA, COMMA_CFA,
920 EXIT_CFA], flags=F_IMMED)
922 IMMEDIATE_CFA = defPrimWord("IMMEDIATE", () -> begin
923 lenAndFlagsAddr = mem[LATEST] + 1
924 mem[lenAndFlagsAddr] = mem[lenAndFlagsAddr] $ F_IMMED
930 EXECUTE_CFA = defPrimWord("EXECUTE", () -> begin
935 INTERPRET_CFA = defWord("INTERPRET",
936 [LIT_CFA, 32, WORD_CFA, # Read next space-delimited word
938 DUP_CFA, FETCH_CFA, ZE_CFA, ZBRANCH_CFA, 3,
939 DROP_CFA, EXIT_CFA, # Exit if TIB is exhausted
941 STATE_CFA, FETCH_CFA, ZBRANCH_CFA, 24,
943 FIND_CFA, QDUP_CFA, ZBRANCH_CFA, 13,
946 LIT_CFA, -1, EQ_CFA, INVERT_CFA, ZBRANCH_CFA, 4,
948 # Immediate: Execute!
949 EXECUTE_CFA, BRANCH_CFA, -26,
951 # Not immediate: Compile!
952 COMMA_CFA, BRANCH_CFA, -29,
954 # No word found, parse number
955 NUMBER_CFA, LIT_CFA, LIT_CFA, COMMA_CFA, COMMA_CFA, BRANCH_CFA, -36,
958 FIND_CFA, QDUP_CFA, ZBRANCH_CFA, 5,
960 # Found word. Execute!
961 DROP_CFA, EXECUTE_CFA, BRANCH_CFA, -44,
963 # No word found, parse number and leave on stack
964 NUMBER_CFA, BRANCH_CFA, -47,
967 PROMPT_CFA = defPrimWord("PROMPT", () -> begin
968 if (mem[STATE] == 0 && currentSource() == STDIN)
975 QUIT_CFA = defWord("QUIT",
976 [LIT_CFA, 0, STATE_CFA, STORE_CFA,
977 LIT_CFA, 0, NUMTIB_CFA, STORE_CFA,
978 RSP0_CFA, RSPSTORE_CFA,
980 INTERPRET_CFA, PROMPT_CFA,
983 ABORT_CFA = defWord("ABORT",
984 [PSP0_CFA, PSPSTORE_CFA, QUIT_CFA])
986 BYE_CFA = defPrimWord("BYE", () -> begin
993 INCLUDE_CFA = defPrimWord("INCLUDE", () -> begin
995 callPrim(mem[WORD_CFA])
997 wordLen = mem[wordAddr-1]
998 word = getString(wordAddr, wordLen)
1002 fname = Pkg.dir("forth","src",word)
1004 error("No file named $word found in current directory or package source directory.")
1007 push!(sources, open(fname, "r"))
1009 # Clear input buffer
1019 initFileName = nothing
1020 if isfile("lib.4th")
1021 initFileName = "lib.4th"
1022 elseif isfile(Pkg.dir("forth","src", "lib.4th"))
1023 initFileName = Pkg.dir("forth","src","lib.4th")
1026 function run(;initialize=true)
1027 # Begin with STDIN as source
1028 push!(sources, STDIN)
1030 global initialized, initFileName
1031 if !initialized && initialize
1032 if initFileName != nothing
1033 print("Including definitions from $initFileName...")
1034 push!(sources, open(initFileName, "r"))
1037 println("No library file found. Only primitive words available.")
1041 # Start with IP pointing to first instruction of outer interpreter
1042 reg.IP = QUIT_CFA + 1
1044 # Primitive processing loop.
1045 # Everyting else is simply a consequence of this loop!
1049 #println("Entering prim $(getPrimName(jmp))")
1053 showerror(STDOUT, ex)
1056 while !isempty(sources) && currentSource() != STDIN
1057 close(pop!(sources))
1061 reg.IP = ABORT_CFA + 1
1069 TRACE_CFA = defPrimWord("TRACE", () -> begin
1070 println("reg.W: $(reg.W) reg.IP: $(reg.IP)")
1071 print("PS: "); printPS()
1072 print("RS: "); printRS()
1079 function dump(startAddr::Int64; count::Int64 = 100, cellsPerLine::Int64 = 10)
1080 chars = Array{Char,1}(cellsPerLine)
1082 lineStartAddr = cellsPerLine*div((startAddr-1),cellsPerLine) + 1
1083 endAddr = startAddr + count - 1
1085 q, r = divrem((endAddr-lineStartAddr+1), cellsPerLine)
1086 numLines = q + (r > 0 ? 1 : 0)
1092 for c in 1:cellsPerLine
1093 if i >= startAddr && i <= endAddr
1095 if mem[i]>=32 && mem[i]<128
1096 chars[c] = Char(mem[i])
1108 println("\t", ASCIIString(chars))
1113 count = reg.PSP - PSP0
1117 for i in (PSP0+1):reg.PSP
1122 println("Parameter stack empty")
1127 count = reg.RSP - RSP0
1131 for i in (RSP0+1):reg.RSP
1136 println("Return stack empty")
1140 DUMP = defPrimWord("DUMP", () -> begin
1145 dump(addr, count=count)