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 FORTH = nextVarAddr; nextVarAddr += 1 # LFA of latest word in system dict
21 CURRENT = nextVarAddr; nextVarAddr += 1 # Current compilation dict
23 RSP0 = nextVarAddr # bottom of RS
24 PSP0 = RSP0 + size_RS # bottom of PS
25 TIB = PSP0 + size_PS # address of terminal input buffer
26 mem[H] = TIB + size_TIB # location of bottom of dictionary
27 mem[FORTH] = 0 # no previous definition
28 mem[CURRENT] = FORTH # Compile words to system dict initially
30 DICT = mem[H] # Save bottom of dictionary as constant
34 RSP::Int64 # Return stack pointer
35 PSP::Int64 # Parameter/data stack pointer
36 IP::Int64 # Instruction pointer
37 W::Int64 # Working register
39 reg = Reg(RSP0, PSP0, 0, 0)
41 # Stack manipulation functions
43 function ensurePSDepth(depth::Int64)
44 if reg.PSP - PSP0 < depth
45 error("Parameter stack underflow.")
49 function ensureRSDepth(depth::Int64)
50 if reg.RSP - RSP0 < depth
51 error("Return stack underflow.")
55 function pushRS(val::Int64)
67 function pushPS(val::Int64)
68 mem[reg.PSP += 1] = val
79 # Handy functions for adding/retrieving strings to/from memory.
81 getString(addr::Int64, len::Int64) = ASCIIString([Char(c) for c in mem[addr:(addr+len-1)]])
83 function putString(str::ASCIIString, addr::Int64)
84 mem[addr:(addr+length(str)-1)] = [Int64(c) for c in str]
87 # Primitive creation and calling functions
89 function defPrim(f::Function; name="nameless")
91 push!(primNames, replace(name, "\004", "EOF"))
93 return -length(primitives)
96 function callPrim(addr::Int64)
97 if addr >=0 || -addr>length(primitives)
98 error("Attempted to execute non-existent primitive at address $addr.")
103 getPrimName(addr::Int64) = primNames[-addr]
105 # Word creation functions
112 function createHeader(name::AbstractString, flags::Int64)
113 mem[mem[H]] = mem[mem[CURRENT]]
114 mem[mem[CURRENT]] = mem[H]
117 mem[mem[H]] = length(name) | flags | NFA_MARK; mem[H] += 1
118 putString(name, mem[H]); mem[H] += length(name)
121 function defPrimWord(name::AbstractString, f::Function; flags::Int64=0)
122 createHeader(name, flags)
124 codeWordAddr = mem[H]
125 mem[codeWordAddr] = defPrim(f, name=name)
131 function defWord(name::AbstractString, wordAddrs::Array{Int64,1}; flags::Int64=0)
132 createHeader(name, flags)
138 for wordAddr in wordAddrs
139 mem[mem[H]] = wordAddr
146 # Variable creation functions
148 function defExistingVar(name::AbstractString, varAddr::Int64; flags::Int64=0)
150 defPrimWord(name, eval(:(() -> begin
156 function defNewVar(name::AbstractString, initial::Array{Int64,1}; flags::Int64=0)
157 createHeader(name, flags)
159 codeWordAddr = mem[H]
162 mem[mem[H]] = DOVAR; mem[H] += 1
163 mem[mem[H]:(mem[H]+length(initial)-1)] = initial; mem[H] += length(initial)
165 return varAddr, codeWordAddr
168 defNewVar(name::AbstractString, initial::Int64; flags::Int64=0) =
169 defNewVar(name, [initial]; flags=flags)
171 function defConst(name::AbstractString, val::Int64; flags::Int64=0)
172 createHeader(name, flags)
174 codeWordAddr = mem[H]
176 mem[mem[H]] = DOCON; mem[H] += 1
177 mem[mem[H]] = val; mem[H] += 1
182 # Threading Primitives (inner interpreter)
184 NEXT = defPrim(() -> begin
190 DOCOL = defPrim(() -> begin
196 DOVAR = defPrim(() -> begin
201 DOCON = defPrim(() -> begin
202 pushPS(mem[reg.W + 1])
206 EXIT_CFA = defPrimWord("EXIT", () -> begin
211 # Dictionary entries for core built-in variables, constants
213 H_CFA = defExistingVar("H", H)
214 FORTH_CFA = defExistingVar("FORTH", FORTH)
215 CURRENT_CFA = defExistingVar("CURRENT", CURRENT)
217 PSP0_CFA = defConst("PSP0", PSP0)
218 RSP0_CFA = defConst("RSP0", RSP0)
220 defConst("DOCOL", DOCOL)
221 defConst("DOCON", DOCON)
222 defConst("DOVAR", DOVAR)
224 defConst("DICT", DICT)
225 defConst("MEMSIZE", size_mem)
227 F_IMMED_CFA = defConst("F_IMMED", F_IMMED)
228 F_HIDDEN_CFA = defConst("F_HIDDEN", F_HIDDEN)
229 F_LENMASK_CFA = defConst("F_LENMASK", F_LENMASK)
230 NFA_MARK_CFA = defConst("NFA_MARK", NFA_MARK)
232 # Basic forth primitives
234 DROP_CFA = defPrimWord("DROP", () -> begin
239 SWAP_CFA = defPrimWord("SWAP", () -> begin
247 DUP_CFA = defPrimWord("DUP", () -> begin
253 OVER_CFA = defPrimWord("OVER", () -> begin
255 pushPS(mem[reg.PSP-1])
259 ROT_CFA = defPrimWord("ROT", () -> begin
269 NROT_CFA = defPrimWord("-ROT", () -> begin
280 TWODROP_CFA = defPrimWord("2DROP", () -> begin
286 TWODUP_CFA = defPrimWord("2DUP", () -> begin
295 TWOSWAP_CFA = defPrimWord("2SWAP", () -> begin
307 TWOOVER_CFA = defPrimWord("2OVER", () -> begin
316 QDUP_CFA = defPrimWord("?DUP", () -> begin
325 INCR_CFA = defPrimWord("1+", () -> begin
331 DECR_CFA = defPrimWord("1-", () -> begin
337 INCR2_CFA = defPrimWord("2+", () -> begin
343 DECR2_CFA = defPrimWord("2-", () -> begin
349 ADD_CFA = defPrimWord("+", () -> begin
356 SUB_CFA = defPrimWord("-", () -> begin
363 MUL_CFA = defPrimWord("*", () -> begin
370 DIVMOD_CFA = defPrimWord("/MOD", () -> begin
379 TWOMUL_CFA = defPrimWord("2*", () -> begin
384 TWODIV_CFA = defPrimWord("2/", () -> begin
389 EQ_CFA = defPrimWord("=", () -> begin
392 pushPS(a==b ? -1 : 0)
396 NE_CFA = defPrimWord("<>", () -> begin
399 pushPS(a!=b ? -1 : 0)
403 LT_CFA = defPrimWord("<", () -> begin
410 GT_CFA = defPrimWord(">", () -> begin
417 LE_CFA = defPrimWord("<=", () -> begin
420 pushPS(a<=b ? -1 : 0)
424 GE_CFA = defPrimWord(">=", () -> begin
427 pushPS(a>=b ? -1 : 0)
431 ZE_CFA = defPrimWord("0=", () -> begin
432 pushPS(popPS() == 0 ? -1 : 0)
436 ZNE_CFA = defPrimWord("0<>", () -> begin
437 pushPS(popPS() != 0 ? -1 : 0)
441 ZLT_CFA = defPrimWord("0<", () -> begin
442 pushPS(popPS() < 0 ? -1 : 0)
446 ZGT_CFA = defPrimWord("0>", () -> begin
447 pushPS(popPS() > 0 ? -1 : 0)
451 ZLE_CFA = defPrimWord("0<=", () -> begin
452 pushPS(popPS() <= 0 ? -1 : 0)
456 ZGE_CFA = defPrimWord("0>=", () -> begin
457 pushPS(popPS() >= 0 ? -1 : 0)
461 AND_CFA = defPrimWord("AND", () -> begin
468 OR_CFA = defPrimWord("OR", () -> begin
475 XOR_CFA = defPrimWord("XOR", () -> begin
482 INVERT_CFA = defPrimWord("INVERT", () -> begin
489 LIT_CFA = defPrimWord("LIT", () -> begin
497 STORE_CFA = defPrimWord("!", () -> begin
504 FETCH_CFA = defPrimWord("@", () -> begin
510 ADDSTORE_CFA = defPrimWord("+!", () -> begin
517 SUBSTORE_CFA = defPrimWord("-!", () -> begin
527 TOR_CFA = defPrimWord(">R", () -> begin
532 FROMR_CFA = defPrimWord("R>", () -> begin
537 RFETCH_CFA = defPrimWord("R@", () -> begin
542 RSPFETCH_CFA = defPrimWord("RSP@", () -> begin
547 RSPSTORE_CFA = defPrimWord("RSP!", () -> begin
552 RDROP_CFA = defPrimWord("RDROP", () -> begin
559 PSPFETCH_CFA = defPrimWord("PSP@", () -> begin
564 PSPSTORE_CFA = defPrimWord("PSP!", () -> begin
571 WFETCH_CFA = defPrimWord("W@", () -> begin
576 WSTORE_CFA = defPrimWord("W!", () -> begin
583 sources = Array{Any,1}()
584 currentSource() = sources[length(sources)]
586 EOF_CFA = defPrimWord("\x04", () -> begin
587 if currentSource() != STDIN
595 EMIT_CFA = defPrimWord("EMIT", () -> begin
600 function raw_mode!(mode::Bool)
601 if ccall(:jl_tty_set_mode, Int32, (Ptr{Void}, Int32), STDIN.handle, mode) != 0
602 throw("FATAL: Terminal unable to enter raw mode.")
608 byte = readbytes(STDIN, 1)[1]
620 KEY_CFA = defPrimWord("KEY", () -> begin
621 pushPS(Int(getKey()))
625 function getLineFromSTDIN()
632 return ASCIIString(line)
636 return string("\x04")
641 line = line[1:length(line)-1]
646 # Strip ANSI escape sequence
647 nextKey = Char(getKey())
650 nextKey = Char(getKey())
651 if nextKey >= '@' || nextKey <= '~'
659 line = string(line, key)
664 SPAN, SPAN_CFA = defNewVar("SPAN", 0)
665 EXPECT_CFA = defPrimWord("EXPECT", () -> begin
669 if currentSource() == STDIN
670 line = getLineFromSTDIN()
672 if !eof(currentSource())
673 line = chomp(readline(currentSource()))
679 mem[SPAN] = min(length(line), maxLen)
680 putString(line[1:mem[SPAN]], addr)
685 BASE, BASE_CFA = defNewVar("BASE", 10)
686 NUMBER_CFA = defPrimWord("NUMBER", () -> begin
688 wordLen = mem[wordAddr-1]
690 s = getString(wordAddr, wordLen)
692 pushPS(parse(Int64, s, mem[BASE]))
697 # Dictionary searches
699 LFATOCFA_CFA = defPrimWord("LFA>CFA", () -> begin
702 lenAndFlags = mem[addr+1]
703 len = lenAndFlags & F_LENMASK
705 pushPS(addr + 2 + len)
710 TOBODY_CFA = defWord(">BODY", [INCR_CFA, EXIT_CFA])
712 CONTEXT, CONTEXT_CFA = defNewVar("CONTEXT", zeros(Int64, 100))
713 mem[CONTEXT] = FORTH_CFA
714 NUMCONTEXT, NUMCONTEXT_CFA = defNewVar("#CONTEXT", 1)
716 FIND_CFA = defPrimWord("FIND", () -> begin
718 countedAddr = popPS()
719 wordAddr = countedAddr + 1
720 wordLen = mem[countedAddr]
721 word = lowercase(getString(wordAddr, wordLen))
723 context = mem[CONTEXT:(CONTEXT+mem[NUMCONTEXT]-1)]
728 for vocabCFA in reverse(context)
729 callPrim(mem[vocabCFA])
732 while (lfa = mem[lfa]) > 0
734 lenAndFlags = mem[lfa+1]
735 len = lenAndFlags & F_LENMASK
736 hidden = (lenAndFlags & F_HIDDEN) == F_HIDDEN
738 if hidden || len != wordLen
742 thisWord = lowercase(getString(lfa+2, len))
756 callPrim(mem[LFATOCFA_CFA])
757 if (lenAndFlags & F_IMMED) == F_IMMED
773 BRANCH_CFA = defPrimWord("BRANCH", () -> begin
774 reg.IP += mem[reg.IP]
778 ZBRANCH_CFA = defPrimWord("0BRANCH", () -> begin
780 reg.IP += mem[reg.IP]
790 LITSTRING_CFA = defPrimWord("LITSTRING", () -> begin
800 TYPE_CFA = defPrimWord("TYPE", () -> begin
803 str = getString(addr, len)
808 # Interpreter/Compiler-specific I/O
810 TIB_CFA = defConst("TIB", TIB)
811 NUMTIB, NUMTIB_CFA = defNewVar("#TIB", 0)
812 TOIN, TOIN_CFA = defNewVar(">IN", 0)
814 QUERY_CFA = defWord("QUERY",
815 [TIB_CFA, LIT_CFA, 160, EXPECT_CFA,
816 SPAN_CFA, FETCH_CFA, NUMTIB_CFA, STORE_CFA,
817 LIT_CFA, 0, TOIN_CFA, STORE_CFA,
820 WORD_CFA = defPrimWord("WORD", () -> begin
823 # Chew up initial occurrences of delim
824 while (mem[TOIN]<mem[NUMTIB] && mem[TIB+mem[TOIN]] == delim)
831 # Start reading in word
833 while (mem[TOIN]<mem[NUMTIB])
834 mem[addr] = mem[TIB+mem[TOIN]]
837 if (mem[addr] == delim)
846 mem[countAddr] = count
854 STATE, STATE_CFA = defNewVar("STATE", 0)
856 COMMA_CFA = defPrimWord(",", () -> begin
857 mem[mem[H]] = popPS()
863 HERE_CFA = defWord("HERE",
864 [H_CFA, FETCH_CFA, EXIT_CFA])
866 HEADER_CFA = defPrimWord("HEADER", () -> begin
868 wordLen = mem[wordAddr-1]
869 word = getString(wordAddr, wordLen)
871 createHeader(word, 0)
876 CREATE_CFA = defWord("CREATE",
877 [LIT_CFA, 32, WORD_CFA, HEADER_CFA,
878 LIT_CFA, DOVAR, COMMA_CFA,
881 DODOES = defPrim(() -> begin
888 DOES_HELPER_CFA = defPrimWord("(DOES>)", () -> begin
890 pushPS(mem[mem[CURRENT]])
891 callPrim(mem[LFATOCFA_CFA])
894 runtimeAddr = popPS()
896 mem[cfa] = defPrim(eval(:(() -> begin
897 pushPS($(runtimeAddr))
899 end)), name="doesPrim")
904 DOES_CFA = defWord("DOES>",
905 [LIT_CFA, LIT_CFA, COMMA_CFA, HERE_CFA, LIT_CFA, 3, ADD_CFA, COMMA_CFA,
906 LIT_CFA, DOES_HELPER_CFA, COMMA_CFA, LIT_CFA, EXIT_CFA, COMMA_CFA, EXIT_CFA],
909 LBRAC_CFA = defPrimWord("[", () -> begin
914 RBRAC_CFA = defPrimWord("]", () -> begin
919 HIDDEN_CFA = defPrimWord("HIDDEN", () -> begin
920 lenAndFlagsAddr = mem[mem[CURRENT]] + 1
921 mem[lenAndFlagsAddr] = mem[lenAndFlagsAddr] $ F_HIDDEN
925 COLON_CFA = defWord(":",
926 [LIT_CFA, 32, WORD_CFA,
928 LIT_CFA, DOCOL, COMMA_CFA,
933 SEMICOLON_CFA = defWord(";",
934 [LIT_CFA, EXIT_CFA, COMMA_CFA,
937 EXIT_CFA], flags=F_IMMED)
939 IMMEDIATE_CFA = defPrimWord("IMMEDIATE", () -> begin
940 lenAndFlagsAddr = mem[mem[CURRENT]] + 1
941 mem[lenAndFlagsAddr] = mem[lenAndFlagsAddr] $ F_IMMED
947 EXECUTE_CFA = defPrimWord("EXECUTE", () -> begin
952 INTERPRET_CFA = defWord("INTERPRET",
953 [LIT_CFA, 32, WORD_CFA, # Read next space-delimited word
955 DUP_CFA, FETCH_CFA, ZE_CFA, ZBRANCH_CFA, 3,
956 DROP_CFA, EXIT_CFA, # Exit if TIB is exhausted
958 STATE_CFA, FETCH_CFA, ZBRANCH_CFA, 24,
960 FIND_CFA, QDUP_CFA, ZBRANCH_CFA, 13,
963 LIT_CFA, -1, EQ_CFA, INVERT_CFA, ZBRANCH_CFA, 4,
965 # Immediate: Execute!
966 EXECUTE_CFA, BRANCH_CFA, -26,
968 # Not immediate: Compile!
969 COMMA_CFA, BRANCH_CFA, -29,
971 # No word found, parse number
972 NUMBER_CFA, LIT_CFA, LIT_CFA, COMMA_CFA, COMMA_CFA, BRANCH_CFA, -36,
975 FIND_CFA, QDUP_CFA, ZBRANCH_CFA, 5,
977 # Found word. Execute!
978 DROP_CFA, EXECUTE_CFA, BRANCH_CFA, -44,
980 # No word found, parse number and leave on stack
981 NUMBER_CFA, BRANCH_CFA, -47,
984 PROMPT_CFA = defPrimWord("PROMPT", () -> begin
985 if (mem[STATE] == 0 && currentSource() == STDIN)
992 QUIT_CFA = defWord("QUIT",
993 [LIT_CFA, 0, STATE_CFA, STORE_CFA,
994 LIT_CFA, 0, NUMTIB_CFA, STORE_CFA,
995 RSP0_CFA, RSPSTORE_CFA,
997 INTERPRET_CFA, PROMPT_CFA,
1000 ABORT_CFA = defWord("ABORT",
1001 [PSP0_CFA, PSPSTORE_CFA, QUIT_CFA])
1003 BYE_CFA = defPrimWord("BYE", () -> begin
1010 INCLUDE_CFA = defPrimWord("INCLUDE", () -> begin
1012 callPrim(mem[WORD_CFA])
1013 wordAddr = popPS()+1
1014 wordLen = mem[wordAddr-1]
1015 word = getString(wordAddr, wordLen)
1019 fname = Pkg.dir("forth","src",word)
1021 error("No file named $word found in current directory or package source directory.")
1024 push!(sources, open(fname, "r"))
1026 # Clear input buffer
1036 initFileName = nothing
1037 if isfile("lib.4th")
1038 initFileName = "lib.4th"
1039 elseif isfile(Pkg.dir("forth","src", "lib.4th"))
1040 initFileName = Pkg.dir("forth","src","lib.4th")
1043 function run(;initialize=true)
1044 # Begin with STDIN as source
1045 push!(sources, STDIN)
1047 global initialized, initFileName
1048 if !initialized && initialize
1049 if initFileName != nothing
1050 print("Including definitions from $initFileName...")
1051 push!(sources, open(initFileName, "r"))
1054 println("No library file found. Only primitive words available.")
1058 # Start with IP pointing to first instruction of outer interpreter
1059 reg.IP = QUIT_CFA + 1
1061 # Primitive processing loop.
1062 # Everyting else is simply a consequence of this loop!
1066 #println("Entering prim $(getPrimName(jmp))")
1070 showerror(STDOUT, ex)
1073 while !isempty(sources) && currentSource() != STDIN
1074 close(pop!(sources))
1078 reg.IP = ABORT_CFA + 1
1086 TRACE_CFA = defPrimWord("TRACE", () -> begin
1087 println("reg.W: $(reg.W) reg.IP: $(reg.IP)")
1088 print("PS: "); printPS()
1089 print("RS: "); printRS()
1096 function dump(startAddr::Int64; count::Int64 = 100, cellsPerLine::Int64 = 10)
1097 chars = Array{Char,1}(cellsPerLine)
1099 lineStartAddr = cellsPerLine*div((startAddr-1),cellsPerLine) + 1
1100 endAddr = startAddr + count - 1
1102 q, r = divrem((endAddr-lineStartAddr+1), cellsPerLine)
1103 numLines = q + (r > 0 ? 1 : 0)
1109 for c in 1:cellsPerLine
1110 if i >= startAddr && i <= endAddr
1112 if mem[i]>=32 && mem[i]<128
1113 chars[c] = Char(mem[i])
1125 println("\t", ASCIIString(chars))
1130 count = reg.PSP - PSP0
1134 for i in (PSP0+1):reg.PSP
1139 println("Parameter stack empty")
1144 count = reg.RSP - RSP0
1148 for i in (RSP0+1):reg.RSP
1153 println("Return stack empty")
1157 DUMP = defPrimWord("DUMP", () -> begin
1162 dump(addr, count=count)