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_LATEST = 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_LATEST] = 0 # no previous definition
28 mem[CURRENT] = FORTH_LATEST # 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 dictWrite(ints::Array{Int64,1})
113 mem[mem[H]:(mem[H]+length(ints)-1)] = ints
114 mem[H] += length(ints)
116 dictWrite(int::Int64) = dictWrite([int])
117 dictWriteString(string::ASCIIString) = dictWrite([Int64(c) for c in string])
119 function createHeader(name::AbstractString, flags::Int64)
120 mem[mem[H]] = mem[mem[CURRENT]]
121 mem[mem[CURRENT]] = mem[H]
124 dictWrite(length(name) | flags | NFA_MARK)
125 dictWriteString(name)
128 function defPrimWord(name::AbstractString, f::Function; flags::Int64=0)
129 createHeader(name, flags)
131 codeWordAddr = mem[H]
132 dictWrite(defPrim(f, name=name))
137 function defWord(name::AbstractString, wordAddrs::Array{Int64,1}; flags::Int64=0)
138 createHeader(name, flags)
148 # Variable creation functions
150 function defExistingVar(name::AbstractString, varAddr::Int64; flags::Int64=0)
152 defPrimWord(name, eval(:(() -> begin
158 function defNewVar(name::AbstractString, initial::Array{Int64,1}; flags::Int64=0)
159 createHeader(name, flags)
161 codeWordAddr = mem[H]
167 return varAddr, codeWordAddr
170 defNewVar(name::AbstractString, initial::Int64; flags::Int64=0) =
171 defNewVar(name, [initial]; flags=flags)
173 function defConst(name::AbstractString, val::Int64; flags::Int64=0)
174 createHeader(name, flags)
176 codeWordAddr = mem[H]
184 # Threading Primitives (inner interpreter)
186 NEXT = defPrim(() -> begin
192 DOCOL = defPrim(() -> begin
198 DOVAR = defPrim(() -> begin
203 DOCON = defPrim(() -> begin
204 pushPS(mem[reg.W + 1])
208 EXIT_CFA = defPrimWord("EXIT", () -> begin
213 # Dictionary entries for core built-in variables, constants
215 H_CFA = defExistingVar("H", H)
216 CURRENT_CFA = defExistingVar("CURRENT", CURRENT)
218 PSP0_CFA = defConst("PSP0", PSP0)
219 RSP0_CFA = defConst("RSP0", RSP0)
221 defConst("DOCOL", DOCOL)
222 defConst("DOCON", DOCON)
223 defConst("DOVAR", DOVAR)
225 defConst("DICT", DICT)
226 defConst("MEMSIZE", size_mem)
228 F_IMMED_CFA = defConst("F_IMMED", F_IMMED)
229 F_HIDDEN_CFA = defConst("F_HIDDEN", F_HIDDEN)
230 F_LENMASK_CFA = defConst("F_LENMASK", F_LENMASK)
231 NFA_MARK_CFA = defConst("NFA_MARK", NFA_MARK)
233 # Basic forth primitives
235 DROP_CFA = defPrimWord("DROP", () -> begin
240 SWAP_CFA = defPrimWord("SWAP", () -> begin
248 DUP_CFA = defPrimWord("DUP", () -> begin
254 OVER_CFA = defPrimWord("OVER", () -> begin
256 pushPS(mem[reg.PSP-1])
260 ROT_CFA = defPrimWord("ROT", () -> begin
270 NROT_CFA = defPrimWord("-ROT", () -> begin
281 TWODROP_CFA = defPrimWord("2DROP", () -> begin
287 TWODUP_CFA = defPrimWord("2DUP", () -> begin
296 TWOSWAP_CFA = defPrimWord("2SWAP", () -> begin
308 TWOOVER_CFA = defPrimWord("2OVER", () -> begin
317 QDUP_CFA = defPrimWord("?DUP", () -> begin
326 INCR_CFA = defPrimWord("1+", () -> begin
332 DECR_CFA = defPrimWord("1-", () -> begin
338 INCR2_CFA = defPrimWord("2+", () -> begin
344 DECR2_CFA = defPrimWord("2-", () -> begin
350 ADD_CFA = defPrimWord("+", () -> begin
357 SUB_CFA = defPrimWord("-", () -> begin
364 MUL_CFA = defPrimWord("*", () -> begin
371 DIVMOD_CFA = defPrimWord("/MOD", () -> begin
380 TWOMUL_CFA = defPrimWord("2*", () -> begin
385 TWODIV_CFA = defPrimWord("2/", () -> begin
390 EQ_CFA = defPrimWord("=", () -> begin
393 pushPS(a==b ? -1 : 0)
397 NE_CFA = defPrimWord("<>", () -> begin
400 pushPS(a!=b ? -1 : 0)
404 LT_CFA = defPrimWord("<", () -> begin
411 GT_CFA = defPrimWord(">", () -> begin
418 LE_CFA = defPrimWord("<=", () -> begin
421 pushPS(a<=b ? -1 : 0)
425 GE_CFA = defPrimWord(">=", () -> begin
428 pushPS(a>=b ? -1 : 0)
432 ZE_CFA = defPrimWord("0=", () -> begin
433 pushPS(popPS() == 0 ? -1 : 0)
437 ZNE_CFA = defPrimWord("0<>", () -> begin
438 pushPS(popPS() != 0 ? -1 : 0)
442 ZLT_CFA = defPrimWord("0<", () -> begin
443 pushPS(popPS() < 0 ? -1 : 0)
447 ZGT_CFA = defPrimWord("0>", () -> begin
448 pushPS(popPS() > 0 ? -1 : 0)
452 ZLE_CFA = defPrimWord("0<=", () -> begin
453 pushPS(popPS() <= 0 ? -1 : 0)
457 ZGE_CFA = defPrimWord("0>=", () -> begin
458 pushPS(popPS() >= 0 ? -1 : 0)
462 AND_CFA = defPrimWord("AND", () -> begin
469 OR_CFA = defPrimWord("OR", () -> begin
476 XOR_CFA = defPrimWord("XOR", () -> begin
483 INVERT_CFA = defPrimWord("INVERT", () -> begin
490 LIT_CFA = defPrimWord("LIT", () -> begin
498 STORE_CFA = defPrimWord("!", () -> begin
505 FETCH_CFA = defPrimWord("@", () -> begin
511 ADDSTORE_CFA = defPrimWord("+!", () -> begin
518 SUBSTORE_CFA = defPrimWord("-!", () -> begin
528 TOR_CFA = defPrimWord(">R", () -> begin
533 FROMR_CFA = defPrimWord("R>", () -> begin
538 RFETCH_CFA = defPrimWord("R@", () -> begin
543 RSPFETCH_CFA = defPrimWord("RSP@", () -> begin
548 RSPSTORE_CFA = defPrimWord("RSP!", () -> begin
553 RDROP_CFA = defPrimWord("RDROP", () -> begin
560 PSPFETCH_CFA = defPrimWord("PSP@", () -> begin
565 PSPSTORE_CFA = defPrimWord("PSP!", () -> begin
572 WFETCH_CFA = defPrimWord("W@", () -> begin
577 WSTORE_CFA = defPrimWord("W!", () -> begin
584 sources = Array{Any,1}()
585 currentSource() = sources[length(sources)]
587 EOF_CFA = defPrimWord("\x04", () -> begin
588 if currentSource() != STDIN
596 EMIT_CFA = defPrimWord("EMIT", () -> begin
601 function raw_mode!(mode::Bool)
602 if ccall(:jl_tty_set_mode, Int32, (Ptr{Void}, Int32), STDIN.handle, mode) != 0
603 throw("FATAL: Terminal unable to enter raw mode.")
609 byte = readbytes(STDIN, 1)[1]
621 KEY_CFA = defPrimWord("KEY", () -> begin
622 pushPS(Int(getKey()))
626 function getLineFromSTDIN()
633 return ASCIIString(line)
637 return string("\x04")
642 line = line[1:length(line)-1]
647 # Strip ANSI escape sequence
648 nextKey = Char(getKey())
651 nextKey = Char(getKey())
652 if nextKey >= '@' || nextKey <= '~'
660 line = string(line, key)
665 SPAN, SPAN_CFA = defNewVar("SPAN", 0)
666 EXPECT_CFA = defPrimWord("EXPECT", () -> begin
670 if currentSource() == STDIN
671 line = getLineFromSTDIN()
673 if !eof(currentSource())
674 line = chomp(readline(currentSource()))
680 mem[SPAN] = min(length(line), maxLen)
681 putString(line[1:mem[SPAN]], addr)
686 BASE, BASE_CFA = defNewVar("BASE", 10)
687 NUMBER_CFA = defPrimWord("NUMBER", () -> begin
689 wordLen = mem[wordAddr-1]
691 s = getString(wordAddr, wordLen)
693 pushPS(parse(Int64, s, mem[BASE]))
698 # Dictionary searches
700 FROMLINK_CFA = defPrimWord("LINK>", () -> begin
703 lenAndFlags = mem[addr+1]
704 len = lenAndFlags & F_LENMASK
706 pushPS(addr + 2 + len)
711 createHeader("FORTH", 0)
713 dictWrite(defPrim(() -> begin
717 dictWrite(FORTH_LATEST)
719 CONTEXT, CONTEXT_CFA = defNewVar("CONTEXT", zeros(Int64, 100))
720 mem[CONTEXT] = FORTH_CFA
721 NUMCONTEXT, NUMCONTEXT_CFA = defNewVar("#CONTEXT", 1)
723 FIND_CFA = defPrimWord("FIND", () -> begin
725 countedAddr = popPS()
726 wordAddr = countedAddr + 1
727 wordLen = mem[countedAddr]
728 word = lowercase(getString(wordAddr, wordLen))
730 context = mem[CONTEXT:(CONTEXT+mem[NUMCONTEXT]-1)]
735 for vocabCFA in reverse(context)
736 lfa = mem[vocabCFA+1]
738 while (lfa = mem[lfa]) > 0
740 lenAndFlags = mem[lfa+1]
741 len = lenAndFlags & F_LENMASK
742 hidden = (lenAndFlags & F_HIDDEN) == F_HIDDEN
744 if hidden || len != wordLen
748 thisWord = lowercase(getString(lfa+2, len))
762 callPrim(mem[FROMLINK_CFA])
763 if (lenAndFlags & F_IMMED) == F_IMMED
779 BRANCH_CFA = defPrimWord("BRANCH", () -> begin
780 reg.IP += mem[reg.IP]
784 ZBRANCH_CFA = defPrimWord("0BRANCH", () -> begin
786 reg.IP += mem[reg.IP]
796 LITSTRING_CFA = defPrimWord("LITSTRING", () -> begin
806 TYPE_CFA = defPrimWord("TYPE", () -> begin
809 str = getString(addr, len)
814 # Interpreter/Compiler-specific I/O
816 TIB_CFA = defConst("TIB", TIB)
817 NUMTIB, NUMTIB_CFA = defNewVar("#TIB", 0)
818 TOIN, TOIN_CFA = defNewVar(">IN", 0)
820 QUERY_CFA = defWord("QUERY",
821 [TIB_CFA, LIT_CFA, 160, EXPECT_CFA,
822 SPAN_CFA, FETCH_CFA, NUMTIB_CFA, STORE_CFA,
823 LIT_CFA, 0, TOIN_CFA, STORE_CFA,
826 WORD_CFA = defPrimWord("WORD", () -> begin
829 # Chew up initial occurrences of delim
830 while (mem[TOIN]<mem[NUMTIB] && mem[TIB+mem[TOIN]] == delim)
837 # Start reading in word
839 while (mem[TOIN]<mem[NUMTIB])
840 mem[addr] = mem[TIB+mem[TOIN]]
843 if (mem[addr] == delim)
852 mem[countAddr] = count
860 STATE, STATE_CFA = defNewVar("STATE", 0)
862 COMMA_CFA = defPrimWord(",", () -> begin
863 mem[mem[H]] = popPS()
869 HERE_CFA = defWord("HERE",
870 [H_CFA, FETCH_CFA, EXIT_CFA])
872 HEADER_CFA = defPrimWord("HEADER", () -> begin
874 wordLen = mem[wordAddr-1]
875 word = getString(wordAddr, wordLen)
877 createHeader(word, 0)
882 CREATE_CFA = defWord("CREATE",
883 [LIT_CFA, 32, WORD_CFA, HEADER_CFA,
884 LIT_CFA, DOVAR, COMMA_CFA,
887 DODOES = defPrim(() -> begin
894 DOES_HELPER_CFA = defPrimWord("(DOES>)", () -> begin
896 pushPS(mem[mem[CURRENT]])
897 callPrim(mem[FROMLINK_CFA])
900 runtimeAddr = popPS()
902 mem[cfa] = defPrim(eval(:(() -> begin
903 pushPS($(runtimeAddr))
905 end)), name="doesPrim")
908 end, flags=F_IMMED | F_HIDDEN)
910 DOES_CFA = defWord("DOES>",
911 [LIT_CFA, LIT_CFA, COMMA_CFA, HERE_CFA, LIT_CFA, 3, ADD_CFA, COMMA_CFA,
912 LIT_CFA, DOES_HELPER_CFA, COMMA_CFA, LIT_CFA, EXIT_CFA, COMMA_CFA, EXIT_CFA],
915 LBRAC_CFA = defPrimWord("[", () -> begin
920 RBRAC_CFA = defPrimWord("]", () -> begin
925 HIDDEN_CFA = defPrimWord("HIDDEN", () -> begin
926 lenAndFlagsAddr = mem[mem[CURRENT]] + 1
927 mem[lenAndFlagsAddr] = mem[lenAndFlagsAddr] $ F_HIDDEN
931 COLON_CFA = defWord(":",
932 [LIT_CFA, 32, WORD_CFA,
934 LIT_CFA, DOCOL, COMMA_CFA,
939 SEMICOLON_CFA = defWord(";",
940 [LIT_CFA, EXIT_CFA, COMMA_CFA,
943 EXIT_CFA], flags=F_IMMED)
945 IMMEDIATE_CFA = defPrimWord("IMMEDIATE", () -> begin
946 lenAndFlagsAddr = mem[mem[CURRENT]] + 1
947 mem[lenAndFlagsAddr] = mem[lenAndFlagsAddr] $ F_IMMED
953 EXECUTE_CFA = defPrimWord("EXECUTE", () -> begin
958 INTERPRET_CFA = defWord("INTERPRET",
959 [LIT_CFA, 32, WORD_CFA, # Read next space-delimited word
961 DUP_CFA, FETCH_CFA, ZE_CFA, ZBRANCH_CFA, 3,
962 DROP_CFA, EXIT_CFA, # Exit if TIB is exhausted
964 STATE_CFA, FETCH_CFA, ZBRANCH_CFA, 24,
966 FIND_CFA, QDUP_CFA, ZBRANCH_CFA, 13,
969 LIT_CFA, -1, EQ_CFA, INVERT_CFA, ZBRANCH_CFA, 4,
971 # Immediate: Execute!
972 EXECUTE_CFA, BRANCH_CFA, -26,
974 # Not immediate: Compile!
975 COMMA_CFA, BRANCH_CFA, -29,
977 # No word found, parse number
978 NUMBER_CFA, LIT_CFA, LIT_CFA, COMMA_CFA, COMMA_CFA, BRANCH_CFA, -36,
981 FIND_CFA, QDUP_CFA, ZBRANCH_CFA, 5,
983 # Found word. Execute!
984 DROP_CFA, EXECUTE_CFA, BRANCH_CFA, -44,
986 # No word found, parse number and leave on stack
987 NUMBER_CFA, BRANCH_CFA, -47,
990 PROMPT_CFA = defPrimWord("PROMPT", () -> begin
991 if (mem[STATE] == 0 && currentSource() == STDIN)
998 QUIT_CFA = defWord("QUIT",
999 [LIT_CFA, 0, STATE_CFA, STORE_CFA,
1000 LIT_CFA, 0, NUMTIB_CFA, STORE_CFA,
1001 RSP0_CFA, RSPSTORE_CFA,
1003 INTERPRET_CFA, PROMPT_CFA,
1006 ABORT_CFA = defWord("ABORT",
1007 [PSP0_CFA, PSPSTORE_CFA, QUIT_CFA])
1009 BYE_CFA = defPrimWord("BYE", () -> begin
1016 INCLUDE_CFA = defPrimWord("INCLUDE", () -> begin
1018 callPrim(mem[WORD_CFA])
1019 wordAddr = popPS()+1
1020 wordLen = mem[wordAddr-1]
1021 word = getString(wordAddr, wordLen)
1025 fname = Pkg.dir("forth","src",word)
1027 error("No file named $word found in current directory or package source directory.")
1030 push!(sources, open(fname, "r"))
1032 # Clear input buffer
1042 initFileName = nothing
1043 if isfile("lib.4th")
1044 initFileName = "lib.4th"
1045 elseif isfile(Pkg.dir("forth","src", "lib.4th"))
1046 initFileName = Pkg.dir("forth","src","lib.4th")
1049 function run(;initialize=true)
1050 # Begin with STDIN as source
1051 push!(sources, STDIN)
1053 global initialized, initFileName
1054 if !initialized && initialize
1055 if initFileName != nothing
1056 print("Including definitions from $initFileName...")
1057 push!(sources, open(initFileName, "r"))
1060 println("No library file found. Only primitive words available.")
1064 # Start with IP pointing to first instruction of outer interpreter
1065 reg.IP = QUIT_CFA + 1
1067 # Primitive processing loop.
1068 # Everyting else is simply a consequence of this loop!
1072 #println("Entering prim $(getPrimName(jmp))")
1076 showerror(STDOUT, ex)
1079 while !isempty(sources) && currentSource() != STDIN
1080 close(pop!(sources))
1084 reg.IP = ABORT_CFA + 1
1092 TRACE_CFA = defPrimWord("TRACE", () -> begin
1093 println("reg.W: $(reg.W) reg.IP: $(reg.IP)")
1094 print("PS: "); printPS()
1095 print("RS: "); printRS()
1102 function dump(startAddr::Int64; count::Int64 = 100, cellsPerLine::Int64 = 10)
1103 chars = Array{Char,1}(cellsPerLine)
1105 lineStartAddr = cellsPerLine*div((startAddr-1),cellsPerLine) + 1
1106 endAddr = startAddr + count - 1
1108 q, r = divrem((endAddr-lineStartAddr+1), cellsPerLine)
1109 numLines = q + (r > 0 ? 1 : 0)
1115 for c in 1:cellsPerLine
1116 if i >= startAddr && i <= endAddr
1118 if mem[i]>=32 && mem[i]<128
1119 chars[c] = Char(mem[i])
1131 println("\t", ASCIIString(chars))
1136 count = reg.PSP - PSP0
1140 for i in (PSP0+1):reg.PSP
1145 println("Parameter stack empty")
1150 count = reg.RSP - RSP0
1154 for i in (RSP0+1):reg.RSP
1159 println("Return stack empty")
1163 DUMP = defPrimWord("DUMP", () -> begin
1168 dump(addr, count=count)