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}()
16 # Memory geography and built-in variables
19 H = nextVarAddr; nextVarAddr += 1 # Next free memory address
20 FORTH_LATEST = nextVarAddr; nextVarAddr += 1 # FORTH dict latest
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 # zero FORTH dict latest (no previous def)
28 mem[CURRENT] = FORTH_LATEST-1 # 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 stringAsInts(str::ASCIIString) = [Int(c) for c in collect(str)]
89 # Primitive creation and calling functions
91 function defPrim(f::Function; name="nameless")
93 push!(primNames, replace(name, "\004", "EOF"))
95 return -length(primitives)
98 function callPrim(addr::Int64)
99 if addr >=0 || -addr>length(primitives)
100 error("Attempted to execute non-existent primitive at address $addr.")
105 getPrimName(addr::Int64) = primNames[-addr]
107 # Word creation functions
114 function dictWrite(ints::Array{Int64,1})
115 mem[mem[H]:(mem[H]+length(ints)-1)] = ints
116 mem[H] += length(ints)
118 dictWrite(int::Int64) = dictWrite([int])
119 dictWriteString(string::ASCIIString) = dictWrite([Int64(c) for c in string])
121 function createHeader(name::AbstractString, flags::Int64)
122 mem[mem[H]] = mem[mem[CURRENT]+1]
123 mem[mem[CURRENT]+1] = mem[H]
126 dictWrite(length(name) | flags | NFA_MARK)
127 dictWriteString(name)
130 function defPrimWord(name::AbstractString, f::Function; flags::Int64=0)
131 createHeader(name, flags)
133 codeWordAddr = mem[H]
134 dictWrite(defPrim(f, name=name))
139 function defWord(name::AbstractString, wordAddrs::Array{Int64,1}; flags::Int64=0)
140 createHeader(name, flags)
150 # Variable creation functions
152 function defExistingVar(name::AbstractString, varAddr::Int64; flags::Int64=0)
154 defPrimWord(name, eval(:(() -> begin
160 function defNewVar(name::AbstractString, initial::Array{Int64,1}; flags::Int64=0)
161 createHeader(name, flags)
163 codeWordAddr = mem[H]
169 return varAddr, codeWordAddr
172 defNewVar(name::AbstractString, initial::Int64; flags::Int64=0) =
173 defNewVar(name, [initial]; flags=flags)
175 function defConst(name::AbstractString, val::Int64; flags::Int64=0)
176 createHeader(name, flags)
178 codeWordAddr = mem[H]
186 # Threading Primitives (inner interpreter)
188 NEXT = defPrim(() -> begin
194 DOCOL = defPrim(() -> begin
200 DOVAR = defPrim(() -> begin
205 DOCON = defPrim(() -> begin
206 pushPS(mem[reg.W + 1])
210 EXIT_CFA = defPrimWord("EXIT", () -> begin
215 # Dictionary entries for core built-in variables, constants
217 H_CFA = defExistingVar("H", H)
219 PSP0_CFA = defConst("PSP0", PSP0)
220 RSP0_CFA = defConst("RSP0", RSP0)
222 defConst("DOCOL", DOCOL)
223 defConst("DOCON", DOCON)
224 defConst("DOVAR", DOVAR)
226 defConst("DICT", DICT)
227 defConst("MEMSIZE", size_mem)
229 F_IMMED_CFA = defConst("F_IMMED", F_IMMED)
230 F_HIDDEN_CFA = defConst("F_HIDDEN", F_HIDDEN)
231 F_LENMASK_CFA = defConst("F_LENMASK", F_LENMASK)
232 NFA_MARK_CFA = defConst("NFA_MARK", NFA_MARK)
234 # Basic forth primitives
236 DROP_CFA = defPrimWord("DROP", () -> begin
241 SWAP_CFA = defPrimWord("SWAP", () -> begin
249 DUP_CFA = defPrimWord("DUP", () -> begin
255 OVER_CFA = defPrimWord("OVER", () -> begin
257 pushPS(mem[reg.PSP-1])
261 ROT_CFA = defPrimWord("ROT", () -> begin
271 NROT_CFA = defPrimWord("-ROT", () -> begin
282 TWODROP_CFA = defPrimWord("2DROP", () -> begin
288 TWODUP_CFA = defPrimWord("2DUP", () -> begin
297 TWOSWAP_CFA = defPrimWord("2SWAP", () -> begin
309 TWOOVER_CFA = defPrimWord("2OVER", () -> begin
318 QDUP_CFA = defPrimWord("?DUP", () -> begin
327 INCR_CFA = defPrimWord("1+", () -> begin
333 DECR_CFA = defPrimWord("1-", () -> begin
339 INCR2_CFA = defPrimWord("2+", () -> begin
345 DECR2_CFA = defPrimWord("2-", () -> begin
351 ADD_CFA = defPrimWord("+", () -> begin
358 SUB_CFA = defPrimWord("-", () -> begin
365 MUL_CFA = defPrimWord("*", () -> begin
372 DIVMOD_CFA = defPrimWord("/MOD", () -> begin
381 TWOMUL_CFA = defPrimWord("2*", () -> begin
386 TWODIV_CFA = defPrimWord("2/", () -> begin
391 EQ_CFA = defPrimWord("=", () -> begin
394 pushPS(a==b ? -1 : 0)
398 NE_CFA = defPrimWord("<>", () -> begin
401 pushPS(a!=b ? -1 : 0)
405 LT_CFA = defPrimWord("<", () -> begin
412 GT_CFA = defPrimWord(">", () -> begin
419 LE_CFA = defPrimWord("<=", () -> begin
422 pushPS(a<=b ? -1 : 0)
426 GE_CFA = defPrimWord(">=", () -> begin
429 pushPS(a>=b ? -1 : 0)
433 ZE_CFA = defPrimWord("0=", () -> begin
434 pushPS(popPS() == 0 ? -1 : 0)
438 ZNE_CFA = defPrimWord("0<>", () -> begin
439 pushPS(popPS() != 0 ? -1 : 0)
443 ZLT_CFA = defPrimWord("0<", () -> begin
444 pushPS(popPS() < 0 ? -1 : 0)
448 ZGT_CFA = defPrimWord("0>", () -> begin
449 pushPS(popPS() > 0 ? -1 : 0)
453 ZLE_CFA = defPrimWord("0<=", () -> begin
454 pushPS(popPS() <= 0 ? -1 : 0)
458 ZGE_CFA = defPrimWord("0>=", () -> begin
459 pushPS(popPS() >= 0 ? -1 : 0)
463 AND_CFA = defPrimWord("AND", () -> begin
470 OR_CFA = defPrimWord("OR", () -> begin
477 XOR_CFA = defPrimWord("XOR", () -> begin
484 INVERT_CFA = defPrimWord("INVERT", () -> begin
491 LIT_CFA = defPrimWord("LIT", () -> begin
499 STORE_CFA = defPrimWord("!", () -> begin
506 FETCH_CFA = defPrimWord("@", () -> begin
512 ADDSTORE_CFA = defPrimWord("+!", () -> begin
519 SUBSTORE_CFA = defPrimWord("-!", () -> begin
529 TOR_CFA = defPrimWord(">R", () -> begin
534 FROMR_CFA = defPrimWord("R>", () -> begin
539 RFETCH_CFA = defPrimWord("R@", () -> begin
544 RSPFETCH_CFA = defPrimWord("RSP@", () -> begin
549 RSPSTORE_CFA = defPrimWord("RSP!", () -> begin
554 RDROP_CFA = defPrimWord("RDROP", () -> begin
561 PSPFETCH_CFA = defPrimWord("PSP@", () -> begin
566 PSPSTORE_CFA = defPrimWord("PSP!", () -> begin
573 WFETCH_CFA = defPrimWord("W@", () -> begin
578 WSTORE_CFA = defPrimWord("W!", () -> begin
585 sources = Array{Any,1}()
586 currentSource() = sources[length(sources)]
588 EOF_CFA = defPrimWord("\x04", () -> begin
589 if currentSource() != STDIN
597 EMIT_CFA = defPrimWord("EMIT", () -> begin
602 function raw_mode!(mode::Bool)
603 if ccall(:jl_tty_set_mode, Int32, (Ptr{Void}, Int32), STDIN.handle, mode) != 0
604 throw("FATAL: Terminal unable to enter raw mode.")
610 byte = readbytes(STDIN, 1)[1]
622 KEY_CFA = defPrimWord("KEY", () -> begin
623 pushPS(Int(getKey()))
627 function getLineFromSTDIN()
634 return ASCIIString(line)
638 return string("\x04")
643 line = line[1:length(line)-1]
648 # Strip ANSI escape sequence
649 nextKey = Char(getKey())
652 nextKey = Char(getKey())
653 if nextKey >= '@' || nextKey <= '~'
661 line = string(line, key)
666 SPAN, SPAN_CFA = defNewVar("SPAN", 0)
667 EXPECT_CFA = defPrimWord("EXPECT", () -> begin
671 if currentSource() == STDIN
672 line = getLineFromSTDIN()
674 if !eof(currentSource())
675 line = chomp(readline(currentSource()))
681 mem[SPAN] = min(length(line), maxLen)
682 putString(line[1:mem[SPAN]], addr)
687 BASE, BASE_CFA = defNewVar("BASE", 10)
688 NUMBER_CFA = defPrimWord("NUMBER", () -> begin
690 wordLen = mem[wordAddr-1]
692 s = getString(wordAddr, wordLen)
694 pushPS(parse(Int64, s, mem[BASE]))
699 # Dictionary searches
701 FROMLINK_CFA = defPrimWord("LINK>", () -> begin
704 lenAndFlags = mem[addr+1]
705 len = lenAndFlags & F_LENMASK
707 pushPS(addr + 2 + len)
712 NUMCONTEXT, NUMCONTEXT_CFA = defNewVar("#CONTEXT", 1)
714 createHeader("FORTH", 0)
716 dictWrite(defPrim(() -> begin
717 mem[CONTEXT + mem[NUMCONTEXT] - 1] = reg.W
720 dictWrite(0) # cell for latest
722 CURRENT_CFA = defExistingVar("CURRENT", CURRENT)
724 # Switch to new FORTH vocabulary cfa
725 mem[FORTH_CFA+1] = mem[mem[CURRENT]+1]
726 mem[CURRENT] = FORTH_CFA
728 CONTEXT, CONTEXT_CFA = defNewVar("CONTEXT", zeros(Int64, 10))
729 mem[CONTEXT] = FORTH_CFA
731 FINDVOCAB_CFA = defPrimWord("FINDVOCAB", () -> begin
733 countedAddr = popPS()
735 wordAddr = countedAddr + 1
736 wordLen = mem[countedAddr]
737 word = lowercase(getString(wordAddr, wordLen))
742 while (lfa = mem[lfa]) > 0
744 lenAndFlags = mem[lfa+1]
745 len = lenAndFlags & F_LENMASK
746 hidden = (lenAndFlags & F_HIDDEN) == F_HIDDEN
748 if hidden || len != wordLen
752 thisWord = lowercase(getString(lfa+2, len))
761 callPrim(mem[FROMLINK_CFA])
762 if (lenAndFlags & F_IMMED) == F_IMMED
775 FIND_CFA = defPrimWord("FIND", () -> begin
777 countedAddr = popPS()
778 context = mem[CONTEXT:(CONTEXT+mem[NUMCONTEXT]-1)]
780 for vocabCFA in reverse(context)
783 callPrim(mem[FINDVOCAB_CFA])
785 callPrim(mem[DUP_CFA])
803 BRANCH_CFA = defPrimWord("BRANCH", () -> begin
804 reg.IP += mem[reg.IP]
808 ZBRANCH_CFA = defPrimWord("0BRANCH", () -> begin
810 reg.IP += mem[reg.IP]
820 LITSTRING_CFA = defPrimWord("LITSTRING", () -> begin
830 TYPE_CFA = defPrimWord("TYPE", () -> begin
833 str = getString(addr, len)
838 # Interpreter/Compiler-specific I/O
840 TIB_CFA = defConst("TIB", TIB)
841 NUMTIB, NUMTIB_CFA = defNewVar("#TIB", 0)
842 TOIN, TOIN_CFA = defNewVar(">IN", 0)
844 QUERY_CFA = defWord("QUERY",
845 [TIB_CFA, LIT_CFA, 160, EXPECT_CFA,
846 SPAN_CFA, FETCH_CFA, NUMTIB_CFA, STORE_CFA,
847 LIT_CFA, 0, TOIN_CFA, STORE_CFA,
850 WORD_CFA = defPrimWord("WORD", () -> begin
853 # Chew up initial occurrences of delim
854 while (mem[TOIN]<mem[NUMTIB] && mem[TIB+mem[TOIN]] == delim)
861 # Start reading in word
863 while (mem[TOIN]<mem[NUMTIB])
864 mem[addr] = mem[TIB+mem[TOIN]]
867 if (mem[addr] == delim)
876 mem[countAddr] = count
884 STATE, STATE_CFA = defNewVar("STATE", 0)
886 COMMA_CFA = defPrimWord(",", () -> begin
887 mem[mem[H]] = popPS()
893 HERE_CFA = defWord("HERE",
894 [H_CFA, FETCH_CFA, EXIT_CFA])
896 HEADER_CFA = defPrimWord("HEADER", () -> begin
898 wordLen = mem[wordAddr-1]
899 word = getString(wordAddr, wordLen)
901 createHeader(word, 0)
906 CREATE_CFA = defWord("CREATE",
907 [LIT_CFA, 32, WORD_CFA, HEADER_CFA,
908 LIT_CFA, DOVAR, COMMA_CFA,
911 DODOES = defPrim(() -> begin
918 DOES_HELPER_CFA = defPrimWord("(DOES>)", () -> begin
920 pushPS(mem[mem[CURRENT]+1])
921 callPrim(mem[FROMLINK_CFA])
924 runtimeAddr = popPS()
926 mem[cfa] = defPrim(eval(:(() -> begin
927 pushPS($(runtimeAddr))
929 end)), name="doesPrim")
932 end, flags=F_IMMED | F_HIDDEN)
934 DOES_CFA = defWord("DOES>",
935 [LIT_CFA, LIT_CFA, COMMA_CFA, HERE_CFA, LIT_CFA, 3, ADD_CFA, COMMA_CFA,
936 LIT_CFA, DOES_HELPER_CFA, COMMA_CFA, LIT_CFA, EXIT_CFA, COMMA_CFA, EXIT_CFA],
939 LBRAC_CFA = defPrimWord("[", () -> begin
944 RBRAC_CFA = defPrimWord("]", () -> begin
949 HIDDEN_CFA = defPrimWord("HIDDEN", () -> begin
950 lenAndFlagsAddr = mem[mem[CURRENT]+1] + 1
951 mem[lenAndFlagsAddr] = mem[lenAndFlagsAddr] $ F_HIDDEN
955 COLON_CFA = defWord(":",
956 [LIT_CFA, 32, WORD_CFA,
958 LIT_CFA, DOCOL, COMMA_CFA,
963 SEMICOLON_CFA = defWord(";",
964 [LIT_CFA, EXIT_CFA, COMMA_CFA,
967 EXIT_CFA], flags=F_IMMED)
969 IMMEDIATE_CFA = defPrimWord("IMMEDIATE", () -> begin
970 lenAndFlagsAddr = mem[mem[CURRENT]+1] + 1
971 mem[lenAndFlagsAddr] = mem[lenAndFlagsAddr] $ F_IMMED
977 EXECUTE_CFA = defPrimWord("EXECUTE", () -> begin
982 INTERPRET_CFA = defWord("INTERPRET",
983 [LIT_CFA, 32, WORD_CFA, # Read next space-delimited word
985 DUP_CFA, FETCH_CFA, ZE_CFA, ZBRANCH_CFA, 3,
986 DROP_CFA, EXIT_CFA, # Exit if TIB is exhausted
988 STATE_CFA, FETCH_CFA, ZBRANCH_CFA, 24,
990 FIND_CFA, QDUP_CFA, ZBRANCH_CFA, 13,
993 LIT_CFA, -1, EQ_CFA, INVERT_CFA, ZBRANCH_CFA, 4,
995 # Immediate: Execute!
996 EXECUTE_CFA, BRANCH_CFA, -26,
998 # Not immediate: Compile!
999 COMMA_CFA, BRANCH_CFA, -29,
1001 # No word found, parse number
1002 NUMBER_CFA, LIT_CFA, LIT_CFA, COMMA_CFA, COMMA_CFA, BRANCH_CFA, -36,
1005 FIND_CFA, QDUP_CFA, ZBRANCH_CFA, 5,
1007 # Found word. Execute!
1008 DROP_CFA, EXECUTE_CFA, BRANCH_CFA, -44,
1010 # No word found, parse number and leave on stack
1011 NUMBER_CFA, BRANCH_CFA, -47,
1014 PROMPT_CFA = defPrimWord("PROMPT", () -> begin
1015 if currentSource() == STDIN
1025 QUIT_CFA = defWord("QUIT",
1026 [LIT_CFA, 0, STATE_CFA, STORE_CFA,
1027 LIT_CFA, 0, NUMTIB_CFA, STORE_CFA,
1028 RSP0_CFA, RSPSTORE_CFA,
1030 INTERPRET_CFA, PROMPT_CFA,
1033 ABORT_CFA = defWord("ABORT",
1034 [PSP0_CFA, PSPSTORE_CFA, QUIT_CFA])
1036 BYE_CFA = defPrimWord("BYE", () -> begin
1043 INCLUDE_CFA = defPrimWord("INCLUDE", () -> begin
1045 callPrim(mem[WORD_CFA])
1046 wordAddr = popPS()+1
1047 wordLen = mem[wordAddr-1]
1048 word = getString(wordAddr, wordLen)
1052 fname = Pkg.dir("forth","src",word)
1054 error("No file named $word found in current directory or package source directory.")
1057 push!(sources, open(fname, "r"))
1059 # Clear input buffer
1069 initFileName = nothing
1070 if isfile("lib.4th")
1071 initFileName = "lib.4th"
1072 elseif isfile(Pkg.dir("forth","src", "lib.4th"))
1073 initFileName = Pkg.dir("forth","src","lib.4th")
1076 function run(;initialize=true)
1077 # Begin with STDIN as source
1078 push!(sources, STDIN)
1080 global initialized, initFileName
1081 if !initialized && initialize
1082 if initFileName != nothing
1083 print("Including definitions from $initFileName...")
1084 push!(sources, open(initFileName, "r"))
1087 println("No library file found. Only primitive words available.")
1091 # Start with IP pointing to first instruction of outer interpreter
1092 reg.IP = QUIT_CFA + 1
1094 # Primitive processing loop.
1095 # Everyting else is simply a consequence of this loop!
1099 #println("Entering prim $(getPrimName(jmp))")
1103 showerror(STDOUT, ex)
1106 while !isempty(sources) && currentSource() != STDIN
1107 close(pop!(sources))
1111 reg.IP = ABORT_CFA + 1
1119 TRACE_CFA = defPrimWord("TRACE", () -> begin
1120 println("reg.W: $(reg.W) reg.IP: $(reg.IP)")
1121 print("PS: "); printPS()
1122 print("RS: "); printRS()
1129 function dump(startAddr::Int64; count::Int64 = 100, cellsPerLine::Int64 = 10)
1130 chars = Array{Char,1}(cellsPerLine)
1132 lineStartAddr = cellsPerLine*div((startAddr-1),cellsPerLine) + 1
1133 endAddr = startAddr + count - 1
1135 q, r = divrem((endAddr-lineStartAddr+1), cellsPerLine)
1136 numLines = q + (r > 0 ? 1 : 0)
1142 for c in 1:cellsPerLine
1143 if i >= startAddr && i <= endAddr
1145 if mem[i]>=32 && mem[i]<128
1146 chars[c] = Char(mem[i])
1158 println("\t", ASCIIString(chars))
1163 count = reg.PSP - PSP0
1167 for i in (PSP0+1):reg.PSP
1172 println("Parameter stack empty")
1177 count = reg.RSP - RSP0
1181 for i in (RSP0+1):reg.RSP
1186 println("Return stack empty")
1190 DUMP = defPrimWord("DUMP", () -> begin
1195 dump(addr, count=count)