3 import Base.REPLCompletions
6 size_mem = 1000000 # 1 mega-int
9 size_RS = 1000 # Return stack size
10 size_PS = 1000 # Parameter stack size
11 size_TIB = 1000 # Terminal input buffer size
14 mem = Array{Int64,1}(size_mem)
15 primitives = Array{Function,1}()
16 primNames = Array{AbstractString,1}()
18 # Memory geography and built-in variables
21 H = nextVarAddr; nextVarAddr += 1 # Next free memory address
22 FORTH_LATEST = nextVarAddr; nextVarAddr += 1 # FORTH dict latest
23 CURRENT = nextVarAddr; nextVarAddr += 1 # Current compilation dict
25 RSP0 = nextVarAddr # bottom of RS
26 PSP0 = RSP0 + size_RS # bottom of PS
27 TIB = PSP0 + size_PS # address of terminal input buffer
28 mem[H] = TIB + size_TIB # location of bottom of dictionary
29 mem[FORTH_LATEST] = 0 # zero FORTH dict latest (no previous def)
30 mem[CURRENT] = FORTH_LATEST-1 # Compile words to system dict initially
32 DICT = mem[H] # Save bottom of dictionary as constant
36 RSP::Int64 # Return stack pointer
37 PSP::Int64 # Parameter/data stack pointer
38 IP::Int64 # Instruction pointer
39 W::Int64 # Working register
41 reg = Reg(RSP0, PSP0, 0, 0)
43 # Stack manipulation functions
45 function ensurePSDepth(depth::Int64)
46 if reg.PSP - PSP0 < depth
47 error("Parameter stack underflow.")
51 function ensureRSDepth(depth::Int64)
52 if reg.RSP - RSP0 < depth
53 error("Return stack underflow.")
57 function pushRS(val::Int64)
69 function pushPS(val::Int64)
70 mem[reg.PSP += 1] = val
81 # Handy functions for adding/retrieving strings to/from memory.
83 getString(addr::Int64, len::Int64) = AbstractString([Char(c) for c in mem[addr:(addr+len-1)]])
85 function putString(str::AbstractString, addr::Int64, maxLen::Int64)
86 len = min(length(str), maxLen)
87 mem[addr:(addr+len-1)] = [Int64(c) for c in str]
90 stringAsInts(str::AbstractString) = [Int(c) for c in collect(str)]
92 # Primitive creation and calling functions
94 function defPrim(f::Function; name="nameless")
96 push!(primNames, replace(name, "\004", "EOF"))
98 return -length(primitives)
101 function callPrim(addr::Int64)
102 if addr >=0 || -addr>length(primitives)
103 error("Attempted to execute non-existent primitive at address $addr.")
108 getPrimName(addr::Int64) = primNames[-addr]
110 # Word creation functions
117 function dictWrite(ints::Array{Int64,1})
118 mem[mem[H]:(mem[H]+length(ints)-1)] = ints
119 mem[H] += length(ints)
121 dictWrite(int::Int64) = dictWrite([int])
122 dictWriteString(string::AbstractString) = dictWrite([Int64(c) for c in string])
124 function createHeader(name::AbstractString, flags::Int64)
125 mem[mem[H]] = mem[mem[CURRENT]+1]
126 mem[mem[CURRENT]+1] = mem[H]
129 dictWrite(length(name) | flags | NFA_MARK)
130 dictWriteString(name)
133 function defPrimWord(name::AbstractString, f::Function; flags::Int64=0)
134 createHeader(name, flags)
136 codeWordAddr = mem[H]
137 dictWrite(defPrim(f, name=name))
142 function defWord(name::AbstractString, wordAddrs::Array{Int64,1}; flags::Int64=0)
143 createHeader(name, flags)
153 # Variable creation functions
155 function defExistingVar(name::AbstractString, varAddr::Int64; flags::Int64=0)
157 defPrimWord(name, eval(:(() -> begin
163 function defNewVar(name::AbstractString, initial::Array{Int64,1}; flags::Int64=0)
164 createHeader(name, flags)
166 codeWordAddr = mem[H]
172 return varAddr, codeWordAddr
175 defNewVar(name::AbstractString, initial::Int64; flags::Int64=0) =
176 defNewVar(name, [initial]; flags=flags)
178 function defConst(name::AbstractString, val::Int64; flags::Int64=0)
179 createHeader(name, flags)
181 codeWordAddr = mem[H]
189 # Threading Primitives (inner interpreter)
191 NEXT = defPrim(() -> begin
197 DOCOL = defPrim(() -> begin
203 DOVAR = defPrim(() -> begin
208 DOCON = defPrim(() -> begin
209 pushPS(mem[reg.W + 1])
213 EXIT_CFA = defPrimWord("EXIT", () -> begin
218 # Dictionary entries for core built-in variables, constants
220 H_CFA = defExistingVar("H", H)
222 PSP0_CFA = defConst("PSP0", PSP0)
223 RSP0_CFA = defConst("RSP0", RSP0)
225 defConst("DOCOL", DOCOL)
226 defConst("DOCON", DOCON)
227 defConst("DOVAR", DOVAR)
229 defConst("DICT", DICT)
230 defConst("MEMSIZE", size_mem)
232 F_IMMED_CFA = defConst("F_IMMED", F_IMMED)
233 F_HIDDEN_CFA = defConst("F_HIDDEN", F_HIDDEN)
234 F_LENMASK_CFA = defConst("F_LENMASK", F_LENMASK)
235 NFA_MARK_CFA = defConst("NFA_MARK", NFA_MARK)
237 # Basic forth primitives
239 DROP_CFA = defPrimWord("DROP", () -> begin
244 SWAP_CFA = defPrimWord("SWAP", () -> begin
252 DUP_CFA = defPrimWord("DUP", () -> begin
258 OVER_CFA = defPrimWord("OVER", () -> begin
260 pushPS(mem[reg.PSP-1])
264 ROT_CFA = defPrimWord("ROT", () -> begin
274 NROT_CFA = defPrimWord("-ROT", () -> begin
285 TWODROP_CFA = defPrimWord("2DROP", () -> begin
291 TWODUP_CFA = defPrimWord("2DUP", () -> begin
300 TWOSWAP_CFA = defPrimWord("2SWAP", () -> begin
312 TWOOVER_CFA = defPrimWord("2OVER", () -> begin
321 QDUP_CFA = defPrimWord("?DUP", () -> begin
330 INCR_CFA = defPrimWord("1+", () -> begin
336 DECR_CFA = defPrimWord("1-", () -> begin
342 INCR2_CFA = defPrimWord("2+", () -> begin
348 DECR2_CFA = defPrimWord("2-", () -> begin
354 ADD_CFA = defPrimWord("+", () -> begin
361 SUB_CFA = defPrimWord("-", () -> begin
368 MUL_CFA = defPrimWord("*", () -> begin
375 DIVMOD_CFA = defPrimWord("/MOD", () -> begin
384 TWOMUL_CFA = defPrimWord("2*", () -> begin
389 TWODIV_CFA = defPrimWord("2/", () -> begin
394 EQ_CFA = defPrimWord("=", () -> begin
397 pushPS(a==b ? -1 : 0)
401 NE_CFA = defPrimWord("<>", () -> begin
404 pushPS(a!=b ? -1 : 0)
408 LT_CFA = defPrimWord("<", () -> begin
415 GT_CFA = defPrimWord(">", () -> begin
422 LE_CFA = defPrimWord("<=", () -> begin
425 pushPS(a<=b ? -1 : 0)
429 GE_CFA = defPrimWord(">=", () -> begin
432 pushPS(a>=b ? -1 : 0)
436 ZE_CFA = defPrimWord("0=", () -> begin
437 pushPS(popPS() == 0 ? -1 : 0)
441 ZNE_CFA = defPrimWord("0<>", () -> begin
442 pushPS(popPS() != 0 ? -1 : 0)
446 ZLT_CFA = defPrimWord("0<", () -> begin
447 pushPS(popPS() < 0 ? -1 : 0)
451 ZGT_CFA = defPrimWord("0>", () -> begin
452 pushPS(popPS() > 0 ? -1 : 0)
456 ZLE_CFA = defPrimWord("0<=", () -> begin
457 pushPS(popPS() <= 0 ? -1 : 0)
461 ZGE_CFA = defPrimWord("0>=", () -> begin
462 pushPS(popPS() >= 0 ? -1 : 0)
466 AND_CFA = defPrimWord("AND", () -> begin
473 OR_CFA = defPrimWord("OR", () -> begin
480 XOR_CFA = defPrimWord("XOR", () -> begin
487 INVERT_CFA = defPrimWord("INVERT", () -> begin
494 LIT_CFA = defPrimWord("LIT", () -> begin
502 STORE_CFA = defPrimWord("!", () -> begin
509 FETCH_CFA = defPrimWord("@", () -> begin
515 ADDSTORE_CFA = defPrimWord("+!", () -> begin
522 SUBSTORE_CFA = defPrimWord("-!", () -> begin
532 TOR_CFA = defPrimWord(">R", () -> begin
537 FROMR_CFA = defPrimWord("R>", () -> begin
542 RFETCH_CFA = defPrimWord("R@", () -> begin
547 RSPFETCH_CFA = defPrimWord("RSP@", () -> begin
552 RSPSTORE_CFA = defPrimWord("RSP!", () -> begin
557 RDROP_CFA = defPrimWord("RDROP", () -> begin
564 PSPFETCH_CFA = defPrimWord("PSP@", () -> begin
569 PSPSTORE_CFA = defPrimWord("PSP!", () -> begin
576 WFETCH_CFA = defPrimWord("W@", () -> begin
581 WSTORE_CFA = defPrimWord("W!", () -> begin
588 sources = Array{Any,1}()
589 currentSource() = sources[length(sources)]
591 CLOSEFILES_CFA = defPrimWord("CLOSEFILES", () -> begin
592 while currentSource() != STDIN
599 EOF_CFA = defPrimWord("\x04", () -> begin
600 if currentSource() != STDIN
608 EMIT_CFA = defPrimWord("EMIT", () -> begin
613 function raw_mode!(mode::Bool)
614 if ccall(:jl_tty_set_mode, Int32, (Ptr{Void}, Int32), STDIN.handle, mode) != 0
615 throw("FATAL: Terminal unable to enter raw mode.")
621 byte = readbytes(STDIN, 1)[1]
633 KEY_CFA = defPrimWord("KEY", () -> begin
634 pushPS(Int(getKey()))
638 function getLineFromSTDIN()
642 slashIdx = findlast(chars, '\\')
645 return join(chars[slashIdx:length(chars)])
651 function backspaceStr(s, bsCount)
653 newLen = max(0, oldLen - bsCount)
654 return join(collect(s)[1:newLen])
663 return AbstractString(line)
667 return string("\x04")
673 line = backspaceStr(line, 1)
677 # Strip ANSI escape sequence
678 nextKey = Char(getKey())
681 nextKey = Char(getKey())
682 if nextKey >= '@' || nextKey <= '~'
689 # Currently do nothing
693 if haskey(REPLCompletions.latex_symbols, frag)
694 print(repeat("\b", length(frag)))
696 comp = REPLCompletions.latex_symbols[frag]
697 line = string(backspaceStr(line, length(frag)), comp)
704 line = string(line, key)
709 SPAN, SPAN_CFA = defNewVar("SPAN", 0)
710 EXPECT_CFA = defPrimWord("EXPECT", () -> begin
714 if currentSource() == STDIN
715 line = getLineFromSTDIN()
717 if !eof(currentSource())
718 line = chomp(readline(currentSource()))
724 mem[SPAN] = min(length(line), maxLen)
725 putString(line, addr, maxLen)
730 BASE, BASE_CFA = defNewVar("BASE", 10)
731 NUMBER_CFA = defPrimWord("NUMBER", () -> begin
733 wordLen = mem[wordAddr-1]
735 s = getString(wordAddr, wordLen)
737 pushPS(parse(Int64, s, mem[BASE]))
742 # Dictionary searches
744 FROMLINK_CFA = defPrimWord("LINK>", () -> begin
747 lenAndFlags = mem[addr+1]
748 len = lenAndFlags & F_LENMASK
750 pushPS(addr + 2 + len)
755 NUMCONTEXT, NUMCONTEXT_CFA = defNewVar("#CONTEXT", 1)
757 createHeader("FORTH", 0)
759 dictWrite(defPrim(() -> begin
760 mem[CONTEXT + mem[NUMCONTEXT] - 1] = reg.W
763 dictWrite(0) # cell for latest
765 CURRENT_CFA = defExistingVar("CURRENT", CURRENT)
767 # Switch to new FORTH vocabulary cfa
768 mem[FORTH_CFA+1] = mem[mem[CURRENT]+1]
769 mem[CURRENT] = FORTH_CFA
771 CONTEXT, CONTEXT_CFA = defNewVar("CONTEXT", zeros(Int64, 10))
772 mem[CONTEXT] = FORTH_CFA
774 FINDVOCAB_CFA = defPrimWord("FINDVOCAB", () -> begin
776 countedAddr = popPS()
778 wordAddr = countedAddr + 1
779 wordLen = mem[countedAddr]
780 word = lowercase(getString(wordAddr, wordLen))
785 while (lfa = mem[lfa]) > 0
787 lenAndFlags = mem[lfa+1]
788 len = lenAndFlags & F_LENMASK
789 hidden = (lenAndFlags & F_HIDDEN) == F_HIDDEN
791 if hidden || len != wordLen
795 thisWord = lowercase(getString(lfa+2, len))
804 callPrim(mem[FROMLINK_CFA])
805 if (lenAndFlags & F_IMMED) == F_IMMED
818 FIND_CFA = defPrimWord("FIND", () -> begin
820 countedAddr = popPS()
821 context = mem[CONTEXT:(CONTEXT+mem[NUMCONTEXT]-1)]
823 for vocabCFA in reverse(context)
826 callPrim(mem[FINDVOCAB_CFA])
828 callPrim(mem[DUP_CFA])
846 BRANCH_CFA = defPrimWord("BRANCH", () -> begin
847 reg.IP += mem[reg.IP]
851 ZBRANCH_CFA = defPrimWord("0BRANCH", () -> begin
853 reg.IP += mem[reg.IP]
863 LITSTRING_CFA = defPrimWord("LITSTRING", () -> begin
873 TYPE_CFA = defPrimWord("TYPE", () -> begin
876 str = getString(addr, len)
881 # Interpreter/Compiler-specific I/O
883 TIB_CFA = defConst("TIB", TIB)
884 NUMTIB, NUMTIB_CFA = defNewVar("#TIB", 0)
885 TOIN, TOIN_CFA = defNewVar(">IN", 0)
887 QUERY_CFA = defWord("QUERY",
888 [TIB_CFA, LIT_CFA, 160, EXPECT_CFA,
889 SPAN_CFA, FETCH_CFA, NUMTIB_CFA, STORE_CFA,
890 LIT_CFA, 0, TOIN_CFA, STORE_CFA,
893 WORD_CFA = defPrimWord("WORD", () -> begin
896 # Chew up initial occurrences of delim
897 while (mem[TOIN]<mem[NUMTIB] && mem[TIB+mem[TOIN]] == delim)
904 # Start reading in word
906 while (mem[TOIN]<mem[NUMTIB])
907 mem[addr] = mem[TIB+mem[TOIN]]
910 if (mem[addr] == delim)
919 mem[countAddr] = count
927 STATE, STATE_CFA = defNewVar("STATE", 0)
929 COMMA_CFA = defPrimWord(",", () -> begin
930 mem[mem[H]] = popPS()
936 HERE_CFA = defWord("HERE",
937 [H_CFA, FETCH_CFA, EXIT_CFA])
939 HEADER_CFA = defPrimWord("HEADER", () -> begin
941 wordLen = mem[wordAddr-1]
942 word = getString(wordAddr, wordLen)
944 createHeader(word, 0)
949 CREATE_CFA = defWord("CREATE",
950 [LIT_CFA, 32, WORD_CFA, HEADER_CFA,
951 LIT_CFA, DOVAR, COMMA_CFA,
954 DODOES = defPrim(() -> begin
961 DOES_HELPER_CFA = defPrimWord("(DOES>)", () -> begin
963 pushPS(mem[mem[CURRENT]+1])
964 callPrim(mem[FROMLINK_CFA])
967 runtimeAddr = popPS()
969 mem[cfa] = defPrim(eval(:(() -> begin
970 pushPS($(runtimeAddr))
972 end)), name="doesPrim")
975 end, flags=F_IMMED | F_HIDDEN)
977 DOES_CFA = defWord("DOES>",
978 [LIT_CFA, LIT_CFA, COMMA_CFA, HERE_CFA, LIT_CFA, 3, ADD_CFA, COMMA_CFA,
979 LIT_CFA, DOES_HELPER_CFA, COMMA_CFA, LIT_CFA, EXIT_CFA, COMMA_CFA, EXIT_CFA],
982 LBRAC_CFA = defPrimWord("[", () -> begin
987 RBRAC_CFA = defPrimWord("]", () -> begin
992 HIDDEN_CFA = defPrimWord("HIDDEN", () -> begin
993 lenAndFlagsAddr = mem[mem[CURRENT]+1] + 1
994 mem[lenAndFlagsAddr] = mem[lenAndFlagsAddr] $ F_HIDDEN
998 COLON_CFA = defWord(":",
999 [LIT_CFA, 32, WORD_CFA,
1001 LIT_CFA, DOCOL, COMMA_CFA,
1006 SEMICOLON_CFA = defWord(";",
1007 [LIT_CFA, EXIT_CFA, COMMA_CFA,
1010 EXIT_CFA], flags=F_IMMED)
1012 IMMEDIATE_CFA = defPrimWord("IMMEDIATE", () -> begin
1013 lenAndFlagsAddr = mem[mem[CURRENT]+1] + 1
1014 mem[lenAndFlagsAddr] = mem[lenAndFlagsAddr] $ F_IMMED
1020 EXECUTE_CFA = defPrimWord("EXECUTE", () -> begin
1025 INTERPRET_CFA = defWord("INTERPRET",
1026 [LIT_CFA, 32, WORD_CFA, # Read next space-delimited word
1028 DUP_CFA, FETCH_CFA, ZE_CFA, ZBRANCH_CFA, 3,
1029 DROP_CFA, EXIT_CFA, # Exit if TIB is exhausted
1031 STATE_CFA, FETCH_CFA, ZBRANCH_CFA, 24,
1033 FIND_CFA, QDUP_CFA, ZBRANCH_CFA, 13,
1036 LIT_CFA, -1, EQ_CFA, INVERT_CFA, ZBRANCH_CFA, 4,
1038 # Immediate: Execute!
1039 EXECUTE_CFA, BRANCH_CFA, -26,
1041 # Not immediate: Compile!
1042 COMMA_CFA, BRANCH_CFA, -29,
1044 # No word found, parse number
1045 NUMBER_CFA, LIT_CFA, LIT_CFA, COMMA_CFA, COMMA_CFA, BRANCH_CFA, -36,
1048 FIND_CFA, QDUP_CFA, ZBRANCH_CFA, 5,
1050 # Found word. Execute!
1051 DROP_CFA, EXECUTE_CFA, BRANCH_CFA, -44,
1053 # No word found, parse number and leave on stack
1054 NUMBER_CFA, BRANCH_CFA, -47,
1057 PROMPT_CFA = defPrimWord("PROMPT", () -> begin
1058 if currentSource() == STDIN
1068 QUIT_CFA = defWord("QUIT",
1069 [LIT_CFA, 0, STATE_CFA, STORE_CFA,
1070 LIT_CFA, 0, NUMTIB_CFA, STORE_CFA,
1071 RSP0_CFA, RSPSTORE_CFA,
1073 INTERPRET_CFA, PROMPT_CFA,
1076 ABORT_CFA = defWord("ABORT",
1077 [CLOSEFILES_CFA, PSP0_CFA, PSPSTORE_CFA, QUIT_CFA])
1079 BYE_CFA = defPrimWord("BYE", () -> begin
1086 INCLUDE_CFA = defPrimWord("INCLUDE", () -> begin
1088 callPrim(mem[WORD_CFA])
1089 wordAddr = popPS()+1
1090 wordLen = mem[wordAddr-1]
1091 word = getString(wordAddr, wordLen)
1095 fname = Pkg.dir("forth","src",word)
1097 error("No file named $word found in current directory or package source directory.")
1100 push!(sources, open(fname, "r"))
1102 # Clear input buffer
1112 initFileName = nothing
1113 if isfile("lib.4th")
1114 initFileName = "lib.4th"
1115 elseif isfile(Pkg.dir("forth","src", "lib.4th"))
1116 initFileName = Pkg.dir("forth","src","lib.4th")
1119 function run(;initialize=true)
1120 # Begin with STDIN as source
1121 push!(sources, STDIN)
1123 global initialized, initFileName
1124 if !initialized && initialize
1125 if initFileName != nothing
1126 print("Including definitions from $initFileName...")
1127 push!(sources, open(initFileName, "r"))
1130 println("No library file found. Only primitive words available.")
1134 # Start with IP pointing to first instruction of outer interpreter
1135 reg.IP = QUIT_CFA + 1
1137 # Primitive processing loop.
1138 # Everyting else is simply a consequence of this loop!
1142 #println("Entering prim $(getPrimName(jmp))")
1146 showerror(STDOUT, ex)
1149 while !isempty(sources) && currentSource() != STDIN
1150 close(pop!(sources))
1154 reg.IP = ABORT_CFA + 1
1162 TRACE_CFA = defPrimWord("TRACE", () -> begin
1163 println("reg.W: $(reg.W) reg.IP: $(reg.IP)")
1164 print("PS: "); printPS()
1165 print("RS: "); printRS()
1172 function dump(startAddr::Int64; count::Int64 = 100, cellsPerLine::Int64 = 10)
1173 chars = Array{Char,1}(cellsPerLine)
1175 lineStartAddr = cellsPerLine*div((startAddr-1),cellsPerLine) + 1
1176 endAddr = startAddr + count - 1
1178 q, r = divrem((endAddr-lineStartAddr+1), cellsPerLine)
1179 numLines = q + (r > 0 ? 1 : 0)
1185 for c in 1:cellsPerLine
1186 if i >= startAddr && i <= endAddr
1188 if mem[i]>=32 && mem[i]<128
1189 chars[c] = Char(mem[i])
1201 println("\t", AbstractString(chars))
1206 count = reg.PSP - PSP0
1210 for i in (PSP0+1):reg.PSP
1215 println("Parameter stack empty")
1220 count = reg.RSP - RSP0
1224 for i in (RSP0+1):reg.RSP
1229 println("Return stack empty")
1233 DUMP = defPrimWord("DUMP", () -> begin
1238 dump(addr, count=count)