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 ensurePSCapacity(toAdd::Int64)
52 if reg.PSP + toAdd >= PSP0 + size_PS
53 error("Parameter stack overflow.")
57 function ensureRSDepth(depth::Int64)
58 if reg.RSP - RSP0 < depth
59 error("Return stack underflow.")
63 function ensureRSCapacity(toAdd::Int64)
64 if reg.RSP + toAdd >= RSP0 + size_RS
65 error("Return stack overflow.")
69 function pushRS(val::Int64)
82 function pushPS(val::Int64)
85 mem[reg.PSP += 1] = val
96 # Handy functions for adding/retrieving strings to/from memory.
98 getString(addr::Int64, len::Int64) = AbstractString([Char(c) for c in mem[addr:(addr+len-1)]])
100 function putString(str::AbstractString, addr::Int64, maxLen::Int64)
101 len = min(length(str), maxLen)
102 mem[addr:(addr+len-1)] = [Int64(c) for c in str]
105 stringAsInts(str::AbstractString) = [Int(c) for c in collect(str)]
107 # Primitive creation and calling functions
109 function defPrim(f::Function; name="nameless")
111 push!(primNames, replace(name, "\004", "EOF"))
113 return -length(primitives)
116 function callPrim(addr::Int64)
117 if addr >=0 || -addr>length(primitives)
118 error("Attempted to execute non-existent primitive at address $addr.")
123 getPrimName(addr::Int64) = primNames[-addr]
125 # Word creation functions
132 function dictWrite(ints::Array{Int64,1})
133 mem[mem[H]:(mem[H]+length(ints)-1)] = ints
134 mem[H] += length(ints)
136 dictWrite(int::Int64) = dictWrite([int])
137 dictWriteString(string::AbstractString) = dictWrite([Int64(c) for c in string])
139 function createHeader(name::AbstractString, flags::Int64)
140 mem[mem[H]] = mem[mem[CURRENT]+1]
141 mem[mem[CURRENT]+1] = mem[H]
144 dictWrite(length(name) | flags | NFA_MARK)
145 dictWriteString(name)
148 function defPrimWord(name::AbstractString, f::Function; flags::Int64=0)
149 createHeader(name, flags)
151 codeWordAddr = mem[H]
152 dictWrite(defPrim(f, name=name))
157 function defWord(name::AbstractString, wordAddrs::Array{Int64,1}; flags::Int64=0)
158 createHeader(name, flags)
168 # Variable creation functions
170 function defExistingVar(name::AbstractString, varAddr::Int64; flags::Int64=0)
172 defPrimWord(name, eval(:(() -> begin
178 function defNewVar(name::AbstractString, initial::Array{Int64,1}; flags::Int64=0)
179 createHeader(name, flags)
181 codeWordAddr = mem[H]
187 return varAddr, codeWordAddr
190 defNewVar(name::AbstractString, initial::Int64; flags::Int64=0) =
191 defNewVar(name, [initial]; flags=flags)
193 function defConst(name::AbstractString, val::Int64; flags::Int64=0)
194 createHeader(name, flags)
196 codeWordAddr = mem[H]
204 # Threading Primitives (inner interpreter)
206 NEXT = defPrim(() -> begin
212 DOCOL = defPrim(() -> begin
218 DOVAR = defPrim(() -> begin
223 DOCON = defPrim(() -> begin
224 pushPS(mem[reg.W + 1])
228 EXIT_CFA = defPrimWord("EXIT", () -> begin
233 # Dictionary entries for core built-in variables, constants
235 H_CFA = defExistingVar("H", H)
237 PSP0_CFA = defConst("PSP0", PSP0)
238 RSP0_CFA = defConst("RSP0", RSP0)
240 defConst("DOCOL", DOCOL)
241 defConst("DOCON", DOCON)
242 defConst("DOVAR", DOVAR)
244 defConst("DICT", DICT)
245 defConst("MEMSIZE", size_mem)
247 F_IMMED_CFA = defConst("F_IMMED", F_IMMED)
248 F_HIDDEN_CFA = defConst("F_HIDDEN", F_HIDDEN)
249 F_LENMASK_CFA = defConst("F_LENMASK", F_LENMASK)
250 NFA_MARK_CFA = defConst("NFA_MARK", NFA_MARK)
252 # Basic forth primitives
254 DROP_CFA = defPrimWord("DROP", () -> begin
259 SWAP_CFA = defPrimWord("SWAP", () -> begin
267 DUP_CFA = defPrimWord("DUP", () -> begin
273 OVER_CFA = defPrimWord("OVER", () -> begin
275 pushPS(mem[reg.PSP-1])
279 ROT_CFA = defPrimWord("ROT", () -> begin
289 NROT_CFA = defPrimWord("-ROT", () -> begin
300 TWODROP_CFA = defPrimWord("2DROP", () -> begin
306 TWODUP_CFA = defPrimWord("2DUP", () -> begin
315 TWOSWAP_CFA = defPrimWord("2SWAP", () -> begin
327 TWOOVER_CFA = defPrimWord("2OVER", () -> begin
336 QDUP_CFA = defPrimWord("?DUP", () -> begin
345 INCR_CFA = defPrimWord("1+", () -> begin
351 DECR_CFA = defPrimWord("1-", () -> begin
357 INCR2_CFA = defPrimWord("2+", () -> begin
363 DECR2_CFA = defPrimWord("2-", () -> begin
369 ADD_CFA = defPrimWord("+", () -> begin
376 SUB_CFA = defPrimWord("-", () -> begin
383 MUL_CFA = defPrimWord("*", () -> begin
390 DIVMOD_CFA = defPrimWord("/MOD", () -> begin
399 TWOMUL_CFA = defPrimWord("2*", () -> begin
404 TWODIV_CFA = defPrimWord("2/", () -> begin
409 EQ_CFA = defPrimWord("=", () -> begin
412 pushPS(a==b ? -1 : 0)
416 NE_CFA = defPrimWord("<>", () -> begin
419 pushPS(a!=b ? -1 : 0)
423 LT_CFA = defPrimWord("<", () -> begin
430 GT_CFA = defPrimWord(">", () -> begin
437 LE_CFA = defPrimWord("<=", () -> begin
440 pushPS(a<=b ? -1 : 0)
444 GE_CFA = defPrimWord(">=", () -> begin
447 pushPS(a>=b ? -1 : 0)
451 ZE_CFA = defPrimWord("0=", () -> begin
452 pushPS(popPS() == 0 ? -1 : 0)
456 ZNE_CFA = defPrimWord("0<>", () -> begin
457 pushPS(popPS() != 0 ? -1 : 0)
461 ZLT_CFA = defPrimWord("0<", () -> begin
462 pushPS(popPS() < 0 ? -1 : 0)
466 ZGT_CFA = defPrimWord("0>", () -> begin
467 pushPS(popPS() > 0 ? -1 : 0)
471 ZLE_CFA = defPrimWord("0<=", () -> begin
472 pushPS(popPS() <= 0 ? -1 : 0)
476 ZGE_CFA = defPrimWord("0>=", () -> begin
477 pushPS(popPS() >= 0 ? -1 : 0)
481 AND_CFA = defPrimWord("AND", () -> begin
488 OR_CFA = defPrimWord("OR", () -> begin
495 XOR_CFA = defPrimWord("XOR", () -> begin
502 INVERT_CFA = defPrimWord("INVERT", () -> begin
509 LIT_CFA = defPrimWord("LIT", () -> begin
517 STORE_CFA = defPrimWord("!", () -> begin
524 FETCH_CFA = defPrimWord("@", () -> begin
530 ADDSTORE_CFA = defPrimWord("+!", () -> begin
537 SUBSTORE_CFA = defPrimWord("-!", () -> begin
547 TOR_CFA = defPrimWord(">R", () -> begin
552 FROMR_CFA = defPrimWord("R>", () -> begin
557 RFETCH_CFA = defPrimWord("R@", () -> begin
562 RSPFETCH_CFA = defPrimWord("RSP@", () -> begin
567 RSPSTORE_CFA = defPrimWord("RSP!", () -> begin
572 RDROP_CFA = defPrimWord("RDROP", () -> begin
579 PSPFETCH_CFA = defPrimWord("PSP@", () -> begin
584 PSPSTORE_CFA = defPrimWord("PSP!", () -> begin
591 WFETCH_CFA = defPrimWord("W@", () -> begin
596 WSTORE_CFA = defPrimWord("W!", () -> begin
603 openFiles = Dict{Int64,IOStream}()
605 SOURCE_ID, SOURCE_ID_CFA = defNewVar("SOURCE-ID", 0)
611 FAM_RO_CFA = defConst("R/O", FAM_RO)
612 FAM_WO_CFA = defConst("W/O", FAM_WO)
614 function fileOpener(create::Bool)
619 fname = getString(fnameAddr, fnameLen)
621 if create && !isfile(fname)
633 openFiles[nextFileID] = open(fname, mode)
640 OPEN_FILE_CFA = defPrimWord("OPEN-FILE", () -> begin
645 CREATE_FILE_CFA = defPrimWord("CREATE-FILE", () -> begin
650 CLOSE_FILE_CFA = defPrimWord("CLOSE-FILE", () -> begin
652 close(openFiles[fid])
653 delete!(openFiles, fid)
657 CLOSE_FILES_CFA = defPrimWord("CLOSE-FILES", () -> begin
658 for fh in values(openFiles)
667 EMIT_CFA = defPrimWord("EMIT", () -> begin
672 function raw_mode!(mode::Bool)
673 if ccall(:jl_tty_set_mode, Int32, (Ptr{Void}, Int32), STDIN.handle, mode) != 0
674 throw("FATAL: Terminal unable to enter raw mode.")
680 byte = readbytes(STDIN, 1)[1]
692 KEY_CFA = defPrimWord("KEY", () -> begin
693 pushPS(Int(getKey()))
697 function getLineFromSTDIN()
701 slashIdx = findlast(chars, '\\')
704 return join(chars[slashIdx:length(chars)])
710 function backspaceStr(s, bsCount)
712 newLen = max(0, oldLen - bsCount)
713 return join(collect(s)[1:newLen])
722 return AbstractString(line)
726 return string("\x04")
732 line = backspaceStr(line, 1)
736 # Strip ANSI escape sequence
737 nextKey = Char(getKey())
740 nextKey = Char(getKey())
741 if nextKey >= '@' || nextKey <= '~'
748 # Currently do nothing
752 if haskey(REPLCompletions.latex_symbols, frag)
753 print(repeat("\b", length(frag)))
755 comp = REPLCompletions.latex_symbols[frag]
756 line = string(backspaceStr(line, length(frag)), comp)
763 line = string(line, key)
768 SPAN, SPAN_CFA = defNewVar("SPAN", 0)
769 EXPECT_CFA = defPrimWord("EXPECT", () -> begin
773 line = getLineFromSTDIN()
775 mem[SPAN] = min(length(line), maxLen)
776 putString(line, addr, maxLen)
781 BASE, BASE_CFA = defNewVar("BASE", 10)
782 NUMBER_CFA = defPrimWord("NUMBER", () -> begin
784 wordLen = mem[wordAddr-1]
786 s = getString(wordAddr, wordLen)
788 pushPS(parse(Int64, s, mem[BASE]))
793 # Dictionary searches
795 FROMLINK_CFA = defPrimWord("LINK>", () -> begin
798 lenAndFlags = mem[addr+1]
799 len = lenAndFlags & F_LENMASK
801 pushPS(addr + 2 + len)
806 NUMCONTEXT, NUMCONTEXT_CFA = defNewVar("#CONTEXT", 1)
808 createHeader("FORTH", 0)
810 dictWrite(defPrim(() -> begin
811 mem[CONTEXT + mem[NUMCONTEXT] - 1] = reg.W
814 dictWrite(0) # cell for latest
816 CURRENT_CFA = defExistingVar("CURRENT", CURRENT)
818 # Switch to new FORTH vocabulary cfa
819 mem[FORTH_CFA+1] = mem[mem[CURRENT]+1]
820 mem[CURRENT] = FORTH_CFA
822 CONTEXT, CONTEXT_CFA = defNewVar("CONTEXT", zeros(Int64, 10))
823 mem[CONTEXT] = FORTH_CFA
825 FINDVOCAB_CFA = defPrimWord("FINDVOCAB", () -> begin
827 countedAddr = popPS()
829 wordAddr = countedAddr + 1
830 wordLen = mem[countedAddr]
831 word = lowercase(getString(wordAddr, wordLen))
836 while (lfa = mem[lfa]) > 0
838 lenAndFlags = mem[lfa+1]
839 len = lenAndFlags & F_LENMASK
840 hidden = (lenAndFlags & F_HIDDEN) == F_HIDDEN
842 if hidden || len != wordLen
846 thisWord = lowercase(getString(lfa+2, len))
855 callPrim(mem[FROMLINK_CFA])
856 if (lenAndFlags & F_IMMED) == F_IMMED
869 FIND_CFA = defPrimWord("FIND", () -> begin
871 countedAddr = popPS()
872 context = mem[CONTEXT:(CONTEXT+mem[NUMCONTEXT]-1)]
874 for vocabCFA in reverse(context)
877 callPrim(mem[FINDVOCAB_CFA])
879 callPrim(mem[DUP_CFA])
897 BRANCH_CFA = defPrimWord("BRANCH", () -> begin
898 reg.IP += mem[reg.IP]
902 ZBRANCH_CFA = defPrimWord("0BRANCH", () -> begin
904 reg.IP += mem[reg.IP]
914 LITSTRING_CFA = defPrimWord("LITSTRING", () -> begin
924 TYPE_CFA = defPrimWord("TYPE", () -> begin
927 str = getString(addr, len)
932 # Interpreter/Compiler-specific I/O
934 TIB_CFA = defConst("TIB", TIB)
935 NUMTIB, NUMTIB_CFA = defNewVar("#TIB", 0)
936 TOIN, TOIN_CFA = defNewVar(">IN", 0)
938 QUERY_CFA = defWord("QUERY",
939 [TIB_CFA, LIT_CFA, 160, EXPECT_CFA,
940 SPAN_CFA, FETCH_CFA, NUMTIB_CFA, STORE_CFA,
941 LIT_CFA, 0, TOIN_CFA, STORE_CFA,
944 WORD_CFA = defPrimWord("WORD", () -> begin
947 # Chew up initial occurrences of delim
948 while (mem[TOIN]<mem[NUMTIB] && mem[TIB+mem[TOIN]] == delim)
955 # Start reading in word
957 while (mem[TOIN]<mem[NUMTIB])
958 mem[addr] = mem[TIB+mem[TOIN]]
961 if (mem[addr] == delim)
970 mem[countAddr] = count
978 STATE, STATE_CFA = defNewVar("STATE", 0)
980 COMMA_CFA = defPrimWord(",", () -> begin
981 mem[mem[H]] = popPS()
987 HERE_CFA = defWord("HERE",
988 [H_CFA, FETCH_CFA, EXIT_CFA])
990 HEADER_CFA = defPrimWord("HEADER", () -> begin
992 wordLen = mem[wordAddr-1]
993 word = getString(wordAddr, wordLen)
995 createHeader(word, 0)
1000 CREATE_CFA = defWord("CREATE",
1001 [LIT_CFA, 32, WORD_CFA, HEADER_CFA,
1002 LIT_CFA, DOVAR, COMMA_CFA,
1005 DODOES = defPrim(() -> begin
1012 DOES_HELPER_CFA = defPrimWord("(DOES>)", () -> begin
1014 pushPS(mem[mem[CURRENT]+1])
1015 callPrim(mem[FROMLINK_CFA])
1018 runtimeAddr = popPS()
1020 mem[cfa] = defPrim(eval(:(() -> begin
1021 pushPS($(runtimeAddr))
1023 end)), name="doesPrim")
1026 end, flags=F_IMMED | F_HIDDEN)
1028 DOES_CFA = defWord("DOES>",
1029 [LIT_CFA, LIT_CFA, COMMA_CFA, HERE_CFA, LIT_CFA, 3, ADD_CFA, COMMA_CFA,
1030 LIT_CFA, DOES_HELPER_CFA, COMMA_CFA, LIT_CFA, EXIT_CFA, COMMA_CFA, EXIT_CFA],
1033 LBRAC_CFA = defPrimWord("[", () -> begin
1038 RBRAC_CFA = defPrimWord("]", () -> begin
1043 HIDDEN_CFA = defPrimWord("HIDDEN", () -> begin
1044 lenAndFlagsAddr = mem[mem[CURRENT]+1] + 1
1045 mem[lenAndFlagsAddr] = mem[lenAndFlagsAddr] $ F_HIDDEN
1049 COLON_CFA = defWord(":",
1050 [LIT_CFA, 32, WORD_CFA,
1052 LIT_CFA, DOCOL, COMMA_CFA,
1057 SEMICOLON_CFA = defWord(";",
1058 [LIT_CFA, EXIT_CFA, COMMA_CFA,
1061 EXIT_CFA], flags=F_IMMED)
1063 IMMEDIATE_CFA = defPrimWord("IMMEDIATE", () -> begin
1064 lenAndFlagsAddr = mem[mem[CURRENT]+1] + 1
1065 mem[lenAndFlagsAddr] = mem[lenAndFlagsAddr] $ F_IMMED
1069 CODE_CFA = defPrimWord("CODE", () -> begin
1071 callPrim(mem[WORD_CFA])
1072 callPrim(mem[HEADER_CFA])
1074 exprString = "() -> begin\n"
1076 if mem[TOIN] >= mem[NUMTIB]
1077 exprString = string(exprString, "\n")
1078 if currentSource() == STDIN
1084 callPrim(mem[EXPECT_CFA])
1085 mem[NUMTIB] = mem[SPAN]
1090 callPrim(mem[WORD_CFA])
1092 thisWord = getString(cAddr+1, mem[cAddr])
1094 if uppercase(thisWord) == "END-CODE"
1098 exprString = string(exprString, " ", thisWord)
1100 exprString = string(exprString, "\nreturn NEXT\nend")
1102 func = eval(parse(exprString))
1103 dictWrite(defPrim(func))
1110 EXECUTE_CFA = defPrimWord("EXECUTE", () -> begin
1115 INTERPRET_CFA = defWord("INTERPRET",
1116 [LIT_CFA, 32, WORD_CFA, # Read next space-delimited word
1118 DUP_CFA, FETCH_CFA, ZE_CFA, ZBRANCH_CFA, 3,
1119 DROP_CFA, EXIT_CFA, # Exit if TIB is exhausted
1121 STATE_CFA, FETCH_CFA, ZBRANCH_CFA, 24,
1123 FIND_CFA, QDUP_CFA, ZBRANCH_CFA, 13,
1126 LIT_CFA, -1, EQ_CFA, INVERT_CFA, ZBRANCH_CFA, 4,
1128 # Immediate: Execute!
1129 EXECUTE_CFA, BRANCH_CFA, -26,
1131 # Not immediate: Compile!
1132 COMMA_CFA, BRANCH_CFA, -29,
1134 # No word found, parse number
1135 NUMBER_CFA, LIT_CFA, LIT_CFA, COMMA_CFA, COMMA_CFA, BRANCH_CFA, -36,
1138 FIND_CFA, QDUP_CFA, ZBRANCH_CFA, 5,
1140 # Found word. Execute!
1141 DROP_CFA, EXECUTE_CFA, BRANCH_CFA, -44,
1143 # No word found, parse number and leave on stack
1144 NUMBER_CFA, BRANCH_CFA, -47,
1147 PROMPT_CFA = defPrimWord("PROMPT", () -> begin
1156 QUIT_CFA = defWord("QUIT",
1157 [LIT_CFA, 0, STATE_CFA, STORE_CFA,
1158 LIT_CFA, 0, NUMTIB_CFA, STORE_CFA,
1159 RSP0_CFA, RSPSTORE_CFA,
1161 INTERPRET_CFA, PROMPT_CFA,
1164 ABORT_CFA = defWord("ABORT",
1165 [CLOSE_FILES_CFA, PSP0_CFA, PSPSTORE_CFA, QUIT_CFA])
1167 BYE_CFA = defPrimWord("BYE", () -> begin
1175 initFileName = nothing
1176 if isfile("lib.4th")
1177 initFileName = "lib.4th"
1178 elseif isfile(Pkg.dir("forth","src", "lib.4th"))
1179 initFileName = Pkg.dir("forth","src","lib.4th")
1182 function run(;initialize=true)
1184 global initialized, initFileName
1185 if !initialized && initialize
1186 if initFileName != nothing
1187 print("Including definitions from $initFileName...")
1193 println("No library file found. Only primitive words available.")
1197 # Start with IP pointing to first instruction of outer interpreter
1198 reg.IP = QUIT_CFA + 1
1200 # Primitive processing loop.
1201 # Everyting else is simply a consequence of this loop!
1205 #println("Entering prim $(getPrimName(jmp))")
1209 showerror(STDOUT, ex)
1213 reg.IP = ABORT_CFA + 1
1221 TRACE_CFA = defPrimWord("TRACE", () -> begin
1222 println("reg.W: $(reg.W) reg.IP: $(reg.IP)")
1223 print("PS: "); printPS()
1224 print("RS: "); printRS()
1231 function dump(startAddr::Int64; count::Int64 = 100, cellsPerLine::Int64 = 10)
1232 chars = Array{Char,1}(cellsPerLine)
1234 lineStartAddr = cellsPerLine*div((startAddr-1),cellsPerLine) + 1
1235 endAddr = startAddr + count - 1
1237 q, r = divrem((endAddr-lineStartAddr+1), cellsPerLine)
1238 numLines = q + (r > 0 ? 1 : 0)
1244 for c in 1:cellsPerLine
1245 if i >= startAddr && i <= endAddr
1247 if mem[i]>=32 && mem[i]<128
1248 chars[c] = Char(mem[i])
1260 println("\t", AbstractString(chars))
1265 count = reg.PSP - PSP0
1269 for i in (PSP0+1):reg.PSP
1274 println("Parameter stack empty")
1279 count = reg.RSP - RSP0
1283 for i in (RSP0+1):reg.RSP
1288 println("Return stack empty")
1292 DUMP = defPrimWord("DUMP", () -> begin
1297 dump(addr, count=count)