# Built-in variables
nextVarAddr = 1
-RSP0 = nextVarAddr; nextVarAddr += 1
-PSP0 = nextVarAddr; nextVarAddr += 1
-HERE = nextVarAddr; nextVarAddr += 1
+H = nextVarAddr; nextVarAddr += 1
LATEST = nextVarAddr; nextVarAddr += 1
-mem[RSP0] = nextVarAddr # bottom of RS
-mem[PSP0] = mem[RSP0] + size_RS # bottom of PS
-TIB = mem[PSP0] + size_PS # address of terminal input buffer
-mem[HERE] = TIB + size_TIB # location of bottom of dictionary
-mem[LATEST] = 0 # no previous definition
+RSP0 = nextVarAddr # bottom of RS
+PSP0 = RSP0 + size_RS # bottom of PS
+TIB = PSP0 + size_PS # address of terminal input buffer
+mem[H] = TIB + size_TIB # location of bottom of dictionary
+mem[LATEST] = 0 # no previous definition
-DICT = mem[HERE] # Save bottom of dictionary as constant
+DICT = mem[H] # Save bottom of dictionary as constant
# VM registers
type Reg
IP::Int64 # Instruction pointer
W::Int64 # Working register
end
-reg = Reg(mem[RSP0], mem[PSP0], 0, 0)
+reg = Reg(RSP0, PSP0, 0, 0)
# Stack manipulation functions
Base.showerror(io::IO, ex::ParamStackUnderflow) = print(io, "Parameter stack underflow.")
Base.showerror(io::IO, ex::ReturnStackUnderflow) = print(io, "Return stack underflow.")
-getRSDepth() = reg.RSP - mem[RSP0]
-getPSDepth() = reg.PSP - mem[PSP0]
+getRSDepth() = reg.RSP - RSP0
+getPSDepth() = reg.PSP - PSP0
function ensurePSDepth(depth::Int64)
if getPSDepth()<depth
# Handy functions for adding/retrieving strings to/from memory.
getString(addr::Int64, len::Int64) = ASCIIString([Char(c) for c in mem[addr:(addr+len-1)]])
+
function putString(str::ASCIIString, addr::Int64)
mem[addr:(addr+length(str)-1)] = [Int64(c) for c in str]
end
function defPrim(f::Function; name="nameless")
push!(primitives, f)
- push!(primNames, replace(replace(name, "\004", "EOF"), "\n", "\\n"))
+ push!(primNames, replace(name, "\004", "EOF"))
return -length(primitives)
end
-callPrim(addr::Int64) = primitives[-addr]()
+function callPrim(addr::Int64)
+ if addr >=0 || -addr>length(primitives)
+ error("Attempted to execute non-existent primitive at address $addr.")
+ else
+ primitives[-addr]()
+ end
+end
getPrimName(addr::Int64) = primNames[-addr]
# Word creation functions
-F_IMMED = 128
-F_HIDDEN = 256
-F_LENMASK = 127
+F_LENMASK = 31
+F_IMMED = 32
+F_HIDDEN = 64
+NFA_MARK = 128
function createHeader(name::AbstractString, flags::Int64)
- mem[mem[HERE]] = mem[LATEST]
- mem[LATEST] = mem[HERE]
- mem[HERE] += 1
+ mem[mem[H]] = mem[LATEST]
+ mem[LATEST] = mem[H]
+ mem[H] += 1
- mem[mem[HERE]] = length(name) | flags; mem[HERE] += 1
- putString(name, mem[HERE]); mem[HERE] += length(name)
+ mem[mem[H]] = length(name) | flags | NFA_MARK; mem[H] += 1
+ putString(name, mem[H]); mem[H] += length(name)
end
function defPrimWord(name::AbstractString, f::Function; flags::Int64=0)
createHeader(name, flags)
- codeWordAddr = mem[HERE]
+ codeWordAddr = mem[H]
mem[codeWordAddr] = defPrim(f, name=name)
- mem[HERE] += 1
+ mem[H] += 1
return codeWordAddr
end
function defWord(name::AbstractString, wordAddrs::Array{Int64,1}; flags::Int64=0)
createHeader(name, flags)
- addr = mem[HERE]
- mem[mem[HERE]] = DOCOL
- mem[HERE] += 1
+ addr = mem[H]
+ mem[mem[H]] = DOCOL
+ mem[H] += 1
for wordAddr in wordAddrs
- mem[mem[HERE]] = wordAddr
- mem[HERE] += 1
+ mem[mem[H]] = wordAddr
+ mem[H] += 1
end
return addr
function defNewVar(name::AbstractString, initial::Int64; flags::Int64=0)
createHeader(name, flags)
- codeWordAddr = mem[HERE]
- varAddr = mem[HERE] + 1
+ codeWordAddr = mem[H]
+ varAddr = mem[H] + 1
- mem[mem[HERE]] = DOVAR; mem[HERE] += 1
- mem[mem[HERE]] = initial; mem[HERE] += 1
+ mem[mem[H]] = DOVAR; mem[H] += 1
+ mem[mem[H]] = initial; mem[H] += 1
return varAddr, codeWordAddr
end
function defConst(name::AbstractString, val::Int64; flags::Int64=0)
createHeader(name, flags)
- codeWordAddr = mem[HERE]
+ codeWordAddr = mem[H]
- mem[mem[HERE]] = DOCON; mem[HERE] += 1
- mem[mem[HERE]] = val; mem[HERE] += 1
+ mem[mem[H]] = DOCON; mem[H] += 1
+ mem[mem[H]] = val; mem[H] += 1
return codeWordAddr
end
# Dictionary entries for core built-in variables, constants
-HERE_CFA = defExistingVar("HERE", HERE)
+H_CFA = defExistingVar("H", H)
LATEST_CFA = defExistingVar("LATEST", LATEST)
-PSP0_CFA = defExistingVar("PSP0", PSP0)
-RSP0_CFA = defExistingVar("RSP0", RSP0)
+
+PSP0_CFA = defConst("PSP0", PSP0)
+RSP0_CFA = defConst("RSP0", RSP0)
defConst("DOCOL", DOCOL)
defConst("DOCON", DOCON)
F_IMMED_CFA = defConst("F_IMMED", F_IMMED)
F_HIDDEN_CFA = defConst("F_HIDDEN", F_HIDDEN)
F_LENMASK_CFA = defConst("F_LENMASK", F_LENMASK)
+NFA_MARK_CFA = defConst("NFA_MARK", NFA_MARK)
# Basic forth primitives
end)
RSPSTORE = defPrimWord("RSP!", () -> begin
- RSP = popPS()
+ reg.RSP = popPS()
return NEXT
end)
end)
PSPSTORE = defPrimWord("PSP!", () -> begin
- PSP = popPS()
+ reg.PSP = popPS()
return NEXT
end)
sources = Array{Any,1}()
currentSource() = sources[length(sources)]
-EOF_CFA = defConst("EOF", 4)
+EOF = defPrimWord("\x04", () -> begin
+ if currentSource() != STDIN
+ close(pop!(sources))
+ return NEXT
+ else
+ return 0
+ end
+end)
EMIT = defPrimWord("EMIT", () -> begin
print(Char(popPS()))
return NEXT
end)
+function raw_mode!(mode::Bool)
+ if ccall(:jl_tty_set_mode, Int32, (Ptr{Void}, Int32), STDIN.handle, mode) != 0
+ throw("FATAL: Terminal unable to enter raw mode.")
+ end
+end
+
+function getKey()
+ raw_mode!(true)
+ byte = readbytes(STDIN, 1)[1]
+ raw_mode!(false)
+
+ if byte == 0x0d
+ return 0x0a
+ elseif byte == 127
+ return 0x08
+ else
+ return byte
+ end
+end
+
+KEY = defPrimWord("KEY", () -> begin
+ pushPS(Int(getKey()))
+ return NEXT
+end)
+
+function getLineFromSTDIN()
+ line = ""
+ while true
+ key = Char(getKey())
+
+ if key == '\n'
+ print(" ")
+ return ASCIIString(line)
+
+ elseif key == '\x04'
+ if isempty(line)
+ return string("\x04")
+ end
+
+ elseif key == '\b'
+ if !isempty(line)
+ line = line[1:length(line)-1]
+ print("\b \b")
+ end
+
+ elseif key == '\e'
+ # Strip ANSI escape sequence
+ nextKey = Char(getKey())
+ if nextKey == '['
+ while true
+ nextKey = Char(getKey())
+ if nextKey >= '@' || nextKey <= '~'
+ break
+ end
+ end
+ end
+
+ else
+ print(key)
+ line = string(line, key)
+ end
+ end
+end
+
SPAN, SPAN_CFA = defNewVar("SPAN", 0)
EXPECT = defPrimWord("EXPECT", () -> begin
maxLen = popPS()
addr = popPS()
- if !eof(currentSource())
- line = chomp(readline(currentSource()))
- mem[SPAN] = min(length(line), maxLen)
- putString(line[1:mem[SPAN]], addr)
+ if currentSource() == STDIN
+ line = getLineFromSTDIN()
else
- mem[SPAN] = 1
- mem[addr] = EOF
+ if !eof(currentSource())
+ line = chomp(readline(currentSource()))
+ else
+ line = "\x04" # eof
+ end
end
+ mem[SPAN] = min(length(line), maxLen)
+ putString(line[1:mem[SPAN]], addr)
+
return NEXT
end)
# Dictionary searches
+TOCFA = defPrimWord(">CFA", () -> begin
+
+ addr = popPS()
+ lenAndFlags = mem[addr+1]
+ len = lenAndFlags & F_LENMASK
+
+ pushPS(addr + 2 + len)
+
+ return NEXT
+end)
+
+TOBODY = defWord(">BODY", [INCR, EXIT])
+
FIND = defPrimWord("FIND", () -> begin
countedAddr = popPS()
word = lowercase(getString(wordAddr, wordLen))
latest = LATEST
+ lenAndFlags = 0
i = 0
while (latest = mem[latest]) > 0
end
end
- pushPS(latest)
-
- return NEXT
-end)
-
-TOCFA = defPrimWord(">CFA", () -> begin
-
- addr = popPS()
- lenAndFlags = mem[addr+1]
- len = lenAndFlags & F_LENMASK
-
- pushPS(addr + 2 + len)
+ if latest > 0
+ pushPS(latest)
+ callPrim(mem[TOCFA])
+ if (lenAndFlags & F_IMMED) == F_IMMED
+ pushPS(1)
+ else
+ pushPS(-1)
+ end
+ else
+ pushPS(countedAddr)
+ pushPS(0)
+ end
return NEXT
end)
-TODFA = defWord(">DFA", [TOCFA, INCR, EXIT])
# Branching
# Outer interpreter
TRACE = defPrimWord("TRACE", () -> begin
- print("RS: "); printRS()
+ println("reg.W: $(reg.W) reg.IP: $(reg.IP)")
print("PS: "); printPS()
+ print("RS: "); printRS()
print("[paused]")
readline()
end)
COMMA = defPrimWord(",", () -> begin
- mem[mem[HERE]] = popPS()
- mem[HERE] += 1
+ mem[mem[H]] = popPS()
+ mem[H] += 1
return NEXT
end)
TOIN, TOIN_CFA = defNewVar(">IN", 0)
QUERY = defWord("QUERY",
- [TIB_CFA, LIT, 80, EXPECT,
+ [TIB_CFA, LIT, 160, EXPECT,
SPAN_CFA, FETCH, NUMTIB_CFA, STORE,
LIT, 0, TOIN_CFA, STORE,
EXIT])
mem[TOIN] += 1
end
- countAddr = mem[HERE]
- addr = mem[HERE]+1
+ countAddr = mem[H]
+ addr = mem[H]+1
# Start reading in word
count = 0
- while (mem[TOIN]<mem[NUMTIB] && mem[TIB+mem[TOIN]] != delim)
+ while (mem[TOIN]<mem[NUMTIB])
mem[addr] = mem[TIB+mem[TOIN]]
+ mem[TOIN] += 1
+
+ if (mem[addr] == delim)
+ break
+ end
+
count += 1
addr += 1
- mem[TOIN] += 1
end
# Record count
return NEXT
end)
+PARSE = defPrimWord("PARSE", () -> begin
+ delim = popPS()
+
+ # Chew up initial occurrences of delim
+ addr = mem[H]
+
+ # Start reading input stream
+ count = 0
+ while (mem[TOIN]<mem[NUMTIB])
+ mem[addr] = mem[TIB+mem[TOIN]]
+ mem[TOIN] += 1
+
+ if (mem[addr] == delim)
+ break
+ end
+
+ count += 1
+ addr += 1
+ end
+
+ pushPS(addr)
+ pushPS(count)
+
+ return NEXT
+end)
+
+BYE = defPrimWord("BYE", () -> begin
+ println("\nBye!")
+ return 0
+end)
+
STATE, STATE_CFA = defNewVar("STATE", 0)
INTERPRET = defWord("INTERPRET",
DUP, FETCH, ZE, ZBRANCH, 3,
DROP, EXIT, # Exit if TIB is exhausted
- STATE_CFA, FETCH, ZBRANCH, 27,
+ STATE_CFA, FETCH, ZBRANCH, 24,
# Compiling
- DUP, FIND, ZBRANCH, 17,
+ FIND, QDUP, ZBRANCH, 13,
# Found word.
- DUP, TOCFA, SWAP, INCR, FETCH, LIT, F_IMMED, AND, ZBRANCH, 4,
+ LIT, -1, EQ, INVERT, ZBRANCH, 4,
+
# Immediate: Execute!
- EXECUTE, BRANCH, -30,
+ EXECUTE, BRANCH, -26,
# Not immediate: Compile!
- COMMA, BRANCH, -33,
+ COMMA, BRANCH, -29,
# No word found, parse number
- NUMBER, BTICK, LIT, COMMA, BRANCH, -39,
+ NUMBER, BTICK, LIT, COMMA, COMMA, BRANCH, -36,
# Interpreting
- DUP, FIND, QDUP, ZBRANCH, 7,
+ FIND, QDUP, ZBRANCH, 5,
# Found word. Execute!
- SWAP, DROP, TOCFA, EXECUTE, BRANCH, -50,
+ DROP, EXECUTE, BRANCH, -44,
# No word found, parse number and leave on stack
- NUMBER, BRANCH, -53,
+ NUMBER, BRANCH, -47,
EXIT]
)
end)
QUIT = defWord("QUIT",
- [RSP0_CFA, RSPSTORE,
+ [LIT, 0, STATE_CFA, STORE,
+ LIT, 0, NUMTIB_CFA, STORE,
+ RSP0_CFA, RSPSTORE,
QUERY,
INTERPRET, PROMPT,
BRANCH,-4])
-BYE = defPrimWord("BYE", () -> begin
- println("Bye!")
- return 0
-end)
+ABORT = defWord("ABORT",
+ [PSP0_CFA, PSPSTORE, QUIT])
INCLUDE = defPrimWord("INCLUDE", () -> begin
+ pushPS(32)
callPrim(mem[WORD])
- wordLen = popPS()
- wordAddr = popPS()
+ wordAddr = popPS()+1
+ wordLen = mem[wordAddr-1]
word = getString(wordAddr, wordLen)
push!(sources, open(word, "r"))
# Compilation
-HEADER = defPrimWord("HEADER", () -> begin
+HERE = defWord("HERE",
+ [H_CFA, FETCH, EXIT])
+HEADER = defPrimWord("HEADER", () -> begin
wordAddr = popPS()+1
wordLen = mem[wordAddr-1]
word = getString(wordAddr, wordLen)
return NEXT
end)
+CREATE = defWord("CREATE",
+ [LIT, 32, WORD, HEADER,
+ LIT, DOVAR, COMMA,
+ EXIT])
+
+DODOES = defPrim(() -> begin
+ pushRS(reg.IP)
+ reg.IP = popPS()
+ pushPS(reg.W + 1)
+ return NEXT
+end, name="DODOES")
+
+DOES_HELPER = defPrimWord("(DOES>)", () -> begin
+
+ pushPS(mem[LATEST])
+ callPrim(mem[TOCFA])
+ cfa = popPS()
+
+ runtimeAddr = popPS()
+
+ mem[cfa] = defPrim(eval(:(() -> begin
+ pushPS($(runtimeAddr))
+ return DODOES
+ end)), name="doesPrim")
+
+ return NEXT
+end, flags=F_IMMED)
+
+DOES = defWord("DOES>",
+ [BTICK, LIT, COMMA, HERE, LIT, 3, ADD, COMMA,
+ BTICK, DOES_HELPER, COMMA, BTICK, EXIT, COMMA, EXIT],
+ flags=F_IMMED)
+
LBRAC = defPrimWord("[", () -> begin
mem[STATE] = 0
return NEXT
end, flags=F_IMMED)
HIDDEN = defPrimWord("HIDDEN", () -> begin
- addr = popPS() + 1
- mem[addr] = mem[addr] $ F_HIDDEN
+ lenAndFlagsAddr = mem[LATEST] + 1
+ mem[lenAndFlagsAddr] = mem[lenAndFlagsAddr] $ F_HIDDEN
return NEXT
end)
-HIDE = defWord("HIDE",
- [WORD,
- FIND,
- HIDDEN,
- EXIT])
-
COLON = defWord(":",
- [WORD,
+ [LIT, 32, WORD,
HEADER,
LIT, DOCOL, COMMA,
- LATEST_CFA, FETCH, HIDDEN,
+ HIDDEN,
RBRAC,
EXIT])
SEMICOLON = defWord(";",
[LIT, EXIT, COMMA,
- LATEST_CFA, FETCH, HIDDEN,
+ HIDDEN,
LBRAC,
EXIT], flags=F_IMMED)
return NEXT
end, flags=F_IMMED)
-TICK = defWord("'",
- [WORD, FIND, TOCFA, EXIT])
-
#### VM loop ####
initFileName = Pkg.dir("forth/src/lib.4th")
end
-function run(;initialize=false)
+function run(;initialize=true)
# Begin with STDIN as source
push!(sources, STDIN)
close(pop!(sources))
end
- mem[STATE] = 0
- mem[NUMTIB] = 0
- reg.PSP = mem[PSP0]
- reg.RSP = mem[RSP0]
- reg.IP = QUIT + 1
+ # QUIT
+ reg.IP = ABORT + 1
jmp = NEXT
end
end
end
function printPS()
- count = reg.PSP - mem[PSP0]
+ count = reg.PSP - PSP0
if count > 0
print("<$count>")
- for i in (mem[PSP0]+1):reg.PSP
+ for i in (PSP0+1):reg.PSP
print(" $(mem[i])")
end
println()
end
function printRS()
- count = reg.RSP - mem[RSP0]
+ count = reg.RSP - RSP0
if count > 0
print("<$count>")
- for i in (mem[RSP0]+1):reg.RSP
+ for i in (RSP0+1):reg.RSP
print(" $(mem[i])")
end
println()
count = popPS()
addr = popPS()
+ println()
dump(addr, count=count)
return NEXT
The Lambda Lab / projects / forth.jl.git / blobdiff