module forth
# VM mem size
-size_mem = 640*1024
+size_mem = 1000000 # 1 mega-int
# Buffer sizes
-size_RS = 1024 # Return stack size
-size_PS = 1024 # Parameter stack size
-size_TIB = 1096 # Terminal input buffer size
-
-# The mem array constitutes the memory of the VM. It has the following geography:
-#
-# mem = +-----------------------+
-# | Built-in Variables |
-# +-----------------------+
-# | Return Stack |
-# +-----------------------+
-# | Parameter Stack |
-# +-----------------------+
-# | Terminal Input Buffer |
-# +-----------------------+
-# | Dictionary |
-# +-----------------------+
-#
-# Note that all words (user-defined, primitive, variables, etc) are included in
-# the dictionary.
-#
-# Simple linear addressing is used with one exception: references to primitive code
-# blocks, which are represented as anonymous functions, appear as negative indicies
-# into the primitives array which contains these functions.
+size_RS = 1000 # Return stack size
+size_PS = 1000 # Parameter stack size
+size_TIB = 1000 # Terminal input buffer size
+# Memory arrays
mem = Array{Int64,1}(size_mem)
primitives = Array{Function,1}()
primNames = Array{ASCIIString,1}()
# 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
-type ParamStackUnderflow <: Exception end
-type ReturnStackUnderflow <: Exception end
-
-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]
-
function ensurePSDepth(depth::Int64)
- if getPSDepth()<depth
- throw(ParamStackUnderflow())
+ if reg.PSP - PSP0 < depth
+ error("Parameter stack underflow.")
end
end
function ensureRSDepth(depth::Int64)
- if getRSDepth()<depth
- throw(ReturnStackUnderflow())
+ if reg.RSP - RSP0 < depth
+ error("Return stack underflow.")
end
end
# 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 $addr.")
+ else
+ primitives[-addr]()
+ end
+end
+getPrimName(addr::Int64) = primNames[-addr]
+
+# Word creation functions
-# Word creation
+F_LENMASK = 31
+F_IMMED = 32
+F_HIDDEN = 64
+NFA_MARK = 128
function createHeader(name::AbstractString, flags::Int64)
- mem[mem[HERE]] = mem[LATEST]
- mem[LATEST] = mem[HERE]
- mem[HERE] += 1
+ mem[mem[H]] = mem[LATEST]
+ mem[LATEST] = mem[H]
+ mem[H] += 1
- mem[mem[HERE]] = length(name) | flags; mem[HERE] += 1
- putString(name, mem[HERE]); mem[HERE] += length(name)
+ mem[mem[H]] = length(name) | flags | NFA_MARK; mem[H] += 1
+ putString(name, mem[H]); mem[H] += length(name)
end
function defPrimWord(name::AbstractString, f::Function; flags::Int64=0)
createHeader(name, flags)
- codeWordAddr = mem[HERE]
+ codeWordAddr = mem[H]
mem[codeWordAddr] = defPrim(f, name=name)
- mem[HERE] += 1
+ mem[H] += 1
return codeWordAddr
end
function defWord(name::AbstractString, wordAddrs::Array{Int64,1}; flags::Int64=0)
createHeader(name, flags)
- addr = mem[HERE]
- mem[mem[HERE]] = DOCOL
- mem[HERE] += 1
+ addr = mem[H]
+ mem[mem[H]] = DOCOL
+ mem[H] += 1
for wordAddr in wordAddrs
- mem[mem[HERE]] = wordAddr
- mem[HERE] += 1
+ mem[mem[H]] = wordAddr
+ mem[H] += 1
end
return addr
end
-# Variable creation
+# Variable creation functions
function defExistingVar(name::AbstractString, varAddr::Int64; flags::Int64=0)
function defNewVar(name::AbstractString, initial::Int64; flags::Int64=0)
createHeader(name, flags)
- codeWordAddr = mem[HERE]
- varAddr = mem[HERE] + 1
+ codeWordAddr = mem[H]
+ varAddr = mem[H] + 1
- f = eval(:(() -> begin
- pushPS($(varAddr))
- return NEXT
- end))
-
- mem[mem[HERE]] = defPrim(f, name=name); 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)
- defPrimWord(name, eval(:(() -> begin
- pushPS($(val))
- return NEXT
- end)))
+ createHeader(name, flags)
- return val
+ codeWordAddr = mem[H]
+
+ mem[mem[H]] = DOCON; mem[H] += 1
+ mem[mem[H]] = val; mem[H] += 1
+
+ return codeWordAddr
end
# Threading Primitives (inner interpreter)
return NEXT
end, name="DOCOL")
-EXIT = defPrimWord("EXIT", () -> begin
+DOVAR = defPrim(() -> begin
+ pushPS(reg.W + 1)
+ return NEXT
+end, name="DOVAR")
+
+DOCON = defPrim(() -> begin
+ pushPS(mem[reg.W + 1])
+ return NEXT
+end, name="DOVAR")
+
+EXIT_CFA = defPrimWord("EXIT", () -> begin
reg.IP = popRS()
return NEXT
end)
+# Dictionary entries for core built-in variables, constants
+
+H_CFA = defExistingVar("H", H)
+LATEST_CFA = defExistingVar("LATEST", LATEST)
+
+PSP0_CFA = defConst("PSP0", PSP0)
+RSP0_CFA = defConst("RSP0", RSP0)
+
+defConst("DOCOL", DOCOL)
+defConst("DOCON", DOCON)
+defConst("DOVAR", DOVAR)
+
+defConst("DICT", DICT)
+defConst("MEMSIZE", size_mem)
+
+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
-DROP = defPrimWord("DROP", () -> begin
+DROP_CFA = defPrimWord("DROP", () -> begin
popPS()
return NEXT
end)
-SWAP = defPrimWord("SWAP", () -> begin
+SWAP_CFA = defPrimWord("SWAP", () -> begin
a = popPS()
b = popPS()
pushPS(a)
return NEXT
end)
-DUP = defPrimWord("DUP", () -> begin
+DUP_CFA = defPrimWord("DUP", () -> begin
ensurePSDepth(1)
pushPS(mem[reg.PSP])
return NEXT
end)
-OVER = defPrimWord("OVER", () -> begin
+OVER_CFA = defPrimWord("OVER", () -> begin
ensurePSDepth(2)
pushPS(mem[reg.PSP-1])
return NEXT
end)
-ROT = defPrimWord("ROT", () -> begin
+ROT_CFA = defPrimWord("ROT", () -> begin
a = popPS()
b = popPS()
c = popPS()
+ pushPS(b)
pushPS(a)
pushPS(c)
- pushPS(b)
return NEXT
end)
-NROT = defPrimWord("-ROT", () -> begin
+NROT_CFA = defPrimWord("-ROT", () -> begin
a = popPS()
b = popPS()
c = popPS()
- pushPS(b)
pushPS(a)
pushPS(c)
+ pushPS(b)
return NEXT
end)
-TWODROP = defPrimWord("2DROP", () -> begin
+
+TWODROP_CFA = defPrimWord("2DROP", () -> begin
popPS()
popPS()
return NEXT
end)
-TWODUP = defPrimWord("2DUP", () -> begin
+TWODUP_CFA = defPrimWord("2DUP", () -> begin
ensurePSDepth(2)
a = mem[reg.PSP-1]
b = mem[reg.PSP]
return NEXT
end)
-TWOSWAP = defPrimWord("2SWAP", () -> begin
+TWOSWAP_CFA = defPrimWord("2SWAP", () -> begin
a = popPS()
b = popPS()
c = popPS()
d = popPS()
pushPS(b)
pushPS(a)
- pushPS(c)
pushPS(d)
+ pushPS(c)
return NEXT
end)
-QDUP = defPrimWord("?DUP", () -> begin
+TWOOVER_CFA = defPrimWord("2OVER", () -> begin
+ ensurePSDepth(4)
+ a = mem[reg.PSP-3]
+ b = mem[reg.PSP-2]
+ pushPS(a)
+ pushPS(b)
+ return NEXT
+end)
+
+QDUP_CFA = defPrimWord("?DUP", () -> begin
ensurePSDepth(1)
val = mem[reg.PSP]
if val != 0
return NEXT
end)
-INCR = defPrimWord("1+", () -> begin
+INCR_CFA = defPrimWord("1+", () -> begin
ensurePSDepth(1)
mem[reg.PSP] += 1
return NEXT
end)
-DECR = defPrimWord("1-", () -> begin
+DECR_CFA = defPrimWord("1-", () -> begin
ensurePSDepth(1)
mem[reg.PSP] -= 1
return NEXT
end)
-INCR2 = defPrimWord("2+", () -> begin
+INCR2_CFA = defPrimWord("2+", () -> begin
ensurePSDepth(1)
mem[reg.PSP] += 2
return NEXT
end)
-DECR2 = defPrimWord("2-", () -> begin
+DECR2_CFA = defPrimWord("2-", () -> begin
ensurePSDepth(1)
mem[reg.PSP] -= 2
return NEXT
end)
-ADD = defPrimWord("+", () -> begin
+ADD_CFA = defPrimWord("+", () -> begin
b = popPS()
a = popPS()
pushPS(a+b)
return NEXT
end)
-SUB = defPrimWord("-", () -> begin
+SUB_CFA = defPrimWord("-", () -> begin
b = popPS()
a = popPS()
pushPS(a-b)
return NEXT
end)
-MUL = defPrimWord("*", () -> begin
+MUL_CFA = defPrimWord("*", () -> begin
b = popPS()
a = popPS()
pushPS(a*b)
return NEXT
end)
-DIVMOD = defPrimWord("/MOD", () -> begin
+DIVMOD_CFA = defPrimWord("/MOD", () -> begin
b = popPS()
a = popPS()
q,r = divrem(a,b)
return NEXT
end)
-TWOMUL = defPrimWord("2*", () -> begin
+TWOMUL_CFA = defPrimWord("2*", () -> begin
pushPS(popPS() << 1)
return NEXT
end)
-TWODIV = defPrimWord("2/", () -> begin
+TWODIV_CFA = defPrimWord("2/", () -> begin
pushPS(popPS() >> 1)
return NEXT
end)
-EQU = defPrimWord("=", () -> begin
+EQ_CFA = defPrimWord("=", () -> begin
b = popPS()
a = popPS()
pushPS(a==b ? -1 : 0)
return NEXT
end)
-NEQU = defPrimWord("<>", () -> begin
+NE_CFA = defPrimWord("<>", () -> begin
b = popPS()
a = popPS()
pushPS(a!=b ? -1 : 0)
return NEXT
end)
-LT = defPrimWord("<", () -> begin
+LT_CFA = defPrimWord("<", () -> begin
b = popPS()
a = popPS()
pushPS(a<b ? -1 : 0)
return NEXT
end)
-GT = defPrimWord(">", () -> begin
+GT_CFA = defPrimWord(">", () -> begin
b = popPS()
a = popPS()
pushPS(a>b ? -1 : 0)
return NEXT
end)
-LE = defPrimWord("<=", () -> begin
+LE_CFA = defPrimWord("<=", () -> begin
b = popPS()
a = popPS()
pushPS(a<=b ? -1 : 0)
return NEXT
end)
-GE = defPrimWord(">=", () -> begin
+GE_CFA = defPrimWord(">=", () -> begin
b = popPS()
a = popPS()
pushPS(a>=b ? -1 : 0)
return NEXT
end)
-ZEQU = defPrimWord("0=", () -> begin
+ZE_CFA = defPrimWord("0=", () -> begin
pushPS(popPS() == 0 ? -1 : 0)
return NEXT
end)
-ZNEQU = defPrimWord("0<>", () -> begin
+ZNE_CFA = defPrimWord("0<>", () -> begin
pushPS(popPS() != 0 ? -1 : 0)
return NEXT
end)
-ZLT = defPrimWord("0<", () -> begin
+ZLT_CFA = defPrimWord("0<", () -> begin
pushPS(popPS() < 0 ? -1 : 0)
return NEXT
end)
-ZGT = defPrimWord("0>", () -> begin
+ZGT_CFA = defPrimWord("0>", () -> begin
pushPS(popPS() > 0 ? -1 : 0)
return NEXT
end)
-ZLE = defPrimWord("0<=", () -> begin
+ZLE_CFA = defPrimWord("0<=", () -> begin
pushPS(popPS() <= 0 ? -1 : 0)
return NEXT
end)
-ZGE = defPrimWord("0>=", () -> begin
+ZGE_CFA = defPrimWord("0>=", () -> begin
pushPS(popPS() >= 0 ? -1 : 0)
return NEXT
end)
-AND = defPrimWord("AND", () -> begin
+AND_CFA = defPrimWord("AND", () -> begin
b = popPS()
a = popPS()
pushPS(a & b)
return NEXT
end)
-OR = defPrimWord("OR", () -> begin
+OR_CFA = defPrimWord("OR", () -> begin
b = popPS()
a = popPS()
pushPS(a | b)
return NEXT
end)
-XOR = defPrimWord("XOR", () -> begin
+XOR_CFA = defPrimWord("XOR", () -> begin
b = popPS()
a = popPS()
pushPS(a $ b)
return NEXT
end)
-INVERT = defPrimWord("INVERT", () -> begin
+INVERT_CFA = defPrimWord("INVERT", () -> begin
pushPS(~popPS())
return NEXT
end)
# Literals
-LIT = defPrimWord("LIT", () -> begin
+LIT_CFA = defPrimWord("LIT", () -> begin
pushPS(mem[reg.IP])
reg.IP += 1
return NEXT
# Memory primitives
-STORE = defPrimWord("!", () -> begin
+STORE_CFA = defPrimWord("!", () -> begin
addr = popPS()
dat = popPS()
mem[addr] = dat
return NEXT
end)
-FETCH = defPrimWord("@", () -> begin
+FETCH_CFA = defPrimWord("@", () -> begin
addr = popPS()
pushPS(mem[addr])
return NEXT
end)
-ADDSTORE = defPrimWord("+!", () -> begin
+ADDSTORE_CFA = defPrimWord("+!", () -> begin
addr = popPS()
toAdd = popPS()
mem[addr] += toAdd
return NEXT
end)
-SUBSTORE = defPrimWord("-!", () -> begin
+SUBSTORE_CFA = defPrimWord("-!", () -> begin
addr = popPS()
toSub = popPS()
mem[addr] -= toSub
end)
-# Built-in variables
-
-HERE_CFA = defExistingVar("HERE", HERE)
-LATEST_CFA = defExistingVar("LATEST", LATEST)
-PSP0_CFA = defExistingVar("PSP0", PSP0)
-RSP0_CFA = defExistingVar("RSP0", RSP0)
-STATE, STATE_CFA = defNewVar("STATE", 0)
-BASE, BASE_CFA = defNewVar("BASE", 10)
-
-# Constants
-
-defConst("VERSION", 1)
-defConst("DOCOL", DOCOL)
-defConst("DICT", DICT)
-F_IMMED = defConst("F_IMMED", 128)
-F_HIDDEN = defConst("F_HIDDEN", 256)
-F_LENMASK = defConst("F_LENMASK", 127)
-
# Return Stack
-TOR = defPrimWord(">R", () -> begin
+TOR_CFA = defPrimWord(">R", () -> begin
pushRS(popPS())
return NEXT
end)
-FROMR = defPrimWord("R>", () -> begin
+FROMR_CFA = defPrimWord("R>", () -> begin
pushPS(popRS())
return NEXT
end)
-RFETCH = defPrimWord("R@", () -> begin
+RFETCH_CFA = defPrimWord("R@", () -> begin
pushPS(mem[reg.RSP])
return NEXT
end)
-RSPFETCH = defPrimWord("RSP@", () -> begin
+RSPFETCH_CFA = defPrimWord("RSP@", () -> begin
pushPS(reg.RSP)
return NEXT
end)
-RSPSTORE = defPrimWord("RSP!", () -> begin
- RSP = popPS()
+RSPSTORE_CFA = defPrimWord("RSP!", () -> begin
+ reg.RSP = popPS()
return NEXT
end)
-RDROP = defPrimWord("RDROP", () -> begin
+RDROP_CFA = defPrimWord("RDROP", () -> begin
popRS()
return NEXT
end)
# Parameter Stack
-PSPFETCH = defPrimWord("PSP@", () -> begin
+PSPFETCH_CFA = defPrimWord("PSP@", () -> begin
pushPS(reg.PSP)
return NEXT
end)
-PSPSTORE = defPrimWord("PSP!", () -> begin
- PSP = popPS()
+PSPSTORE_CFA = defPrimWord("PSP!", () -> begin
+ reg.PSP = popPS()
return NEXT
end)
# Working Register
-WFETCH = defPrimWord("W@", () -> begin
+WFETCH_CFA = defPrimWord("W@", () -> begin
pushPS(reg.W)
return NEXT
end)
-WSTORE = defPrimWord("W!", () -> begin
+WSTORE_CFA = defPrimWord("W!", () -> begin
reg.W = popPS()
return NEXT
end)
sources = Array{Any,1}()
currentSource() = sources[length(sources)]
-defConst("TIB", TIB)
-NUMTIB, NUMTIB_CFA = defNewVar("#TIB", 0)
-TOIN, TOIN_CFA = defNewVar(">IN", 0)
-EOF = defConst("EOF", 4)
-
-KEY = defPrimWord("KEY", () -> begin
- if mem[TOIN] >= mem[NUMTIB]
- mem[TOIN] = 0
-
- if !eof(currentSource())
- line = readline(currentSource())
- mem[NUMTIB] = length(line)
- putString(line, TIB)
- else
- mem[NUMTIB] = 1
- mem[TIB] = EOF
- end
+EOF_CFA = defPrimWord("\x04", () -> begin
+ if currentSource() != STDIN
+ close(pop!(sources))
+ return NEXT
+ else
+ return 0
end
-
- pushPS(mem[TIB + mem[TOIN]])
- mem[TOIN] += 1
-
- return NEXT
end)
-EMIT = defPrimWord("EMIT", () -> begin
+EMIT_CFA = defPrimWord("EMIT", () -> begin
print(Char(popPS()))
return NEXT
end)
-WORD = defPrimWord("WORD", () -> begin
+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
- eof_char = Char(EOF)
- c = eof_char
+KEY_CFA = defPrimWord("KEY", () -> begin
+ pushPS(Int(getKey()))
+ return NEXT
+end)
- skip_to_end = false
+function getLineFromSTDIN()
+ line = ""
while true
+ key = Char(getKey())
- callPrim(mem[KEY])
- c = Char(popPS())
+ if key == '\n'
+ print(" ")
+ return ASCIIString(line)
- if c == '\\'
- skip_to_end = true
- continue
- end
+ elseif key == '\x04'
+ if isempty(line)
+ return string("\x04")
+ end
- if skip_to_end
- if c == '\n' || c == eof_char
- skip_to_end = false
+ elseif key == '\b'
+ if !isempty(line)
+ line = line[1:length(line)-1]
+ print("\b \b")
end
- continue
- end
- if c == ' ' || c == '\t'
- continue
- 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
- break
+ else
+ print(key)
+ line = string(line, key)
+ end
end
+end
- wordAddr = mem[HERE]
- offset = 0
-
- if c == '\n' || c == eof_char
- # Treat newline as a special word
+SPAN, SPAN_CFA = defNewVar("SPAN", 0)
+EXPECT_CFA = defPrimWord("EXPECT", () -> begin
+ maxLen = popPS()
+ addr = popPS()
- mem[wordAddr + offset] = Int64(c)
- pushPS(wordAddr)
- pushPS(1)
- return NEXT
+ if currentSource() == STDIN
+ line = getLineFromSTDIN()
+ else
+ if !eof(currentSource())
+ line = chomp(readline(currentSource()))
+ else
+ line = "\x04" # eof
+ end
end
- while true
- mem[wordAddr + offset] = Int64(c)
- offset += 1
+ mem[SPAN] = min(length(line), maxLen)
+ putString(line[1:mem[SPAN]], addr)
- callPrim(mem[KEY])
- c = Char(popPS())
+ return NEXT
+end)
- if c == ' ' || c == '\t' || c == '\n' || c == eof_char
- # Rewind KEY
- mem[TOIN] -= 1
- break
- end
- end
+BASE, BASE_CFA = defNewVar("BASE", 10)
+NUMBER_CFA = defPrimWord("NUMBER", () -> begin
+ wordAddr = popPS()+1
+ wordLen = mem[wordAddr-1]
- wordLen = offset
+ s = getString(wordAddr, wordLen)
- pushPS(wordAddr)
- pushPS(wordLen)
+ pushPS(parse(Int64, s, mem[BASE]))
return NEXT
end)
-NUMBER = defPrimWord("NUMBER", () -> begin
+# Dictionary searches
- wordLen = popPS()
- wordAddr = popPS()
+TOCFA_CFA = defPrimWord(">CFA", () -> begin
- s = getString(wordAddr, wordLen)
+ addr = popPS()
+ lenAndFlags = mem[addr+1]
+ len = lenAndFlags & F_LENMASK
- try
- pushPS(parse(Int64, s, mem[BASE]))
- pushPS(0)
- catch
- pushPS(1) # Error indication
- end
+ pushPS(addr + 2 + len)
return NEXT
end)
-# Dictionary searches
+TOBODY_CFA = defWord(">BODY", [INCR_CFA, EXIT_CFA])
-FIND = defPrimWord("FIND", () -> begin
+FIND_CFA = defPrimWord("FIND", () -> begin
- wordLen = popPS()
- wordAddr = popPS()
+ countedAddr = popPS()
+ wordAddr = countedAddr + 1
+ wordLen = mem[countedAddr]
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_CFA])
+ 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
-BRANCH = defPrimWord("BRANCH", () -> begin
+BRANCH_CFA = defPrimWord("BRANCH", () -> begin
reg.IP += mem[reg.IP]
return NEXT
end)
-ZBRANCH = defPrimWord("0BRANCH", () -> begin
+ZBRANCH_CFA = defPrimWord("0BRANCH", () -> begin
if (popPS() == 0)
reg.IP += mem[reg.IP]
else
return NEXT
end)
+# Strings
+
+LITSTRING_CFA = defPrimWord("LITSTRING", () -> begin
+ len = mem[reg.IP]
+ reg.IP += 1
+ pushPS(reg.IP)
+ pushPS(len)
+ reg.IP += len
+
+ return NEXT
+end)
+
+TYPE_CFA = defPrimWord("TYPE", () -> begin
+ len = popPS()
+ addr = popPS()
+ str = getString(addr, len)
+ print(str)
+ return NEXT
+end)
+
+# Interpreter/Compiler-specific I/O
+
+TIB_CFA = defConst("TIB", TIB)
+NUMTIB, NUMTIB_CFA = defNewVar("#TIB", 0)
+TOIN, TOIN_CFA = defNewVar(">IN", 0)
+
+QUERY_CFA = defWord("QUERY",
+ [TIB_CFA, LIT_CFA, 160, EXPECT_CFA,
+ SPAN_CFA, FETCH_CFA, NUMTIB_CFA, STORE_CFA,
+ LIT_CFA, 0, TOIN_CFA, STORE_CFA,
+ EXIT_CFA])
+
+WORD_CFA = defPrimWord("WORD", () -> begin
+ delim = popPS()
+
+ # Chew up initial occurrences of delim
+ while (mem[TOIN]<mem[NUMTIB] && mem[TIB+mem[TOIN]] == delim)
+ mem[TOIN] += 1
+ end
+
+ countAddr = mem[H]
+ addr = mem[H]+1
+
+ # Start reading in word
+ 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
+
+ # Record count
+ mem[countAddr] = count
+ pushPS(countAddr)
+
+ return NEXT
+end)
+
# Compilation
-CREATE = defPrimWord("CREATE", () -> begin
+STATE, STATE_CFA = defNewVar("STATE", 0)
+
+COMMA_CFA = defPrimWord(",", () -> begin
+ mem[mem[H]] = popPS()
+ mem[H] += 1
+
+ return NEXT
+end)
- wordLen = popPS()
- wordAddr = popPS()
+HERE_CFA = defWord("HERE",
+ [H_CFA, FETCH_CFA, EXIT_CFA])
+
+HEADER_CFA = defPrimWord("HEADER", () -> begin
+ wordAddr = popPS()+1
+ wordLen = mem[wordAddr-1]
word = getString(wordAddr, wordLen)
createHeader(word, 0)
return NEXT
end)
-COMMA = defPrimWord(",", () -> begin
- mem[mem[HERE]] = popPS()
- mem[HERE] += 1
+CREATE_CFA = defWord("CREATE",
+ [LIT_CFA, 32, WORD_CFA, HEADER_CFA,
+ LIT_CFA, DOVAR, COMMA_CFA,
+ EXIT_CFA])
+DODOES = defPrim(() -> begin
+ pushRS(reg.IP)
+ reg.IP = popPS()
+ pushPS(reg.W + 1)
return NEXT
-end)
+end, name="DODOES")
+
+DOES_HELPER_CFA = defPrimWord("(DOES>)", () -> begin
+
+ pushPS(mem[LATEST])
+ callPrim(mem[TOCFA_CFA])
+ cfa = popPS()
+
+ runtimeAddr = popPS()
-LBRAC = defPrimWord("[", () -> begin
+ mem[cfa] = defPrim(eval(:(() -> begin
+ pushPS($(runtimeAddr))
+ return DODOES
+ end)), name="doesPrim")
+
+ return NEXT
+end, flags=F_IMMED)
+
+DOES_CFA = defWord("DOES>",
+ [LIT_CFA, LIT_CFA, COMMA_CFA, HERE_CFA, LIT_CFA, 3, ADD_CFA, COMMA_CFA,
+ LIT_CFA, DOES_HELPER_CFA, COMMA_CFA, LIT_CFA, EXIT_CFA, COMMA_CFA, EXIT_CFA],
+ flags=F_IMMED)
+
+LBRAC_CFA = defPrimWord("[", () -> begin
mem[STATE] = 0
return NEXT
end, flags=F_IMMED)
-RBRAC = defPrimWord("]", () -> begin
+RBRAC_CFA = defPrimWord("]", () -> begin
mem[STATE] = 1
return NEXT
end, flags=F_IMMED)
-HIDDEN = defPrimWord("HIDDEN", () -> begin
- addr = popPS() + 1
- mem[addr] = mem[addr] $ F_HIDDEN
+HIDDEN_CFA = defPrimWord("HIDDEN", () -> begin
+ lenAndFlagsAddr = mem[LATEST] + 1
+ mem[lenAndFlagsAddr] = mem[lenAndFlagsAddr] $ F_HIDDEN
return NEXT
end)
-HIDE = defWord("HIDE",
- [WORD,
- FIND,
- HIDDEN,
- EXIT])
-
-COLON = defWord(":",
- [WORD,
- CREATE,
- LIT, DOCOL, COMMA,
- LATEST_CFA, FETCH, HIDDEN,
- RBRAC,
- EXIT])
+COLON_CFA = defWord(":",
+ [LIT_CFA, 32, WORD_CFA,
+ HEADER_CFA,
+ LIT_CFA, DOCOL, COMMA_CFA,
+ HIDDEN_CFA,
+ RBRAC_CFA,
+ EXIT_CFA])
-SEMICOLON = defWord(";",
- [LIT, EXIT, COMMA,
- LATEST_CFA, FETCH, HIDDEN,
- LBRAC,
- EXIT], flags=F_IMMED)
+SEMICOLON_CFA = defWord(";",
+ [LIT_CFA, EXIT_CFA, COMMA_CFA,
+ HIDDEN_CFA,
+ LBRAC_CFA,
+ EXIT_CFA], flags=F_IMMED)
-IMMEDIATE = defPrimWord("IMMEDIATE", () -> begin
+IMMEDIATE_CFA = defPrimWord("IMMEDIATE", () -> begin
lenAndFlagsAddr = mem[LATEST] + 1
mem[lenAndFlagsAddr] = mem[lenAndFlagsAddr] $ F_IMMED
return NEXT
end, flags=F_IMMED)
-TICK = defWord("'",
- [STATE_CFA, FETCH, ZBRANCH, 7,
- FROMR, DUP, INCR, TOR, FETCH, EXIT,
- WORD, FIND, TOCFA, EXIT])
+# Outer Interpreter
-# Strings
-
-LITSTRING = defPrimWord("LITSTRING", () -> begin
- len = mem[reg.IP]
- reg.IP += 1
- pushPS(reg.IP)
- pushPS(len)
- reg.IP += len
-
- return NEXT
-end)
-
-TELL = defPrimWord("TELL", () -> begin
- len = popPS()
- addr = popPS()
- str = getString(addr, len)
- print(str)
- return NEXT
-end)
-
-# Outer interpreter
-
-EXECUTE = defPrimWord("EXECUTE", () -> begin
+EXECUTE_CFA = defPrimWord("EXECUTE", () -> begin
reg.W = popPS()
return mem[reg.W]
end)
-type ParseError <: Exception
- wordName::ASCIIString
-end
-Base.showerror(io::IO, ex::ParseError) = print(io, "Parse error at word: '$(ex.wordName)'.")
-
-INTERPRET = defPrimWord("INTERPRET", () -> begin
-
- callPrim(mem[WORD])
-
- wordName = getString(mem[reg.PSP-1], mem[reg.PSP])
- #println("... ", replace(replace(wordName, "\004", "EOF"), "\n", "\\n"), " ...")
+INTERPRET_CFA = defWord("INTERPRET",
+ [LIT_CFA, 32, WORD_CFA, # Read next space-delimited word
- callPrim(mem[TWODUP])
- callPrim(mem[FIND])
+ DUP_CFA, FETCH_CFA, ZE_CFA, ZBRANCH_CFA, 3,
+ DROP_CFA, EXIT_CFA, # Exit if TIB is exhausted
- wordAddr = mem[reg.PSP]
+ STATE_CFA, FETCH_CFA, ZBRANCH_CFA, 24,
+ # Compiling
+ FIND_CFA, QDUP_CFA, ZBRANCH_CFA, 13,
- if wordAddr>0
- # Word in dictionary
+ # Found word.
+ LIT_CFA, -1, EQ_CFA, INVERT_CFA, ZBRANCH_CFA, 4,
- isImmediate = (mem[wordAddr+1] & F_IMMED) != 0
- callPrim(mem[TOCFA])
+ # Immediate: Execute!
+ EXECUTE_CFA, BRANCH_CFA, -26,
- callPrim(mem[ROT]) # get rid of extra copy of word string details
- popPS()
- popPS()
+ # Not immediate: Compile!
+ COMMA_CFA, BRANCH_CFA, -29,
- if mem[STATE] == 0 || isImmediate
- # Execute!
- return callPrim(mem[EXECUTE])
- else
- # Append CFA to dictionary
- callPrim(mem[COMMA])
- end
- else
- # Not in dictionary, assume number
-
- popPS()
+ # No word found, parse number
+ NUMBER_CFA, LIT_CFA, LIT_CFA, COMMA_CFA, COMMA_CFA, BRANCH_CFA, -36,
+
+ # Interpreting
+ FIND_CFA, QDUP_CFA, ZBRANCH_CFA, 5,
- callPrim(mem[NUMBER])
+ # Found word. Execute!
+ DROP_CFA, EXECUTE_CFA, BRANCH_CFA, -44,
- if popPS() != 0
- throw(ParseError(wordName))
- end
+ # No word found, parse number and leave on stack
+ NUMBER_CFA, BRANCH_CFA, -47,
+ EXIT_CFA])
- if mem[STATE] == 0
- # Number already on stack!
- else
- # Append literal to dictionary
- pushPS(LIT)
- callPrim(mem[COMMA])
- callPrim(mem[COMMA])
- end
+PROMPT_CFA = defPrimWord("PROMPT", () -> begin
+ if (mem[STATE] == 0 && currentSource() == STDIN)
+ println(" ok")
end
return NEXT
end)
-QUIT = defWord("QUIT",
- [RSP0_CFA, RSPSTORE,
- INTERPRET,
- BRANCH,-2])
+QUIT_CFA = defWord("QUIT",
+ [LIT_CFA, 0, STATE_CFA, STORE_CFA,
+ LIT_CFA, 0, NUMTIB_CFA, STORE_CFA,
+ RSP0_CFA, RSPSTORE_CFA,
+ QUERY_CFA,
+ INTERPRET_CFA, PROMPT_CFA,
+ BRANCH_CFA,-4])
-BYE = defPrimWord("BYE", () -> begin
- return 0
-end)
+ABORT_CFA = defWord("ABORT",
+ [PSP0_CFA, PSPSTORE_CFA, QUIT_CFA])
-PROMPT = defPrimWord("PROMPT", () -> begin
- println(" ok")
+BYE_CFA = defPrimWord("BYE", () -> begin
+ println("\nBye!")
+ return 0
end)
-NL = defPrimWord("\n", () -> begin
- if mem[STATE] == 0 && currentSource() == STDIN
- callPrim(mem[PROMPT])
- end
- return NEXT
-end, flags=F_IMMED)
+# File I/O
-INCLUDE = defPrimWord("INCLUDE", () -> begin
- callPrim(mem[WORD])
- wordLen = popPS()
- wordAddr = popPS()
+INCLUDE_CFA = defPrimWord("INCLUDE", () -> begin
+ pushPS(32)
+ callPrim(mem[WORD_CFA])
+ wordAddr = popPS()+1
+ wordLen = mem[wordAddr-1]
word = getString(wordAddr, wordLen)
push!(sources, open(word, "r"))
return NEXT
end)
-EOF_WORD = defPrimWord("\x04", () -> begin
- if currentSource() != STDIN
- close(currentSource())
- end
-
- pop!(sources)
-
- if length(sources)>0
- if currentSource() == STDIN
- callPrim(mem[PROMPT])
- end
-
- return NEXT
- else
- return 0
- end
-end, flags=F_IMMED)
-
-# Odds and Ends
-CHAR = defPrimWord("CHAR", () -> begin
- callPrim(mem[WORD])
- wordLen = popPS()
- wordAddr = popPS()
- word = getString(wordAddr, wordLen)
- pushPS(Int64(word[1]))
-
- return NEXT
-end)
+#### VM loop ####
initialized = false
initFileName = nothing
initFileName = Pkg.dir("forth/src/lib.4th")
end
-
-#### VM loop ####
function run(;initialize=true)
# Begin with STDIN as source
push!(sources, STDIN)
end
# Start with IP pointing to first instruction of outer interpreter
- reg.IP = QUIT + 1
+ reg.IP = QUIT_CFA + 1
# Primitive processing loop.
# Everyting else is simply a consequence of this loop!
jmp = NEXT
while jmp != 0
try
- #println("Evaluating prim ", jmp," ", primNames[-jmp])
+ #println("Entering prim $(getPrimName(jmp))")
jmp = callPrim(jmp)
catch ex
close(pop!(sources))
end
- mem[STATE] = 0
- mem[NUMTIB] = 0
- reg.IP = QUIT + 1
+ # QUIT
+ reg.IP = ABORT_CFA + 1
jmp = NEXT
end
end
# Debugging tools
+TRACE_CFA = defPrimWord("TRACE", () -> begin
+ println("reg.W: $(reg.W) reg.IP: $(reg.IP)")
+ print("PS: "); printPS()
+ print("RS: "); printRS()
+ print("[paused]")
+ readline()
+
+ return NEXT
+end)
+
function dump(startAddr::Int64; count::Int64 = 100, cellsPerLine::Int64 = 10)
chars = Array{Char,1}(cellsPerLine)
end
function printPS()
- count = reg.PSP - mem[PSP0]
+ count = reg.PSP - PSP0
if count > 0
print("<$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