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
+size_RS = 1000 # Return stack size
+size_PS = 1000 # Parameter stack size
+size_TIB = 1000 # Terminal input buffer size
# The mem array constitutes the memory of the VM. It has the following geography:
#
# the dictionary.
#
# Simple linear addressing is used with one exception: references to primitive code
-# blocks, which are represented as anonymous functions, appear the negative index
-# into the primitives array which contains only these functions.
+# blocks, which are represented as anonymous functions, appear as negative indicies
+# into the primitives array which contains these functions.
mem = Array{Int64,1}(size_mem)
primitives = Array{Function,1}()
+primNames = Array{ASCIIString,1}()
# Built-in variables
PSP::Int64 # Parameter/data stack pointer
IP::Int64 # Instruction pointer
W::Int64 # Working register
- X::Int64 # Extra register
end
-reg = Reg(mem[RSP0], mem[PSP0], 0, 0, 0)
+reg = Reg(mem[RSP0], mem[PSP0], 0, 0)
-# Stack manipulation
+# Stack manipulation functions
-type StackUnderflow <: Exception end
+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(StackUnderflow())
+ throw(ParamStackUnderflow())
end
end
function ensureRSDepth(depth::Int64)
if getRSDepth()<depth
- throw(StackUnderflow())
+ throw(ReturnStackUnderflow())
end
end
return val
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
+
# Primitive creation and calling functions
+function defPrim(f::Function; name="nameless")
+ push!(primitives, f)
+ push!(primNames, replace(replace(name, "\004", "EOF"), "\n", "\\n"))
+
+ return -length(primitives)
+end
+
+callPrim(addr::Int64) = primitives[-addr]()
+
+# Word creation functions
+
function createHeader(name::AbstractString, flags::Int64)
mem[mem[HERE]] = mem[LATEST]
mem[LATEST] = mem[HERE]
mem[HERE] += 1
mem[mem[HERE]] = length(name) | flags; mem[HERE] += 1
- mem[mem[HERE]:(mem[HERE]+length(name)-1)] = [Int(c) for c in name]; mem[HERE] += length(name)
+ putString(name, mem[HERE]); mem[HERE] += length(name)
end
-function defPrim(name::AbstractString, f::Function; flags::Int64=0)
+function defPrimWord(name::AbstractString, f::Function; flags::Int64=0)
createHeader(name, flags)
codeWordAddr = mem[HERE]
- push!(primitives, f)
- mem[codeWordAddr] = -length(primitives)
+ mem[codeWordAddr] = defPrim(f, name=name)
mem[HERE] += 1
return codeWordAddr
end
-callPrim(addr::Int64) = primitives[-addr]()
+function defWord(name::AbstractString, wordAddrs::Array{Int64,1}; flags::Int64=0)
+ createHeader(name, flags)
+
+ addr = mem[HERE]
+ mem[mem[HERE]] = DOCOL
+ mem[HERE] += 1
+
+ for wordAddr in wordAddrs
+ mem[mem[HERE]] = wordAddr
+ mem[HERE] += 1
+ end
+
+ return addr
+end
+
+# Variable creation functions
function defExistingVar(name::AbstractString, varAddr::Int64; flags::Int64=0)
- defPrim(name, eval(:(() -> begin
+
+ defPrimWord(name, eval(:(() -> begin
pushPS($(varAddr))
- return mem[NEXT]
+ return NEXT
end)))
end
function defNewVar(name::AbstractString, initial::Int64; flags::Int64=0)
createHeader(name, flags)
+ codeWordAddr = mem[HERE]
varAddr = mem[HERE] + 1
- push!(primitives, eval(:(() -> begin
- pushPS($(varAddr))
- return mem[NEXT]
- end)))
- mem[mem[HERE]] = -length(primitives); mem[HERE] += 1
+ mem[mem[HERE]] = DOVAR; mem[HERE] += 1
mem[mem[HERE]] = initial; mem[HERE] += 1
- return varAddr
+ return varAddr, codeWordAddr
end
function defConst(name::AbstractString, val::Int64; flags::Int64=0)
- defPrim(name, eval(:(() -> begin
- pushPS($(val))
- return mem[NEXT]
- end)))
-
- return val
-end
-
-function defWord(name::AbstractString, wordAddrs::Array{Int64,1}; flags::Int64=0)
createHeader(name, flags)
- addr = mem[HERE]
- mem[mem[HERE]] = mem[DOCOL]
- mem[HERE] += 1
-
- for wordAddr in wordAddrs
- mem[mem[HERE]] = wordAddr
- mem[HERE] += 1
- end
+ mem[mem[HERE]] = DOCON; mem[HERE] += 1
+ mem[mem[HERE]] = val; mem[HERE] += 1
- return addr
+ return val
end
# Threading Primitives (inner interpreter)
-NEXT = defPrim("NEXT", () -> begin
+NEXT = defPrim(() -> begin
reg.W = mem[reg.IP]
reg.IP += 1
return mem[reg.W]
-end)
+end, name="NEXT")
-DOCOL = defPrim("DOCOL", () -> begin
+DOCOL = defPrim(() -> begin
pushRS(reg.IP)
reg.IP = reg.W + 1
- return mem[NEXT]
-end)
+ return NEXT
+end, name="DOCOL")
+
+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 = defPrim("EXIT", () -> begin
+EXIT = defPrimWord("EXIT", () -> begin
reg.IP = popRS()
- return mem[NEXT]
+ return NEXT
end)
+# Dictionary entries for core built-in variables, constants
+
+HERE_CFA = defExistingVar("HERE", HERE)
+LATEST_CFA = defExistingVar("LATEST", LATEST)
+PSP0_CFA = defExistingVar("PSP0", PSP0)
+RSP0_CFA = defExistingVar("RSP0", RSP0)
+
+defConst("DOCOL", DOCOL)
+defConst("DOCON", DOCON)
+defConst("DOVAR", DOVAR)
+
+defConst("DICT", DICT)
+defConst("MEMSIZE", size_mem)
+
+F_IMMED = defConst("F_IMMED", 128)
+F_HIDDEN = defConst("F_HIDDEN", 256)
+F_LENMASK = defConst("F_LENMASK", 127)
+
# Basic forth primitives
-DROP = defPrim("DROP", () -> begin
+DROP = defPrimWord("DROP", () -> begin
popPS()
- return mem[NEXT]
+ return NEXT
end)
-SWAP = defPrim("SWAP", () -> begin
+SWAP = defPrimWord("SWAP", () -> begin
a = popPS()
b = popPS()
pushPS(a)
pushPS(b)
- return mem[NEXT]
+ return NEXT
end)
-DUP = defPrim("DUP", () -> begin
+DUP = defPrimWord("DUP", () -> begin
+ ensurePSDepth(1)
pushPS(mem[reg.PSP])
- return mem[NEXT]
+ return NEXT
end)
-OVER = defPrim("OVER", () -> begin
+OVER = defPrimWord("OVER", () -> begin
ensurePSDepth(2)
pushPS(mem[reg.PSP-1])
- return mem[NEXT]
+ return NEXT
end)
-ROT = defPrim("ROT", () -> begin
+ROT = defPrimWord("ROT", () -> begin
a = popPS()
b = popPS()
c = popPS()
+ pushPS(b)
pushPS(a)
pushPS(c)
- pushPS(b)
- return mem[NEXT]
+ return NEXT
end)
-NROT = defPrim("-ROT", () -> begin
+NROT = defPrimWord("-ROT", () -> begin
a = popPS()
b = popPS()
c = popPS()
- pushPS(b)
pushPS(a)
pushPS(c)
- return mem[NEXT]
+ pushPS(b)
+ return NEXT
end)
-TWODROP = defPrim("2DROP", () -> begin
+
+TWODROP = defPrimWord("2DROP", () -> begin
popPS()
popPS()
- return mem[NEXT]
+ return NEXT
end)
-TWODUP = defPrim("2DUP", () -> begin
+TWODUP = defPrimWord("2DUP", () -> begin
ensurePSDepth(2)
a = mem[reg.PSP-1]
b = mem[reg.PSP]
pushPS(a)
pushPS(b)
- return mem[NEXT]
+ return NEXT
end)
-TWOSWAP = defPrim("2SWAP", () -> begin
+TWOSWAP = defPrimWord("2SWAP", () -> begin
a = popPS()
b = popPS()
c = popPS()
d = popPS()
pushPS(b)
pushPS(a)
- pushPS(c)
pushPS(d)
- return mem[NEXT]
+ pushPS(c)
+ return NEXT
+end)
+
+TWOOVER = defPrimWord("2OVER", () -> begin
+ ensurePSDepth(4)
+ a = mem[reg.PSP-3]
+ b = mem[reg.PSP-2]
+ pushPS(a)
+ pushPS(b)
+ return NEXT
end)
-QDUP = defPrim("?DUP", () -> begin
+QDUP = defPrimWord("?DUP", () -> begin
ensurePSDepth(1)
val = mem[reg.PSP]
if val != 0
pushPS(val)
end
- return mem[NEXT]
+ return NEXT
end)
-INCR = defPrim("1+", () -> begin
+INCR = defPrimWord("1+", () -> begin
ensurePSDepth(1)
mem[reg.PSP] += 1
- return mem[NEXT]
+ return NEXT
end)
-DECR = defPrim("1-", () -> begin
+DECR = defPrimWord("1-", () -> begin
ensurePSDepth(1)
mem[reg.PSP] -= 1
- return mem[NEXT]
+ return NEXT
end)
-INCR2 = defPrim("2+", () -> begin
+INCR2 = defPrimWord("2+", () -> begin
ensurePSDepth(1)
mem[reg.PSP] += 2
- return mem[NEXT]
+ return NEXT
end)
-DECR2 = defPrim("2-", () -> begin
+DECR2 = defPrimWord("2-", () -> begin
ensurePSDepth(1)
mem[reg.PSP] -= 2
- return mem[NEXT]
+ return NEXT
end)
-ADD = defPrim("+", () -> begin
+ADD = defPrimWord("+", () -> begin
b = popPS()
a = popPS()
pushPS(a+b)
- return mem[NEXT]
+ return NEXT
end)
-SUB = defPrim("-", () -> begin
+SUB = defPrimWord("-", () -> begin
b = popPS()
a = popPS()
pushPS(a-b)
- return mem[NEXT]
+ return NEXT
end)
-MUL = defPrim("*", () -> begin
+MUL = defPrimWord("*", () -> begin
b = popPS()
a = popPS()
pushPS(a*b)
- return mem[NEXT]
+ return NEXT
end)
-DIVMOD = defPrim("/MOD", () -> begin
+DIVMOD = defPrimWord("/MOD", () -> begin
b = popPS()
a = popPS()
q,r = divrem(a,b)
pushPS(r)
pushPS(q)
- return mem[NEXT]
+ return NEXT
+end)
+
+TWOMUL = defPrimWord("2*", () -> begin
+ pushPS(popPS() << 1)
+ return NEXT
end)
-EQU = defPrim("=", () -> begin
+TWODIV = defPrimWord("2/", () -> begin
+ pushPS(popPS() >> 1)
+ return NEXT
+end)
+
+EQU = defPrimWord("=", () -> begin
b = popPS()
a = popPS()
pushPS(a==b ? -1 : 0)
- return mem[NEXT]
+ return NEXT
end)
-NEQU = defPrim("<>", () -> begin
+NEQU = defPrimWord("<>", () -> begin
b = popPS()
a = popPS()
pushPS(a!=b ? -1 : 0)
- return mem[NEXT]
+ return NEXT
end)
-LT = defPrim("<", () -> begin
+LT = defPrimWord("<", () -> begin
b = popPS()
a = popPS()
pushPS(a<b ? -1 : 0)
- return mem[NEXT]
+ return NEXT
end)
-GT = defPrim(">", () -> begin
+GT = defPrimWord(">", () -> begin
b = popPS()
a = popPS()
pushPS(a>b ? -1 : 0)
- return mem[NEXT]
+ return NEXT
end)
-LE = defPrim("<=", () -> begin
+LE = defPrimWord("<=", () -> begin
b = popPS()
a = popPS()
pushPS(a<=b ? -1 : 0)
- return mem[NEXT]
+ return NEXT
end)
-GE = defPrim(">=", () -> begin
+GE = defPrimWord(">=", () -> begin
b = popPS()
a = popPS()
pushPS(a>=b ? -1 : 0)
- return mem[NEXT]
+ return NEXT
end)
-ZEQU = defPrim("0=", () -> begin
+ZEQU = defPrimWord("0=", () -> begin
pushPS(popPS() == 0 ? -1 : 0)
- return mem[NEXT]
+ return NEXT
end)
-ZNEQU = defPrim("0<>", () -> begin
+ZNEQU = defPrimWord("0<>", () -> begin
pushPS(popPS() != 0 ? -1 : 0)
- return mem[NEXT]
+ return NEXT
end)
-ZLT = defPrim("0<", () -> begin
+ZLT = defPrimWord("0<", () -> begin
pushPS(popPS() < 0 ? -1 : 0)
- return mem[NEXT]
+ return NEXT
end)
-ZGT = defPrim("0>", () -> begin
+ZGT = defPrimWord("0>", () -> begin
pushPS(popPS() > 0 ? -1 : 0)
- return mem[NEXT]
+ return NEXT
end)
-ZLE = defPrim("0<=", () -> begin
+ZLE = defPrimWord("0<=", () -> begin
pushPS(popPS() <= 0 ? -1 : 0)
- return mem[NEXT]
+ return NEXT
end)
-ZGE = defPrim("0>=", () -> begin
+ZGE = defPrimWord("0>=", () -> begin
pushPS(popPS() >= 0 ? -1 : 0)
- return mem[NEXT]
+ return NEXT
end)
-AND = defPrim("AND", () -> begin
+AND = defPrimWord("AND", () -> begin
b = popPS()
a = popPS()
pushPS(a & b)
- return mem[NEXT]
+ return NEXT
end)
-OR = defPrim("OR", () -> begin
+OR = defPrimWord("OR", () -> begin
b = popPS()
a = popPS()
pushPS(a | b)
- return mem[NEXT]
+ return NEXT
end)
-XOR = defPrim("XOR", () -> begin
+XOR = defPrimWord("XOR", () -> begin
b = popPS()
a = popPS()
pushPS(a $ b)
- return mem[NEXT]
+ return NEXT
end)
-INVERT = defPrim("INVERT", () -> begin
+INVERT = defPrimWord("INVERT", () -> begin
pushPS(~popPS())
- return mem[NEXT]
+ return NEXT
end)
# Literals
-LIT = defPrim("LIT", () -> begin
+LIT = defPrimWord("LIT", () -> begin
pushPS(mem[reg.IP])
reg.IP += 1
- return mem[NEXT]
+ return NEXT
end)
# Memory primitives
-STORE = defPrim("!", () -> begin
+STORE = defPrimWord("!", () -> begin
addr = popPS()
dat = popPS()
mem[addr] = dat
- return mem[NEXT]
+ return NEXT
end)
-FETCH = defPrim("@", () -> begin
+FETCH = defPrimWord("@", () -> begin
addr = popPS()
pushPS(mem[addr])
- return mem[NEXT]
+ return NEXT
end)
-ADDSTORE = defPrim("+!", () -> begin
+ADDSTORE = defPrimWord("+!", () -> begin
addr = popPS()
toAdd = popPS()
mem[addr] += toAdd
- return mem[NEXT]
+ return NEXT
end)
-SUBSTORE = defPrim("-!", () -> begin
+SUBSTORE = defPrimWord("-!", () -> begin
addr = popPS()
toSub = popPS()
mem[addr] -= toSub
- return mem[NEXT]
+ return NEXT
end)
-# Built-in variables
-
-defExistingVar("HERE", HERE)
-defExistingVar("LATEST", LATEST)
-defExistingVar("PSP0", PSP0)
-defExistingVar("RSP0", RSP0)
-STATE = defNewVar("STATE", 0)
-BASE = 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 = defPrim(">R", () -> begin
+TOR = defPrimWord(">R", () -> begin
pushRS(popPS())
- return mem[NEXT]
+ return NEXT
end)
-FROMR = defPrim("R>", () -> begin
+FROMR = defPrimWord("R>", () -> begin
pushPS(popRS())
- return mem[NEXT]
+ return NEXT
+end)
+
+RFETCH = defPrimWord("R@", () -> begin
+ pushPS(mem[reg.RSP])
+ return NEXT
end)
-RSPFETCH = defPrim("RSP@", () -> begin
+RSPFETCH = defPrimWord("RSP@", () -> begin
pushPS(reg.RSP)
- return mem[NEXT]
+ return NEXT
end)
-RSPSTORE = defPrim("RSP!", () -> begin
+RSPSTORE = defPrimWord("RSP!", () -> begin
RSP = popPS()
- return mem[NEXT]
+ return NEXT
end)
-RDROP = defPrim("RDROP", () -> begin
+RDROP = defPrimWord("RDROP", () -> begin
popRS()
- return mem[NEXT]
+ return NEXT
end)
# Parameter Stack
-PSPFETCH = defPrim("PSP@", () -> begin
+PSPFETCH = defPrimWord("PSP@", () -> begin
pushPS(reg.PSP)
- return mem[NEXT]
+ return NEXT
end)
-PSPSTORE = defPrim("PSP!", () -> begin
+PSPSTORE = defPrimWord("PSP!", () -> begin
PSP = popPS()
- return mem[NEXT]
+ return NEXT
+end)
+
+# Working Register
+
+WFETCH = defPrimWord("W@", () -> begin
+ pushPS(reg.W)
+ return NEXT
+end)
+
+WSTORE = defPrimWord("W!", () -> begin
+ reg.W = popPS()
+ return NEXT
end)
# I/O
+sources = Array{Any,1}()
+currentSource() = sources[length(sources)]
+
defConst("TIB", TIB)
-NUMTIB = defNewVar("#TIB", 0)
-TOIN = defNewVar(">IN", 0)
+NUMTIB, NUMTIB_CFA = defNewVar("#TIB", 0)
+TOIN, TOIN_CFA = defNewVar(">IN", 0)
+EOF = defConst("EOF", 4)
-KEY = defPrim("KEY", () -> begin
+KEY = defPrimWord("KEY", () -> begin
if mem[TOIN] >= mem[NUMTIB]
mem[TOIN] = 0
- line = readline()
- mem[NUMTIB] = length(line)
- mem[TIB:(TIB+mem[NUMTIB]-1)] = [Int64(c) for c in collect(line)]
+
+ if !eof(currentSource())
+ line = readline(currentSource())
+ mem[NUMTIB] = length(line)
+ putString(line, TIB)
+ else
+ mem[NUMTIB] = 1
+ mem[TIB] = EOF
+ end
end
pushPS(mem[TIB + mem[TOIN]])
mem[TOIN] += 1
- return mem[NEXT]
+ return NEXT
end)
-EMIT = defPrim("EMIT", () -> begin
+EMIT = defPrimWord("EMIT", () -> begin
print(Char(popPS()))
- return mem[NEXT]
+ return NEXT
end)
-WORD = defPrim("WORD", () -> begin
-
- c = -1
+WORD = defPrimWord("WORD", () -> begin
- skip_to_end = false
- while true
+ eof_char = Char(EOF)
+ c = eof_char
+ while true
callPrim(mem[KEY])
c = Char(popPS())
- if c == '\\'
- skip_to_end = true
- continue
- end
-
- if skip_to_end
- if c == '\n'
- skip_to_end = false
- end
- continue
- end
-
if c == ' ' || c == '\t'
continue
end
wordAddr = mem[HERE]
offset = 0
+ if c == '\n' || c == eof_char
+ # Treat newline as a special word
+
+ mem[wordAddr + offset] = Int64(c)
+ pushPS(wordAddr)
+ pushPS(1)
+ return NEXT
+ end
+
while true
mem[wordAddr + offset] = Int64(c)
offset += 1
callPrim(mem[KEY])
c = Char(popPS())
- if c == ' ' || c == '\t' || c == '\n'
+ if c == ' ' || c == '\t' || c == '\n' || c == eof_char
+ # Rewind KEY
+ mem[TOIN] -= 1
break
end
end
pushPS(wordAddr)
pushPS(wordLen)
- return mem[NEXT]
+ return NEXT
end)
-NUMBER = defPrim("NUMBER", () -> begin
+BASE, BASE_CFA = defNewVar("BASE", 10)
+NUMBER = defPrimWord("NUMBER", () -> begin
wordLen = popPS()
wordAddr = popPS()
- s = ASCIIString([Char(c) for c in mem[wordAddr:(wordAddr+wordLen-1)]])
+ s = getString(wordAddr, wordLen)
try
pushPS(parse(Int64, s, mem[BASE]))
pushPS(1) # Error indication
end
- return mem[NEXT]
+ return NEXT
end)
# Dictionary searches
-FIND = defPrim("FIND", () -> begin
+FIND = defPrimWord("FIND", () -> begin
wordLen = popPS()
wordAddr = popPS()
- word = ASCIIString([Char(c) for c in mem[wordAddr:(wordAddr+wordLen-1)]])
+ word = lowercase(getString(wordAddr, wordLen))
- latest = mem[LATEST]
+ latest = LATEST
- while latest>0
+ i = 0
+ while (latest = mem[latest]) > 0
lenAndFlags = mem[latest+1]
len = lenAndFlags & F_LENMASK
hidden = (lenAndFlags & F_HIDDEN) == F_HIDDEN
if hidden || len != wordLen
- latest = mem[latest]
continue
end
thisAddr = latest+2
- thisWord = ASCIIString([Char(c) for c in mem[thisAddr:(thisAddr+len-1)]])
+ thisWord = lowercase(getString(thisAddr, len))
- if thisWord == word
+ if lowercase(thisWord) == lowercase(word)
break
end
end
pushPS(latest)
- return mem[NEXT]
+ return NEXT
end)
-TOCFA = defPrim(">CFA", () -> begin
+TOCFA = defPrimWord(">CFA", () -> begin
addr = popPS()
lenAndFlags = mem[addr+1]
pushPS(addr + 2 + len)
- return mem[NEXT]
+ return NEXT
end)
TODFA = defWord(">DFA", [TOCFA, INCR, EXIT])
+# Branching
+
+BRANCH = defPrimWord("BRANCH", () -> begin
+ reg.IP += mem[reg.IP]
+ return NEXT
+end)
+
+ZBRANCH = defPrimWord("0BRANCH", () -> begin
+ if (popPS() == 0)
+ reg.IP += mem[reg.IP]
+ else
+ reg.IP += 1
+ end
+
+ return NEXT
+end)
+
# Compilation
-CREATE = defPrim("CREATE", () -> begin
+STATE, STATE_CFA = defNewVar("STATE", 0)
+
+HEADER = defPrimWord("HEADER", () -> begin
wordLen = popPS()
wordAddr = popPS()
- word = ASCIIString([Char(c) for c in mem[wordAddr:(wordAddr+wordLen-1)]])
+ word = getString(wordAddr, wordLen)
- mem[mem[HERE]] = mem[LATEST]; mem[HERE] += 1
- mem[LATEST] = mem[HERE]
- mem[mem[HERE]] = wordLen; mem[HERE] += 1
+ createHeader(word, 0)
- mem[mem[HERE]:(mem[HERE]+wordLen-1)] = collect(Int64, word)
- mem[HERE] += wordLen
-
- return mem[NEXT]
+ return NEXT
end)
-COMMA = defPrim(",", () -> begin
+COMMA = defPrimWord(",", () -> begin
mem[mem[HERE]] = popPS()
mem[HERE] += 1
- return mem[NEXT]
+ return NEXT
end)
-LBRAC = defPrim("[", () -> begin
+LBRAC = defPrimWord("[", () -> begin
mem[STATE] = 0
- return mem[NEXT]
-end, flags=F_IMMEDIATE)
+ return NEXT
+end, flags=F_IMMED)
-RBRAC = defPrim("]", () -> begin
+RBRAC = defPrimWord("]", () -> begin
mem[STATE] = 1
- return mem[NEXT]
-end, flags=F_IMMEDIATE)
+ return NEXT
+end, flags=F_IMMED)
-HIDDEN = defPrim("HIDDEN", () -> begin
+HIDDEN = defPrimWord("HIDDEN", () -> begin
addr = popPS() + 1
mem[addr] = mem[addr] $ F_HIDDEN
- reurn mem[NEXT]
+ return NEXT
end)
HIDE = defWord("HIDE",
COLON = defWord(":",
[WORD,
- CREATE,
+ HEADER,
LIT, DOCOL, COMMA,
- LATEST, FETCH, HIDDEN,
+ LATEST_CFA, FETCH, HIDDEN,
RBRAC,
EXIT])
SEMICOLON = defWord(";",
[LIT, EXIT, COMMA,
- LATEST, FETCH, HIDDEN,
+ LATEST_CFA, FETCH, HIDDEN,
LBRAC,
- EXIT], flags=F_IMMEDIATE)
+ EXIT], flags=F_IMMED)
-IMMEDIATE = defPrim("IMMEDIATE", () -> begin
+IMMEDIATE = defPrimWord("IMMEDIATE", () -> begin
lenAndFlagsAddr = mem[LATEST] + 1
- mem[lenAndFlagsAddr] = mem[lenAndFlagsAddr] $ F_IMMEDIATE
- return mem[NEXT]
-end, flags=F_IMMEDIATE)
+ mem[lenAndFlagsAddr] = mem[lenAndFlagsAddr] $ F_IMMED
+ return NEXT
+end, flags=F_IMMED)
+
+TICK = defWord("'",
+ [WORD, FIND, TOCFA, EXIT])
+
+BTICK = defWord("[']",
+ [FROMR, DUP, INCR, TOR, FETCH, EXIT])
+
+# CREATE and DOES>
+
+CREATE = defWord("CREATE",
+ [WORD,
+ HEADER,
+ LIT, DOVAR, COMMA, EXIT]);
+
+DODOES = defPrim(() -> begin
+ pushRS(reg.IP)
+ reg.IP = reg.W + 1
+ return NEXT
+end, name="DOCOL")
+
+defConst("DODOES", DODOES)
+
+FROMDOES_PAREN = defWord("(DOES>)",
+ [DODOES, LATEST, FETCH, TOCFA, STORE, EXIT])
+
+FROMDOES = defWord("DOES>",
+ [BTICK, FROMDOES_PAREN, COMMA, BTICK, EXIT, COMMA,
+ BTICK, LIT, COMMA, LATEST, FETCH, TODFA, COMMA], flags=F_IMMED)
+
+
+# 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
+ 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)'.")
+
+DEBUG, DEBUG_CFA = defNewVar("DEBUG", 0)
+
+INTERPRET = defPrimWord("INTERPRET", () -> begin
+
+ callPrim(mem[WORD])
+
+ wordName = getString(mem[reg.PSP-1], mem[reg.PSP])
+ if mem[DEBUG] != 0
+ println("... ", replace(replace(wordName, "\004", "EOF"), "\n", "\\n"), " ...")
+ end
+
+ callPrim(mem[TWODUP])
+ callPrim(mem[FIND])
+
+ wordAddr = mem[reg.PSP]
+
+ if wordAddr>0
+ # Word in dictionary
+
+ isImmediate = (mem[wordAddr+1] & F_IMMED) != 0
+ callPrim(mem[TOCFA])
+
+ callPrim(mem[NROT]) # get rid of extra copy of word string details
+ popPS()
+ popPS()
+
+ 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()
+
+ callPrim(mem[NUMBER])
+
+ if popPS() != 0
+ throw(ParseError(wordName))
+ end
+
+ if mem[STATE] == 0
+ # Number already on stack!
+ else
+ # Append literal to dictionary
+ pushPS(LIT)
+ callPrim(mem[COMMA])
+ callPrim(mem[COMMA])
+ end
+ end
+
+ return NEXT
+end)
+
+QUIT = defWord("QUIT",
+ [RSP0_CFA, RSPSTORE,
+ INTERPRET,
+ BRANCH,-2])
+
+BYE = defPrimWord("BYE", () -> begin
+ return 0
+end)
+
+PROMPT = defPrimWord("PROMPT", () -> begin
+ println(" ok")
+end)
+
+NL = defPrimWord("\n", () -> begin
+ if mem[STATE] == 0 && currentSource() == STDIN
+ callPrim(mem[PROMPT])
+ end
+ return NEXT
+end, flags=F_IMMED)
+
+INCLUDE = defPrimWord("INCLUDE", () -> begin
+ callPrim(mem[WORD])
+ wordLen = popPS()
+ wordAddr = popPS()
+ word = getString(wordAddr, wordLen)
+
+ push!(sources, open(word, "r"))
+
+ # Clear input buffer
+ mem[NUMTIB] = 0
+
+ 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)
+
+initialized = false
+initFileName = nothing
+if isfile("lib.4th")
+ initFileName = "lib.4th"
+elseif isfile(Pkg.dir("forth/src/lib.4th"))
+ initFileName = Pkg.dir("forth/src/lib.4th")
+end
+
#### VM loop ####
-function runVM()
+function run(;initialize=true)
+ # Begin with STDIN as source
+ push!(sources, STDIN)
+
+ global initialized, initFileName
+ if !initialized && initialize
+ if initFileName != nothing
+ print("Including definitions from $initFileName...")
+ push!(sources, open(initFileName, "r"))
+ initialized = true
+ else
+ println("No library file found. Only primitive words available.")
+ end
+ end
+
+ # Start with IP pointing to first instruction of outer interpreter
+ reg.IP = QUIT + 1
+
+ # Primitive processing loop.
+ # Everyting else is simply a consequence of this loop!
jmp = NEXT
- while (jmp = callPrim(jmp)) != 0 end
+ while jmp != 0
+ try
+ if mem[DEBUG] != 0
+ println("Evaluating prim ", jmp," ", primNames[-jmp])
+ end
+
+ jmp = callPrim(jmp)
+
+ catch ex
+ showerror(STDOUT, ex)
+ println()
+
+ while !isempty(sources) && currentSource() != STDIN
+ close(pop!(sources))
+ end
+
+ mem[STATE] = 0
+ mem[NUMTIB] = 0
+ reg.PSP = mem[PSP0]
+ reg.RSP = mem[RSP0]
+ reg.IP = QUIT + 1
+ jmp = NEXT
+ end
+ end
end
# Debugging tools
function dump(startAddr::Int64; count::Int64 = 100, cellsPerLine::Int64 = 10)
chars = Array{Char,1}(cellsPerLine)
- for i in 0:(count-1)
- addr = startAddr + i
- if i%cellsPerLine == 0
- print("$addr:")
- end
-
- print("\t$(mem[addr]) ")
+ lineStartAddr = cellsPerLine*div((startAddr-1),cellsPerLine) + 1
+ endAddr = startAddr + count - 1
+
+ q, r = divrem((endAddr-lineStartAddr+1), cellsPerLine)
+ numLines = q + (r > 0 ? 1 : 0)
+
+ i = lineStartAddr
+ for l in 1:numLines
+ print(i,":")
+
+ for c in 1:cellsPerLine
+ if i >= startAddr && i <= endAddr
+ print("\t",mem[i])
+ if mem[i]>=32 && mem[i]<128
+ chars[c] = Char(mem[i])
+ else
+ chars[c] = '.'
+ end
+ else
+ print("\t")
+ chars[c] = ' '
+ end
- if (mem[addr]>=32 && mem[addr]<176)
- chars[i%cellsPerLine + 1] = Char(mem[addr])
- else
- chars[i%cellsPerLine + 1] = '.'
+ i += 1
end
- if i%cellsPerLine == cellsPerLine-1
- println(string("\t", ASCIIString(chars)))
- end
+ println("\t", ASCIIString(chars))
end
end
end
end
+DUMP = defPrimWord("DUMP", () -> begin
+ count = popPS()
+ addr = popPS()
+
+ dump(addr, count=count)
+
+ return NEXT
+end)
+
end
The Lambda Lab / projects / forth.jl.git / blobdiff