callPrim(addr::Int64) = primitives[-addr]()
-# Word creation
+# Word creation functions
function createHeader(name::AbstractString, flags::Int64)
mem[mem[HERE]] = mem[LATEST]
return addr
end
-# Variable creation
+# Variable creation functions
function defExistingVar(name::AbstractString, varAddr::Int64; flags::Int64=0)
codeWordAddr = mem[HERE]
varAddr = mem[HERE] + 1
- f = eval(:(() -> begin
- pushPS($(varAddr))
- return NEXT
- end))
-
- mem[mem[HERE]] = defPrim(f, name=name); mem[HERE] += 1
+ mem[mem[HERE]] = DOVAR; mem[HERE] += 1
mem[mem[HERE]] = initial; mem[HERE] += 1
return varAddr, codeWordAddr
end
function defConst(name::AbstractString, val::Int64; flags::Int64=0)
- defPrimWord(name, eval(:(() -> begin
- pushPS($(val))
- return NEXT
- end)))
+ createHeader(name, flags)
+
+ mem[mem[HERE]] = DOCON; mem[HERE] += 1
+ mem[mem[HERE]] = val; mem[HERE] += 1
return val
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 = defPrimWord("EXIT", () -> begin
reg.IP = popRS()
return NEXT
a = popPS()
b = popPS()
c = popPS()
+ pushPS(b)
pushPS(a)
pushPS(c)
- pushPS(b)
return NEXT
end)
a = popPS()
b = popPS()
c = popPS()
- pushPS(b)
pushPS(a)
pushPS(c)
+ pushPS(b)
return NEXT
end)
+
TWODROP = defPrimWord("2DROP", () -> begin
popPS()
popPS()
d = popPS()
pushPS(b)
pushPS(a)
- pushPS(c)
pushPS(d)
+ 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)
return NEXT
end)
+TWOMUL = defPrimWord("2*", () -> begin
+ pushPS(popPS() << 1)
+ return NEXT
+end)
+
+TWODIV = defPrimWord("2/", () -> begin
+ pushPS(popPS() >> 1)
+ return NEXT
+end)
+
EQU = defPrimWord("=", () -> begin
b = popPS()
a = popPS()
defConst("VERSION", 1)
defConst("DOCOL", DOCOL)
+defConst("DOCON", DOCON)
+defConst("DOVAR", DOVAR)
defConst("DICT", DICT)
F_IMMED = defConst("F_IMMED", 128)
F_HIDDEN = defConst("F_HIDDEN", 256)
return NEXT
end)
+RFETCH = defPrimWord("R@", () -> begin
+ pushPS(mem[reg.RSP])
+ return NEXT
+end)
+
RSPFETCH = defPrimWord("RSP@", () -> begin
pushPS(reg.RSP)
return NEXT
end, flags=F_IMMED)
TICK = defWord("'",
- [STATE_CFA, FETCH, ZBRANCH, 7,
- FROMR, DUP, INCR, TOR, FETCH, EXIT,
- WORD, FIND, TOCFA, EXIT])
+ [WORD, FIND, TOCFA, EXIT])
+
+BTICK = defWord("[']",
+ [FROMR, DUP, INCR, TOR, FETCH, EXIT])
+
# Strings
return mem[reg.W]
end)
+type ParseError <: Exception
+ wordName::ASCIIString
+end
+Base.showerror(io::IO, ex::ParseError) = print(io, "Parse error at word: '$(ex.wordName)'.")
+
+DEBUG, DEBUG_CFA = defNewVar("DEBUG", 0)
+
INTERPRET = defPrimWord("INTERPRET", () -> begin
callPrim(mem[WORD])
wordName = getString(mem[reg.PSP-1], mem[reg.PSP])
- #println("... ", replace(replace(wordName, "\004", "EOF"), "\n", "\\n"), " ...")
+ if mem[DEBUG] != 0
+ println("... ", replace(replace(wordName, "\004", "EOF"), "\n", "\\n"), " ...")
+ end
callPrim(mem[TWODUP])
callPrim(mem[FIND])
isImmediate = (mem[wordAddr+1] & F_IMMED) != 0
callPrim(mem[TOCFA])
- callPrim(mem[ROT]) # get rid of extra copy of word string details
+ callPrim(mem[NROT]) # get rid of extra copy of word string details
popPS()
popPS()
callPrim(mem[NUMBER])
if popPS() != 0
- println("Parse error at word: '$wordName'")
- return NEXT
+ throw(ParseError(wordName))
end
if mem[STATE] == 0
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 run()
+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
jmp = NEXT
while jmp != 0
try
- #println("Evaluating prim ", jmp," ", primNames[-jmp])
+ 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