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:
#
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
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 = defPrimWord("DROP", () -> begin
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()
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
return NEXT
end)
+RFETCH = defPrimWord("R@", () -> begin
+ pushPS(mem[reg.RSP])
+ return NEXT
+end)
+
RSPFETCH = defPrimWord("RSP@", () -> begin
pushPS(reg.RSP)
return NEXT
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
- end
-
- pushPS(mem[TIB + mem[TOIN]])
- mem[TOIN] += 1
-
- return NEXT
-end)
-
EMIT = defPrimWord("EMIT", () -> begin
print(Char(popPS()))
return NEXT
end)
-WORD = defPrimWord("WORD", () -> begin
-
- eof_char = Char(EOF)
- c = eof_char
-
- skip_to_end = false
- while true
-
- callPrim(mem[KEY])
- c = Char(popPS())
-
- if c == '\\'
- skip_to_end = true
- continue
- end
-
- if skip_to_end
- if c == '\n' || c == eof_char
- skip_to_end = false
- end
- continue
- end
-
- if c == ' ' || c == '\t'
- continue
- end
-
- break
- 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())
+SPAN, SPAN_CFA = defNewVar("SPAN", 0)
+EXPECT = defPrimWord("EXPECT", () -> begin
+ maxLen = popPS()
+ addr = popPS()
- if c == ' ' || c == '\t' || c == '\n' || c == eof_char
- # Rewind KEY
- mem[TOIN] -= 1
- break
- end
+ if !eof(currentSource())
+ line = readline(currentSource())
+ mem[SPAN] = max(length(line), maxLen)
+ putString(line[1:mem[SPAN]], addr)
+ else
+ mem[SPAN] = 1
+ mem[addr] = EOF
end
- wordLen = offset
-
- pushPS(wordAddr)
- pushPS(wordLen)
-
return NEXT
end)
+BASE, BASE_CFA = defNewVar("BASE", 10)
NUMBER = defPrimWord("NUMBER", () -> begin
- wordLen = popPS()
- wordAddr = popPS()
+ wordAddr = popPS()+1
+ wordLen = mem[wordAddr-1]
s = getString(wordAddr, wordLen)
- try
- pushPS(parse(Int64, s, mem[BASE]))
- pushPS(0)
- catch
- pushPS(1) # Error indication
- end
+ pushPS(parse(Int64, s, mem[BASE]))
return NEXT
end)
FIND = defPrimWord("FIND", () -> begin
- wordLen = popPS()
- wordAddr = popPS()
+ countedAddr = popPS()
+ wordAddr = countedAddr + 1
+ wordLen = mem[countedAddr]
word = lowercase(getString(wordAddr, wordLen))
latest = LATEST
return NEXT
end)
-# Compilation
+# Strings
+
+LITSTRING = defPrimWord("LITSTRING", () -> begin
+ len = mem[reg.IP]
+ reg.IP += 1
+ pushPS(reg.IP)
+ pushPS(len)
+ reg.IP += len
+
+ return NEXT
+end)
-CREATE = defPrimWord("CREATE", () -> begin
+TYPE = defPrimWord("TYPE", () -> begin
+ len = popPS()
+ addr = popPS()
+ str = getString(addr, len)
+ print(str)
+ return NEXT
+end)
+
+# Outer interpreter
+defConst("TIB", TIB)
+NUMTIB, NUMTIB_CFA = defNewVar("#TIB", 0)
+TOIN, TOIN_CFA = defNewVar(">IN", 0)
+
+QUERY = defWord("QUERY",
+ [LIT, TIB, LIT, 80, EXPECT,
+ LIT, SPAN, FETCH, NUMTIB, STORE,
+ LIT, 0, TOIN, STORE,
+ EXIT])
+
+EXECUTE = defPrimWord("EXECUTE", () -> begin
+ reg.W = popPS()
+ return mem[reg.W]
+end)
+
+STATE, STATE_CFA = defNewVar("STATE", 0)
+
+INTERPRET = defWord("INTERPRET",
+ [LIT, 32, WORD, # Read next space-delimited word
+
+ DUP, FETCH, ZEQ, ZBRANCH, 3,
+ DROP, EXIT, # Exit if TIB is exhausted
+
+ STATE_CFA, FETCH, ZBRANCH, 26,
+ # Compiling
+ DUP, FIND, ZBRANCH, 17,
+
+ # Found word.
+ DUP, TOCFA, SWAP, INCR, FETCH, LIT, F_IMMED, AND, ZBRANCH, 4,
+ # Immediate: Execute!
+ EXECUTE, BRANCH, -30,
+
+ # Not immediate: Compile!
+ COMMA, BRANCH, -33,
+
+ # No word found, parse number
+ NUMBER, BTICK, LIT, COMMA, BRANCH, -39,
+
+ # Interpreting
+ DUP, FIND, ZBRANCH, 5,
+
+ # Found word. Execute!
+ TOCFA, EXECUTE, BRANCH, -47,
+
+ # No word found, parse number and leave on stack
+ NUMBER, BRANCH, -50,
+ EXIT]
+)
+
+PROMPT = defPrimWord("PROMPT", () -> begin
+ if (mem[STATE] == 0 and currentSource() == STDIN)
+ println(" ok")
+ end
+end)
+
+QUIT = defWord("QUIT",
+ [RSP0_CFA, RSPSTORE,
+ QUERY,
+ INTERPRET, PROMPT
+ BRANCH,-3])
+
+BYE = defPrimWord("BYE", () -> begin
+ return 0
+end)
+
+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)
+
+# Compilation
+
+HEADER = defPrimWord("HEADER", () -> begin
+
+ wordAddr = popPS()+1
+ wordLen = mem[wordAddr-1]
+ word = getString(wordAddr, wordLen)
+
createHeader(word, 0)
return NEXT
COLON = defWord(":",
[WORD,
- CREATE,
+ HEADER,
LIT, DOCOL, COMMA,
LATEST_CFA, FETCH, HIDDEN,
RBRAC,
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])
-# Strings
+BTICK = defWord("[']",
+ [FROMR, DUP, INCR, TOR, FETCH, EXIT])
-LITSTRING = defPrimWord("LITSTRING", () -> begin
- len = mem[reg.IP]
- reg.IP += 1
- pushPS(reg.IP)
- pushPS(len)
- reg.IP += len
+# CREATE and DOES>
- return NEXT
-end)
+CREATE = defWord("CREATE",
+ [WORD,
+ HEADER,
+ LIT, DOVAR, COMMA, EXIT]);
-TELL = defPrimWord("TELL", () -> begin
- len = popPS()
- addr = popPS()
- str = getString(addr, len)
- print(str)
+DODOES = defPrim(() -> begin
+ pushRS(reg.IP)
+ reg.IP = reg.W + 1
return NEXT
-end)
-
-# Outer interpreter
-
-EXECUTE = defPrimWord("EXECUTE", () -> begin
- reg.W = popPS()
- return mem[reg.W]
-end)
-
-INTERPRET = defPrimWord("INTERPRET", () -> begin
-
- callPrim(mem[WORD])
-
- wordName = getString(mem[reg.PSP-1], mem[reg.PSP])
- #println("... ", replace(replace(wordName, "\004", "EOF"), "\n", "\\n"), " ...")
-
- callPrim(mem[TWODUP])
- callPrim(mem[FIND])
-
- wordAddr = mem[reg.PSP]
+end, name="DOCOL")
- if wordAddr>0
- # Word in dictionary
+defConst("DODOES", DODOES)
- isImmediate = (mem[wordAddr+1] & F_IMMED) != 0
- callPrim(mem[TOCFA])
+FROMDOES_PAREN = defWord("(DOES>)",
+ [DODOES, LATEST, FETCH, TOCFA, STORE, EXIT])
- callPrim(mem[ROT]) # get rid of extra copy of word string details
- popPS()
- popPS()
+FROMDOES = defWord("DOES>",
+ [BTICK, FROMDOES_PAREN, COMMA, BTICK, EXIT, COMMA,
+ BTICK, LIT, COMMA, LATEST, FETCH, TODFA, COMMA], flags=F_IMMED)
+
- 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()
+#### VM loop ####
- callPrim(mem[NUMBER])
+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
- if popPS() != 0
- println("Parse error at word: '$wordName'")
- return NEXT
- end
+function run(;initialize=false)
+ # Begin with STDIN as source
+ push!(sources, STDIN)
- if mem[STATE] == 0
- # Number already on stack!
+ global initialized, initFileName
+ if !initialized && initialize
+ if initFileName != nothing
+ print("Including definitions from $initFileName...")
+ push!(sources, open(initFileName, "r"))
+ initialized = true
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])
+ println("No library file found. Only primitive words available.")
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 ####
-function run()
- # Begin with STDIN as source
- push!(sources, STDIN)
# 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
The Lambda Lab / projects / forth.jl.git / blobdiff