X-Git-Url: https://thelambdalab.xyz/gitweb/index.cgi?p=forth.jl.git;a=blobdiff_plain;f=src%2Fforth.jl;h=9439dead46913871d9255834a9272713cad19433;hp=cdb56d56b46dc1edcbfd15f1040b2fcd266e7723;hb=6cb12b03e2a154214fc60d7c437e650e79fb42e5;hpb=f998451ad1e6486ab7f9db3204bf830e82cb0f94

diff --git a/src/forth.jl b/src/forth.jl
index cdb56d5..9439dea 100644
--- a/src/forth.jl
+++ b/src/forth.jl
@@ -8,27 +8,7 @@ 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:
-#
-# 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.
-
+# Memory arrays
 mem = Array{Int64,1}(size_mem)
 primitives = Array{Function,1}()
 primNames = Array{ASCIIString,1}()
@@ -36,18 +16,16 @@ 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
@@ -56,28 +34,19 @@ 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
 
@@ -133,25 +102,26 @@ 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
@@ -159,13 +129,13 @@ 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
@@ -184,11 +154,11 @@ end
 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
@@ -196,10 +166,10 @@ 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
@@ -228,17 +198,18 @@ DOCON = defPrim(() -> begin
     return NEXT
 end, name="DOVAR")
 
-EXIT = defPrimWord("EXIT", () -> begin
+EXIT_CFA = defPrimWord("EXIT", () -> begin
     reg.IP = popRS()
     return NEXT
 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)
@@ -250,15 +221,16 @@ 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)
@@ -266,19 +238,19 @@ SWAP = defPrimWord("SWAP", () -> begin
     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()
@@ -288,7 +260,7 @@ ROT = defPrimWord("ROT", () -> begin
     return NEXT
 end)
 
-NROT = defPrimWord("-ROT", () -> begin
+NROT_CFA = defPrimWord("-ROT", () -> begin
     a = popPS()
     b = popPS()
     c = popPS()
@@ -299,13 +271,13 @@ NROT = defPrimWord("-ROT", () -> begin
 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]
@@ -314,7 +286,7 @@ TWODUP = defPrimWord("2DUP", () -> begin
     return NEXT
 end)
 
-TWOSWAP = defPrimWord("2SWAP", () -> begin
+TWOSWAP_CFA = defPrimWord("2SWAP", () -> begin
     a = popPS()
     b = popPS()
     c = popPS()
@@ -326,7 +298,7 @@ TWOSWAP = defPrimWord("2SWAP", () -> begin
     return NEXT
 end)
 
-TWOOVER = defPrimWord("2OVER", () -> begin
+TWOOVER_CFA = defPrimWord("2OVER", () -> begin
     ensurePSDepth(4)
     a = mem[reg.PSP-3]
     b = mem[reg.PSP-2]
@@ -335,7 +307,7 @@ TWOOVER = defPrimWord("2OVER", () -> begin
     return NEXT
 end)
 
-QDUP = defPrimWord("?DUP", () -> begin
+QDUP_CFA = defPrimWord("?DUP", () -> begin
     ensurePSDepth(1)
     val = mem[reg.PSP]
     if val != 0
@@ -344,52 +316,52 @@ QDUP = defPrimWord("?DUP", () -> begin
     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)
@@ -398,117 +370,117 @@ DIVMOD = defPrimWord("/MOD", () -> begin
     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)
 
-EQ = defPrimWord("=", () -> begin
+EQ_CFA = defPrimWord("=", () -> begin
     b = popPS()
     a = popPS()
     pushPS(a==b ? -1 : 0)
     return NEXT
 end)
 
-NE = 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)
 
-ZE = defPrimWord("0=", () -> begin
+ZE_CFA = defPrimWord("0=", () -> begin
     pushPS(popPS() == 0 ? -1 : 0)
     return NEXT
 end)
 
-ZNE = 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
@@ -516,27 +488,27 @@ end)
 
 # 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
@@ -546,56 +518,56 @@ end)
 
 # 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
+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
+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)
@@ -605,39 +577,107 @@ end)
 sources = Array{Any,1}()
 currentSource() = sources[length(sources)]
 
-EOF = defPrimWord("\x04", () -> begin
-    close(pop!(sources))
-    if !isempty(sources)
+EOF_CFA = defPrimWord("\x04", () -> begin
+    if currentSource() != STDIN
+        close(pop!(sources))
         return NEXT
     else
         return 0
     end
 end)
 
-EMIT = defPrimWord("EMIT", () -> begin
+EMIT_CFA = 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_CFA = 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
+EXPECT_CFA = 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] = 4 # 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)
 
 BASE, BASE_CFA = defNewVar("BASE", 10)
-NUMBER = defPrimWord("NUMBER", () -> begin
+NUMBER_CFA = defPrimWord("NUMBER", () -> begin
     wordAddr = popPS()+1
     wordLen = mem[wordAddr-1]
 
@@ -650,7 +690,20 @@ end)
 
 # Dictionary searches
 
-FIND = defPrimWord("FIND", () -> begin
+TOCFA_CFA = defPrimWord(">CFA", () -> begin
+
+    addr = popPS()
+    lenAndFlags = mem[addr+1]
+    len = lenAndFlags & F_LENMASK
+
+    pushPS(addr + 2 + len)
+
+    return NEXT
+end)
+
+TOBODY_CFA = defWord(">BODY", [INCR_CFA, EXIT_CFA])
+
+FIND_CFA = defPrimWord("FIND", () -> begin
 
     countedAddr = popPS()
     wordAddr = countedAddr + 1
@@ -658,6 +711,7 @@ FIND = defPrimWord("FIND", () -> begin
     word = lowercase(getString(wordAddr, wordLen))
 
     latest = LATEST
+    lenAndFlags = 0
     
     i = 0
     while (latest = mem[latest]) > 0
@@ -677,32 +731,31 @@ FIND = defPrimWord("FIND", () -> begin
         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)
 
-TOPFA = defWord(">PFA", [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
@@ -714,7 +767,7 @@ end)
 
 # Strings
 
-LITSTRING = defPrimWord("LITSTRING", () -> begin
+LITSTRING_CFA = defPrimWord("LITSTRING", () -> begin
     len = mem[reg.IP]
     reg.IP += 1
     pushPS(reg.IP)
@@ -724,7 +777,7 @@ LITSTRING = defPrimWord("LITSTRING", () -> begin
     return NEXT
 end)
 
-TYPE = defPrimWord("TYPE", () -> begin
+TYPE_CFA = defPrimWord("TYPE", () -> begin
     len = popPS()
     addr = popPS()
     str = getString(addr, len)
@@ -732,44 +785,19 @@ TYPE = defPrimWord("TYPE", () -> begin
     return NEXT
 end)
 
-# Outer interpreter
-
-TRACE = defPrimWord("TRACE", () -> begin
-    println("reg.W: $(reg.W) reg.IP: $(reg.IP)")
-    print("PS: "); printPS()
-    print("RS: "); printRS()
-    print("[paused]")
-    readline()
-
-    return NEXT
-end)
-
-COMMA = defPrimWord(",", () -> begin
-    mem[mem[HERE]] = popPS()
-    mem[HERE] += 1
-
-    return NEXT
-end)
-
-BTICK = defWord("[']",
-    [FROMR, DUP, INCR, TOR, FETCH, EXIT])
-
-EXECUTE = defPrimWord("EXECUTE", () -> begin
-    reg.W = popPS()
-    return mem[reg.W]
-end)
+# Interpreter/Compiler-specific I/O
 
 TIB_CFA = defConst("TIB", TIB)
 NUMTIB, NUMTIB_CFA = defNewVar("#TIB", 0)
 TOIN, TOIN_CFA = defNewVar(">IN", 0)
 
-QUERY = defWord("QUERY",
-    [TIB_CFA, LIT, 160, EXPECT,
-    SPAN_CFA, FETCH, NUMTIB_CFA, STORE,
-    LIT, 0, TOIN_CFA, STORE,
-    EXIT])
+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 = defPrimWord("WORD", () -> begin
+WORD_CFA = defPrimWord("WORD", () -> begin
     delim = popPS()
 
     # Chew up initial occurrences of delim
@@ -777,8 +805,8 @@ WORD = defPrimWord("WORD", () -> begin
         mem[TOIN] += 1
     end
 
-    countAddr = mem[HERE]
-    addr = mem[HERE]+1
+    countAddr = mem[H]
+    addr = mem[H]+1
 
     # Start reading in word
     count = 0
@@ -801,73 +829,139 @@ WORD = defPrimWord("WORD", () -> begin
     return NEXT
 end)
 
-PARSE = defPrimWord("PARSE", () -> begin
-    delim = popPS()
+# Compilation
 
-    # Chew up initial occurrences of delim
-    addr = mem[HERE]
+STATE, STATE_CFA = defNewVar("STATE", 0)
 
-    # Start reading input stream
-    count = 0
-    while (mem[TOIN]<mem[NUMTIB])
-        mem[addr] = mem[TIB+mem[TOIN]]
-        mem[TOIN] += 1
+COMMA_CFA = defPrimWord(",", () -> begin
+    mem[mem[H]] = popPS()
+    mem[H] += 1
 
-        if (mem[addr] == delim)
-            break
-        end
+    return NEXT
+end)
 
-        count += 1
-        addr += 1
-    end
+HERE_CFA = defWord("HERE",
+    [H_CFA, FETCH_CFA, EXIT_CFA])
 
-    pushPS(addr)
-    pushPS(count)
+HEADER_CFA = defPrimWord("HEADER", () -> begin
+    wordAddr = popPS()+1
+    wordLen = mem[wordAddr-1]
+    word = getString(wordAddr, wordLen)
+
+    createHeader(word, 0)
 
     return NEXT
 end)
 
-BYE = defPrimWord("BYE", () -> begin
-    println("Bye!")
-    return 0
+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, name="DODOES")
+
+DOES_HELPER_CFA = defPrimWord("(DOES>)", () -> begin
+
+    pushPS(mem[LATEST])
+    callPrim(mem[TOCFA_CFA])
+    cfa = popPS()
+
+    runtimeAddr = popPS()
+
+    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_CFA = defPrimWord("]", () -> begin
+    mem[STATE] = 1
+    return NEXT
+end, flags=F_IMMED)
+
+HIDDEN_CFA = defPrimWord("HIDDEN", () -> begin
+    lenAndFlagsAddr = mem[LATEST] + 1
+    mem[lenAndFlagsAddr] = mem[lenAndFlagsAddr] $ F_HIDDEN
+    return NEXT
 end)
 
-STATE, STATE_CFA = defNewVar("STATE", 0)
+COLON_CFA = defWord(":",
+    [LIT_CFA, 32, WORD_CFA,
+    HEADER_CFA,
+    LIT_CFA, DOCOL, COMMA_CFA,
+    HIDDEN_CFA,
+    RBRAC_CFA,
+    EXIT_CFA])
+
+SEMICOLON_CFA = defWord(";",
+    [LIT_CFA, EXIT_CFA, COMMA_CFA,
+    HIDDEN_CFA,
+    LBRAC_CFA,
+    EXIT_CFA], flags=F_IMMED)
+
+IMMEDIATE_CFA = defPrimWord("IMMEDIATE", () -> begin
+    lenAndFlagsAddr = mem[LATEST] + 1
+    mem[lenAndFlagsAddr] = mem[lenAndFlagsAddr] $ F_IMMED
+    return NEXT
+end, flags=F_IMMED)
+
+# Outer Interpreter
+
+EXECUTE_CFA = defPrimWord("EXECUTE", () -> begin
+    reg.W = popPS()
+    return mem[reg.W]
+end)
 
-INTERPRET = defWord("INTERPRET",
-    [LIT, 32, WORD, # Read next space-delimited word
+INTERPRET_CFA = defWord("INTERPRET",
+    [LIT_CFA, 32, WORD_CFA, # Read next space-delimited word
 
-    DUP, FETCH, ZE, ZBRANCH, 3,
-        DROP, EXIT, # Exit if TIB is exhausted
+    DUP_CFA, FETCH_CFA, ZE_CFA, ZBRANCH_CFA, 3,
+        DROP_CFA, EXIT_CFA, # Exit if TIB is exhausted
 
-    STATE_CFA, FETCH, ZBRANCH, 31,
+    STATE_CFA, FETCH_CFA, ZBRANCH_CFA, 24,
         # Compiling
-        DUP, FIND, QDUP, ZBRANCH, 19,
+        FIND_CFA, QDUP_CFA, ZBRANCH_CFA, 13,
 
             # Found word. 
-            SWAP, DROP,
-            DUP, TOCFA, SWAP, INCR, FETCH, LIT, F_IMMED, AND, ZBRANCH, 4,
+            LIT_CFA, -1, EQ_CFA, INVERT_CFA, ZBRANCH_CFA, 4,
+
                 # Immediate: Execute!
-                EXECUTE, BRANCH, -33,
+                EXECUTE_CFA, BRANCH_CFA, -26,
 
                 # Not immediate: Compile!
-                COMMA, BRANCH, -36,
+                COMMA_CFA, BRANCH_CFA, -29,
 
             # No word found, parse number
-            NUMBER, BTICK, LIT, COMMA, COMMA, BRANCH, -43,
+            NUMBER_CFA, LIT_CFA, LIT_CFA, COMMA_CFA, COMMA_CFA, BRANCH_CFA, -36,
         
        # Interpreting
-        DUP, FIND, QDUP, ZBRANCH, 7,
+        FIND_CFA, QDUP_CFA, ZBRANCH_CFA, 5,
 
             # Found word. Execute!
-            SWAP, DROP, TOCFA, EXECUTE, BRANCH, -54,
+            DROP_CFA, EXECUTE_CFA, BRANCH_CFA, -44,
 
             # No word found, parse number and leave on stack
-            NUMBER, BRANCH, -57,
-    EXIT]
-)
+            NUMBER_CFA, BRANCH_CFA, -47,
+    EXIT_CFA])
 
-PROMPT = defPrimWord("PROMPT", () -> begin
+PROMPT_CFA = defPrimWord("PROMPT", () -> begin
     if (mem[STATE] == 0 && currentSource() == STDIN)
         println(" ok")
     end
@@ -875,20 +969,27 @@ PROMPT = defPrimWord("PROMPT", () -> begin
     return NEXT
 end)
 
-QUIT = defWord("QUIT",
-    [LIT, 0, STATE_CFA, STORE,
-    LIT, 0, NUMTIB_CFA, STORE,
-    RSP0_CFA, FETCH, RSPSTORE,
-    QUERY,
-    INTERPRET, PROMPT,
-    BRANCH,-4])
+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])
+
+ABORT_CFA = defWord("ABORT",
+    [PSP0_CFA, PSPSTORE_CFA, QUIT_CFA])
+
+BYE_CFA = defPrimWord("BYE", () -> begin
+    println("\nBye!")
+    return 0
+end)
 
-ABORT = defWord("ABORT",
-    [PSP0_CFA, FETCH, PSPSTORE, QUIT])
+# File I/O
 
-INCLUDE = defPrimWord("INCLUDE", () -> begin
+INCLUDE_CFA = defPrimWord("INCLUDE", () -> begin
     pushPS(32)
-    callPrim(mem[WORD])
+    callPrim(mem[WORD_CFA])
     wordAddr = popPS()+1
     wordLen = mem[wordAddr-1]
     word = getString(wordAddr, wordLen)
@@ -901,60 +1002,6 @@ INCLUDE = defPrimWord("INCLUDE", () -> begin
     return NEXT
 end)
 
-# Compilation
-
-HEADER = defPrimWord("HEADER", () -> begin
-    wordAddr = popPS()+1
-    wordLen = mem[wordAddr-1]
-    word = getString(wordAddr, wordLen)
-
-    createHeader(word, 0)
-
-    return NEXT
-end)
-
-LBRAC = defPrimWord("[", () -> begin
-    mem[STATE] = 0
-    return NEXT
-end, flags=F_IMMED)
-
-RBRAC = defPrimWord("]", () -> begin
-    mem[STATE] = 1
-    return NEXT
-end, flags=F_IMMED)
-
-HIDDEN = defPrimWord("HIDDEN", () -> begin
-    addr = popPS() + 1
-    mem[addr] = mem[addr] $ F_HIDDEN
-    return NEXT
-end)
-
-HIDE = defWord("HIDE",
-    [LIT, 32, WORD,
-    FIND,
-    HIDDEN,
-    EXIT])
-
-COLON = defWord(":",
-    [LIT, 32, WORD,
-    HEADER,
-    LIT, DOCOL, COMMA,
-    LATEST_CFA, FETCH, HIDDEN,
-    RBRAC,
-    EXIT])
-
-SEMICOLON = defWord(";",
-    [LIT, EXIT, COMMA,
-    LATEST_CFA, FETCH, HIDDEN,
-    LBRAC,
-    EXIT], flags=F_IMMED)
-
-IMMEDIATE = defPrimWord("IMMEDIATE", () -> begin
-    lenAndFlagsAddr = mem[LATEST] + 1
-    mem[lenAndFlagsAddr] = mem[lenAndFlagsAddr] $ F_IMMED
-    return NEXT
-end, flags=F_IMMED)
-
 
 #### VM loop ####
 
@@ -982,7 +1029,7 @@ function run(;initialize=true)
     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!
@@ -1001,7 +1048,7 @@ function run(;initialize=true)
             end
 
             # QUIT
-            reg.IP = ABORT + 1
+            reg.IP = ABORT_CFA + 1
             jmp = NEXT
         end
     end
@@ -1009,6 +1056,16 @@ 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)
 
@@ -1043,11 +1100,11 @@ function dump(startAddr::Int64; count::Int64 = 100, cellsPerLine::Int64 = 10)
 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()
@@ -1057,11 +1114,11 @@ function printPS()
 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()
@@ -1074,6 +1131,7 @@ DUMP = defPrimWord("DUMP", () -> begin
     count = popPS()
     addr = popPS()
 
+    println()
     dump(addr, count=count)
 
     return NEXT