module forth
-# VM memory size
-size_memory = 640*1024
+# VM mem size
+size_mem = 640*1024
# Buffer sizes
-size_SysVar = 16 #
+size_BIVar = 16 #
size_RS = 1024 # Return stack size
size_PS = 1024 # Parameter stack size
size_TIB = 4096 # Terminal input buffer size
# The following array constitutes the memory of the VM. It has the following geography:
#
-# memory = +-----------------------+
+# mem = +-----------------------+
# | Built-in Variables |
# +-----------------------+
# | Return Stack |
# +-----------------------+
#
# Note that all words (user-defined, primitive, variables, etc) are included in
-# the dictionary. Additionally, all
+# 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.
-memory = Array{Int64,1}(size_memory)
+mem = Array{Int64,1}(size_mem)
primitives = Array{Function,1}()
# Built-in variables
nextVarAddr = 1
RSP0 = nextVarAddr; nextVarAddr += 1
PSP0 = nextVarAddr; nextVarAddr += 1
+TIB = nextVarAddr; nextVarAddr += 1
HERE = nextVarAddr; nextVarAddr += 1
LATEST = nextVarAddr; nextVarAddr += 1
-memory[RSP0] = size_BIVar # bottom of RS
-memory[PSP0] = memory[RSP0] + size_RS # bottom of PS
-TIB = memory[PSP0] + size_PS # address of terminal input buffer
-memory[HERE] = TIB + size_TIB # location of bottom of dictionary
-memory[LATEST] = 0 # no previous definition
-
+mem[RSP0] = size_BIVar # bottom of RS
+mem[PSP0] = mem[RSP0] + size_RS # bottom of PS
+mem[TIB] = mem[PSP0] + size_PS # address of terminal input buffer
+mem[HERE] = mem[TIB] + size_TIB # location of bottom of dictionary
+mem[LATEST] = 0 # no previous definition
# Stack manipulation functions
function pushRS(reg::Reg, val::Int64)
- memory[reg.RSP+=1] = val
+ mem[reg.RSP+=1] = val
end
function popRS(reg::Reg)
- val = memory[reg.RSP]
+ val = mem[reg.RSP]
reg.RSP -= 1
return val
end
function pushPS(reg::Reg, val::Int64)
- memory[reg.PSP += 1] = val
+ mem[reg.PSP += 1] = val
end
function popPS(reg::Reg)
- val = memory[reg.PSP]
+ val = mem[reg.PSP]
reg.PSP -= 1
return val
end
# Primitive creation and calling functions
-function defPrim(name::AbstractString, f::Function)
- global latest, here
+function createHeader(name::AbstractString)
+ mem[mem[HERE]] = mem[LATEST]
+ mem[LATEST] = mem[HERE]
+ mem[HERE] += 1
- memory[here] = latest
- latest = here
- here += 1
+ mem[mem[HERE]] = length(name); mem[HERE] += 1
+ mem[mem[HERE]:(mem[HERE]+length(name)-1)] = [Int(c) for c in name]; mem[HERE] += length(name)
+end
- memory[here] = length(name); here += 1
- memory[here:(here+length(name)-1)] = [Int(c) for c in name]; here += length(name)
+function defPrim(name::AbstractString, f::Function)
+ createHeader(name)
push!(primitives, f)
- memory[here] = -length(primitives)
- here += 1
+ mem[mem[HERE]] = -length(primitives)
+ mem[HERE] += 1
return -length(primitives)
end
callPrim(reg::Reg, addr::Int64) = primitives[-addr](reg)
-function defSysVar(name::AbstractString, varAddr::Int64)
- global latest, here
-
- memory[here] = latest
- latest = here
- here += 1
+defExistingVar(name::AbstractString, varAddr::Int64) = defPrim(name, eval(:((reg) -> begin
+ pushPS(reg, $(varAddr))
+ return NEXT
+end)))
- memory[here] = length(name); here += 1
- memory[here:(here+length(name)-1)] = [Int(c) for c in name]; here += length(name)
+defConst(name::AbstractString, val::Int64) = defPrim(name, eval(:((reg) -> begin
+ pushPS(reg, $(val))
+ return NEXT
+end)))
- push!(primitives, eval(:((reg::Reg) -> begin
+function defNewVar(name::AbstractString, initial::Int64)
+ createHeader(name)
+
+ varAddr = mem[HERE] + 1
+ push!(primitives, eval(:((reg) -> begin
pushPS(reg, $(varAddr))
return NEXT
end)))
- memory[here] = -length(primitives)
- here += 1
+ mem[mem[HERE]] = -length(primitives); mem[HERE] += 1
+
+ mem[mem[HERE]] = inital; mem[HERE] += 1
return varAddr
end
-defConst(name::AbstractString, val::Int64) = defSysVar(name, val)
-
# Threading Primitives
NEXT = defPrim("NEXT", (reg) -> begin
- reg.W = memory[reg.IP]
+ reg.W = mem[reg.IP]
reg.IP += 1
- X = memory[reg.W]
+ X = mem[reg.W]
return X
end)
end)
SWAP = defPrim("SWAP", (reg) -> begin
- memory[reg.PSP], memory[reg.PSP-1] = memory[reg.PSP-1], memory[reg.PSP]
+ mem[reg.PSP], mem[reg.PSP-1] = mem[reg.PSP-1], mem[reg.PSP]
return NEXT
end)
DUP = defPrim("DUP", (reg) -> begin
- pushPS(reg, memory[reg.PSP])
+ pushPS(reg, mem[reg.PSP])
return NEXT
end)
LIT = defPrim("LIT", (reg) -> begin
- pushPS(reg, memory[reg.IP])
+ pushPS(reg, mem[reg.IP])
reg.IP += 1
return NEXT
end)
STORE = defPrim("!", (reg) -> begin
addr = popPS(reg)
dat = popPS(reg)
- memory[addr] = dat
+ mem[addr] = dat
return NEXT
end)
FETCH = defPrim("@", (reg) -> begin
addr = popPS(reg)
- pushPS(reg, memory[addr])
+ pushPS(reg, mem[addr])
return NEXT
end)
ADDSTORE = defPrim("+!", (reg) -> begin
addr = popPS(reg)
toAdd = popPS(reg)
- memory[addr] += toAdd
+ mem[addr] += toAdd
return NEXT
end)
SUBSTORE = defPrim("-!", (reg) -> begin
addr = popPS(reg)
toSub = popPS(reg)
- memory[addr] -= toSub
+ mem[addr] -= toSub
return NEXT
end)
# Built-in variables
+defExistingVar("HERE", HERE)
+defExistingVar("LATEST", LATEST)
+defExistingVar("PSP0", PSP0)
+defExistingVar("RSP0", RSP0)
+defNewVar("STATE", 0)
+defNewVar("BASE", 10)
# Constants
# I/O
-defConst("TIB", tib)
-defVar("#TIB", :numtib)
-defVar(">IN", :toin)
-
-KEY = defPrim("KEY", (reg) -> begin
- if toin >= numtib
-
- end
-
- return NEXT
-end)
-
-EMIT = defPrim("EMIT", (reg) -> begin
+#defConst("TIB", tib)
+#defVar("#TIB", :numtib)
+#defVar(">IN", :toin)
+#
+#KEY = defPrim("KEY", (reg) -> begin
+# if toin >= numtib
+#
+# end
+#
+# return NEXT
+#end)
+#
+#EMIT = defPrim("EMIT", (reg) -> begin
+#
+# return NEXT
+#end)
+#
+#WORD = defPrim("WORD", (reg) -> begin
+#
+# return NEXT
+#end)
+#
+#NUMBER = defPrim("NUMBER", (reg) -> begin
+#
+# return NEXT
+#end)
+#
+#### VM loop ####
+#function runVM(reg::Reg)
+# jmp = NEXT
+# while (jmp = callPrim(reg, jmp)) != 0 end
+#end
- return NEXT
-end)
+# Debugging tools
-WORD = defPrim("WORD", (reg) -> begin
+function coredump(startAddr::Int64; count::Int64 = 16, cellsPerLine::Int64 = 8)
+ chars = Array{Char,1}(cellsPerLine)
- return NEXT
-end)
+ for i in 0:(count-1)
+ addr = startAddr + i
+ if i%cellsPerLine == 0
+ print("$addr:")
+ end
-NUMBER = defPrim("NUMBER", (reg) -> begin
+ print("\t$(mem[addr]) ")
- return NEXT
-end)
+ if (mem[addr]>=32 && mem[addr]<176)
+ chars[i%cellsPerLine + 1] = Char(mem[addr])
+ else
+ chars[i%cellsPerLine + 1] = '.'
+ end
-#### VM loop ####
-function runVM(reg::Reg)
- jmp = NEXT
- while (jmp = callPrim(reg, jmp)) != 0 end
+ if i%cellsPerLine == cellsPerLine-1
+ println(string("\t", ASCIIString(chars)))
+ end
+ end
end
end