module forth
-RS = Array{Int64, 1}(1024)
-RSP = 0
+# VM mem size
+size_mem = 640*1024
+
+# Buffer sizes
+size_BIVar = 16 #
+size_RS = 1024 # Return stack size
+size_PS = 1024 # Parameter stack size
+size_TIB = 4096 # 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 the negative index
+# into the primitives array which contains only these functions.
+
+mem = Array{Int64,1}(size_mem)
+primitives = Array{Function,1}()
-PS = Array{Int64, 1}(1024)
-PSP =0
-
-IP = 0
-W = 0
-X = 0
-
-jmp = 0
-
-primitives = Array{Expr,1}()
-memory = Array{Int64,1}(64*1024)
-LATEST = 0
-HERE = 1
-
-# Intperpreter state
-
-STATE = 0
-
-# Current radix
+# Built-in variables
-BASE = 10
+nextVarAddr = 1
+RSP0 = nextVarAddr; nextVarAddr += 1
+PSP0 = nextVarAddr; nextVarAddr += 1
+HERE = nextVarAddr; nextVarAddr += 1
+LATEST = nextVarAddr; nextVarAddr += 1
+
+mem[RSP0] = size_BIVar # 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
+
+# VM registers
+type Reg
+ RSP::Int64 # Return stack pointer
+ 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)
-# Stack manipulation macros
+# Stack manipulation functions
function pushRS(val::Int64)
- global RSP
- RS[RSP += 1] = val
+ mem[reg.RSP+=1] = val
end
function popRS()
- global RSP
- val = RS[RSP]
- RSP -= 1
+ val = mem[reg.RSP]
+ reg.RSP -= 1
return val
end
function pushPS(val::Int64)
- global PSP
- PS[PSP += 1] = val
+ mem[reg.PSP += 1] = val
end
function popPS()
- global PSP
- val = PS[PSP]
- PSP -= 1
+ val = mem[reg.PSP]
+ reg.PSP -= 1
return val
end
-# Primitive creation functions
+# Primitive creation and calling functions
-function defPrim(name::AbstractString, expr::Expr)
- global HERE, LATEST
+function createHeader(name::AbstractString, flags::Int64)
+ mem[mem[HERE]] = mem[LATEST]
+ mem[LATEST] = mem[HERE]
+ mem[HERE] += 1
- memory[HERE] = LATEST
- LATEST = HERE
- 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)
+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; flags::Int64=0)
+ createHeader(name, flags)
- push!(primitives, expr)
- memory[HERE] = -length(primitives)
- codeword = HERE
- HERE += 1
+ push!(primitives, f)
+ mem[mem[HERE]] = -length(primitives)
+ mem[HERE] += 1
- return codeword
+ return -length(primitives)
end
-defVar(name::AbstractString, var::Expr) = defPrim(name, Expr(:call, :pushPS, var))
-defConst(name::AbstractString, val::Int64) = defPrim(name, Expr(:call, :pushPS, :val))
+callPrim(addr::Int64) = primitives[-addr]()
+
+function defExistingVar(name::AbstractString, varAddr::Int64; flags::Int64=0)
+ defPrim(name, eval(:(() -> begin
+ pushPS($(varAddr))
+ return NEXT
+ end)))
+end
+
+function defConst(name::AbstractString, val::Int64; flags::Int64=0)
+ defPrim(name, eval(:(() -> begin
+ pushPS($(val))
+ return NEXT
+ end)))
+end
+
+function defNewVar(name::AbstractString, initial::Int64; flags::Int64=0)
+ createHeader(name, flags)
+
+ varAddr = mem[HERE] + 1
+ push!(primitives, eval(:(() -> begin
+ pushPS($(varAddr))
+ return NEXT
+ end)))
+ mem[mem[HERE]] = -length(primitives); mem[HERE] += 1
+
+ mem[mem[HERE]] = initial; mem[HERE] += 1
+
+ return varAddr
+end
# Threading Primitives
-NEXT = defPrim("NEXT", :(begin
- W = memory[IP]
- IP += 1
- X = memory[W]
- jmp = X
-end))
+NEXT = defPrim("NEXT", () -> begin
+ reg.W = mem[reg.IP]
+ reg.IP += 1
+ X = mem[reg.W]
+ return X
+end)
-DOCOL = defPrim("DOCOL", :(begin
- pushRS(IP)
- IP = W + 1
- jmp = NEXT
-end))
+DOCOL = defPrim("DOCOL", () -> begin
+ pushRS(reg.IP)
+ reg.IP = reg.W + 1
+ return NEXT
+end)
-EXIT = defPrim("EXIT", :(begin
- IP = popRS()
- jmp = NEXT
-end))
+EXIT = defPrim("EXIT", () -> begin
+ reg.IP = popRS()
+ return NEXT
+end)
# Basic forth primitives
-DROP = defPrim("DROP", :(begin
+DROP = defPrim("DROP", () -> begin
popPS()
- jmp = NEXT
-end))
+ return NEXT
+end)
-SWAP = defPrim("SWAP", :(begin
- PS[PSP], PS[PSP-1] = PS[PSP-1], PS[PS]
- jmp = NEXT
-end))
+SWAP = defPrim("SWAP", () -> begin
+ mem[reg.PSP], mem[reg.PSP-1] = mem[reg.PSP-1], mem[reg.PSP]
+ return NEXT
+end)
-DUP = defPrim("DUP", :(begin
- pushPS(PS[PSP])
- jmp = NEXT
-end))
+DUP = defPrim("DUP", () -> begin
+ pushPS(mem[reg.PSP])
+ return NEXT
+end)
-LIT = defPrim("LIT", :(begin
- pushPS(memory[IP])
- IP += 1
- jmp = NEXT
-end))
+LIT = defPrim("LIT", () -> begin
+ pushPS(mem[reg.IP])
+ reg.IP += 1
+ return NEXT
+end)
# Memory primitives
-STORE = defPrim("!", :(begin
+STORE = defPrim("!", () -> begin
addr = popPS()
dat = popPS()
- memory[addr] = dat
- jmp = NEXT
-end))
+ mem[addr] = dat
+ return NEXT
+end)
-FETCH = defPrim("@", :(begin
+FETCH = defPrim("@", () -> begin
addr = popPS()
- pushPS(memory[addr])
- jmp = NEXT
-end))
+ pushPS(mem[addr])
+ return NEXT
+end)
-ADDSTORE = defPrim("+!", :(begin
+ADDSTORE = defPrim("+!", () -> begin
addr = popPS()
toAdd = popPS()
- memory[addr] += toAdd
- jmp = NEXT
-end))
+ mem[addr] += toAdd
+ return NEXT
+end)
-SUBSTORE = defPrim("-!", :(begin
+SUBSTORE = defPrim("-!", () -> begin
addr = popPS()
toSub = popPS()
- memory[addr] -= toSub
- jmp = NEXT
-end))
+ mem[addr] -= toSub
+ return NEXT
+end)
# Built-in variables
-defVar("STATE", :STATE)
-defVar("HERE", :HERE)
-defVar("LATEST", :LATEST)
-defVAR("BASE", :BASE)
+defExistingVar("HERE", HERE)
+defExistingVar("LATEST", LATEST)
+defExistingVar("PSP0", PSP0)
+defExistingVar("RSP0", RSP0)
+defNewVar("STATE", 0)
+defNewVar("BASE", 10)
# Constants
# Return Stack
-TOR = defPrim(">R", :(pushRS(popPS())))
-FROMR = defPrim("R>", :(pushPS(popRS())))
-RSPFETCH = defPrim("RSP@", :(pushPS(RSP)))
-RSPSTORE = defPrim("RSP!", :(RSP = popPS()))
-RDROP = defPrim("RDROP", :(popRS()))
+TOR = defPrim(">R", () -> begin
+ pushRS(popPS())
+ return NEXT
+end)
+
+FROMR = defPrim("R>", () -> begin
+ pushPS(popRS())
+ return NEXT
+end)
+
+RSPFETCH = defPrim("RSP@", () -> begin
+ pushPS(RSP)
+ return NEXT
+end)
+
+RSPSTORE = defPrim("RSP!", () -> begin
+ RSP = popPS()
+ return NEXT
+end)
+
+RDROP = defPrim("RDROP", () -> begin
+ popRS()
+ return NEXT
+end)
# Parameter Stack
-PSPFETCH = defPrim("PSP@", :(pushPS(PSP)))
-PSPSTORE = defPrim("PSP!", :(PSP = popPS()))
+PSPFETCH = defPrim("PSP@", () -> begin
+ pushPS(PSP)
+ return NEXT
+end)
+
+PSPSTORE = defPrim("PSP!", () -> begin
+ PSP = popPS()
+ return NEXT
+end)
+
+# I/O
+
+defConst("TIB", TIB)
+NUMTIB = defNewVar("#TIB", 0)
+TOIN = defNewVar(">IN", TIB)
+
+#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
+
+# Debugging tools
+
+function coredump(startAddr::Int64; count::Int64 = 16, cellsPerLine::Int64 = 8)
+ chars = Array{Char,1}(cellsPerLine)
+
+ for i in 0:(count-1)
+ addr = startAddr + i
+ if i%cellsPerLine == 0
+ print("$addr:")
+ end
+
+ print("\t$(mem[addr]) ")
+
+ if (mem[addr]>=32 && mem[addr]<176)
+ chars[i%cellsPerLine + 1] = Char(mem[addr])
+ else
+ chars[i%cellsPerLine + 1] = '.'
+ end
+
+ if i%cellsPerLine == cellsPerLine-1
+ println(string("\t", ASCIIString(chars)))
+ end
+ end
+end
-# VM loop
-jmp = NEXT
-function runVM()
- while true
- eval(primitives[-memory[jmp]])
+function dumpPS()
+ count = reg.PSP - mem[PSP0]
+
+ if count > 0
+ print("<$count>")
+ for i in (mem[PSP0]+1):reg.PSP
+ print(" $(mem[i])")
+ end
+ println()
+ else
+ println("Parameter stack empty")
end
end
The Lambda Lab / projects / forth.jl.git / blobdiff