X-Git-Url: https://thelambdalab.xyz/gitweb/index.cgi?a=blobdiff_plain;f=src%2Fforth.jl;h=4b625bc146eb19cbcc36a51f6ab414789726645d;hb=03de266dbc3975cfa2f3b07de2d58ff642f4bf76;hp=91eea4f228e63f0cee7fc8d3b77806b6a4fc7f5a;hpb=1060539f1cf03aa9225443762bad93d384fb4f0a;p=forth.jl.git diff --git a/src/forth.jl b/src/forth.jl index 91eea4f..4b625bc 100644 --- a/src/forth.jl +++ b/src/forth.jl @@ -31,6 +31,7 @@ size_TIB = 1096 # Terminal input buffer size mem = Array{Int64,1}(size_mem) primitives = Array{Function,1}() +primNames = Array{ASCIIString,1}() # Built-in variables @@ -127,6 +128,8 @@ function defPrim(name::AbstractString, f::Function; flags::Int64=0) mem[codeWordAddr] = -length(primitives) mem[HERE] += 1 + push!(primNames, name) + return codeWordAddr end @@ -142,6 +145,7 @@ end function defNewVar(name::AbstractString, initial::Int64; flags::Int64=0) createHeader(name, flags) + codeWordAddr = mem[HERE] varAddr = mem[HERE] + 1 push!(primitives, eval(:(() -> begin pushPS($(varAddr)) @@ -151,7 +155,7 @@ function defNewVar(name::AbstractString, initial::Int64; flags::Int64=0) mem[mem[HERE]] = initial; mem[HERE] += 1 - return varAddr + return varAddr, codeWordAddr end function defConst(name::AbstractString, val::Int64; flags::Int64=0) @@ -471,12 +475,12 @@ end) # Built-in variables -defExistingVar("HERE", HERE) -defExistingVar("LATEST", LATEST) -defExistingVar("PSP0", PSP0) -defExistingVar("RSP0", RSP0) -STATE = defNewVar("STATE", 0) -BASE = defNewVar("BASE", 10) +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 @@ -529,8 +533,8 @@ end) # I/O defConst("TIB", TIB) -NUMTIB = defNewVar("#TIB", 0) -TOIN = defNewVar(">IN", 0) +NUMTIB, NUMTIB_CFA = defNewVar("#TIB", 0) +TOIN, TOIN_CFA = defNewVar(">IN", 0) KEY = defPrim("KEY", () -> begin if mem[TOIN] >= mem[NUMTIB] @@ -583,6 +587,15 @@ WORD = defPrim("WORD", () -> begin wordAddr = mem[HERE] offset = 0 + if c == '\n' + # Treat newline as a special word + + mem[wordAddr + offset] = Int64(c) + pushPS(wordAddr) + pushPS(1) + return mem[NEXT] + end + while true mem[wordAddr + offset] = Int64(c) offset += 1 @@ -591,6 +604,8 @@ WORD = defPrim("WORD", () -> begin c = Char(popPS()) if c == ' ' || c == '\t' || c == '\n' + # Rewind KEY + mem[TOIN] -= 1 break end end @@ -626,7 +641,7 @@ FIND = defPrim("FIND", () -> begin wordLen = popPS() wordAddr = popPS() - word = getString(wordAddr, wordLen) + word = lowercase(getString(wordAddr, wordLen)) latest = LATEST @@ -641,9 +656,9 @@ FIND = defPrim("FIND", () -> begin end thisAddr = latest+2 - thisWord = getString(thisAddr, len) + thisWord = lowercase(getString(thisAddr, len)) - if thisWord == word + if lowercase(thisWord) == lowercase(word) break end end @@ -759,10 +774,115 @@ LITSTRING = defPrim("LITSTRING", () -> begin return mem[NEXT] end) +TELL = defPrim("TELL", () -> begin + len = popPS() + addr = popPS() + str = getString(addr, len) + print(str) + return mem[NEXT] +end) + +# Outer interpreter + +INTERPRET = defPrim("INTERPRET", () -> begin + + callPrim(mem[WORD]) + + wordName = getString(mem[reg.PSP-1], mem[reg.PSP]) + println("... ", replace(wordName, "\n", "\\n"), " ...") + + callPrim(mem[TWODUP]) + callPrim(mem[FIND]) + + wordAddr = mem[reg.PSP] + + + if wordAddr>0 + # Word in dictionary + + isImmediate = (mem[wordAddr+1] & F_IMMED) != 0 + callPrim(mem[TOCFA]) + + callPrim(mem[ROT]) # get rid of extra copy of word string details + popPS() + popPS() + + if mem[STATE] == 0 || isImmediate + # Execute! + return mem[popPS()] + else + # Append CFA to dictionary + callPrim(mem[COMMA]) + end + else + # Not in dictionary, assume number + + popPS() + + callPrim(mem[NUMBER]) + + if popPS() != 0 + println("Parse error at word: '$wordName'") + return mem[NEXT] + else + end + + if mem[STATE] == 0 + # Number already on stack! + else + # Append literal to dictionary + pushPS(LIT) + callPrim(mem[COMMA]) + callPrim(mem[COMMA]) + end + end + + return mem[NEXT] +end) + +QUIT = defWord("QUIT", + [RSP0_CFA, RSPSTORE, + INTERPRET, + BRANCH,-2]) + +NL = defPrim("\n", () -> begin + if mem[STATE] == 0 + println(" ok") + end + return mem[NEXT] +end) + +# Odds and Ends + +CHAR = defPrim("CHAR", () -> begin + callPrim(mem[WORD]) + wordLen = popPS() + wordAddr = popPS() + word = getString(wordAddr, wordLen) + pushPS(Int64(word[1])) + + return mem[NEXT] +end) + +EXECUTE = defPrim("EXECUTE", () -> begin + return mem[popPS()] +end) + +BYE = defPrim("BYE", () -> begin + return 0 +end) + #### VM loop #### function runVM() + # Start with IP pointing to first instruction of outer interpreter + reg.IP = QUIT + 1 + + # Primitive processing loop. + # Everyting else is simply a consequence of this loop! jmp = mem[NEXT] - while (jmp = callPrim(jmp)) != 0 end + while (jmp = callPrim(jmp)) != 0 + println("Evaluating prim $jmp [$(primNames[-jmp])]") + end end # Debugging tools