X-Git-Url: https://thelambdalab.xyz/gitweb/index.cgi?a=blobdiff_plain;f=src%2Fforth.jl;h=90cf1cfafee4e3e56c9924d38dbb86ca428abf8a;hb=6162399a858a397add5ed60ba33f31a4d6dba4c2;hp=64d2d23720f1173d0ab9a244538dacb06e38e0ea;hpb=7f2c4e5ef814e84cee84cba32667418cec15af12;p=forth.jl.git

diff --git a/src/forth.jl b/src/forth.jl
index 64d2d23..90cf1cf 100644
--- a/src/forth.jl
+++ b/src/forth.jl
@@ -1,12 +1,12 @@
 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:
 #
@@ -122,9 +122,14 @@ function defPrim(f::Function; name="nameless")
 end
 
 callPrim(addr::Int64) = primitives[-addr]()
+getPrimName(addr::Int64) = primNames[-addr]
 
 # Word creation functions
 
+F_IMMED = 128
+F_HIDDEN = 256
+F_LENMASK = 127
+
 function createHeader(name::AbstractString, flags::Int64)
     mem[mem[HERE]] = mem[LATEST]
     mem[LATEST] = mem[HERE]
@@ -184,10 +189,12 @@ end
 function defConst(name::AbstractString, val::Int64; flags::Int64=0)
     createHeader(name, flags)
 
+    codeWordAddr = mem[HERE]
+
     mem[mem[HERE]] = DOCON; mem[HERE] += 1
     mem[mem[HERE]] = val; mem[HERE] += 1
 
-    return val
+    return codeWordAddr
 end
 
 # Threading Primitives (inner interpreter)
@@ -219,6 +226,24 @@ EXIT = defPrimWord("EXIT", () -> begin
     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_CFA = defConst("F_IMMED", F_IMMED)
+F_HIDDEN_CFA = defConst("F_HIDDEN", F_HIDDEN)
+F_LENMASK_CFA = defConst("F_LENMASK", F_LENMASK)
+
 # Basic forth primitives
 
 DROP = defPrimWord("DROP", () -> begin
@@ -376,14 +401,14 @@ TWODIV = defPrimWord("2/", () -> begin
     return NEXT
 end)
 
-EQU = defPrimWord("=", () -> begin
+EQ = defPrimWord("=", () -> begin
     b = popPS()
     a = popPS()
     pushPS(a==b ? -1 : 0)
     return NEXT
 end)
 
-NEQU = defPrimWord("<>", () -> begin
+NE = defPrimWord("<>", () -> begin
     b = popPS()
     a = popPS()
     pushPS(a!=b ? -1 : 0)
@@ -418,12 +443,12 @@ GE = defPrimWord(">=", () -> begin
     return NEXT
 end)
 
-ZEQU = defPrimWord("0=", () -> begin
+ZE = defPrimWord("0=", () -> begin
     pushPS(popPS() == 0 ? -1 : 0)
     return NEXT
 end)
 
-ZNEQU = defPrimWord("0<>", () -> begin
+ZNE = defPrimWord("0<>", () -> begin
     pushPS(popPS() != 0 ? -1 : 0)
     return NEXT
 end)
@@ -512,27 +537,6 @@ SUBSTORE = defPrimWord("-!", () -> begin
 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("DOCOL", DOCOL)
-defConst("DOCON", DOCON)
-defConst("DOVAR", DOVAR)
-
-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
@@ -594,113 +598,38 @@ end)
 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)
+EOF_CFA = defConst("EOF", 4)
 
 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 = chomp(readline(currentSource()))
+        mem[SPAN] = min(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)
@@ -709,8 +638,9 @@ end)
 
 FIND = defPrimWord("FIND", () -> begin
 
-    wordLen = popPS()
-    wordAddr = popPS()
+    countedAddr = popPS()
+    wordAddr = countedAddr + 1
+    wordLen = mem[countedAddr]
     word = lowercase(getString(wordAddr, wordLen))
 
     latest = LATEST
@@ -749,7 +679,7 @@ TOCFA = defPrimWord(">CFA", () -> begin
     return NEXT
 end)
 
-TODFA = defWord(">DFA", [TOCFA, INCR, EXIT])
+TOPFA = defWord(">PFA", [TOCFA, INCR, EXIT])
 
 # Branching
 
@@ -768,15 +698,33 @@ ZBRANCH = defPrimWord("0BRANCH", () -> begin
     return NEXT
 end)
 
-# Compilation
+# Strings
 
-HEADER = defPrimWord("HEADER", () -> begin
+LITSTRING = defPrimWord("LITSTRING", () -> begin
+    len = mem[reg.IP]
+    reg.IP += 1
+    pushPS(reg.IP)
+    pushPS(len)
+    reg.IP += len
 
-    wordLen = popPS()
-    wordAddr = popPS()
-    word = getString(wordAddr, wordLen)
+    return NEXT
+end)
 
-    createHeader(word, 0)
+TYPE = defPrimWord("TYPE", () -> begin
+    len = popPS()
+    addr = popPS()
+    str = getString(addr, len)
+    print(str)
+    return NEXT
+end)
+
+# Outer interpreter
+
+TRACE = defPrimWord("TRACE", () -> begin
+    print("RS: "); printRS()
+    print("PS: "); printPS()
+    print("[paused]")
+    readline()
 
     return NEXT
 end)
@@ -788,139 +736,119 @@ COMMA = defPrimWord(",", () -> begin
     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)
+BTICK = defWord("[']",
+    [FROMR, DUP, INCR, TOR, FETCH, EXIT])
 
-HIDDEN = defPrimWord("HIDDEN", () -> begin
-    addr = popPS() + 1
-    mem[addr] = mem[addr] $ F_HIDDEN
-    return NEXT
+EXECUTE = defPrimWord("EXECUTE", () -> begin
+    reg.W = popPS()
+    return mem[reg.W]
 end)
 
-HIDE = defWord("HIDE",
-    [WORD,
-    FIND,
-    HIDDEN,
-    EXIT])
+TIB_CFA = defConst("TIB", TIB)
+NUMTIB, NUMTIB_CFA = defNewVar("#TIB", 0)
+TOIN, TOIN_CFA = defNewVar(">IN", 0)
 
-COLON = defWord(":",
-    [WORD,
-    HEADER,
-    LIT, DOCOL, COMMA,
-    LATEST_CFA, FETCH, HIDDEN,
-    RBRAC,
+QUERY = defWord("QUERY",
+    [TIB_CFA, LIT, 80, EXPECT,
+    SPAN_CFA, FETCH, NUMTIB_CFA, STORE,
+    LIT, 0, TOIN_CFA, STORE,
     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)
+WORD = defPrimWord("WORD", () -> begin
+    delim = popPS()
 
-TICK = defWord("'",
-    [WORD, FIND, TOCFA, EXIT])
+    # Chew up initial occurrences of delim
+    while (mem[TOIN]<mem[NUMTIB] && mem[TIB+mem[TOIN]] == delim)
+        mem[TOIN] += 1
+    end
 
-BTICK = defWord("[']",
-    [FROMR, DUP, INCR, TOR, FETCH, EXIT])
+    countAddr = mem[HERE]
+    addr = mem[HERE]+1
 
+    # Start reading in word
+    count = 0
+    while (mem[TOIN]<mem[NUMTIB])
+        mem[addr] = mem[TIB+mem[TOIN]]
+        mem[TOIN] += 1
 
-# Strings
+        if (mem[addr] == delim)
+            break
+        end
 
-LITSTRING = defPrimWord("LITSTRING", () -> begin
-    len = mem[reg.IP]
-    reg.IP += 1
-    pushPS(reg.IP)
-    pushPS(len)
-    reg.IP += len
+        count += 1
+        addr += 1
+    end
 
-    return NEXT
-end)
+    # Record count
+    mem[countAddr] = count
+    pushPS(countAddr)
 
-TELL = defPrimWord("TELL", () -> begin
-    len = popPS()
-    addr = popPS()
-    str = getString(addr, len)
-    print(str)
     return NEXT
 end)
 
-# Outer interpreter
+PARSE = defPrimWord("PARSE", () -> begin
+    delim = popPS()
 
-EXECUTE = defPrimWord("EXECUTE", () -> begin
-    reg.W = popPS()
-    return mem[reg.W]
-end)
+    # Chew up initial occurrences of delim
+    addr = mem[HERE]
 
-type ParseError <: Exception
-    wordName::ASCIIString
-end
-Base.showerror(io::IO, ex::ParseError) = print(io, "Parse error at word: '$(ex.wordName)'.")
+    # Start reading input stream
+    count = 0
+    while (mem[TOIN]<mem[NUMTIB])
+        mem[addr] = mem[TIB+mem[TOIN]]
+        mem[TOIN] += 1
 
-DEBUG, DEBUG_CFA = defNewVar("DEBUG", 0)
+        if (mem[addr] == delim)
+            break
+        end
 
-INTERPRET = defPrimWord("INTERPRET", () -> begin
+        count += 1
+        addr += 1
+    end
 
-    callPrim(mem[WORD])
+    pushPS(addr)
+    pushPS(count)
 
-    wordName = getString(mem[reg.PSP-1], mem[reg.PSP])
-    if mem[DEBUG] != 0
-        println("... ", replace(replace(wordName, "\004", "EOF"), "\n", "\\n"), " ...")
-    end
+    return NEXT
+end)
 
-    callPrim(mem[TWODUP])
-    callPrim(mem[FIND])
+STATE, STATE_CFA = defNewVar("STATE", 0)
 
-    wordAddr = mem[reg.PSP]
+INTERPRET = defWord("INTERPRET",
+    [LIT, 32, WORD, # Read next space-delimited word
 
-    if wordAddr>0
-        # Word in dictionary
+    DUP, FETCH, ZE, ZBRANCH, 3,
+        DROP, EXIT, # Exit if TIB is exhausted
 
-        isImmediate = (mem[wordAddr+1] & F_IMMED) != 0
-        callPrim(mem[TOCFA])
+    STATE_CFA, FETCH, ZBRANCH, 28,
+        # Compiling
+        DUP, FIND, ZBRANCH, 17,
 
-        callPrim(mem[NROT]) # get rid of extra copy of word string details
-        popPS()
-        popPS()
+            # Found word. 
+            DUP, TOCFA, SWAP, INCR, FETCH, LIT, F_IMMED, AND, ZBRANCH, 4,
+                # Immediate: Execute!
+                EXECUTE, BRANCH, -30,
 
-        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
+                # Not immediate: Compile!
+                COMMA, BRANCH, -33,
 
-        popPS()
+            # No word found, parse number
+            BTICK, LIT, COMMA, NUMBER, COMMA, BRANCH, -40,
+        
+       # Interpreting
+        DUP, FIND, QDUP, ZBRANCH, 7,
 
-        callPrim(mem[NUMBER])
+            # Found word. Execute!
+            SWAP, DROP, TOCFA, EXECUTE, BRANCH, -51,
 
-        if popPS() != 0
-            throw(ParseError(wordName))
-        end
+            # No word found, parse number and leave on stack
+            NUMBER, BRANCH, -54,
+    EXIT]
+)
 
-        if mem[STATE] == 0
-            # Number already on stack!
-        else
-            # Append literal to dictionary
-            pushPS(LIT)
-            callPrim(mem[COMMA])
-            callPrim(mem[COMMA])
-        end
+PROMPT = defPrimWord("PROMPT", () -> begin
+    if (mem[STATE] == 0 && currentSource() == STDIN)
+        println(" ok")
     end
 
     return NEXT
@@ -928,28 +856,20 @@ end)
 
 QUIT = defWord("QUIT",
     [RSP0_CFA, RSPSTORE,
-    INTERPRET,
-    BRANCH,-2])
+    QUERY,
+    INTERPRET, PROMPT,
+    BRANCH,-4])
 
 BYE = defPrimWord("BYE", () -> begin
+    println("Bye!")
     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
+    pushPS(32)
     callPrim(mem[WORD])
-    wordLen = popPS()
-    wordAddr = popPS()
+    wordAddr = popPS()+1
+    wordLen = mem[wordAddr-1]
     word = getString(wordAddr, wordLen)
 
     push!(sources, open(word, "r"))
@@ -960,36 +880,66 @@ INCLUDE = defPrimWord("INCLUDE", () -> begin
     return NEXT
 end)
 
-EOF_WORD = defPrimWord("\x04", () -> begin
-    if currentSource() != STDIN
-        close(currentSource())
-    end
+# Compilation
 
-    pop!(sources)
+HEADER = defPrimWord("HEADER", () -> begin
+    wordAddr = popPS()+1
+    wordLen = mem[wordAddr-1]
+    word = getString(wordAddr, wordLen)
 
-    if length(sources)>0
-        if currentSource() == STDIN
-            callPrim(mem[PROMPT])
-        end
+    createHeader(word, 0)
 
-        return NEXT
-    else
-        return 0
-    end
-end, flags=F_IMMED)
+    return NEXT
+end)
 
-# Odds and Ends
+LBRAC = defPrimWord("[", () -> begin
+    mem[STATE] = 0
+    return NEXT
+end, flags=F_IMMED)
 
-CHAR = defPrimWord("CHAR", () -> begin
-    callPrim(mem[WORD])
-    wordLen = popPS()
-    wordAddr = popPS()
-    word = getString(wordAddr, wordLen)
-    pushPS(Int64(word[1]))
+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)
+
+TICK = defWord("'",
+    [LIT, 32, WORD, FIND, TOCFA, EXIT])
+
+
+#### VM loop ####
+
 initialized = false
 initFileName = nothing
 if isfile("lib.4th")
@@ -998,9 +948,7 @@ elseif isfile(Pkg.dir("forth/src/lib.4th"))
     initFileName = Pkg.dir("forth/src/lib.4th")
 end
 
-
-#### VM loop ####
-function run(;initialize=true)
+function run(;initialize=false)
     # Begin with STDIN as source
     push!(sources, STDIN)
 
@@ -1023,10 +971,7 @@ function run(;initialize=true)
     jmp = NEXT
     while jmp != 0
         try
-            if mem[DEBUG] != 0
-                println("Evaluating prim ", jmp," ", primNames[-jmp])
-            end
-
+            #println("Entering prim $(getPrimName(jmp))")
             jmp = callPrim(jmp)
 
         catch ex