From: Tim Vaughan <tgvaughan@gmail.com>
Date: Sun, 17 Apr 2016 12:48:42 +0000 (+1200)
Subject: Added arithmetic operations
X-Git-Url: https://thelambdalab.xyz/gitweb/index.cgi?p=forth.jl.git;a=commitdiff_plain;h=4fc8dd4ebaa234f2a3e5798508c2d8a3987b421a

Added arithmetic operations
---

diff --git a/src/forth.jl b/src/forth.jl
index edca589..e8478a4 100644
--- a/src/forth.jl
+++ b/src/forth.jl
@@ -155,6 +155,18 @@ function defConst(name::AbstractString, val::Int64; flags::Int64=0)
     return val
 end
 
+function defWord(name::AbstractString, wordAddrs::Array{Int64,1}; flags::Int64=0)
+    createHeader(name, flags)
+
+    mem[mem[HERE]] = DOCOL
+    mem[HERE] += 1
+
+    for wordAddr in wordAddrs
+        mem[mem[HERE]] = wordAddr
+        mem[HERE] += 1
+    end
+end
+
 # Threading Primitives
 
 NEXT = defPrim("NEXT", () -> begin
@@ -258,6 +270,48 @@ QDUP = defPrim("?DUP", () -> begin
     return NEXT
 end)
 
+INCR = defPrim("1+", () -> begin
+    ensurePSDepth(1)
+    mem[reg.PSP] += 1
+    return NEXT
+end)
+
+DECR = defPrim("1-", () -> begin
+    ensurePSDepth(1)
+    mem[reg.PSP] -= 1
+    return NEXT
+end)
+
+ADD = defPrim("+", () -> begin
+    a = popPS()
+    b = popPS()
+    pushPS(a+b)
+    return NEXT
+end)
+
+SUB = defPrim("-", () -> begin
+    a = popPS()
+    b = popPS()
+    pushPS(b-a)
+    return NEXT
+end)
+
+MUL = defPrim("*", () -> begin
+    a = popPS()
+    b = popPS()
+    pushPS(a*b)
+    return NEXT
+end)
+
+DIVMOD = defPrim("/MOD", () -> begin
+    a = popPS()
+    b = popPS()
+    q,r = divrem(b,a)
+    pushPS(r)
+    pushPS(q)
+    return NEXT
+end)
+
 LIT = defPrim("LIT", () -> begin
     pushPS(mem[reg.IP])
     reg.IP += 1
@@ -484,11 +538,13 @@ TOCFA = defPrim(">CFA", () -> begin
     lenAndFlags = mem[addr+1]
     len = lenAndFlags & F_LENMASK
 
-    pushPS(addr + 1 + len)
+    pushPS(addr + 2 + len)
 
     return NEXT
 end)
 
+TODFA = defWord(">DFA", [TOCFA, INCR1, EXIT])
+
 #### VM loop ####
 #function runVM(reg::Reg)
 #    jmp = NEXT