From bc72871b5a63fc748a71d55d87afca3746d8d219 Mon Sep 17 00:00:00 2001
From: Tim Vaughan <tgvaughan@gmail.com>
Date: Sun, 10 Apr 2016 01:19:05 +1200
Subject: [PATCH] Getting somewhere.

---
 src/forth.jl | 39 +++++++++++++++++++++++++++++++++------
 1 file changed, 33 insertions(+), 6 deletions(-)

diff --git a/src/forth.jl b/src/forth.jl
index 0aa33d7..67dd77d 100644
--- a/src/forth.jl
+++ b/src/forth.jl
@@ -1,20 +1,47 @@
 module forth
 
-RS = Array{Int64, 1}()
-DS = Array{Int64, 1}()
+RS = Array{Int, 1}()
+DS = Array{Int, 1}()
+
+IP = 0
+W = 0
+X = 0
+jmp = nothing
 
 primitives = Array{Expr,1}()
-memory = Array{Int,1}()
-headers = Array{Tuple{AbstractString, Int},1}
+memory = Array{Int64,1}()
+headers = Array{Tuple{AbstractString, Int64},1}()
 
 function addPrim(name::AbstractString, expr::Expr)
     push!(primitives, expr)
     push!(memory, -length(primitives))
-    push!(headers, length(memory))
+    push!(headers, (name, length(memory)))
+    
+    return expr
 end
 
-addPrim("docol", :(begin
+NEXT = addPrim("next", :(begin
+    W = memory[IP]
+    IP += 1
+    X = memory[W]
+    jmp = primitives[-X]
+end))
 
+DOCOL = addPrim("docol", :(begin
+    push!(RS, IP)
+    IP = W + 1
+    jmp = NEXT
 end))
 
+EXIT = addPrim("exit", :(begin
+    IP = pop!(RS)
+    jmp = NEXT
+end))
+
+# VM loop
+#jmp = NEXT
+#while true
+#    eval(jmp)
+#end
+
 end
-- 
2.20.1