PATCH: Implementation of current() function

[robin]

The attached patch implements the current() function in Sablotron.
It works for me, but I haven't tested it comprehensively.

There's a bit of fuzz because I've manually removed irrelevant
changes from the patch.

If you try it, let me know if it works for you too...

 .robin.

-- 
Are we not drawn onward, we few, drawn onward to new era?

diff -aur Sablot-0.40/Sablot/context.cpp Sablot-0.40-patched/Sablot/context.cpp
--- Sablot-0.40/Sablot/context.cpp      Fri Jun 30 11:23:25 2000
+++ Sablot-0.40-patched/Sablot/context.cpp      Wed Jul  5 02:24:18 2000
@@ -67,6 +67,7 @@
 Context::Context()
 {
     array = new CList;
+    currentNode = NULL;
     position = -1;
 }
 
@@ -85,6 +86,19 @@
         return NULL;
 };
 
+Vertex *Context::getCurrentNode() const
+{
+    if (currentNode)
+        return currentNode;
+    else
+        return current();
+}
+
+void Context::setCurrentNode(Vertex * v)
+{
+    currentNode = v;
+}
+
 void Context::reset()
 {
     if (!array -> number())
@@ -152,6 +166,7 @@
 {
     Context *newc = new Context;
     delete NZ(newc -> array);
+    newc -> currentNode = currentNode;
     newc -> array = array;
     array -> incRefCount();
     newc -> reset();
diff -aur Sablot-0.40/Sablot/context.h Sablot-0.40-patched/Sablot/context.h
--- Sablot-0.40/Sablot/context.h        Fri Jun 30 11:23:25 2000
+++ Sablot-0.40-patched/Sablot/context.h        Wed Jul  5 02:08:55 2000
@@ -68,6 +68,10 @@
     ~Context();
     Vertex 
         *current() const;
+    Vertex
+        *getCurrentNode() const;
+    void
+        setCurrentNode(Vertex *);
     void    
         reset();
     Bool 
@@ -99,6 +103,8 @@
 protected:
     CList 
         *array;
+    Vertex
+        *currentNode;
 };
 
 #endif  //ifndef ContextHIncl
diff -aur Sablot-0.40/Sablot/expr.cpp Sablot-0.40-patched/Sablot/expr.cpp
--- Sablot-0.40/Sablot/expr.cpp Fri Jun 30 11:23:25 2000
+++ Sablot-0.40-patched/Sablot/expr.cpp Wed Jul  5 14:56:07 2000
@@ -868,7 +868,9 @@
     Vertex 
         *baseV = (*c)[baseIndex],
         *v;
+    Vertex *currentNode = c->getCurrentNode();
     c = new Context;
+    c->setCurrentNode(currentNode);
 
     switch(ax)
     {
@@ -2731,6 +2734,14 @@
             else
                 retxpr.setAtom(Str(""));
         }; break;
+
+    case EXFF_CURRENT:
+        {
+            Context *newc = new Context;
+            newc -> set (c -> getCurrentNode());
+            retxpr.setAtom (newc);
+        }; break;
+
     default:
         Err1(ET_FUNC_NOT_SUPPORTED, getFuncName(functor));
     }
@@ -2746,7 +2757,8 @@
         c = new Context;
         return OK;
     };
-    E( args[0] -> createContext(myctxt = c, baseNdx) );
+    ( myctxt = c ) -> setCurrentNode ( c->getCurrentNode() );
+    E( args[0] -> createContext(myctxt, baseNdx) );
     E( createLPContextSum(1, c = myctxt) );
     delete myctxt;
     return OK;
diff -aur Sablot-0.40/Sablot/verts.cpp Sablot-0.40-patched/Sablot/verts.cpp
--- Sablot-0.40/Sablot/verts.cpp        Fri Jun 30 11:23:25 2000
+++ Sablot-0.40-patched/Sablot/verts.cpp        Wed Jul  5 14:57:17 2000
@@ -1106,6 +1106,7 @@
     if (c -> isFinished())
         return OK;
 
+    c->setCurrentNode(NULL);
     situation.pushCurrV(this);
     Vertex *v = c -> current();
     assert(v);