change goal and term expansions, change call/N to use goal expansions

src/prolog/machine/machine_indices.rs

@@ -211,6 +211,8 @@ pub enum IndexPtr {
     DynamicUndefined, // a predicate, declared as dynamic, whose location in code is as yet undefined.
     Undefined,
     Index(usize),
+    UserGoalExpansion,
+    UserTermExpansion
 }
 
 #[derive(Clone, Ord, PartialOrd, Eq, PartialEq)]
@@ -309,7 +311,6 @@ pub enum REPLCodePtr {
 #[derive(Clone, PartialEq)]
 pub enum CodePtr {
     BuiltInClause(BuiltInClauseType, LocalCodePtr), // local is the successor call.
-    CallN(usize, LocalCodePtr, bool),               // arity, local, last call.
     Local(LocalCodePtr),
     DynamicTransaction(DynamicTransactionType, LocalCodePtr), // the type of transaction, the return pointer.
     REPL(REPLCodePtr, LocalCodePtr),                          // the REPL code, the return pointer.
@@ -320,7 +321,6 @@ impl CodePtr {
     pub fn local(&self) -> LocalCodePtr {
         match self {
             &CodePtr::BuiltInClause(_, ref local)
-          | &CodePtr::CallN(_, ref local, _)
           | &CodePtr::Local(ref local) => local.clone(),
             &CodePtr::VerifyAttrInterrupt(p) => LocalCodePtr::DirEntry(p),
             &CodePtr::REPL(_, p) | &CodePtr::DynamicTransaction(_, p) => p,
@@ -418,7 +418,7 @@ impl Add<usize> for CodePtr {
           | p @ CodePtr::VerifyAttrInterrupt(_)
           | p @ CodePtr::DynamicTransaction(..) => p,
             CodePtr::Local(local) => CodePtr::Local(local + rhs),
-            CodePtr::CallN(_, local, _) | CodePtr::BuiltInClause(_, local) => {
+            CodePtr::BuiltInClause(_, local) => {
                 CodePtr::Local(local + rhs)
             }
         }
@@ -491,6 +491,19 @@ impl IndexStore {
         }
     }
 
+    pub fn add_term_and_goal_expansion_indices(&mut self) {
+        self.code_dir.insert((clause_name!("term_expansion"), 2), 
+                             CodeIndex(Rc::new(RefCell::new(
+                                 (IndexPtr::UserTermExpansion,
+                                  clause_name!("user"))
+                             ))));
+        self.code_dir.insert((clause_name!("goal_expansion"), 2), 
+                             CodeIndex(Rc::new(RefCell::new(
+                                 (IndexPtr::UserGoalExpansion,
+                                  clause_name!("user"))
+                             ))));
+    }
+    
     #[inline]
     pub fn remove_clause_subsection(&mut self, module: ClauseName, name: ClauseName, arity: usize) {
         self.dynamic_code_dir.swap_remove(&(module, name, arity));