Misc. tweaks to vector slicing implementation

* Minor style/format changes

* Fix a signed/unsigned comparison compiler warning

* Use a non-fatal error for non-integral slice indices so we can
  report any further scripting errors instead of stopping the parse
  right there

NEWS

@@ -94,6 +94,12 @@ New Functionality
   is available in the events: ``ssl_extension_pre_shared_key_client_hello``
   and ``ssl_extension_pre_shared_key_server_hello``.
 
+- Add support for vector slicing operations.  For example::
+
+    local v = vector(1, 2, 3, 4, 5);
+    v[2:4] = vector(6, 7, 8);        # v is now [1, 2, 6, 7, 8, 5]
+    print v[:4];                     # prints [1, 2, 6, 7]
+
 Changed Functionality
 ---------------------
 

src/Expr.cc

@@ -3200,27 +3200,26 @@ void IndexExpr::Assign(Frame* f, Val* v, Opcode op)
 	switch ( v1->Type()->Tag() ) {
 	case TYPE_VECTOR:
 		{
-		const ListVal *lv = v2->AsListVal();
+		const ListVal* lv = v2->AsListVal();
 		VectorVal* v1_vect = v1->AsVectorVal();
 
 		if ( lv->Length() > 1 )
 			{
-			int len = v1_vect->Size();
+			auto len = v1_vect->Size();
 			bro_int_t first = get_slice_index(lv->Index(0)->CoerceToInt(), len);
 			bro_int_t last = get_slice_index(lv->Index(1)->CoerceToInt(), len);
 
 			// Remove the elements from the vector within the slice
-			for ( int idx = first; idx < last; idx++ )
+			for ( auto idx = first; idx < last; idx++ )
 				v1_vect->Remove(first);
 
 			// Insert the new elements starting at the first position
 			VectorVal* v_vect = v->AsVectorVal();
-			for ( int idx = 0; idx < v_vect->Size(); idx++, first++ )
+
-				{
+			for ( auto idx = 0u; idx < v_vect->Size(); idx++, first++ )
 				v1_vect->Insert(first, v_vect->Lookup(idx)->Ref());
-				}
 			}
-		else if ( !v1_vect->Assign(v2, v, op) )
+		else if ( ! v1_vect->Assign(v2, v, op) )
 			{
 			if ( v )
 				{

src/Val.cc

@@ -3417,6 +3417,7 @@ bool VectorVal::Insert(unsigned int index, Val* element)
 		}
 
 	vector<Val*>::iterator it;
+
 	if ( index < val.vector_val->size() )
 		it = std::next(val.vector_val->begin(), index);
 	else

src/Val.h

@@ -1197,8 +1197,8 @@ public:
 	// Insert an element at a specific position into the underlying vector.
 	bool Insert(unsigned int index, Val* element);
 
-	// Removes an element or a range of elements from a specific position.
+	// Removes an element at a specific position.
-	bool Remove(unsigned int start_index);
+	bool Remove(unsigned int index);
 
 protected:
 	friend class Val;

src/parse.y

@@ -484,8 +484,10 @@ expr:
 			set_location(@1, @6);
 			Expr* low = $3 ? $3 : new ConstExpr(val_mgr->GetCount(0));
 			Expr* high = $5 ? $5 : new SizeExpr($1);
+
 			if ( ! IsIntegral(low->Type()->Tag()) || ! IsIntegral(high->Type()->Tag()) )
-				reporter->FatalError("slice notation must have integral values as indexes");
+				reporter->Error("slice notation must have integral values as indexes");
+
 			ListExpr* le = new ListExpr(low);
 			le->Append(high);
 			$$ = new IndexExpr($1, le, true);