parser: node locations are not nullable

[nit.git] / src / parser / xss / nodes.xss

diff --git a/src/parser/xss/nodes.xss b/src/parser/xss/nodes.xss
index 22dda4e..d6df697 100644 (file)
--- a/src/parser/xss/nodes.xss
+++ b/src/parser/xss/nodes.xss
@@ -1,25 +1,28 @@
-/* This file is part of NIT ( http://www.nitlanguage.org ).
- *
- * Copyright 2008 Jean Privat <jean@pryen.org>
- * Based on algorithms developped for ( http://www.sablecc.org/ ).
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
+$ // This file is part of NIT ( http://www.nitlanguage.org ).
+$ //
+$ // Copyright 2008 Jean Privat <jean@pryen.org>
+$ // Based on algorithms developped for ( http://www.sablecc.org/ ).
+$ //
+$ // Licensed under the Apache License, Version 2.0 (the "License");
+$ // you may not use this file except in compliance with the License.
+$ // You may obtain a copy of the License at
+$ //
+$ //     http://www.apache.org/licenses/LICENSE-2.0
+$ //
+$ // Unless required by applicable law or agreed to in writing, software
+$ // distributed under the License is distributed on an "AS IS" BASIS,
+$ // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+$ // See the License for the specific language governing permissions and
+$ // limitations under the License.
 
 $ template make_abs_nodes()
 # Root of the AST hierarchy
 abstract class PNode
-       readable var _location: nullable Location
+       var _location: nullable Location
+
+       # Location is set during AST building. Once built, location cannon be null
+       # However, manual instanciated nodes may need mode care
+       fun location: Location do return _location.as(not null)
 end
 
 # Ancestor of all tokens
@@ -30,7 +33,7 @@ end
 # Ancestor of all productions
 abstract class Prod
 special PNode
-       fun location=(loc: nullable Location) do _location = loc
+       fun location=(loc: Location) do _location = loc
 end
 $ end template
 
@@ -63,21 +66,6 @@ redef class PNode
        # Visit all nodes in reverse order.
        # Thus, call "v.visit(e)" for each node e starting from the last child
        fun visit_all_reverse(v: Visitor) is abstract
-
-       # Give a human readable location of the node.
-       fun locate: String
-       do
-               if location == null then
-                       return "????"
-               end
-               return location.to_s
-       end
-
-       # Debug method: output a message prefixed with the location.
-       fun printl(str: String)
-       do
-               print("{locate}: {str}\n")
-       end
 end
 
 redef class Token
@@ -87,28 +75,33 @@ redef class Token
 end
 
 redef class Prod
-       # The first token of the production node
-       readable writable var _first_token: nullable Token
-
-       # The last token of the production node
-       readable writable var _last_token: nullable Token
-
        redef fun replace_with(n: PNode)
         do
                 super
                 assert n isa Prod
-                n.first_token = first_token
-                n.last_token = last_token
                 n.location = location
         end
 end
 
 # Abstract standard visitor
 class Visitor
+       # What the visitor do when a node is visited
+        # Concrete visitors should redefine this method.
+        protected fun visit(e: nullable PNode) is abstract
+
         # Ask the visitor to visit a given node.
         # Usually automatically called by visit_all* methods.
-        # Concrete visitors should redefine this method.
-        fun visit(e: nullable PNode) is abstract
+       # This methos should not be redefined
+        fun enter_visit(e: nullable PNode)
+       do
+               var old = _current_node
+               _current_node = e
+               visit(e)
+               _current_node = old
+       end
+
+       # The current visited node
+       readable var _current_node: nullable PNode = null
 end
 
 $ end template