1 /* This file is part of NIT ( http://www.nitlanguage.org ).
3 * Copyright 2008 Jean Privat <jean@pryen.org>
4 * Based on algorithms developped for ( http://www.sablecc.org/ ).
6 * Licensed under the Apache License, Version 2.0 (the "License");
7 * you may not use this file except in compliance with the License.
8 * You may obtain a copy of the License at
10 * http://www.apache.org/licenses/LICENSE-2.0
12 * Unless required by applicable law or agreed to in writing, software
13 * distributed under the License is distributed on an "AS IS" BASIS,
14 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
15 * See the License for the specific language governing permissions and
16 * limitations under the License.
19 $ template make_abs_nodes()
20 # Root of the AST hierarchy
22 readable var _location: nullable Location
25 # Ancestor of all tokens
30 # Ancestor of all productions
33 fun location=(loc: nullable Location) do _location = loc
37 $ template make_nodes()
39 # Parent of the node in the AST
40 readable writable var _parent: nullable PNode
42 # Remove a child from the AST
43 fun remove_child(child: PNode)
45 replace_child(child, null)
48 # Replace a child with an other node in the AST
49 fun replace_child(old_child: PNode, new_child: nullable PNode) is abstract
51 # Replace itself with an other node in the AST
52 fun replace_with(node: PNode)
54 if (_parent != null) then
55 _parent.replace_child(self, node)
59 # Visit all nodes in order.
60 # Thus, call "v.visit(e)" for each node e
61 fun visit_all(v: Visitor) is abstract
63 # Visit all nodes in reverse order.
64 # Thus, call "v.visit(e)" for each node e starting from the last child
65 fun visit_all_reverse(v: Visitor) is abstract
67 # Debug method: output a message prefixed with the location.
68 fun printl(str: String)
70 if location == null then
73 print("{location}: {str}\n")
79 redef fun visit_all(v: Visitor) do end
80 redef fun visit_all_reverse(v: Visitor) do end
81 redef fun replace_child(old_child: PNode, new_child: nullable PNode) do end
85 # The first token of the production node
86 readable writable var _first_token: nullable Token
88 # The last token of the production node
89 readable writable var _last_token: nullable Token
91 redef fun replace_with(n: PNode)
95 n.first_token = first_token
96 n.last_token = last_token
101 # Abstract standard visitor
103 # What the visitor do when a node is visited
104 # Concrete visitors should redefine this method.
105 protected fun visit(e: nullable PNode) is abstract
107 # Ask the visitor to visit a given node.
108 # Usually automatically called by visit_all* methods.
109 # This methos should not be redefined
110 fun enter_visit(e: nullable PNode)
112 var old = _current_node
118 # The current visited node
119 readable var _current_node: nullable PNode = null