vala/valatypeofexpression.vala

   1 /* valatypeofexpression.vala
   2  *
   3  * Copyright (C) 2006-2010  Jürg Billeter
   4  *
   5  * This library is free software; you can redistribute it and/or
   6  * modify it under the terms of the GNU Lesser General Public
   7  * License as published by the Free Software Foundation; either
   8  * version 2.1 of the License, or (at your option) any later version.
   9
  10  * This library is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13  * Lesser General Public License for more details.
  14
  15  * You should have received a copy of the GNU Lesser General Public
  16  * License along with this library; if not, write to the Free Software
  17  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301  USA
  18  *
  19  * Author:
  20  *      Jürg Billeter <j@bitron.ch>
  21  */
  22
  23 using GLib;
  24
  25 /**
  26  * Represents a typeof expression in the source code.
  27  */
  28 public class Vala.TypeofExpression : Expression {
  29         /**
  30          * The type to be retrieved.
  31          */
  32         public DataType type_reference {
  33                 get { return _data_type; }
  34                 set {
  35                         _data_type = value;
  36                         _data_type.parent_node = this;
  37                 }
  38         }
  39
  40         private DataType _data_type;
  41
  42         /**
  43          * Creates a new typeof expression.
  44          *
  45          * @param type   a data type
  46          * @param source reference to source code
  47          * @return       newly created typeof expression
  48          */
  49         public TypeofExpression (DataType type, SourceReference source) {
  50                 type_reference = type;
  51                 source_reference = source;
  52         }
  53
  54         public override void accept (CodeVisitor visitor) {
  55                 visitor.visit_typeof_expression (this);
  56
  57                 visitor.visit_expression (this);
  58         }
  59
  60         public override void accept_children (CodeVisitor visitor) {
  61                 type_reference.accept (visitor);
  62         }
  63
  64         public override bool is_pure () {
  65                 return true;
  66         }
  67
  68         public override void replace_type (DataType old_type, DataType new_type) {
  69                 if (type_reference == old_type) {
  70                         type_reference = new_type;
  71                 }
  72         }
  73
  74         public override bool check (CodeContext context) {
  75                 if (checked) {
  76                         return !error;
  77                 }
  78
  79                 checked = true;
  80
  81                 type_reference.check (context);
  82
  83                 value_type = context.analyzer.type_type;
  84
  85                 return !error;
  86         }
  87
  88         public override void emit (CodeGenerator codegen) {
  89                 codegen.visit_typeof_expression (this);
  90
  91                 codegen.visit_expression (this);
  92         }
  93 }