vala/valayieldstatement.vala

   1 /* valayieldstatement.vala
   2  *
   3  * Copyright (C) 2008-2010  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 /**
  24  * Represents a yield statement in the source code.
  25  */
  26 public class Vala.YieldStatement : CodeNode, Statement {
  27         /**
  28          * The expression to yield or the method call to yield to.
  29          */
  30         public Expression? yield_expression {
  31                 get { return _yield_expression; }
  32                 set {
  33                         _yield_expression = value;
  34                         if (_yield_expression != null) {
  35                                 _yield_expression.parent_node = this;
  36                         }
  37                 }
  38         }
  39
  40         private Expression _yield_expression;
  41
  42         /**
  43          * Creates a new yield statement.
  44          *
  45          * @param yield_expression the yield expression
  46          * @param source_reference reference to source code
  47          * @return                 newly created yield statement
  48          */
  49         public YieldStatement (Expression? yield_expression, SourceReference? source_reference = null) {
  50                 this.yield_expression = yield_expression;
  51                 this.source_reference = source_reference;
  52         }
  53
  54         public override void accept (CodeVisitor visitor) {
  55                 visitor.visit_yield_statement (this);
  56         }
  57
  58         public override void accept_children (CodeVisitor visitor) {
  59                 if (yield_expression != null) {
  60                         yield_expression.accept (visitor);
  61
  62                         visitor.visit_end_full_expression (yield_expression);
  63                 }
  64         }
  65
  66         public override void replace_expression (Expression old_node, Expression new_node) {
  67                 if (yield_expression == old_node) {
  68                         yield_expression = new_node;
  69                 }
  70         }
  71
  72         public override bool check (CodeContext context) {
  73                 if (yield_expression != null) {
  74                         yield_expression.check (context);
  75                         error = yield_expression.error;
  76                 }
  77
  78                 context.analyzer.current_method.yield_count++;
  79
  80                 return !error;
  81         }
  82
  83         public override void emit (CodeGenerator codegen) {
  84                 if (yield_expression != null) {
  85                         yield_expression.emit (codegen);
  86
  87                         codegen.visit_end_full_expression (yield_expression);
  88                 }
  89
  90                 codegen.visit_yield_statement (this);
  91         }
  92 }
  93