conditionalexpression.java

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/* gnu.classpath.tools.gjdoc.expr.ConditionalExpression
   Copyright (C) 2004 Free Software Foundation, Inc.

This file is part of GNU Classpath.

GNU Classpath is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2, or (at your option)
any later version.
 
GNU Classpath is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
General Public License for more details.

You should have received a copy of the GNU General Public License
along with GNU Classpath; see the file COPYING.  If not, write to the
Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
02111-1307 USA. */

package gnu.classpath.tools.gjdoc.expr;

class ConditionalExpression
   implements Expression
{
   private Expression condition;
   private Expression ifTrue;
   private Expression ifFalse;
   
   ConditionalExpression(Expression condition, Expression ifTrue, Expression ifFalse)
   {
      this.condition = condition;
      this.ifTrue = ifTrue;
      this.ifFalse = ifFalse;
   }

   public ConstantExpression evaluate(Context context)
      throws IllegalExpressionException
   {
      ConstantExpression conditionValue = condition.evaluate(context);
      ConstantExpression ifTrueValue = ifTrue.evaluate(context);
      ConstantExpression ifFalseValue = ifFalse.evaluate(context);

      if (Type.BOOLEAN != conditionValue.getType()) {
         throw new IllegalExpressionException("condition must be boolean");
      }
      else {
         boolean cond = ((ConstantBoolean)conditionValue).booleanValue();
         if (cond) {
            return ifTrueValue;
         }
         else {
            return ifFalseValue;
         }
      }
   }
}