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1   ////////////////////////////////////////////////////////////////////////////////
2   // MillScript: an Open Spice interpreter and batch website creation tool
3   // Copyright (C) 2001-2004 Open World Ltd
4   //
5   // This file is part of MillScript.
6   //
7   // MillScript is free software; you can redistribute it and/or modify it under
8   // the terms of the GNU General Public License as published by the Free
9   // Software Foundation; either version 2 of the License, or (at your option)
10  // any later version.
11  //
12  // MillScript is distributed in the hope that it will be useful, but WITHOUT
13  // ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
14  // FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
15  // more details.
16  //
17  // You should have received a copy of the GNU General Public License along with
18  // MillScript; if not, write to the Free Software Foundation, Inc., 59 Temple
19  // Place, Suite 330, Boston, MA  02111-1307  USA
20  ////////////////////////////////////////////////////////////////////////////////
21  package org.millscript.millscript.expr;
22  
23  import org.millscript.millscript.action.AndAction;
24  import org.millscript.millscript.vm.CompilerState;
25  
26  /**
27   * This class implements an <code>and</code> expression. This expression always
28   * returns one result.
29   *
30   * @see org.millscript.millscript.syntax.AndSyntax
31   * @see AndAction
32   */
33  public final class AndExpr extends Expr< AndAction > implements OneResult {
34  
35      /**
36       * The left hand side expression
37       */
38      private final Expr< ? > lhs;
39  
40      /**
41       * The right hand side expression
42       */
43      private final Expr< ? > rhs;
44  
45      /**
46       * Creates a new <code>And</code> expression with the specifed left and
47       * right hand side expressions.
48       *
49       * @param   l   the left hand side expression, which must return a single
50       *              result
51       * @param   r   the right hand side expression, which must return a single
52       *              result
53       */
54      public AndExpr( final Expr< ? > l, final Expr< ? > r ) {
55          lhs = CheckExpr.make( l );
56          rhs = CheckExpr.make( r );
57      }
58  
59      /**
60       * @see org.millscript.millscript.expr.Expr#compileIt()
61       */
62      @Override
63      public AndAction compileIt() {
64          return new AndAction( lhs.compile(), rhs.compile() );
65      }
66  
67      /**
68       * @see org.millscript.millscript.expr.Expr#resolve(org.millscript.millscript.vm.CompilerState)
69       */
70      @Override
71      public void resolve( final CompilerState state ) {
72          this.lhs.resolve( state );
73          this.rhs.resolve( state );
74      }
75  
76      /**
77       * @see org.millscript.millscript.expr.Expr#showComponents(int)
78       */
79      @Override
80      void showComponents( final int n ) {
81          this.lhs.show( n );
82          this.rhs.show( n );
83      }
84  
85  }