code: /**
   * Copyright (c) 2004-2005, Regents of the University of California
   * All rights reserved.
   *
   * Redistribution and use in source and binary forms, with or without
   * modification, are permitted provided that the following conditions
   * are met:
   *
   * Redistributions of source code must retain the above copyright notice,
   * this list of conditions and the following disclaimer.
   *
   * Redistributions in binary form must reproduce the above copyright
   * notice, this list of conditions and the following disclaimer in the
   * documentation and/or other materials provided with the distribution.
   *
   * Neither the name of the University of California, Los Angeles nor the
   * names of its contributors may be used to endorse or promote products
   * derived from this software without specific prior written permission.
   *
   * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
   * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
   * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
   * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
   * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
   * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
   * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
   * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
   * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
   * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
   * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
   */
  
  package jintgen.jigir;
  
  import cck.parser.SourcePoint;
  import jintgen.isdl.OperandTypeDecl;
  import jintgen.isdl.parser.Token;
  import jintgen.types.TypeRef;
  
  /**
   * The <code>CallExpr</code> class represents a subroutine call within the IR. Subroutines can be called for
   * side effects and produce results in the IR, allowing factoring of common pieces of code.
   *
   * @author Ben L. Titzer
   */
  public class ReadExpr extends Expr {
  
      /**
       * The <code>method</code> field stores a string that represents the name of the subroutine being called.
       */
      public final Token method;
  
      public final TypeRef typeRef;
  
      public final Token operand;
  
      protected OperandTypeDecl.Accessor accessor;
  
      /**
       * The constructor of the <code>ReadExpr</code> class simply initializes the references to the subroutine
       * name and arguments.
       *
       * @param m the name of the subroutine as a string
       */
      public ReadExpr(Token m, TypeRef t, Token o) {
          method = m;
          typeRef = t;
          operand = o;
      }
  
      /**
       * The <code>accept()</code> method implements one half of the visitor pattern so that client visitors can
       * traverse the syntax tree easily and in an extensible way.
       *
       * @param v the visitor to accept
       */
      public void accept(CodeVisitor v) {
          v.visit(this);
      }
  
      /**
       * The <code>accept()</code> method implements one half of the visitor pattern for rebuilding of
       * expressions. This visitor allows code to be slightly modified while only writing visit methods for the
       * parts of the syntax tree affected.
       *
       * @param r the rebuilder to accept
       * @return the result of calling the appropriate <code>visit()</code> method of the rebuilder
       */
      public <Res, Env> Res accept(CodeAccumulator<Res, Env> r, Env env) {
          return r.visit(this, env);
      }
  
      /**
       * The <code>toString()</code> method recursively converts this expression to a string. For binary
       * operations, inner expressions will be nested within parentheses if their precedence is lower than the
       * precedence of the parent expression.
       *
       * @return a string representation of this expression
       */
      public String toString() {
          return "read : "+typeRef +" ("+operand+ ')';
      }
  
      /**
       * The <code>getPrecedence()</code> method gets the binding precedence for this expression. This is used
       * to compute when inner expressions must be nested within parentheses in order to preserve the implied
       * order of evaluation.
       *
       * @return an integer representing the precedence of this expression; higher numbers are higher
       *         precedence
       */
      public int getPrecedence() {
          return PREC_TERM;
      }
  
      public SourcePoint getSourcePoint() {
          return method.getSourcePoint();
      }
  
      public void setAccessor(OperandTypeDecl.Accessor m) {
          accessor = m;
      }
  
      public OperandTypeDecl.Accessor getAccessor() {
          return accessor;
      }
  }
  