package edu.gac.max.mcs388.s2000.compiler_support;

/** The Register class is used to represent a register of the target
 * architecture (MIPS).  For now it is little more than the
 * $<var>whatever</var> name of the register, but this class might
 * well be evolved.
 *
 * <p> Written 7 Feb 1997 by
 * <a href="http://www.gac.edu/~max/">Max Hailperin</a>
 * <a href="mailto:max@gac.edu">&lt;max@gac.edu&gt;</a> */

public class Register{
  String name;

  /** The constructor that takes a single String argument expects it to be
   the name of the register, without the $. */
  public Register(String n){
    name = "$" + n;
  }

  /** The constructor which takes a prefix String and then an integer is
   for members of numbered families of registers, e.g. one could do
   <code>new Register("t", 0)</code> to create <code>$t0</code>. */
  public Register(String prefix, int num){
    this(prefix + num);
  }

  /** The toString conversion (which is automatically invoked if a Regiser
   is added to a String) provides the name, inclusive of the $. */
  public String toString(){
    return name;
  }

  /** The equals method is overriden such that Registers are equal if their
       names are equal */
  public boolean equals(Object other){
    if(other instanceof Register)
      return name.equals(((Register)other).name);
    else
      return super.equals(other);
  }
  
  /** The hashCode method is overriden to reflect the name-based equality. */
  public int hashCode(){
    return name.hashCode();
  }
}