1 2 package java_cup; 3 4 /** This class represents a reduce action within the parse table. 5 * The action simply stores the production that it reduces with and 6 * responds to queries about its type. 7 * 8 * @version last updated: 11/25/95 9 * @author Scott Hudson 10 */ 11 public class reduce_action extends parse_action { 12 13 /*-----------------------------------------------------------*/ 14 /*--- Constructor(s) ----------------------------------------*/ 15 /*-----------------------------------------------------------*/ 16 17 /** Simple constructor. 18 * @param prod the production this action reduces with. 19 */ 20 public reduce_action(production prod ) throws internal_error 21 { 22 /* sanity check */ 23 if (prod == null) 24 throw new internal_error( 25 "Attempt to create a reduce_action with a null production"); 26 27 _reduce_with = prod; 28 } 29 30 /*-----------------------------------------------------------*/ 31 /*--- (Access to) Instance Variables ------------------------*/ 32 /*-----------------------------------------------------------*/ 33 34 /** The production we reduce with. */ 35 protected production _reduce_with; 36 37 /** The production we reduce with. */ 38 public production reduce_with() {return _reduce_with;} 39 40 /*-----------------------------------------------------------*/ 41 /*--- General Methods ---------------------------------------*/ 42 /*-----------------------------------------------------------*/ 43 44 /** Quick access to type of action. */ 45 public int kind() {return REDUCE;} 46 47 /*. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .*/ 48 49 /** Equality test. */ 50 public boolean equals(reduce_action other) 51 { 52 return other != null && other.reduce_with() == reduce_with(); 53 } 54 55 /*. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .*/ 56 57 /** Generic equality test. */ 58 public boolean equals(Object other) 59 { 60 if (other instanceof reduce_action) 61 return equals((reduce_action)other); 62 else 63 return false; 64 } 65 66 /*. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .*/ 67 68 /** Compute a hash code. */ 69 public int hashCode() 70 { 71 /* use the hash code of the production we are reducing with */ 72 return reduce_with().hashCode(); 73 } 74 75 76 /** Convert to string. */ 77 public String toString() 78 { 79 return "REDUCE(" + reduce_with().index() + ")"; 80 } 81 82 /*-----------------------------------------------------------*/ 83 84 }; 85
