java_cup.reduce_action Maven / Gradle / Ivy
package java_cup;
/** This class represents a reduce action within the parse table.
* The action simply stores the production that it reduces with and
* responds to queries about its type.
*
* @version last updated: 11/25/95
* @author Scott Hudson
*/
public class reduce_action extends parse_action {
/*-----------------------------------------------------------*/
/*--- Constructor(s) ----------------------------------------*/
/*-----------------------------------------------------------*/
/** Simple constructor.
* @param prod the production this action reduces with.
*/
public reduce_action(production prod ) throws internal_error
{
/* sanity check */
if (prod == null)
throw new internal_error(
"Attempt to create a reduce_action with a null production");
_reduce_with = prod;
}
/*-----------------------------------------------------------*/
/*--- (Access to) Instance Variables ------------------------*/
/*-----------------------------------------------------------*/
/** The production we reduce with. */
protected production _reduce_with;
/** The production we reduce with. */
public production reduce_with() {return _reduce_with;}
/*-----------------------------------------------------------*/
/*--- General Methods ---------------------------------------*/
/*-----------------------------------------------------------*/
/** Quick access to type of action. */
public int kind() {return REDUCE;}
/*. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .*/
/** Equality test. */
public boolean equals(reduce_action other)
{
return other != null && other.reduce_with() == reduce_with();
}
/*. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .*/
/** Generic equality test. */
public boolean equals(Object other)
{
if (other instanceof reduce_action)
return equals((reduce_action)other);
else
return false;
}
/*. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .*/
/** Compute a hash code. */
public int hashCode()
{
/* use the hash code of the production we are reducing with */
return reduce_with().hashCode();
}
/** Convert to string. */
public String toString()
{
return "REDUCE(with prod " + reduce_with().index() + ")";
}
/*-----------------------------------------------------------*/
}