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