java_cup.parse_reduce_table Maven / Gradle / Ivy
/*
* Copyright 2021 EPAM Systems, Inc
*
* See the NOTICE file distributed with this work for additional information
* regarding copyright ownership. Licensed under the Apache License,
* Version 2.0 (the "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
* License for the specific language governing permissions and limitations under
* the License.
*/
package java_cup;
import java.util.Enumeration;
/** This class represents the complete "reduce-goto" table of the parser.
* It has one row for each state in the parse machines, and a column for
* each terminal symbol. Each entry contains a state number to shift to
* as the last step of a reduce.
*
* @see java_cup.parse_reduce_row
* @version last updated: 11/25/95
* @author Scott Hudson
*/
public class parse_reduce_table {
/*-----------------------------------------------------------*/
/*--- Constructor(s) ----------------------------------------*/
/*-----------------------------------------------------------*/
/** Simple constructor. Note: all terminals, non-terminals, and productions
* must already have been entered, and the viable prefix recognizer should
* have been constructed before this is called.
*/
public parse_reduce_table()
{
/* determine how many states we are working with */
_num_states = lalr_state.number();
/* allocate the array and fill it in with empty rows */
under_state = new parse_reduce_row[_num_states];
for (int i=0; i<_num_states; i++)
under_state[i] = new parse_reduce_row();
}
/*-----------------------------------------------------------*/
/*--- (Access to) Instance Variables ------------------------*/
/*-----------------------------------------------------------*/
/** How many rows/states in the machine/table. */
protected int _num_states;
/** How many rows/states in the machine/table. */
public int num_states() {return _num_states;}
/*. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .*/
/** Actual array of rows, one per state */
public parse_reduce_row[] under_state;
/*-----------------------------------------------------------*/
/*--- General Methods ---------------------------------------*/
/*-----------------------------------------------------------*/
/** Convert to a string. */
public String toString()
{
String result;
lalr_state goto_st;
int cnt;
result = "-------- REDUCE_TABLE --------\n";
for (int row = 0; row < num_states(); row++)
{
result += "From state #" + row + "\n";
cnt = 0;
for (int col = 0; col < under_state[row].size(); col++)
{
/* pull out the table entry */
goto_st = under_state[row].under_non_term[col];
/* if it has action in it, print it */
if (goto_st != null)
{
result += " [non term " + col + "->";
result += "state " + goto_st.index() + "]";
/* end the line after the 3rd one */
cnt++;
if (cnt == 3)
{
result += "\n";
cnt = 0;
}
}
}
/* finish the line if we haven't just done that */
if (cnt != 0) result += "\n";
}
result += "-----------------------------";
return result;
}
/*-----------------------------------------------------------*/
}