itec.minicompiler
Class FollowSet

java.lang.Object
  itec.minicompiler.FollowSet

All Implemented Interfaces:

ConstantsInterface

public class FollowSet

extends java.lang.Object

implements ConstantsInterface

The FollowSet implements the FOLLOW-Sets of all non-terminals in the grammar. As a most adequate structure the HashSet is used to implement a particular FOLLOW-Set of a non-terminal. In a Hashtable the several HashSets are brought together.

To get the several FOLLOW-Sets the algorithm in the book

"COMPILERS Principles, Techniques and Tools" by Aho, Sethi, Ullmann

was used. The entries were mainly calculated by hand.

Version:

1.0 (29.09.2004)

Author:

Stefan Leitner, Stefan Schauer

Field Summary

private java.util.Hashtable

follow The overall structure of all the FOLLOW-Sets.

Fields inherited from interface itec.minicompiler.ConstantsInterface

ACTUALPARAMETERS, AND, ARRAY, ARRAYTYPE, ASSIGNMENT, BECOMES, BEGIN, COLON, COMMA, CONST, DECLARATIONS, DIV, DO, ELSE, ELSIF, EMPTY, END, EPSILON, EQUAL, ERR_EXP_ARRAY, ERR_EXP_BECOMES, ERR_EXP_COLON, ERR_EXP_COMMA, ERR_EXP_DO, ERR_EXP_END, ERR_EXP_EQUAL, ERR_EXP_IDENT, ERR_EXP_IF, ERR_EXP_LPAREN, ERR_EXP_MODULE, ERR_EXP_OF, ERR_EXP_PERIOD, ERR_EXP_PROCEDURE, ERR_EXP_RBRAK, ERR_EXP_RECORD, ERR_EXP_REPEAT, ERR_EXP_RPAREN, ERR_EXP_SEMICOLON, ERR_EXP_THEN, ERR_EXP_UNTIL, ERR_EXP_WHILE, ERR_INV_FACTOR, ERR_INV_STATEMENT, ERR_INV_TYPE, ERR_INVALID_CHARACTER, ERR_NOT_EXP_DECLARATIONS, ERR_NOT_EXP_FACTOR, ERR_NOT_EXP_STATEMENT, ERR_NOT_EXP_TYPE, ERR_NOT_TERMINATED, ERR_NUMBER_TOO_HIGH, EXPRESSION, FACTOR, FIELDLIST, FORMALPARAMETERS, FPSECTION, GEQ, GREATER, IDENT, IDENTLIST, IF, IFSTATEMENT, KEYWORD, LBRAK, LEQ, LESS, LPAREN, MINICOMP, MINUS, MOD, MODULE, NOT, NOTEQUAL, NUMBER, OF, OR, PERIOD, PLUS, PROCEDURE, PROCEDUREBODY, PROCEDURECALL, PROCEDUREDECLARATION, PROCEDUREHEADING, RBRAK, RECORD, RECORDTYPE, REPEAT, REPEATSTATEMENT, RPAREN, SELECTOR, SEMICOLON, SIMPLEEXPRESSION, SINGLE, STATEMENT, STATEMENTSEQUENCE, TERM, THEN, TIMES, TYP, TYPE, UNTIL, VAR, WHILE, WHILESTATEMENT

Constructor Summary

FollowSet()
Initialize the FOLLOW-Set of each particular non-terminal in the grammar.

Method Summary

java.util.HashSet

getFollow(int nonTerminal) Return the FOLLOW-Set of a nonTerminal.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

follow

private java.util.Hashtable follow

The overall structure of all the FOLLOW-Sets. The Hashtable contains the FOLLOW-Sets of the different non-terminals. Each entry is a HashSet as implementation of a FOLLOW-Set.

Constructor Detail

FollowSet

public FollowSet()

Initialize the FOLLOW-Set of each particular non-terminal in the grammar. The values of the several HashSets were mainly calculated by hand and checked for errors with JCoco.

Method Detail

getFollow

public java.util.HashSet getFollow(int nonTerminal)

Return the FOLLOW-Set of a nonTerminal.

Parameters:

nonTerminal - A non-terminal in the grammar

Returns:

A HashSet implementing the FOLLOW-Set of nonTerminal