me.jaimegarza.syntax.algorithm

Class LalrAlgorithmicSupport

java.lang.Object

me.jaimegarza.syntax.algorithm.BaseAlgorithmicSupport

me.jaimegarza.syntax.algorithm.LalrAlgorithmicSupport

All Implemented Interfaces:

AlgorithmicSupport

public class LalrAlgorithmicSupport
extends BaseAlgorithmicSupport

Field Summary

Fields inherited from class me.jaimegarza.syntax.algorithm.BaseAlgorithmicSupport

environment, runtimeData

Constructor Summary

Constructors

Constructor and Description
LalrAlgorithmicSupport(Environment environment) Construct the supporting utility algorithm class for LALR

Method Summary

Modifier and Type	Method and Description
void	addAllLookaheads(Dot marker, Dot auxiliary) Simply put lookaheads of auxiliary into marker
boolean	addLookaheadsToState(State[] I, int state, List<Dot> dots) For algorithms that support look ahead per state, this method will add all the lookaheads of the passed dots into the state's dots.
LookAhead	computeLookAhead(Rule rule, RuleItem item) Compute the lookahead set of a rule on a specific item
boolean	dotContains(Dot dot, int terminalId) Checks a dot to see if it contains the symbol
String	getPrintableLookahead(Dot dot) Print the lookaheads in a dot
boolean	hasFollows() Does this algorithm support follow sets?
void	initializeDot(Dot dot) This dot is brand new, and used for a state.
boolean	isMultiPass()
void	mergeLookaheads(Dot from, Dot to) Merge one marker dot's lookaheads into a destination.
boolean	supportsLookahead() Does this algorithm support lookaheads

Methods inherited from class java.lang.Object

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

Constructor Detail

LalrAlgorithmicSupport

public LalrAlgorithmicSupport(Environment environment)

Construct the supporting utility algorithm class for LALR

Parameters:

environment - is the calling environment

Method Detail

supportsLookahead

public boolean supportsLookahead()

Description copied from interface: AlgorithmicSupport

Does this algorithm support lookaheads

Returns:

true if it does

addLookaheadsToState

public boolean addLookaheadsToState(State[] I,
                                    int state,
                                    List<Dot> dots)

Description copied from interface: AlgorithmicSupport

For algorithms that support look ahead per state, this method will add all the lookaheads of the passed dots into the state's dots.

Parameters:

I - is the array of states

state - is the state number

dots - is the list of marker Dots

Returns:

true if lookadeas added

computeLookAhead

public LookAhead computeLookAhead(Rule rule,
                                  RuleItem item)

Description copied from interface: AlgorithmicSupport

Compute the lookahead set of a rule on a specific item

Parameters:

rule - is the rule where the lookahead begins

item - is the dot position to start lookahead computations.

Returns:

the new Lookahead, or null

mergeLookaheads

public void mergeLookaheads(Dot from,
                            Dot to)

Description copied from interface: AlgorithmicSupport

Merge one marker dot's lookaheads into a destination.

Parameters:

from - is the source of the lookaheads

to - is the second auxiliary dot

addAllLookaheads

public void addAllLookaheads(Dot marker,
                             Dot auxiliary)

Description copied from interface: AlgorithmicSupport

Simply put lookaheads of auxiliary into marker

Parameters:

marker - is the receiving marker

auxiliary - is the originating set of lookaheads

getPrintableLookahead

public String getPrintableLookahead(Dot dot)

Description copied from interface: AlgorithmicSupport

Print the lookaheads in a dot

Parameters:

dot - is the dot to print

Returns:

the printable string

dotContains

public boolean dotContains(Dot dot,
                           int terminalId)

Description copied from interface: AlgorithmicSupport

Checks a dot to see if it contains the symbol

Parameters:

dot - the dot to check

terminalId - is the symbol

Returns:

true or false

isMultiPass

public boolean isMultiPass()

Returns:

true if the algorithm needs multiple passes

initializeDot

public void initializeDot(Dot dot)

Description copied from interface: AlgorithmicSupport

This dot is brand new, and used for a state. Initialize it

Parameters:

dot - is the dot to initialize

hasFollows

public boolean hasFollows()

Description copied from interface: AlgorithmicSupport

Does this algorithm support follow sets?

Returns:

true if it has follow elements