edu.osu.ling.pep
Enum ParserOption

java.lang.Object
  java.lang.Enum<ParserOption>
      edu.osu.ling.pep.ParserOption

All Implemented Interfaces:

Serializable, Comparable<ParserOption>

public enum ParserOption
extends Enum<ParserOption>

An option used to configure an Earley parser.

Version:

$LastChangedRevision: 556 $

Author:

Scott Martin

Enum Constant Summary

IGNORE_TERMINAL_CASE
Signals whether an Earley parser should ignore the case of terminal tokens.

PREDICT_FOR_PRETERMINALS
Whether the Earley parser should make predictions based on pre-terminal categories.

Method Summary

Boolean	getDefaultValue() Gets the default value for this option.
String	toString() Gets a string representation of this Earley parser option.
static ParserOption	valueOf(String name) Returns the enum constant of this type with the specified name.
static ParserOption[]	values() Returns an array containing the constants of this enum type, in the order they're declared.

Methods inherited from class java.lang.Enum

clone, compareTo, equals, getDeclaringClass, hashCode, name, ordinal, valueOf

Methods inherited from class java.lang.Object

finalize, getClass, notify, notifyAll, wait, wait, wait

Enum Constant Detail

IGNORE_TERMINAL_CASE

public static final ParserOption IGNORE_TERMINAL_CASE

Signals whether an Earley parser should ignore the case of terminal tokens. If this is set to true, the tokens John and john will be treated as equivalent, but they will be treated as distinct tokens if this is set to false.

Default value: Boolean.FALSE.

Since:

0.2

PREDICT_FOR_PRETERMINALS

public static final ParserOption PREDICT_FOR_PRETERMINALS

Whether the Earley parser should make predictions based on pre-terminal categories. If this is true, the parser will make a prediction for every grammar entry where the left side is a category it has predicted for and the right side is a terminal. For example, in a grammar where the pre-terminal category N can expand to dog, boy, or man and a rule exists where NP expands to Det N, the parser will predict

• N -> dog
• N -> boy
• N -> man

whenever it is able to predict NP (or any other rule that can expand to N).

Alternatively, if this option is specified as false, the parser will only complete (as opposed to predict) for those terminals it actually encounters in the input string, instead of predicting for every possible terminal.

Default value: Boolean.FALSE.

Method Detail

getDefaultValue

public Boolean getDefaultValue()

Gets the default value for this option.

toString

public String toString()

Gets a string representation of this Earley parser option.

Overrides:

toString in class Enum<ParserOption>

Returns:

OPTION_NAME=option default value

valueOf

public static ParserOption valueOf(String name)

Returns the enum constant of this type with the specified name. The string must match exactly an identifier used to declare an enum constant in this type. (Extraneous whitespace characters are not permitted.)

Parameters:

name - the name of the enum constant to be returned.

Returns:

the enum constant with the specified name

Throws:

IllegalArgumentException - if this enum type has no constant with the specified name

values

public static final ParserOption[] values()

Returns an array containing the constants of this enum type, in the order they're declared. This method may be used to iterate over the constants as follows:

for(ParserOption c : ParserOption.values())
        System.out.println(c);

Returns:

an array containing the constants of this enum type, in the order they're declared