CUP Parser Generator for Java 10k · java_cup.lalr_item_set

Modifier and Type	Field and Description
protected Hashtable<K, V>	_all A hash table to implement the set.
protected Integer	hashcode_cache Cached hashcode for this set.

Access	Constructor and Description
public	lalr_item_set() Constructor for an empty set.
public	lalr_item_set(lalr_item_set indicates set we should copy from. other) Constructor for cloning from another set.

Method Summary

Modifier and Type	Method and Description
public lalr_item	add(lalr_item the item being added. itm) Add a singleton item, merging lookahead sets if the item is already part of the set.
public void	add(lalr_item_set the set to be added. other) Add a complete set, merging lookaheads where items are already in the set
public Enumeration<E>	all() Access to all elements of the set.
public void	compute_closure() Compute the closure of the set using the LALR closure rules.
public boolean	contains(lalr_item the item in question. itm) Does the set contain a particular item?
public boolean	equals(lalr_item_set other) Equality comparison.
public boolean	equals(Object the reference object with which to compare. other) Overrides java.lang.Object.equals. Generic equality comparison.
public lalr_item	find(lalr_item the item we are looking for. itm) Return the item in the set matching a particular item (or null if not found)
public lalr_item	get_one() Remove and return one item from the set (done in hash order).
public int	hashCode() Overrides java.lang.Object.hashCode. Return hash code.
public boolean	is_subset_of(lalr_item_set the other set in question. other) Is this set an (improper) subset of another?
public boolean	is_superset_of(lalr_item_set the other set in question. other) Is this set an (improper) superset of another?
protected void	not_null(Object the object we are testing. obj) Helper function for null test.
public void	remove(lalr_item the item to remove. itm) Remove a single item if it is in the set.
public void	remove(lalr_item_set the set to remove. other) Remove (set subtract) a complete set.
public int	size() Size of the set
public String	toString() Overrides java.lang.Object.toString. Convert to string.

Inherited from java.lang.Object:: clone finalize getClass notify notifyAll wait wait wait

_all	back to summary
protected Hashtable<K, V> _all A hash table to implement the set. We store the items using themselves as keys.

hashcode_cache	back to summary
protected Integer hashcode_cache Cached hashcode for this set.

lalr_item_set	back to summary
public lalr_item_set() Constructor for an empty set.

lalr_item_set	back to summary
public lalr_item_set(lalr_item_set other) throws internal_error Constructor for cloning from another set. Parameters other:lalr_item_set indicates set we should copy from.

Method Detail

add	back to summary
public lalr_item add(lalr_item itm) throws internal_error Add a singleton item, merging lookahead sets if the item is already part of the set. returns the element of the set that was added or merged into. Parameters itm:lalr_item the item being added.

add

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public lalr_item add(lalr_item itm) throws internal_error

Add a singleton item, merging lookahead sets if the item is already part of the set. returns the element of the set that was added or merged into.

Parameters

itm:lalr_item: the item being added.

add	back to summary
public void add(lalr_item_set other) throws internal_error Add a complete set, merging lookaheads where items are already in the set Parameters other:lalr_item_set the set to be added.

add

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public void add(lalr_item_set other) throws internal_error

Add a complete set, merging lookaheads where items are already in the set

Parameters

other:lalr_item_set: the set to be added.

all	back to summary
public Enumeration<E> all() Access to all elements of the set.

compute_closure	back to summary
public void compute_closure() throws internal_error Compute the closure of the set using the LALR closure rules. Basically for every item of the form: [L ::= a N alpha, l] (where N is a a non terminal and alpha is a string of symbols) make sure there are also items of the form: [N ::= beta, first(alpha l)] corresponding to each production of N. Items with identical cores but differing lookahead sets are merged by creating a new item with the same core and the union of the lookahead sets (the LA in LALR stands for "lookahead merged" and this is where the merger is). This routine assumes that nullability and first sets have been computed for all productions before it is called.

compute_closure

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public void compute_closure() throws internal_error

Compute the closure of the set using the LALR closure rules. Basically for every item of the form:

  [L ::= a *N alpha, l]

(where N is a a non terminal and alpha is a string of symbols) make sure there are also items of the form:

  [N ::= *beta, first(alpha l)]

corresponding to each production of N. Items with identical cores but differing lookahead sets are merged by creating a new item with the same core and the union of the lookahead sets (the LA in LALR stands for "lookahead merged" and this is where the merger is). This routine assumes that nullability and first sets have been computed for all productions before it is called.

contains	back to summary
public boolean contains(lalr_item itm) Does the set contain a particular item? Parameters itm:lalr_item the item in question.

contains

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public boolean contains(lalr_item itm)

Does the set contain a particular item?

Parameters

itm:lalr_item: the item in question.

equals	back to summary
public boolean equals(lalr_item_set other) Equality comparison.

equals back to summary

equals	back to summary
public boolean equals(Object other) Overrides java.lang.Object.equals. Generic equality comparison. Parameters other:Object Doc from java.lang.Object.equals. the reference object with which to compare. Returns:boolean Doc from java.lang.Object.equals. `true` if this object is the same as the obj argument; `false` otherwise.

public boolean equals(Object other)

Overrides java.lang.Object.equals.

Generic equality comparison.

Parameters

other:Object

Doc from java.lang.Object.equals.

the reference object with which to compare.

Returns:boolean

Doc from java.lang.Object.equals.

true if this object is the same as the obj argument; false otherwise.

find	back to summary
public lalr_item find(lalr_item itm) Return the item in the set matching a particular item (or null if not found) Parameters itm:lalr_item the item we are looking for.

find

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public lalr_item find(lalr_item itm)

Return the item in the set matching a particular item (or null if not found)

Parameters

itm:lalr_item: the item we are looking for.

get_one	back to summary
public lalr_item get_one() throws internal_error Remove and return one item from the set (done in hash order).

hashCode	back to summary
public int hashCode() Overrides java.lang.Object.hashCode. Return hash code. Returns:int Doc from java.lang.Object.hashCode. a hash code value for this object.

hashCode

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public int hashCode()

Overrides java.lang.Object.hashCode.

Return hash code.

Returns:int

Doc from java.lang.Object.hashCode.

a hash code value for this object.

is_subset_of	back to summary
public boolean is_subset_of(lalr_item_set other) throws internal_error Is this set an (improper) subset of another? Parameters other:lalr_item_set the other set in question.

is_subset_of

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public boolean is_subset_of(lalr_item_set other) throws internal_error

Is this set an (improper) subset of another?

Parameters

other:lalr_item_set: the other set in question.

is_superset_of	back to summary
public boolean is_superset_of(lalr_item_set other) throws internal_error Is this set an (improper) superset of another? Parameters other:lalr_item_set the other set in question.

is_superset_of

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public boolean is_superset_of(lalr_item_set other) throws internal_error

Is this set an (improper) superset of another?

Parameters

other:lalr_item_set: the other set in question.

not_null	back to summary
protected void not_null(Object obj) throws internal_error Helper function for null test. Throws an interal_error exception if its parameter is null. Parameters obj:Object the object we are testing.

not_null

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protected void not_null(Object obj) throws internal_error

Helper function for null test. Throws an interal_error exception if its parameter is null.

Parameters

obj:Object: the object we are testing.

remove	back to summary
public void remove(lalr_item itm) throws internal_error Remove a single item if it is in the set. Parameters itm:lalr_item the item to remove.

remove

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public void remove(lalr_item itm) throws internal_error

Remove a single item if it is in the set.

Parameters

itm:lalr_item: the item to remove.

remove	back to summary
public void remove(lalr_item_set other) throws internal_error Remove (set subtract) a complete set. Parameters other:lalr_item_set the set to remove.

remove

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public void remove(lalr_item_set other) throws internal_error

Remove (set subtract) a complete set.

Parameters

other:lalr_item_set: the set to remove.

size	back to summary
public int size() Size of the set

toString	back to summary
public String toString() Overrides java.lang.Object.toString. Convert to string. Returns:String Doc from java.lang.Object.toString. a string representation of the object.

toString

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public String toString()

Overrides java.lang.Object.toString.

Convert to string.

Returns:String

Doc from java.lang.Object.toString.

a string representation of the object.

public Class lalr_item_set

Field Summary

Constructor Summary

Method Summary

Field Detail

Constructor Detail

Method Detail