Package it.unive.lisa.util.datastructures.regex

Class TopAtom

java.lang.Object

it.unive.lisa.util.datastructures.regex.RegularExpression

it.unive.lisa.util.datastructures.regex.Atom

it.unive.lisa.util.datastructures.regex.TopAtom

All Implemented Interfaces:

TransitionSymbol<RegularExpression>, java.lang.Comparable<RegularExpression>

public final class TopAtom
extends Atom

A RegularExpression representing a sequence of unknown characters of arbitrary length.

Nested Class Summary

Nested classes/interfaces inherited from class it.unive.lisa.util.datastructures.regex.RegularExpression

RegularExpression.PartialSubstring

Field Summary

Fields

Modifier and Type	Field	Description
static TopAtom	INSTANCE	The singleton instance.
static java.lang.String	STRING	The string used to represent this regular expression.

Fields inherited from class it.unive.lisa.util.datastructures.regex.Atom

EPSILON

Fields inherited from interface it.unive.lisa.util.datastructures.automaton.TransitionSymbol

UNKNOWN_SYMBOL

Method Summary

Modifier and Type	Method	Description
protected int	compareToAux(RegularExpression other)	Auxiliary RegularExpression.compareTo(RegularExpression) that can safely assume that other is an object of the same class as this.
boolean	contains(java.lang.String s)	Yields true if and only if this regular expression always contains the given string.
boolean	endsWith(java.lang.String s)	Yields true if and only if this regular expression always ends with the given string.
RegularExpression[]	explode()	Yields a new regular expression that is the exploded version of this one, that is, where all atoms have been broken down to the composition of the characters that compose their inner strings.
boolean	is(java.lang.String str)	Yields true if and only if this regular expression corresponds to the given string.
boolean	isEmpty()	Yields true if and only if this regular expression corresponds to the empty string or to no strings at all.
int	maxLength()	Yields the maximum length of this symbol.
boolean	mayContain(java.lang.String s)	Yields true if and only if this regular expression may contain the given string.
boolean	mayEndWith(java.lang.String s)	Yields true if and only if this regular expression may end with the given string.
boolean	mayStartWith(java.lang.String s)	Yields true if and only if this regular expression may start with the given string.
int	minLength()	Yields the minimum length of this symbol.
RegularExpression	reverse()	Yields a new symbol that corresponds to this one, but read back-to-front.
boolean	startsWith(java.lang.String s)	Yields true if and only if this regular expression always starts with the given string.
protected java.util.Set<RegularExpression.PartialSubstring>	substringAux(int charsToSkip, int missingChars)	Returns the set of all possible substrings of this regular expression, starting at the given index (inclusive) and ending at the given index (exclusive).
<A extends Automaton<A,T>,T extends TransitionSymbol<T>> A	toAutomaton(AutomataFactory<A,T> factory)	Transforms this regular expression into its equivalent automaton.
protected RegularExpression	topAsEmptyString()	Yields a new regular expression where all TopAtom are assumed to have length zero.
protected RegularExpression	topAsSingleChar()	Yields a new regular expression where all TopAtom are assumed to have length one.

Methods inherited from class it.unive.lisa.util.datastructures.regex.Atom

equals, getString, hashCode, readsWhiteSpaceString, repeat, simplify, toString, trimLeft, trimRight, unrollStarToFixedLength

Methods inherited from class it.unive.lisa.util.datastructures.regex.RegularExpression

asAtom, asComp, asEmptySet, asOr, asStar, comp, compareTo, isAtom, isComp, isEmptySet, isEpsilon, isOr, isStar, or, star, substring

Methods inherited from class java.lang.Object

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

Field Detail

STRING

public static final java.lang.String STRING

The string used to represent this regular expression.

See Also:

Constant Field Values

INSTANCE

public static final TopAtom INSTANCE

The singleton instance.

Method Detail

toAutomaton

public <A extends Automaton<A,T>,T extends TransitionSymbol<T>> A toAutomaton(AutomataFactory<A,T> factory)

Description copied from class: RegularExpression

Transforms this regular expression into its equivalent automaton.

Overrides:

toAutomaton in class Atom

Type Parameters:

A - the concrete type of Automaton that this method yields

T - the concrete type of TransitionSymbols that instances of A have on their transitions

Parameters:

factory - the factory that can be used to create the automaton

Returns:

the automaton

substringAux

protected java.util.Set<RegularExpression.PartialSubstring> substringAux(int charsToSkip,
                                                                         int missingChars)

Description copied from class: RegularExpression

Returns the set of all possible substrings of this regular expression, starting at the given index (inclusive) and ending at the given index (exclusive). Each substring is decorated with the number of characters that are still missing to reach the beginning of the substring, and the number of characters that still need to be added to the string to reach the desired length.

Overrides:

substringAux in class Atom

Parameters:

charsToSkip - the number of characters to skip before starting to collect the substring

missingChars - the number of missing characters to complete the substring

Returns:

the set of partial substrings

isEmpty

public boolean isEmpty()

Description copied from class: RegularExpression

Yields true if and only if this regular expression corresponds to the empty string or to no strings at all.

Overrides:

isEmpty in class Atom

Returns:

true if that condition holds

is

public boolean is(java.lang.String str)

Description copied from class: RegularExpression

Yields true if and only if this regular expression corresponds to the given string.

Overrides:

is in class Atom

Parameters:

str - the string

Returns:

true if that condition holds

maxLength

public int maxLength()

Description copied from interface: TransitionSymbol

Yields the maximum length of this symbol.

Specified by:

maxLength in interface TransitionSymbol<RegularExpression>

Overrides:

maxLength in class Atom

Returns:

the maximum length

minLength

public int minLength()

Description copied from interface: TransitionSymbol

Yields the minimum length of this symbol.

Specified by:

minLength in interface TransitionSymbol<RegularExpression>

Overrides:

minLength in class Atom

Returns:

the minimum length

mayContain

public boolean mayContain(java.lang.String s)

Description copied from class: RegularExpression

Yields true if and only if this regular expression may contain the given string.

Overrides:

mayContain in class Atom

Parameters:

s - the string

Returns:

true if that condition holds

contains

public boolean contains(java.lang.String s)

Description copied from class: RegularExpression

Yields true if and only if this regular expression always contains the given string.

Overrides:

contains in class Atom

Parameters:

s - the string

Returns:

true if that condition holds

mayStartWith

public boolean mayStartWith(java.lang.String s)

Description copied from class: RegularExpression

Yields true if and only if this regular expression may start with the given string.

Overrides:

mayStartWith in class Atom

Parameters:

s - the string

Returns:

true if that condition holds

startsWith

public boolean startsWith(java.lang.String s)

Description copied from class: RegularExpression

Yields true if and only if this regular expression always starts with the given string.

Overrides:

startsWith in class Atom

Parameters:

s - the string

Returns:

true if that condition holds

mayEndWith

public boolean mayEndWith(java.lang.String s)

Description copied from class: RegularExpression

Yields true if and only if this regular expression may end with the given string.

Overrides:

mayEndWith in class Atom

Parameters:

s - the string

Returns:

true if that condition holds

endsWith

public boolean endsWith(java.lang.String s)

Description copied from class: RegularExpression

Yields true if and only if this regular expression always ends with the given string.

Overrides:

endsWith in class Atom

Parameters:

s - the string

Returns:

true if that condition holds

topAsSingleChar

protected RegularExpression topAsSingleChar()

Description copied from class: RegularExpression

Yields a new regular expression where all TopAtom are assumed to have length one.

Overrides:

topAsSingleChar in class Atom

Returns:

the regular expression with shrinked top regular expressions

topAsEmptyString

protected RegularExpression topAsEmptyString()

Description copied from class: RegularExpression

Yields a new regular expression where all TopAtom are assumed to have length zero.

Overrides:

topAsEmptyString in class Atom

Returns:

the regular expression with empty top regular expressions

reverse

public RegularExpression reverse()

Description copied from interface: TransitionSymbol

Yields a new symbol that corresponds to this one, but read back-to-front.

Specified by:

reverse in interface TransitionSymbol<RegularExpression>

Overrides:

reverse in class Atom

Returns:

the reversed symbol

explode

public RegularExpression[] explode()

Description copied from class: RegularExpression

Yields a new regular expression that is the exploded version of this one, that is, where all atoms have been broken down to the composition of the characters that compose their inner strings.

Overrides:

explode in class Atom

Returns:

the exploded regular expression

compareToAux

protected int compareToAux(RegularExpression other)

Description copied from class: RegularExpression

Auxiliary RegularExpression.compareTo(RegularExpression) that can safely assume that other is an object of the same class as this.

Overrides:

compareToAux in class Atom

Parameters:

other - the other regular expression

Returns:

a negative integer, zero, or a positive integer as this object is less than, equal to, or greater than the specified object