Package org.basex.query.value.item

Class Dummy

java.lang.Object

org.basex.query.expr.ExprInfo

org.basex.query.expr.Expr

org.basex.query.value.Value

org.basex.query.value.item.Item

org.basex.query.value.item.Dummy

All Implemented Interfaces:

Iterable<Item>

public final class Dummy
extends Item

Dummy item (only used at compile time).

Author:

BaseX Team 2005-21, BSD License, Christian Gruen

Field Summary

Fields inherited from class org.basex.query.value.item.Item

UNDEF

Fields inherited from class org.basex.query.value.Value

type

Constructor Summary

Constructors

Constructor	Description
Dummy(SeqType seqType, Data data)	Constructor.

Method Summary

Modifier and Type	Method	Description
boolean	bool(InputInfo ii)	Returns a boolean representation of the value.
boolean	comparable(Item item)	Checks if the items can be compared.
Data	data()	Returns the data reference bound to this expression.
boolean	ddo()	Indicates if this expression returns nodes in document order without duplicates.
int	diff(Item item, Collation coll, InputInfo ii)	Returns the difference between the current and the specified item.
boolean	eq(Item item, Collation coll, StaticContext sc, InputInfo ii)	Compares the items for equality.
boolean	equals(Object obj)	This function is e.g.
void	plan(QueryPlan plan)	Creates a query plan.
void	plan(QueryString qs)	Creates a query string.
boolean	sameKey(Item item, InputInfo ii)	Compares the items for equality.
SeqType	seqType()	Returns the static type of the resulting value.
byte[]	string(InputInfo ii)	Returns a string representation of the value.
String	toJava()	Returns a Java representation of the value.

Methods inherited from class org.basex.query.value.item.Item

atomItem, atomSize, atomValue, cache, dbl, dec, description, ebv, equiv, flt, hash, input, instanceOf, item, itemAt, iter, itr, materialize, persistent, refineType, reverse, score, size, subsequence, test, typeId, xdmInfo

Methods inherited from class org.basex.query.value.Value

accept, checkUp, compile, copy, count, exprSize, has, inline, inlineable, isEmpty, isItem, iter, iterator, materialize, serialize, serialize, serialize, value

Methods inherited from class org.basex.query.expr.Expr

arg, args, atomIter, data, funcType, hasFreeVars, indexAccessible, isSimple, markTailCalls, mergeEbv, optimize, simplifyFor, typeCheck, uses, vacuous, visitAll

Methods inherited from class org.basex.query.expr.ExprInfo

toErrorString, toString

Methods inherited from class java.lang.Object

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

Methods inherited from interface java.lang.Iterable

forEach, spliterator

Constructor Details

Dummy

public Dummy(SeqType seqType,
 Data data)

Constructor.

Parameters:

seqType - sequence type

data - data reference (can be null)

Method Details

seqType

public SeqType seqType()

Description copied from class: Expr

Returns the static type of the resulting value.

Overrides:

seqType in class Item

Returns:

result of check

data

public Data data()

Description copied from class: Expr

Returns the data reference bound to this expression. This method is currently overwritten by DBNode, DBNodeSeq, AxisPath and VarRef.

Overrides:

data in class Expr

Returns:

data reference (can be null)

ddo

public boolean ddo()

Description copied from class: Expr

Indicates if this expression returns nodes in document order without duplicates.

Overrides:

ddo in class Item

Returns:

result of check

string

public byte[] string(InputInfo ii)

Description copied from class: Item

Returns a string representation of the value.

Specified by:

string in class Item

Parameters:

ii - input info (can be null)

Returns:

string value

bool

public boolean bool(InputInfo ii)

Description copied from class: Item

Returns a boolean representation of the value.

Overrides:

bool in class Item

Parameters:

ii - input info (can be null)

Returns:

boolean value

eq

public boolean eq(Item item,
 Collation coll,
 StaticContext sc,
 InputInfo ii)

Description copied from class: Item

Compares the items for equality.

Specified by:

eq in class Item

Parameters:

item - item to be compared

coll - collation (can be null)

sc - static context; required for comparing items of type xs:QName (can be null)

ii - input info (can be null)

Returns:

result of check

sameKey

public boolean sameKey(Item item,
 InputInfo ii)

Description copied from class: Item

Compares the items for equality.

Overrides:

sameKey in class Item

Parameters:

item - item to be compared

ii - input info (can be null)

Returns:

result of check

diff

public int diff(Item item,
 Collation coll,
 InputInfo ii)

Description copied from class: Item

Returns the difference between the current and the specified item. This function is overwritten by the corresponding implementations.

Overrides:

diff in class Item

Parameters:

item - item to be compared

coll - collation (can be null)

ii - input info (can be null)

Returns:

difference

comparable

public boolean comparable(Item item)

Description copied from class: Item

Checks if the items can be compared.

Overrides:

comparable in class Item

Parameters:

item - item to be compared

Returns:

result of check

toJava

public String toJava()

Description copied from class: Value

Returns a Java representation of the value.

Specified by:

toJava in class Value

Returns:

Java object

equals

public boolean equals(Object obj)

Description copied from class: Expr

This function is e.g. called by:

• If.optimize(CompileContext), Switch.optimize(CompileContext), Typeswitch.optimize(CompileContext), in order to discard identical expressions.
• CmpR.mergeEbv(Expr, boolean, CompileContext) or CmpSR.mergeEbv(Expr, boolean, CompileContext), in order to merge expressions with identical input.
• CmpG.optimize(CompileContext) or CmpV.optimize(CompileContext), in order to pre-evaluate equality tests.
• CmpG.optimize(CompileContext) or Pos.get(Expr, CmpV.OpV, InputInfo, CompileContext), in order to compare the start and end value.
• PathCache, in order to find identical root values at runtime.

Specified by:

equals in class Expr

plan

public void plan(QueryPlan plan)

Description copied from class: ExprInfo

Creates a query plan.

Overrides:

plan in class Item

Parameters:

plan - expression plan

plan

public void plan(QueryString qs)

Description copied from class: ExprInfo

Creates a query string.

Specified by:

plan in class ExprInfo

Parameters:

qs - query string builder