Modifier and Type | Field and Description |
---|---|
static ValueIter |
ITER
Empty iterator.
|
static Empty |
SEQ
Single instance.
|
Modifier and Type | Method and Description |
---|---|
Item |
atomItem(QueryContext qc,
InputInfo ii)
Evaluates the expression and returns zero or one atomized item, or an error.
|
long |
atomSize()
Computes the number of atomized items.
|
Value |
atomValue(InputInfo ii)
Evaluates the expression and returns the atomized items.
|
String |
description()
Returns a string description of the expression.
|
Item |
ebv(QueryContext qc,
InputInfo ii)
Checks if the effective boolean value can be computed for this expression:
If it yields an empty sequence,
Bln.FALSE will be returned. |
int |
hash(InputInfo ii)
Returns a hash code for this value.
|
boolean |
homogeneous()
Checks if all items of this value share the same type.
|
boolean |
isEmpty()
Tests if this is an empty sequence.
|
boolean |
isVacuous()
Tests if this is a vacuous expression (empty sequence or error function).
|
Item |
item(QueryContext qc,
InputInfo ii)
Evaluates the expression and returns the resulting item,
or a
null reference if the expression yields an empty sequence. |
Item |
itemAt(long pos)
Gets the item at the given position in the value.
|
ValueIter |
iter()
Returns an iterator.
|
boolean |
iterable()
Indicates if the items returned by this expression are iterable, i.e., if returned nodes are
in document order and contain no duplicates.
|
Value |
materialize(InputInfo ii)
Materializes streamable values, or returns a self reference.
|
void |
plan(FElem plan)
Creates an expression tree.
|
SeqType |
seqType()
Returns the static type of the resulting value.
|
long |
size()
Returns the sequence size or 1.
|
Item |
test(QueryContext qc,
InputInfo ii)
Performs a predicate test and returns the item the if test was successful.
|
Object |
toJava()
Returns a Java representation of the value.
|
String |
toString() |
int |
writeTo(Item[] arr,
int index)
Writes this value's items out to the given array.
|
accept, atomValue, cache, checkUp, compile, copy, count, exprSize, has, inline, isValue, iter, iterator, removable, serialize, serialize, value
atomIter, data, hasFreeVars, indexAccessible, inlineAll, isFunction, markTailCalls, optimize, optimizeEbv, sameAs, typeCheck, uses, visitAll
public static final Empty SEQ
public static final ValueIter ITER
public boolean isEmpty()
Expr
Empty
class, which represents the empty sequence.public boolean isVacuous()
Expr
public long size()
Expr
public Object toJava()
Value
public Item item(QueryContext qc, InputInfo ii)
Expr
null
reference if the expression yields an empty sequence.
If this method is not overwritten, Expr.iter(QueryContext)
must be implemented by an
expression, as it may be called by this method.public Item ebv(QueryContext qc, InputInfo ii)
Expr
Checks if the effective boolean value can be computed for this expression:
Bln.FALSE
will be returned.
A single numeric item may later be evaluated as positional predicate.
public Item test(QueryContext qc, InputInfo ii)
Expr
public SeqType seqType()
Expr
public boolean iterable()
Expr
AxisPath
.public int hash(InputInfo ii)
Value
public int writeTo(Item[] arr, int index)
Value
public Item itemAt(long pos)
Value
public boolean homogeneous()
Value
homogeneous
in class Value
public Value materialize(InputInfo ii)
Value
materialize
in class Value
ii
- input infopublic Value atomValue(InputInfo ii)
Value
public Item atomItem(QueryContext qc, InputInfo ii)
Expr
public long atomSize()
Value
public void plan(FElem plan)
ExprInfo
public String description()
ExprInfo
ExprInfo.toString()
method,
arguments are not included in the output.description
in class Value
Copyright © 2005–2015 BaseX Team. All rights reserved.