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java.lang.Objectnet.sf.saxon.expr.ComputedExpression
net.sf.saxon.expr.PathExpression
public final class PathExpression
An expression that establishes a set of nodes by following relationships between nodes in the document. Specifically, it consists of a start expression which defines a set of nodes, and a Step which defines a relationship to be followed from those nodes to create a new set of nodes.
Field Summary |
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Fields inherited from class net.sf.saxon.expr.ComputedExpression |
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lineNumber, NO_ARGUMENTS, staticProperties |
Constructor Summary | |
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PathExpression(Expression start,
Expression step)
Constructor |
Method Summary | |
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Expression |
analyze(StaticContext env)
Type-check the expression |
int |
computeCardinality()
Determine the static cardinality of the expression |
int |
computeDependencies()
Determine which aspects of the context the expression depends on. |
int |
computeSpecialProperties()
Get the static properties of this expression (other than its type). |
void |
display(int level,
NamePool pool)
Diagnostic print of expression structure |
boolean |
equals(Object other)
Is this expression the same as another expression? |
Expression |
getAllExceptLastStep()
Get all steps before the last. |
Expression |
getFirstStep()
Get the first step in this expression. |
ItemType |
getItemType()
Determine the data type of the items returned by this exprssion |
Expression |
getLastStep()
Get the last step in this expression. |
Expression |
getRemainingSteps()
Get all steps after the first. |
Expression[] |
getSubExpressions()
Get the immediate subexpressions of this expression |
int |
hashCode()
get HashCode for comparing two expressions |
SequenceIterator |
iterate(XPathContext context)
Iterate the path-expression in a given context |
Object |
map(Item item,
XPathContext context,
Object info)
Mapping function, from a node returned by the start iteration, to a sequence returned by the child. |
Expression |
promote(PromotionOffer offer)
Promote this expression if possible |
Expression |
simplify()
Simplify an expression |
Methods inherited from class net.sf.saxon.expr.ComputedExpression |
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computeStaticProperties, dynamicError, effectiveBooleanValue, evaluateAsString, evaluateItem, getCardinality, getDependencies, getIntrinsicDependencies, getLineNumber, getSpecialProperties, markTailFunctionCalls, setLineNumber, typeError |
Methods inherited from class java.lang.Object |
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clone, finalize, getClass, notify, notifyAll, toString, wait, wait, wait |
Constructor Detail |
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public PathExpression(Expression start, Expression step)
start
- A node-set expression denoting the absolute or relative set of nodes from which the
navigation path should start.step
- The step to be followed from each node in the start expression to yield a new
node-setMethod Detail |
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public final ItemType getItemType()
getItemType
in interface Expression
public Expression simplify() throws XPathException
simplify
in interface Expression
simplify
in class ComputedExpression
XPathException
- if an error is discovered during expression
rewritingpublic Expression analyze(StaticContext env) throws XPathException
analyze
in interface Expression
env
- the static context of the expression
XPathException
- if an error is discovered during this phase
(typically a type error)public Expression promote(PromotionOffer offer) throws XPathException
promote
in interface Expression
promote
in class ComputedExpression
offer
- details of the offer, for example the offer to move
expressions that don't depend on the context to an outer level in
the containing expression
XPathException
- if any error is detectedpublic Expression[] getSubExpressions()
getSubExpressions
in interface Expression
getSubExpressions
in class ComputedExpression
public int computeDependencies()
computeDependencies
in class ComputedExpression
public int computeSpecialProperties()
computeSpecialProperties
in class ComputedExpression
public int computeCardinality()
computeCardinality
in class ComputedExpression
public boolean equals(Object other)
equals
in class Object
public int hashCode()
hashCode
in class Object
public Expression getFirstStep()
public Expression getRemainingSteps()
public Expression getLastStep()
public Expression getAllExceptLastStep()
public SequenceIterator iterate(XPathContext context) throws XPathException
iterate
in interface Expression
iterate
in class ComputedExpression
context
- the evaluation context
XPathException
- if any dynamic error occurs evaluating the
expressionpublic Object map(Item item, XPathContext context, Object info) throws XPathException
map
in interface MappingFunction
item
- The item to be mapped.
If context is supplied, this must be the same as context.currentItem().context
- The processing context. This is supplied only for mapping constructs that
set the context node, position, and size. Otherwise it is null.info
- Arbitrary information supplied by the creator of the MappingIterator. It must be
read-only and immutable for the duration of the iteration.
XPathException
public void display(int level, NamePool pool)
display
in interface Expression
level
- indentation level for this expression
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