net.sf.saxon.expr.flwor
Class WhereClause

java.lang.Object
  net.sf.saxon.expr.flwor.Clause
      net.sf.saxon.expr.flwor.WhereClause

public class WhereClause
extends Clause

A "where" clause in a FLWOR expression

Field Summary

Fields inherited from class net.sf.saxon.expr.flwor.Clause

COUNT, FOR, GROUPBYCLAUSE, LET, ORDERBYCLAUSE, WHERE, WINDOW

Constructor Summary

WhereClause(Expression predicate)

Method Summary

WhereClause	copy()
void	explain(ExpressionPresenter out) Diagnostic print of expression structure.
void	gatherVariableReferences(ExpressionVisitor visitor, Binding binding, List<VariableReference> references) Build a list of all references to a variables declared in this clause
Expression	getBaseExpression()
int	getClauseKey() Get a keyword identifying what kind of clause this is
Expression	getPredicate()
TuplePull	getPullStream(TuplePull base, XPathContext context) Get a tuple stream that implements the functionality of this clause, taking its input from another tuple stream which this clause modifies
TuplePush	getPushStream(TuplePush destination, XPathContext context) Get a push-mode tuple stream that implements the functionality of this clause, supplying its output to another tuple stream
void	processSubExpressions(ExpressionProcessor processor) Process the subexpressions of this clause
void	refineVariableType(ExpressionVisitor visitor, List<VariableReference> references, Expression returnExpr) Supply improved type information to the expressions that contain references to the variables declared in this clause
void	setPredicate(Expression predicate)
String	toString()
void	typeCheck(ExpressionVisitor visitor) Type-check the expression

Methods inherited from class net.sf.saxon.expr.flwor.Clause

getRangeVariables, optimize

Methods inherited from class java.lang.Object

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

Constructor Detail

WhereClause

public WhereClause(Expression predicate)

Method Detail

getClauseKey

public int getClauseKey()

Description copied from class: Clause

Get a keyword identifying what kind of clause this is

Specified by:

getClauseKey in class Clause

Returns:

the kind of clause

getPredicate

public Expression getPredicate()

setPredicate

public void setPredicate(Expression predicate)

copy

public WhereClause copy()

Specified by:

copy in class Clause

typeCheck

public void typeCheck(ExpressionVisitor visitor)
               throws XPathException

Type-check the expression

Overrides:

typeCheck in class Clause

Parameters:

visitor - the ExpressionVisitor, providing access to static context information

Throws:

XPathException - if any error is detected

getPullStream

public TuplePull getPullStream(TuplePull base,
                               XPathContext context)

Get a tuple stream that implements the functionality of this clause, taking its input from another tuple stream which this clause modifies

Specified by:

getPullStream in class Clause

Parameters:

base - the input tuple stream

context - the dynamic evaluation context

Returns:

the output tuple stream

gatherVariableReferences

public void gatherVariableReferences(ExpressionVisitor visitor,
                                     Binding binding,
                                     List<VariableReference> references)

Description copied from class: Clause

Build a list of all references to a variables declared in this clause

Overrides:

gatherVariableReferences in class Clause

Parameters:

visitor - the expression visitor

binding - a variable declared in this clause

references - the list of variable references, initially empty, to which the method will append

refineVariableType

public void refineVariableType(ExpressionVisitor visitor,
                               List<VariableReference> references,
                               Expression returnExpr)

Description copied from class: Clause

Supply improved type information to the expressions that contain references to the variables declared in this clause

Overrides:

refineVariableType in class Clause

Parameters:

visitor - the expression visitor

references - the list of variable references

returnExpr - the expression in the return clause

getPushStream

public TuplePush getPushStream(TuplePush destination,
                               XPathContext context)

Get a push-mode tuple stream that implements the functionality of this clause, supplying its output to another tuple stream

Specified by:

getPushStream in class Clause

Parameters:

destination - the output tuple stream

context - the dynamic evaluation context

Returns:

the push tuple stream that implements the functionality of this clause of the FLWOR expression

processSubExpressions

public void processSubExpressions(ExpressionProcessor processor)
                           throws XPathException

Process the subexpressions of this clause

Specified by:

processSubExpressions in class Clause

Parameters:

processor - the expression processor used to process the subexpressions

Throws:

XPathException - if any error is detected

getBaseExpression

public Expression getBaseExpression()

explain

public void explain(ExpressionPresenter out)

Diagnostic print of expression structure. The abstract expression tree is written to the supplied output destination.

Specified by:

explain in class Clause

Parameters:

out - the expression presenter used to display the structure

toString

public String toString()

Overrides:

toString in class Object