org.exist.xquery
Class ForExpr

java.lang.Object
  extended byorg.exist.xquery.AbstractExpression
      extended byorg.exist.xquery.BindingExpression
          extended byorg.exist.xquery.ForExpr
All Implemented Interfaces:
Expression

public class ForExpr
extends BindingExpression

Represents an XQuery "for" expression.

Author:
Wolfgang Meier

Field Summary
 
Fields inherited from interface org.exist.xquery.Expression
DOT_TEST, EXPRESSION_ID_INVALID, IGNORE_CONTEXT, IN_PREDICATE, IN_UPDATE, IN_WHERE_CLAUSE, NO_CONTEXT_ID, SINGLE_STEP_EXECUTION
 
Constructor Summary
ForExpr(XQueryContext context)
           
 
Method Summary
 void analyze(AnalyzeContextInfo contextInfo, OrderSpec[] orderBy)
           
 void dump(ExpressionDumper dumper)
          Write a diagnostic dump of the expression to the passed ExpressionDumper.
 Sequence eval(Sequence contextSequence, Item contextItem, Sequence resultSequence)
          This implementation tries to process the "where" clause in advance, i.e.
 int returnsType()
          The static return type of the expression.
 void setPositionalVariable(java.lang.String var)
          A "for" expression may have an optional positional variable whose QName can be set via this method.
 java.lang.String toString()
           
 
Methods inherited from class org.exist.xquery.BindingExpression
analyze, eval, preselect, resetState, setInputSequence, setOrderSpecs, setReturnExpression, setSequenceType, setVariable, setWhereExpression
 
Methods inherited from class org.exist.xquery.AbstractExpression
accept, eval, getASTNode, getCardinality, getContextDocSet, getContextId, getDependencies, getExpressionId, setASTNode, setContextDocSet, setPrimaryAxis
 
Methods inherited from class java.lang.Object
equals, getClass, hashCode, notify, notifyAll, wait, wait, wait
 

Constructor Detail

ForExpr

public ForExpr(XQueryContext context)
Method Detail

setPositionalVariable

public void setPositionalVariable(java.lang.String var)
A "for" expression may have an optional positional variable whose QName can be set via this method.

Parameters:
var -

analyze

public void analyze(AnalyzeContextInfo contextInfo,
                    OrderSpec[] orderBy)
             throws XPathException
Specified by:
analyze in class BindingExpression
Throws:
XPathException

eval

public Sequence eval(Sequence contextSequence,
                     Item contextItem,
                     Sequence resultSequence)
              throws XPathException
This implementation tries to process the "where" clause in advance, i.e. in one single step. This is possible if the input sequence is a node set and the where expression has no dependencies on other variables than those declared in this "for" statement.

Specified by:
eval in class BindingExpression
Throws:
XPathException
See Also:
Expression.eval(Sequence, Item)

dump

public void dump(ExpressionDumper dumper)
Description copied from interface: Expression
Write a diagnostic dump of the expression to the passed ExpressionDumper.

Parameters:
dumper - the expression dumper to write to

toString

public java.lang.String toString()

returnsType

public int returnsType()
Description copied from interface: Expression
The static return type of the expression. This method should return one of the type constants defined in class Type. If the return type cannot be determined statically, return Type.ITEM.

Specified by:
returnsType in interface Expression
Overrides:
returnsType in class BindingExpression


Copyright (C) Wolfgang Meier. All rights reserved.