org.exist.xquery.functions
Class FunMatches

java.lang.Object
  extended by org.exist.xquery.AbstractExpression
      extended by org.exist.xquery.PathExpr
          extended by org.exist.xquery.Function
              extended by org.exist.xquery.functions.FunMatches
All Implemented Interfaces:
CompiledXQuery, Expression, IndexUseReporter, Optimizable, CompiledExpression
Direct Known Subclasses:
FunReplace, FunTokenize

public class FunMatches
extends Function
implements Optimizable, IndexUseReporter

Implements the fn:matches() function. Based on the java.util.regex package for regular expression support.

Author:
Wolfgang Meier (wolfgang@exist-db.org)

Field Summary
static FunctionSignature[] signatures
           
 
Fields inherited from class org.exist.xquery.Function
BUILTIN_FUNCTION_NS
 
Fields inherited from interface org.exist.xquery.Expression
DOT_TEST, EXPRESSION_ID_INVALID, IGNORE_CONTEXT, IN_NODE_CONSTRUCTOR, IN_PREDICATE, IN_UPDATE, IN_WHERE_CLAUSE, NEED_INDEX_INFO, NO_CONTEXT_ID, SINGLE_STEP_EXECUTION, USE_TREE_TRAVERSAL
 
Constructor Summary
FunMatches(XQueryContext context, FunctionSignature signature)
           
 
Method Summary
 void analyze(AnalyzeContextInfo contextInfo)
          Statically analyze the expression and its subexpressions.
 boolean canOptimize(Sequence contextSequence)
           
 Sequence eval(Sequence contextSequence, Item contextItem)
          Evaluate the expression represented by this object.
 int getDependencies()
          Returns Dependency.DEFAULT_DEPENDENCIES.
 int getOptimizeAxis()
           
 boolean hasUsedIndex()
           
 boolean optimizeOnSelf()
           
 NodeSet preSelect(Sequence contextSequence, boolean useContext)
           
 void reset()
          Reset the compiled expression tree.
 void resetState(boolean postOptimization)
          Called to inform an expression that it should reset to its initial state.
 int returnsType()
          The static return type of the expression.
 void setArguments(List arguments)
          Set the (static) arguments for this function from a list of expressions.
 
Methods inherited from class org.exist.xquery.Function
accept, createFunction, dump, getArgument, getArgumentCount, getArguments, getASTNode, getCardinality, getName, getParent, getSignature, isCalledAs, setASTNode, setParent, setPrimaryAxis, toString
 
Methods inherited from class org.exist.xquery.PathExpr
add, add, addPath, addPredicate, dump, getContext, getDocumentSet, getExpression, getLastExpression, getLength, getLiteralValue, getSource, isValid, replaceExpression, replaceLastExpression, setContext, setSource
 
Methods inherited from class org.exist.xquery.AbstractExpression
eval, getContextDocSet, getContextId, getExpressionId, setContextDocSet
 
Methods inherited from class java.lang.Object
equals, getClass, hashCode, notify, notifyAll, wait, wait, wait
 
Methods inherited from interface org.exist.xquery.Expression
accept, dump, eval, getASTNode, getCardinality, getContextDocSet, getContextId, getExpressionId, setASTNode, setContextDocSet, setPrimaryAxis
 
Methods inherited from interface org.exist.xquery.CompiledXQuery
eval
 

Field Detail

signatures

public static final FunctionSignature[] signatures
Constructor Detail

FunMatches

public FunMatches(XQueryContext context,
                  FunctionSignature signature)
Parameters:
context -
Method Detail

setArguments

public void setArguments(List arguments)
                  throws XPathException
Description copied from class: Function
Set the (static) arguments for this function from a list of expressions. This will also check the type and cardinality of the passed argument expressions.

Overrides:
setArguments in class Function
Throws:
XPathException

canOptimize

public boolean canOptimize(Sequence contextSequence)
Specified by:
canOptimize in interface Optimizable

optimizeOnSelf

public boolean optimizeOnSelf()
Specified by:
optimizeOnSelf in interface Optimizable

getOptimizeAxis

public int getOptimizeAxis()
Specified by:
getOptimizeAxis in interface Optimizable

preSelect

public NodeSet preSelect(Sequence contextSequence,
                         boolean useContext)
                  throws XPathException
Specified by:
preSelect in interface Optimizable
Throws:
XPathException

getDependencies

public int getDependencies()
Description copied from class: AbstractExpression
Returns Dependency.DEFAULT_DEPENDENCIES.

Specified by:
getDependencies in interface Expression
Overrides:
getDependencies in class Function
Returns:
set of bit-flags
See Also:
Expression.getDependencies()

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 Function

hasUsedIndex

public boolean hasUsedIndex()
Specified by:
hasUsedIndex in interface IndexUseReporter

analyze

public void analyze(AnalyzeContextInfo contextInfo)
             throws XPathException
Description copied from interface: Expression
Statically analyze the expression and its subexpressions. During the static analysis phase, the query engine can detect unknown variables and some type errors.

Specified by:
analyze in interface Expression
Overrides:
analyze in class Function
Throws:
XPathException

eval

public Sequence eval(Sequence contextSequence,
                     Item contextItem)
              throws XPathException
Description copied from interface: Expression
Evaluate the expression represented by this object. Depending on the context in which this expression is executed, either the context sequence, the context item or both of them may be set. An implementing class should know how to handle this. The general contract is as follows: if the Dependency.CONTEXT_ITEM bit is set in the bit field returned by Expression.getDependencies(), the eval method will be called once for every item in the context sequence. The contextItem parameter will be set to the current item. Otherwise, the eval method will only be called once for the whole context sequence and contextItem will be null. eXist tries to process the entire context set in one, single step whenever possible. Thus, most classes only expect context to contain a list of nodes which represents the current context of the expression. The position() function in XPath is an example for an expression, which requires both, context sequence and context item to be set. The context sequence might be a node set, a sequence of atomic values or a single node or atomic value.

Specified by:
eval in interface Expression
Specified by:
eval in class Function
Parameters:
contextSequence - the current context sequence.
contextItem - a single item, taken from context. This defines the item, the expression should work on.
Throws:
XPathException

reset

public void reset()
Description copied from interface: CompiledXQuery
Reset the compiled expression tree. Discard all temporary expression results.

Specified by:
reset in interface CompiledXQuery
Specified by:
reset in interface CompiledExpression
Overrides:
reset in class PathExpr

resetState

public void resetState(boolean postOptimization)
Description copied from interface: Expression
Called to inform an expression that it should reset to its initial state. All cached data in the expression object should be dropped. For example, the xmldb:document() function calls this method whenever the input document set has changed.

Specified by:
resetState in interface Expression
Overrides:
resetState in class PathExpr


Copyright (C) Wolfgang Meier. All rights reserved.