# CodepointsToString
Keywords: net.sf.saxon.functions.CodepointsToString class

## net.sf.saxon.functions
Class CodepointsToString

    java.lang.Object
      net.sf.saxon.expr.Expression
          net.sf.saxon.expr.FunctionCall
              net.sf.saxon.functions.SystemFunction
                  net.sf.saxon.functions.CodepointsToString

All Implemented Interfaces:
  Serializable, SourceLocator, Container, EvaluableItem, SequenceIterable, InstructionInfoProvider

    public class CodepointsToString

extends SystemFunction

This class supports the function codepoints-to-string

See Also:
  Serialized Form

Field Summary

Fields inherited from class net.sf.saxon.expr.Expression
`EVALUATE_METHOD, ITERATE_METHOD, PROCESS_METHOD`

Constructor Summary
`CodepointsToString()`

Method Summary
`Item` `evaluateItem(XPathContext c)` Evaluate
`Expression` `preEvaluate(StaticContext env)` Pre-evaluate a function at compile time.
`static CharSequence` `unicodeToString(SequenceIterator chars, XPathContext context)` Return the Unicode string corresponding to a given sequence of Unicode code values

Methods inherited from class net.sf.saxon.functions.SystemFunction
`checkArguments, computeCardinality, computeSpecialProperties, display, getDetails, getErrorCodeForTypeErrors, getItemType, main, makeSystemFunction, optimize, setDetails`

Methods inherited from class net.sf.saxon.expr.FunctionCall
`getArguments, getDisplayName, getFunctionNameCode, getNumberOfArguments, iterateSubExpressions, promote, replaceSubExpression, setArguments, setFunctionNameCode, simplify, typeCheck`

Methods inherited from class net.sf.saxon.expr.Expression

`adoptChildExpression, checkPermittedContents, computeDependencies, computeStaticProperties, doPromotion, effectiveBooleanValue, evaluateAsString, getCardinality, getColumnNumber, getContainingProcedure, getDependencies, getExecutable, getHostLanguage, getImplementationMethod, getInstructionInfo, getIntrinsicDependencies, getLineNumber, getLocationId, getLocationProvider, getParentExpression, getPublicId, getSlotsUsed, getSpecialProperties, getSystemId, hasBadParentPointer, iterate, markTailFunctionCalls, process, resetStaticProperties, setLocationId, setParentExpression, setParentExpression, suppressValidation`

Methods inherited from class java.lang.Object
`equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait`

Constructor Detail

### CodepointsToString

    public CodepointsToString()

Method Detail

### preEvaluate

    public Expression preEvaluate(StaticContext env)
                           throws XPathException

  Pre-evaluate a function at compile time. Functions that do not allow pre-evaluation, or that need access to context information, can override this method.

  Overrides:
    `preEvaluate` in class `FunctionCall`
  Throws:
    `XPathException`

### evaluateItem

    public Item evaluateItem(XPathContext c)
                      throws XPathException

  Evaluate

  Specified by:
    `evaluateItem` in interface `EvaluableItem`
  Overrides:
    `evaluateItem` in class `Expression`
  Parameters:
    `c` - The context in which the expression is to be evaluated
  Returns:
    the node or atomic value that results from evaluating the expression; or null to indicate that the result is an empty sequence
  Throws:
    `XPathException` - if any dynamic error occurs evaluating the expression

### unicodeToString

    public static CharSequence unicodeToString(SequenceIterator chars,
                                               XPathContext context)
                                        throws XPathException

  Return the Unicode string corresponding to a given sequence of Unicode code values

  Parameters:
    `chars` - iterator delivering the characters as integer values
    `context` - the evaluation context
  Throws:
    `XPathException` - if any of the integers is not the codepoint of a valid XML character

Copyright (C) Michael H. Kay. All rights reserved.