Package net.sf.saxon.expr.instruct

## Class NamespaceConstructor

- java.lang.Object
- - net.sf.saxon.expr.Expression
  - - net.sf.saxon.expr.instruct.Instruction
    - - net.sf.saxon.expr.instruct.SimpleNodeConstructor
      - - net.sf.saxon.expr.instruct.NamespaceConstructor

- All Implemented Interfaces:
    `ExportAgent`, `TailCallReturner`, `Locatable`, `IdentityComparable`, `Traceable`

      public class NamespaceConstructor
      extends SimpleNodeConstructor

  A namespace constructor instruction. (xsl:namespace in XSLT 2.0, or namespace{}{} in XQuery 1.1)

- - ### Field Summary

    - ### Fields inherited from class net.sf.saxon.expr.instruct.SimpleNodeConstructor

      `selectOp`

    - ### Fields inherited from class net.sf.saxon.expr.Expression

      `EFFECTIVE_BOOLEAN_VALUE, EVALUATE_METHOD, ITEM_FEED_METHOD, ITERATE_METHOD, MAX_COST, MAX_SEQUENCE_LENGTH, MAX_STRING_LENGTH, PROCESS_METHOD, staticProperties, UNBOUNDED_LOWER, UNBOUNDED_UPPER, UPDATE_METHOD, WATCH_METHOD`

  - ### Constructor Summary

    Constructors
    Constructor | Description
    --- | ---
    `NamespaceConstructor​(Expression name)` | Create an xsl:namespace instruction for dynamic construction of namespace nodes

  - ### Method Summary

    All Methods Instance Methods Concrete Methods
    Modifier and Type | Method | Description
    --- | --- | ---
    `Expression` | `copy​(RebindingMap rebindings)` | Copy an expression.
    `NodeInfo` | `evaluateItem​(XPathContext context)` | Evaluate as an expression.
    `NodeName` | `evaluateNodeName​(XPathContext context)` | Run-time method to compute the name of the node being constructed.
    `void` | `export​(ExpressionPresenter out)` | Diagnostic print of expression structure.
    `int` | `getCardinality()` | Determine the static cardinality of the expression.
    `int` | `getInstructionNameCode()` | Set the name of this instruction for diagnostic and tracing purposes
    `ItemType` | `getItemType()` | Get the item type of the items returned by evaluating this instruction
    `Expression` | `getNameExp()` |
    `void` | `localTypeCheck​(ExpressionVisitor visitor, ContextItemStaticInfo contextItemType)` | Method to perform type-checking specific to the kind of instruction
    `java.lang.Iterable<Operand>` | `operands()` | Get the immediate sub-expressions of this expression, with information about the relationship of each expression to its parent expression.
    `void` | `processValue​(java.lang.CharSequence value, Outputter output, XPathContext context)` | Process the value of the node, to create the new node.
    `void` | `setNameExp​(Expression nameExp)` |

    - ### Methods inherited from class net.sf.saxon.expr.instruct.SimpleNodeConstructor

      `allowExtractingCommonSubexpressions, alwaysCreatesNewNodes, checkContent, computeCardinality, computeSpecialProperties, getSelect, getStreamerName, isLocal, iterate, mayCreateNewNodes, optimize, processLeavingTail, setSelect, typeCheck`

    - ### Methods inherited from class net.sf.saxon.expr.instruct.Instruction

      `assembleParams, assembleTunnelParams, dynamicError, evaluateAsString, getExpressionName, getImplementationMethod, getNetCost, getSourceLocator, isInstruction, isXSLT, process, someOperandCreatesNewNodes`

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

      `addToPathMap, adoptChildExpression, checkedOperands, checkForUpdatingSubexpressions, checkPermittedContents, computeDependencies, computeHashCode, computeStaticProperties, dynamicError, effectiveBooleanValue, equals, evaluatePendingUpdates, explain, getConfiguration, getCost, getDependencies, getEvaluationMethod, getExtraProperty, getIntegerBounds, getInterpretedExpression, getIntrinsicDependencies, getLocalRetainedStaticContext, getLocation, getObjectName, getPackageData, getParentExpression, getProperties, getProperty, getRetainedStaticContext, getScopingExpression, getSlotsUsed, getSpecialProperties, getStaticBaseURI, getStaticBaseURIString, getStaticType, getStaticUType, getTracingTag, hasCompatibleStaticContext, hashCode, hasSpecialProperty, hasVariableBinding, identityHashCode, implementsStaticTypeCheck, isCallOn, isEqual, isIdentical, isLiftable, isMultiThreaded, isStaticPropertiesKnown, isSubtreeExpression, isUpdatingExpression, isVacuousExpression, markTailFunctionCalls, operandList, operandSparseList, optimizeChildren, prepareForStreaming, resetLocalStaticProperties, restoreParentPointers, setEvaluationMethod, setExtraProperty, setFiltered, setFlattened, setLocation, setParentExpression, setRetainedStaticContext, setRetainedStaticContextLocally, setRetainedStaticContextThoroughly, setStaticProperty, simplify, simplifyChildren, staticTypeCheck, suppressValidation, toPattern, toShortString, toString, typeCheckChildren, typeError, unordered, verifyParentPointers`

    - ### Methods inherited from class java.lang.Object

      `clone, finalize, getClass, notify, notifyAll, wait, wait, wait`

    - ### Methods inherited from interface net.sf.saxon.trace.Traceable

      `gatherProperties`

- - ### Constructor Detail

    - #### NamespaceConstructor

          public NamespaceConstructor​(Expression name)

      Create an xsl:namespace instruction for dynamic construction of namespace nodes
      Parameters:
        `name` - the expression to evaluate the name of the node (that is, the prefix)

  - ### Method Detail

    - #### getNameExp

          public Expression getNameExp()

    - #### setNameExp

          public void setNameExp​(Expression nameExp)

    - #### operands

          public java.lang.Iterable<Operand> operands()

      Description copied from class: `Expression`
      Get the immediate sub-expressions of this expression, with information about the relationship of each expression to its parent expression. Default implementation works off the results of iterateSubExpressions()

      If the expression is a Callable, then it is required that the order of the operands returned by this function is the same as the order of arguments supplied to the corresponding call() method.

      Overrides:
        `operands` in class `SimpleNodeConstructor`
      Returns:
        an iterator containing the sub-expressions of this expression

    - #### getInstructionNameCode

          public int getInstructionNameCode()

      Set the name of this instruction for diagnostic and tracing purposes
      Overrides:
        `getInstructionNameCode` in class `Instruction`
      Returns:
        a code identifying the instruction: typically but not always the fingerprint of a name in the XSLT namespace

    - #### getItemType

          public ItemType getItemType()

      Description copied from class: `Instruction`
      Get the item type of the items returned by evaluating this instruction
      Overrides:
        `getItemType` in class `Instruction`
      Returns:
        the static item type of the instruction

    - #### getCardinality

          public int getCardinality()

      Description copied from class: `Expression`
      Determine the static cardinality of the expression. This establishes how many items there will be in the result of the expression, at compile time (i.e., without actually evaluating the result.
      Overrides:
        `getCardinality` in class `Expression`
      Returns:
        one of the values Cardinality.ONE_OR_MORE, Cardinality.ZERO_OR_MORE, Cardinality.EXACTLY_ONE, Cardinality.ZERO_OR_ONE, Cardinality.EMPTY. This default implementation returns ZERO_OR_MORE (which effectively gives no information).

    - #### localTypeCheck

          public void localTypeCheck​(ExpressionVisitor visitor,
                                     ContextItemStaticInfo contextItemType)
                              throws XPathException

      Description copied from class: `SimpleNodeConstructor`
      Method to perform type-checking specific to the kind of instruction
      Specified by:
        `localTypeCheck` in class `SimpleNodeConstructor`
      Parameters:
        `visitor` - an expression visitor
        `contextItemType` - the static type of the context item
      Throws:
        `XPathException` - if a type error is detected

    - #### copy

          public Expression copy​(RebindingMap rebindings)

      Copy an expression. This makes a deep copy.
      Specified by:
        `copy` in class `Expression`
      Parameters:
        `rebindings` -
      Returns:
        the copy of the original expression

    - #### evaluateNodeName

          public NodeName evaluateNodeName​(XPathContext context)
                                    throws XPathException

      Description copied from class: `SimpleNodeConstructor`
      Run-time method to compute the name of the node being constructed. This is overridden for nodes that have a name. The default implementation returns null, which is suitable for unnamed nodes such as comments
      Overrides:
        `evaluateNodeName` in class `SimpleNodeConstructor`
      Parameters:
        `context` - the XPath dynamic evaluation context
      Returns:
        the name pool nameCode identifying the name of the constructed node
      Throws:
        `XPathException` - if any failure occurs

    - #### processValue

          public void processValue​(java.lang.CharSequence value,
                                   Outputter output,
                                   XPathContext context)
                            throws XPathException

      Description copied from class: `SimpleNodeConstructor`
      Process the value of the node, to create the new node.
      Specified by:
        `processValue` in class `SimpleNodeConstructor`
      Parameters:
        `value` - the string value of the new node
        `output` - the destination for the result
        `context` - the dynamic evaluation context
      Throws:
        `XPathException` - if a dynamic error occurs

    - #### evaluateItem

          public NodeInfo evaluateItem​(XPathContext context)
                                throws XPathException

      Evaluate as an expression. We rely on the fact that when these instructions are generated by XQuery, there will always be a valueExpression to evaluate the content
      Overrides:
        `evaluateItem` in class `SimpleNodeConstructor`
      Parameters:
        `context` - 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

    - #### export

          public void export​(ExpressionPresenter out)
                      throws XPathException

      Diagnostic print of expression structure. The abstract expression tree is written to the supplied output destination.
      Specified by:
        `export` in interface `ExportAgent`
      Specified by:
        `export` in class `Expression`
      Parameters:
        `out` - the expression presenter used to display the structure
      Throws:
        `XPathException` - if the export fails, for example if an expression is found that won't work in the target environment.