Package net.sf.saxon.expr.instruct

## Class ApplyTemplates

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

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

      public class ApplyTemplates
      extends Instruction
      implements ITemplateCall, ComponentInvocation

  An instruction representing an xsl:apply-templates element in the stylesheet

- - ### Nested Class Summary

    Nested Classes
    Modifier and Type | Class | Description
    --- | --- | ---
    `protected static class` | `ApplyTemplates.ApplyTemplatesPackage` | An ApplyTemplatesPackage is an object that encapsulates the sequence of nodes to be processed, the mode, the parameters to be supplied, and the execution context.

  - ### Field Summary

    Fields
    Modifier and Type | Field | Description
    --- | --- | ---
    `protected boolean` | `implicitSelect` |
    `protected boolean` | `inStreamableConstruct` |
    `protected Mode` | `mode` |
    `protected RuleManager` | `ruleManager` |
    `protected boolean` | `useCurrentMode` |
    `protected boolean` | `useTailRecursion` |

    - ### 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
    Modifier | Constructor | Description
    --- | --- | ---
    `protected` | `ApplyTemplates()` |
    `` | `ApplyTemplates​(Expression select, boolean useCurrentMode, boolean useTailRecursion, boolean implicitSelect, boolean inStreamableConstruct, Mode mode, RuleManager ruleManager)` | Construct an apply-templates instruction

  - ### Method Summary

    All Methods Instance Methods Concrete Methods
    Modifier and Type | Method | Description
    --- | --- | ---
    `PathMap.PathMapNodeSet` | `addToPathMap​(PathMap pathMap, PathMap.PathMapNodeSet pathMapNodeSet)` | Add a representation of this expression to a PathMap.
    `protected TailCall` | `apply​(Outputter output, XPathContext context, boolean returnTailCall)` |
    `Expression` | `copy​(RebindingMap rebindings)` | Copy an expression.
    `void` | `export​(ExpressionPresenter out)` | Diagnostic print of expression structure.
    `WithParam[]` | `getActualParams()` | Get the actual parameters passed to the called template
    `int` | `getBindingSlot()` | Get the binding slot to be used (for the explicit or implicit reference to the mode).
    `Component` | `getFixedTarget()` | Get the target component if this is known in advance, that is, if the target component is private or final, or in some other cases such as xsl:original.
    `int` | `getImplementationMethod()` | An implementation of Expression must provide at least one of the methods evaluateItem(), iterate(), or process().
    `int` | `getInstructionNameCode()` | Get the name of this instruction for diagnostic and tracing purposes
    `int` | `getIntrinsicDependencies()` | Determine the intrinsic dependencies of an expression, that is, those which are not derived from the dependencies of its subexpressions.
    `Mode` | `getMode()` | Get the Mode
    `RuleManager` | `getRuleManager()` |
    `Expression` | `getSelect()` | Get the select expression
    `Expression` | `getSelectExpression()` | Get the select expression
    `Expression` | `getSeparatorExpression()` |
    `java.lang.String` | `getStreamerName()` | Get the (partial) name of a class that supports streaming of this kind of expression
    `SymbolicName` | `getSymbolicName()` | Get the symbolic name of the mode that this invocation references
    `Component.M` | `getTargetMode​(XPathContext context)` | Establish the target mode, at run-time.
    `WithParam[]` | `getTunnelParams()` | Get the tunnel parameters passed to the called template
    `protected void` | `init​(Expression select, boolean useCurrentMode, boolean useTailRecursion, Mode mode)` |
    `boolean` | `isImplicitSelect()` | Ask if the select expression was implicit
    `protected NodeInfo` | `makeSeparator​(XPathContext context)` |
    `boolean` | `mayCreateNewNodes()` | Determine whether this instruction creates new nodes.
    `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.
    `Expression` | `optimize​(ExpressionVisitor visitor, ContextItemStaticInfo contextInfo)` | Perform optimisation of an expression and its subexpressions.
    `void` | `process​(Outputter output, XPathContext context)` | Process the instruction, without returning any tail calls
    `TailCall` | `processLeavingTail​(Outputter output, XPathContext context)` | ProcessLeavingTail: called to do the real work of this instruction.
    `void` | `setActualParams​(WithParam[] params)` |
    `void` | `setBindingSlot​(int slot)` | Set the binding slot to be used (for the explicit or implicit reference to the mode).
    `void` | `setMode​(SimpleMode target)` | Set the mode to be used.
    `void` | `setSelect​(Expression select)` | Set the select expression
    `void` | `setSeparatorExpression​(Expression separator)` | Set the separator expression (Saxon extension)
    `void` | `setTunnelParams​(WithParam[] params)` |
    `Expression` | `simplify()` | Simplify an expression.
    `Expression` | `typeCheck​(ExpressionVisitor visitor, ContextItemStaticInfo contextInfo)` | Perform type checking of an expression and its subexpressions.
    `boolean` | `usesCurrentMode()` | Ask if mode="#current" was specified
    `boolean` | `useTailRecursion()` | Ask if tail recursion is to be used

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

      `alwaysCreatesNewNodes, assembleParams, assembleTunnelParams, computeCardinality, computeSpecialProperties, dynamicError, evaluateAsString, evaluateItem, getExpressionName, getItemType, getNetCost, getSourceLocator, isInstruction, isXSLT, iterate, someOperandCreatesNewNodes`

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

      `adoptChildExpression, allowExtractingCommonSubexpressions, checkedOperands, checkForUpdatingSubexpressions, checkPermittedContents, computeDependencies, computeHashCode, computeStaticProperties, dynamicError, effectiveBooleanValue, equals, evaluatePendingUpdates, explain, getCardinality, getConfiguration, getCost, getDependencies, getEvaluationMethod, getExtraProperty, getIntegerBounds, getInterpretedExpression, 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, 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`

- - ### Field Detail

    - #### useCurrentMode

          protected boolean useCurrentMode

    - #### useTailRecursion

          protected boolean useTailRecursion

    - #### mode

          protected Mode mode

    - #### implicitSelect

          protected boolean implicitSelect

    - #### inStreamableConstruct

          protected boolean inStreamableConstruct

    - #### ruleManager

          protected RuleManager ruleManager

  - ### Constructor Detail

    - #### ApplyTemplates

          protected ApplyTemplates()

    - #### ApplyTemplates

          public ApplyTemplates​(Expression select,
                                boolean useCurrentMode,
                                boolean useTailRecursion,
                                boolean implicitSelect,
                                boolean inStreamableConstruct,
                                Mode mode,
                                RuleManager ruleManager)

      Construct an apply-templates instruction
      Parameters:
        `select` - the select expression
        `useCurrentMode` - true if mode="#current" was specified
        `useTailRecursion` - true if this instruction is the last in its template
        `implicitSelect` - true if the select expression is implicit, that is, if there was no explicit select expression in the call. This information is used only to make error messages more meaningful.
        `mode` - the mode specified on apply-templates

  - ### Method Detail

    - #### init

          protected void init​(Expression select,
                              boolean useCurrentMode,
                              boolean useTailRecursion,
                              Mode mode)

    - #### setMode

          public void setMode​(SimpleMode target)

      Set the mode to be used.
      Parameters:
        `target` - the attribute set to be used

    - #### setSeparatorExpression

          public void setSeparatorExpression​(Expression separator)

      Set the separator expression (Saxon extension)

    - #### getSeparatorExpression

          public Expression getSeparatorExpression()

    - #### getActualParams

          public WithParam[] getActualParams()

      Get the actual parameters passed to the called template
      Specified by:
        `getActualParams` in interface `ITemplateCall`
      Returns:
        the non-tunnel parameters

    - #### getTunnelParams

          public WithParam[] getTunnelParams()

      Get the tunnel parameters passed to the called template
      Specified by:
        `getTunnelParams` in interface `ITemplateCall`
      Returns:
        the tunnel parameters

    - #### setActualParams

          public void setActualParams​(WithParam[] params)

    - #### setTunnelParams

          public void setTunnelParams​(WithParam[] params)

    - #### 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.

      Specified by:
        `operands` in class `Instruction`
      Returns:
        an iterator containing the sub-expressions of this expression

    - #### getInstructionNameCode

          public int getInstructionNameCode()

      Get 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

    - #### getImplementationMethod

          public int getImplementationMethod()

      An implementation of Expression must provide at least one of the methods evaluateItem(), iterate(), or process(). This method indicates which of these methods is prefered. For instructions this is the process() method.
      Overrides:
        `getImplementationMethod` in class `Instruction`
      Returns:
        the implementation method, for example `Expression.ITERATE_METHOD` or `Expression.EVALUATE_METHOD` or `Expression.PROCESS_METHOD`

    - #### simplify

          public Expression simplify()
                              throws XPathException

      Simplify an expression. This performs any static optimization (by rewriting the expression as a different expression).
      Overrides:
        `simplify` in class `Expression`
      Returns:
        the simplified expression (or the original if unchanged, or if modified in-situ)
      Throws:
        `XPathException` - if an error is discovered during expression rewriting

    - #### typeCheck

          public Expression typeCheck​(ExpressionVisitor visitor,
                                      ContextItemStaticInfo contextInfo)
                               throws XPathException

      Description copied from class: `Expression`
      Perform type checking of an expression and its subexpressions. This is the second phase of static optimization.

      This checks statically that the operands of the expression have the correct type; if necessary it generates code to do run-time type checking or type conversion. A static type error is reported only if execution cannot possibly succeed, that is, if a run-time type error is inevitable. The call may return a modified form of the expression.

      This method is called after all references to functions and variables have been resolved to the declaration of the function or variable. However, the types of such functions and variables may not be accurately known if they have not been explicitly declared.

      Overrides:
        `typeCheck` in class `Expression`
      Parameters:
        `visitor` - an expression visitor
        `contextInfo` - Information available statically about the context item: whether it is (possibly) absent; its static type; its streaming posture.
      Returns:
        the original expression, rewritten to perform necessary run-time type checks, and to perform other type-related optimizations
      Throws:
        `XPathException` - if an error is discovered during this phase (typically a type error)

    - #### optimize

          public Expression optimize​(ExpressionVisitor visitor,
                                     ContextItemStaticInfo contextInfo)
                              throws XPathException

      Description copied from class: `Expression`
      Perform optimisation of an expression and its subexpressions. This is the third and final phase of static optimization.

      This method is called after all references to functions and variables have been resolved to the declaration of the function or variable, and after all type checking has been done.

      Overrides:
        `optimize` in class `Expression`
      Parameters:
        `visitor` - an expression visitor
        `contextInfo` - the static type of "." at the point where this expression is invoked. The parameter is set to null if it is known statically that the context item will be undefined. If the type of the context item is not known statically, the argument is set to `Type.ITEM_TYPE`
      Returns:
        the original expression, rewritten if appropriate to optimize execution
      Throws:
        `XPathException` - if an error is discovered during this phase (typically a type error)

    - #### getIntrinsicDependencies

          public int getIntrinsicDependencies()

      Description copied from class: `Expression`
      Determine the intrinsic dependencies of an expression, that is, those which are not derived from the dependencies of its subexpressions. For example, position() has an intrinsic dependency on the context position, while (position()+1) does not. The default implementation of the method returns 0, indicating "no dependencies".
      Overrides:
        `getIntrinsicDependencies` in class `Expression`
      Returns:
        a set of bit-significant flags identifying the "intrinsic" dependencies. The flags are documented in class net.sf.saxon.value.StaticProperty

    - #### getRuleManager

          public RuleManager getRuleManager()

    - #### copy

          public Expression copy​(RebindingMap rebindings)

      Copy an expression. This makes a deep copy.
      Specified by:
        `copy` in class `Expression`
      Parameters:
        `rebindings` - a mutable list of (old binding, new binding) pairs that is used to update the bindings held in any local variable references that are copied.
      Returns:
        the copy of the original expression

    - #### mayCreateNewNodes

          public final boolean mayCreateNewNodes()

      Determine whether this instruction creates new nodes. This implementation returns true (which is almost invariably the case, so it's not worth doing any further analysis to find out more precisely).
      Overrides:
        `mayCreateNewNodes` in class `Instruction`
      Returns:
        true if the instruction creates new nodes under some input conditions (or if it can't be proved that it doesn't)

    - #### process

          public void process​(Outputter output,
                              XPathContext context)
                       throws XPathException

      Description copied from class: `Instruction`
      Process the instruction, without returning any tail calls
      Overrides:
        `process` in class `Instruction`
      Parameters:
        `output` - the destination for the result
        `context` - The dynamic context, giving access to the current node,
      Throws:
        `XPathException` - if a dynamic error occurs

    - #### processLeavingTail

          public TailCall processLeavingTail​(Outputter output,
                                             XPathContext context)
                                      throws XPathException

      Description copied from class: `Instruction`
      ProcessLeavingTail: called to do the real work of this instruction. This method must be implemented in each subclass. The results of the instruction are written to the current Receiver, which can be obtained via the Controller.
      Specified by:
        `processLeavingTail` in interface `TailCallReturner`
      Specified by:
        `processLeavingTail` in class `Instruction`
      Parameters:
        `output` - the destination for the result
        `context` - The dynamic context of the transformation, giving access to the current node, the current variables, etc.
      Returns:
        null if the instruction has completed execution; or a TailCall indicating a function call or template call that is delegated to the caller, to be made after the stack has been unwound so as to save stack space.
      Throws:
        `XPathException` - if a dynamic error occurs during the evaluation of the instruction

    - #### makeSeparator

          protected NodeInfo makeSeparator​(XPathContext context)
                                    throws XPathException

      Throws:
        `XPathException`

    - #### apply

          protected TailCall apply​(Outputter output,
                                   XPathContext context,
                                   boolean returnTailCall)
                            throws XPathException

      Throws:
        `XPathException`

    - #### getTargetMode

          public Component.M getTargetMode​(XPathContext context)

      Establish the target mode, at run-time. This (a) resolves overrides across packages, and (b) handles mode="#current".
      Parameters:
        `context` - the dynamic context
      Returns:
        the mode to be used, as a Component

    - #### getSelectExpression

          public Expression getSelectExpression()

      Get the select expression
      Returns:
        the select expression

    - #### isImplicitSelect

          public boolean isImplicitSelect()

      Ask if the select expression was implicit
      Returns:
        true if no select attribute was explicitly specified

    - #### useTailRecursion

          public boolean useTailRecursion()

      Ask if tail recursion is to be used
      Returns:
        true if tail recursion is used

    - #### usesCurrentMode

          public boolean usesCurrentMode()

      Ask if mode="#current" was specified
      Returns:
        true if mode="#current" was specified

    - #### getMode

          public Mode getMode()

      Get the Mode
      Returns:
        the mode, or null if mode="#current" was specified

    - #### getFixedTarget

          public Component getFixedTarget()

      Get the target component if this is known in advance, that is, if the target component is private or final, or in some other cases such as xsl:original. Otherwise, return null.
      Specified by:
        `getFixedTarget` in interface `ComponentInvocation`
      Returns:
        the bound component if the binding has been fixed

    - #### getSymbolicName

          public SymbolicName getSymbolicName()

      Get the symbolic name of the mode that this invocation references
      Specified by:
        `getSymbolicName` in interface `ComponentInvocation`
      Returns:
        the symbolic name of the mode used by this instructon, or null if the instruction uses mode="#current"

    - #### addToPathMap

          public PathMap.PathMapNodeSet addToPathMap​(PathMap pathMap,
                                                     PathMap.PathMapNodeSet pathMapNodeSet)

      Add a representation of this expression to a PathMap. The PathMap captures a map of the nodes visited by an expression in a source tree.

      The default implementation of this method assumes that an expression does no navigation other than the navigation done by evaluating its subexpressions, and that the subexpressions are evaluated in the same context as the containing expression. The method must be overridden for any expression where these assumptions do not hold. For example, implementations exist for AxisExpression, ParentExpression, and RootExpression (because they perform navigation), and for the doc(), document(), and collection() functions because they create a new navigation root. Implementations also exist for PathExpression and FilterExpression because they have subexpressions that are evaluated in a different context from the calling expression.

      Overrides:
        `addToPathMap` in class `Expression`
      Parameters:
        `pathMap` - the PathMap to which the expression should be added
        `pathMapNodeSet` - the PathMapNodeSet to which the paths embodied in this expression should be added
      Returns:
        the pathMapNodeSet representing the points in the source document that are both reachable by this expression, and that represent possible results of this expression. For an expression that does navigation, it represents the end of the arc in the path map that describes the navigation route. For other expressions, it is the same as the input pathMapNode.

    - #### 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` - output destination
      Throws:
        `XPathException` - if the export fails, for example if an expression is found that won't work in the target environment.

    - #### getSelect

          public Expression getSelect()

      Get the select expression
      Returns:
        the select expression

    - #### setSelect

          public void setSelect​(Expression select)

      Set the select expression
      Parameters:
        `select` - the select expression

    - #### setBindingSlot

          public void setBindingSlot​(int slot)

      Set the binding slot to be used (for the explicit or implicit reference to the mode). This is the offset within the binding vector of the containing component where the actual target template is to be found. The target template is not held directly in the CallTemplate instruction itself because it can be overridden in a using package.
      Specified by:
        `setBindingSlot` in interface `ComponentInvocation`
      Parameters:
        `slot` - the offset in the binding vector of the containing package where the target template can be found.

    - #### getBindingSlot

          public int getBindingSlot()

      Get the binding slot to be used (for the explicit or implicit reference to the mode). This is the offset within the binding vector of the containing component where the actual target template is to be found.
      Specified by:
        `getBindingSlot` in interface `ComponentInvocation`
      Returns:
        the offset in the binding vector of the containing package where the target template can be found.

    - #### getStreamerName

          public java.lang.String getStreamerName()

      Description copied from class: `Expression`
      Get the (partial) name of a class that supports streaming of this kind of expression
      Overrides:
        `getStreamerName` in class `Expression`
      Returns:
        the partial name of a class that can be instantiated to provide streaming support in Saxon-EE, or null if there is no such class