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.
- addToPathMap in interface Expression
pathMap
- the PathMap to which the expression should be addedpathMapNodeSet
-
- the pathMapNode representing the focus established by this expression, in the case where this
expression is the first operand of a path expression or filter 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.
call
protected SequenceIterator call(ValueRepresentation[] argValues,
XPathContext context)
throws XPathException
Call an extension function previously identified using the bind() method. A subclass
can override this method.
argValues
- The values of the argumentscontext
- The XPath dynamic evaluation context
- The value returned by the extension function
computeCardinality
public int computeCardinality()
Compute the static cardinality of this expression
- computeCardinality in interface Expression
copy
public Expression copy()
Copy an expression. This makes a deep copy.
- copy in interface Expression
- the copy of the original expression
getField
protected Object getField(Field field,
Object instance)
throws java.lang.IllegalAccessException
Access a field. This method is provided separately so that it can be refined in a subclass.
For example, a subclass might perform tracing of calls, or might trap exceptions.
field
- The field to be retrievedinstance
- The object whose field is to be retrieved. This is set to null if the
field is static.
getIntrinsicDependencies
public int getIntrinsicDependencies()
Determine which aspects of the context the expression depends on. The result is
a bitwise-or'ed value composed from constants such as XPathContext.VARIABLES and
XPathContext.CURRENT_NODE
- getIntrinsicDependencies in interface Expression
getItemType
public ItemType getItemType(TypeHierarchy th)
Determine the data type of the expression, if possible. All expressions return
sequences, in general; this method determines the type of the items within the
sequence, assuming that (a) this is known in advance, and (b) it is the same for
all items in the sequence.
This method will always return a result, though it may be the best approximation
that is available at the time.
- getItemType in interface Expression
th
- the type hierarchy cache
getTargetClass
public Class getTargetClass()
Get the class containing the method being called
- the class containing the target method
getTargetMethod
public AccessibleObject getTargetMethod()
Get the target method (or field, or constructor) being called
- the target method, field, or constructor
init
public void init(StructuredQName functionName,
Class theClass,
AccessibleObject object,
Configuration config)
Initialization: creates an ExtensionFunctionCall
functionName
- the name of the function, for display purposestheClass
- the Java class containing the method to be calledobject
- the method, field, or constructor of the Java class to be calledconfig
- the Saxon configuration
invokeConstructor
protected Object invokeConstructor(Constructor constructor,
Object[] params)
throws java.lang.InstantiationException,
java.lang.IllegalAccessException,
java.lang.reflect.InvocationTargetException
Invoke a constructor. This method is provided separately so that it can be refined in a subclass.
For example, a subclass might perform tracing of calls, or might trap exceptions.
constructor
- The constructor to be invokedparams
- The parameters to be passed to the constructor
- The object returned by the constructor
invokeMethod
protected Object invokeMethod(Method method,
Object instance,
Object[] params)
throws java.lang.IllegalAccessException,
java.lang.reflect.InvocationTargetException
Invoke a method. This method is provided separately so that it can be refined in a subclass.
For example, a subclass might perform tracing of calls, or might trap exceptions.
method
- The method to be invokedinstance
- The object on which the method is to be invoked. This is set to null if the
method is static.params
- The parameters to be passed to the method
- The object returned by the method
preEvaluate
public Expression preEvaluate(ExpressionVisitor visitor)
preEvaluate: this method suppresses compile-time evaluation by doing nothing
(because the external function might have side-effects and might use the context)
- preEvaluate in interface FunctionCall
visitor
- an expression visitor
toCamelCase
public static String toCamelCase(String name,
boolean debug,
PrintStream diag)
Convert a name to camelCase (by removing hyphens and changing the following
letter to capitals)
name
- the name to be converted to camelCasedebug
- true if tracing is requireddiag
- the output stream for diagnostic trace output