public class PartialApply extends ExpressionThis expression class implements the operation of currying (or performing partial application) of a function. That is, it takes a function and a set of argument bindings as input, and produces a new function as output.
All Methods Instance Methods Concrete Methods Modifier and Type Method Description
computeCardinality()Compute the static cardinality of this expression
computeHashCode()Hashcode supporting equals()
computeSpecialProperties()Compute the special properties of this expression.
copy(RebindingMap rebindings)Copy an expression.
equals(java.lang.Object other)Is this expression the same as another expression?
evaluateItem(XPathContext context)Evaluate this expression at run-time
export(ExpressionPresenter out)Diagnostic print of expression structure.
getElaborator()Make an elaborator for this expression
getExpressionName()Get a name identifying the kind of expression, in terms meaningful to a user.
getImplementationMethod()An implementation of Expression must provide at least one of the methods evaluateItem(), iterate(), or process().
getItemType()Determine the static item type of the expression, as precisely possible.
operands()Get the immediate sub-expressions of this expression, with information about the relationship of each expression to its parent expression.
toString()The toString() method for an expression attempts to give a representation of the expression in an XPath-like form.
typeCheck(ExpressionVisitor visitor, ContextItemStaticInfo contextInfo)Perform type checking of an expression and its subexpressions.
Methods inherited from class net.sf.saxon.expr.Expression
addToPathMap, adoptChildExpression, allowExtractingCommonSubexpressions, checkedOperands, checkForUpdatingSubexpressions, checkPermittedContents, computeDependencies, computeStaticProperties, dispatchTailCall, dynamicError, effectiveBooleanValue, evaluateAsString, explain, getCardinality, getConfiguration, getCost, getDependencies, getEvaluationMethod, getExtraProperty, getIntegerBounds, getIntrinsicDependencies, getLocalRetainedStaticContext, getLocation, getNetCost, getObjectName, getPackageData, getParentExpression, getProperties, getProperty, getRetainedStaticContext, getScopingExpression, getSlotsUsed, getSpecialProperties, getStaticBaseURI, getStaticBaseURIString, getStaticType, getStaticUType, getStreamerName, getTracingTag, hasCompatibleStaticContext, hashCode, hasSpecialProperty, hasVariableBinding, identityHashCode, implementsStaticTypeCheck, isCallOn, isEqual, isIdentical, isInstruction, isLiftable, isMultiThreaded, isStaticPropertiesKnown, isSubtreeExpression, isUpdatingExpression, isVacuousExpression, iterate, makeElaborator, markTailFunctionCalls, operandList, operandSparseList, optimize, optimizeChildren, prepareForStreaming, process, resetLocalStaticProperties, restoreParentPointers, setEvaluationMethod, setExtraProperty, setFiltered, setFlattened, setLocation, setParentExpression, setRetainedStaticContext, setRetainedStaticContextLocally, setRetainedStaticContextThoroughly, setStaticProperty, simplify, simplifyChildren, staticTypeCheck, supportsLazyEvaluation, suppressValidation, toPattern, toShortString, typeCheckChildren, typeError, unordered, verifyParentPointers, withLocation
Methods inherited from class java.lang.Object
clone, finalize, getClass, notify, notifyAll, wait, wait, wait
public PartialApply(Expression base, Expression boundArguments)Create a partial function application expression
base- the expression that returns the function to be called
boundArguments- an array in which each element is either an expression to be bound to the corresponding argument, or null to represent a placeholder ("?" in the source syntax)
public Expression getBaseExpression()
public void setBaseExpression(Expression base)
public int getNumberOfPlaceHolders()
public Expression typeCheck(ExpressionVisitor visitor, ContextItemStaticInfo contextInfo) throws XPathExceptionPerform 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.
visitor- an expression visitor
contextInfo- Information available statically about the context item: whether it is (possibly) absent; its static type; its streaming posture.
- the original expression, rewritten to perform necessary run-time type checks, and to perform other type-related optimizations
XPathException- if an error is discovered during this phase (typically a type error)
public ItemType getItemType()Determine the static item type of the expression, as precisely possible. All expression 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 should always return a result, though it may be the best approximation that is available at the time.
protected int computeSpecialProperties()Compute the special properties of this expression. These properties are denoted by a bit-significant integer, possible values are in class
StaticProperty. The "special" properties are properties other than cardinality and dependencies, and most of them relate to properties of node sequences, for example whether the nodes are in document order.
public 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.
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.
public int getNumberOfArguments()
public Expression getArgument(int n)
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 provided directly. The other methods will always be available indirectly, using an implementation that relies on one of the other methods.
public boolean equals(java.lang.Object other)Is this expression the same as another expression?
protected int computeHashCode()Hashcode supporting equals()
public void export(ExpressionPresenter out) throws XPathExceptionDiagnostic print of expression structure. The abstract expression tree is written to the supplied output destination.
protected int computeCardinality()Compute the static cardinality of this expression
- Specified by:
- the computed cardinality, as one of the values
StaticProperty.ALLOWS_ZERO_OR_MORE. May also return
StaticProperty.ALLOWS_ZEROif the result is known to be an empty sequence, or
StaticProperty.ALLOWS_MANYif if is known to return a sequence of length two or more.
public Expression copy(RebindingMap rebindings)Copy an expression. This makes a deep copy.
public java.lang.String toString()
For subclasses of Expression that represent XPath expressions, the result should always be a string that parses as an XPath 3.0 expression. The expression produced should be equivalent to the original making certain assumptions about the static context. In general the expansion will make no assumptions about namespace bindings, except that (a) the prefix "xs" is used to refer to the XML Schema namespace, and (b) the default funcion namespace is assumed to be the "fn" namespace.
In the case of XSLT instructions and XQuery expressions, the toString() method gives an abstracted view of the syntax that is not designed in general to be parseable.
public FunctionItem evaluateItem(XPathContext context) throws XPathExceptionEvaluate this expression at run-time
public java.lang.String getExpressionName()Get a name identifying the kind of expression, in terms meaningful to a user.