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java.lang.Object net.sf.saxon.expr.Expression net.sf.saxon.expr.FunctionCall
public abstract class FunctionCall
Abstract superclass for calls to system-defined and user-defined functions
Field Summary | |
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protected Expression[] |
argument
The array of expressions representing the actual parameters to the function call |
Fields inherited from class net.sf.saxon.expr.Expression |
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EFFECTIVE_BOOLEAN_VALUE, EVALUATE_METHOD, EVENT_FEED_METHOD, ITEM_FEED_METHOD, ITERATE_METHOD, locationId, MAX_SEQUENCE_LENGTH, MAX_STRING_LENGTH, PROCESS_METHOD, PUSH_SELECTION, staticProperties, UNBOUNDED_LOWER, UNBOUNDED_UPPER, WATCH_METHOD |
Constructor Summary | |
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FunctionCall()
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Method Summary | |
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PathMap.PathMapNodeSet |
addExternalFunctionCallToPathMap(PathMap pathMap,
PathMap.PathMapNodeSet pathMapNodes)
Add a representation of this expression to a PathMap. |
protected int |
checkArgumentCount(int min,
int max)
Check number of arguments. |
protected abstract void |
checkArguments(ExpressionVisitor visitor)
Method supplied by each class of function to check arguments during parsing, when all the argument expressions have been read |
boolean |
equals(Object o)
Determine whether two expressions are equivalent |
void |
explain(ExpressionPresenter out)
Diagnostic print of expression structure. |
Expression[] |
getArguments()
Get the expressions supplied as actual arguments to the function |
String |
getDisplayName()
Get the name of the function for display in messages |
String |
getExpressionName()
Get a name identifying the kind of expression, in terms meaningful to a user. |
StructuredQName |
getFunctionName()
Get the qualified of the function being called |
int |
getNumberOfArguments()
Determine the number of actual arguments supplied in the function call |
int |
hashCode()
Get hashCode in support of equals() method |
Iterator<Expression> |
iterateSubExpressions()
Get the immediate subexpressions of this expression |
Expression |
optimize(ExpressionVisitor visitor,
ExpressionVisitor.ContextItemType contextItemType)
Perform optimisation of an expression and its subexpressions. |
Expression |
preEvaluate(ExpressionVisitor visitor)
Pre-evaluate a function at compile time. |
Expression |
promote(PromotionOffer offer,
Expression parent)
Promote this expression if possible |
boolean |
replaceSubExpression(Expression original,
Expression replacement)
Replace one subexpression by a replacement subexpression |
void |
setArguments(Expression[] args)
Method called by the expression parser when all arguments have been supplied |
void |
setFunctionName(StructuredQName name)
Set the name of the function being called |
Expression |
simplify(ExpressionVisitor visitor)
Simplify the function call. |
protected Expression |
simplifyArguments(ExpressionVisitor visitor)
Simplify the arguments of the function. |
String |
toString()
The toString() method for an expression attempts to give a representation of the expression in an XPath-like form, but there is no guarantee that the syntax will actually be true XPath. |
Expression |
typeCheck(ExpressionVisitor visitor,
ExpressionVisitor.ContextItemType contextItemType)
Type-check the expression. |
Methods inherited from class java.lang.Object |
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clone, finalize, getClass, notify, notifyAll, wait, wait, wait |
Field Detail |
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protected Expression[] argument
Constructor Detail |
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public FunctionCall()
Method Detail |
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public final void setFunctionName(StructuredQName name)
name
- the name of the functionpublic StructuredQName getFunctionName()
public final int getNumberOfArguments()
public void setArguments(Expression[] args)
args
- the expressions contained in the argument list of the function callpublic Expression[] getArguments()
public Expression simplify(ExpressionVisitor visitor) throws XPathException
simplify
in class Expression
visitor
- an expression visitor
XPathException
- if an error is discovered during expression
rewritingprotected final Expression simplifyArguments(ExpressionVisitor visitor) throws XPathException
visitor
- an expression visitor
XPathException
- if an error occurspublic Expression typeCheck(ExpressionVisitor visitor, ExpressionVisitor.ContextItemType contextItemType) throws XPathException
typeCheck
in class Expression
visitor
- an expression visitorcontextItemType
- 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
XPathException
- if an error is discovered during this phase
(typically a type error)public Expression optimize(ExpressionVisitor visitor, ExpressionVisitor.ContextItemType contextItemType) throws XPathException
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.
optimize
in class Expression
visitor
- an expression visitorcontextItemType
- 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
XPathException
- if an error is discovered during this phase
(typically a type error)public Expression preEvaluate(ExpressionVisitor visitor) throws XPathException
visitor
- an expression visitor
XPathException
- if evaluation failspublic Expression promote(PromotionOffer offer, Expression parent) throws XPathException
promote
in class Expression
offer
- details of the offer, for example the offer to move
expressions that don't depend on the context to an outer level in
the containing expressionparent
- the containing expression in the expression tree
XPathException
- if any error is detectedprotected abstract void checkArguments(ExpressionVisitor visitor) throws XPathException
visitor
- the expression visitor
XPathException
- if the arguments are incorrectprotected int checkArgumentCount(int min, int max) throws XPathException
min
- the minimum number of arguments allowedmax
- the maximum number of arguments allowed
XPathException
- if the number of arguments is out of rangepublic Iterator<Expression> iterateSubExpressions()
iterateSubExpressions
in class Expression
public boolean replaceSubExpression(Expression original, Expression replacement)
replaceSubExpression
in class Expression
original
- the original subexpressionreplacement
- the replacement subexpression
public PathMap.PathMapNodeSet addExternalFunctionCallToPathMap(PathMap pathMap, PathMap.PathMapNodeSet pathMapNodes)
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.
pathMap
- the PathMap to which the expression should be addedpathMapNodes
- the node in the PathMap representing the focus at the point where this expression
is called. Set to null if this expression appears at the top level, in which case the expression, if it
is registered in the path map at all, must create a new path map root.
public final String getExpressionName()
getExpressionName
in class Expression
public final String getDisplayName()
public String toString()
toString
in class Expression
public void explain(ExpressionPresenter out)
explain
in class Expression
out
- the expression presenter used to display the structurepublic boolean equals(Object o)
equals
in class Object
public int hashCode()
hashCode
in class Object
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