net.sf.saxon.expr

Class Assignation

public abstract class Assignation extends ComputedExpression implements Binding

Assignation is an abstract superclass for the kinds of expression that declare range variables: for, some, and every.

Field Summary
protected Expression	action
protected RangeVariableDeclaration	declaration
protected int	nameCode
protected Expression	sequence
protected int	slotNumber
protected String	variableName

Method Summary
ValueRepresentation	evaluateVariable(XPathContext context) Get the value of the range variable
protected Binding[]	extendBindingList(Binding[] in) Extend an array of variable bindings to include the binding(s) defined in this expression
Expression	getAction() Get the action expression
int	getLocalSlotNumber() If this is a local variable held on the local stack frame, return the corresponding slot number.
int	getRequiredSlots() Get the number of slots required.
RangeVariableDeclaration	getVariableDeclaration() Get the variable declaration
int	getVariableFingerprint()
String	getVariableName(NamePool pool) Get the display name of the range variable, for diagnostics only
int	getVariableNameCode()
boolean	isAssignable() Test whether it is permitted to assign to the variable using the saxon:assign extension element.
boolean	isGlobal() Indicate whether the binding is local or global.
Iterator	iterateSubExpressions() Get the immediate subexpressions of this expression
Expression	promote(PromotionOffer offer) Promote this expression if possible
protected Expression	promoteWhereClause(Binding positionBinding) Promote a WHERE clause whose condition doesn't depend on the variable being bound.
void	setAction(Expression action) Add the "return" or "satisfies" expression, and fix up all references to the range variable that occur within that expression
void	setSequence(Expression sequence) Set the "sequence" expression - the one to which the variable is bound
void	setSlotNumber(int nr) Set the slot number for the range variable
void	setVariableDeclaration(RangeVariableDeclaration decl) Set the reference to the variable declaration
Expression	simplify(StaticContext env) Simplify the expression
void	suppressValidation(int validationMode) Suppress validation on contained element constructors, on the grounds that the parent element is already performing validation.

Field Detail

declaration

protected transient RangeVariableDeclaration declaration

Method Detail

evaluateVariable

public ValueRepresentation evaluateVariable(XPathContext context)

Get the value of the range variable

extendBindingList

protected Binding[] extendBindingList(Binding[] in)

Extend an array of variable bindings to include the binding(s) defined in this expression

getAction

public Expression getAction()

Get the action expression

getLocalSlotNumber

public int getLocalSlotNumber()

If this is a local variable held on the local stack frame, return the corresponding slot number. In other cases, return -1.

getRequiredSlots

public int getRequiredSlots()

Get the number of slots required. Normally 1, except for a FOR expression with an AT clause, where it is 2.

getVariableDeclaration

public RangeVariableDeclaration getVariableDeclaration()

Get the variable declaration

getVariableName

public String getVariableName(NamePool pool)

Get the display name of the range variable, for diagnostics only

Test whether it is permitted to assign to the variable using the saxon:assign extension element. This will only be for an XSLT global variable where the extra attribute saxon:assignable="yes" is present.

isGlobal

public final boolean isGlobal()

Indicate whether the binding is local or global. A global binding is one that has a fixed value for the life of a query or transformation; any other binding is local.

iterateSubExpressions

public Iterator iterateSubExpressions()

Get the immediate subexpressions of this expression

promote

public Expression promote(PromotionOffer offer)

Promote this expression if possible

promoteWhereClause

protected Expression promoteWhereClause(Binding positionBinding)

Promote a WHERE clause whose condition doesn't depend on the variable being bound. This rewrites an expression of the form

let $i := SEQ return if (C) then R else ()

to the form:

if (C) then (let $i := SEQ return R) else ()

setAction

public void setAction(Expression action)

Add the "return" or "satisfies" expression, and fix up all references to the range variable that occur within that expression

Parameters: action the expression that occurs after the "return" keyword of a "for" expression, the "satisfies" keyword of "some/every", or the ":=" operator of a "let" expression.

This method must be called after calling setVariableDeclaration()