net.sf.saxon.expr

Class QuantifiedExpression

class QuantifiedExpression extends Assignation

A QuantifiedExpression tests whether some/all items in a sequence satisfy some condition.
Method Summary
intcomputeCardinality()
Determine the static cardinality
intcomputeSpecialProperties()
Determine the special properties of this expression
voiddisplay(int level, NamePool pool, PrintStream out)
Diagnostic print of expression structure
booleaneffectiveBooleanValue(XPathContext context)
Get the result as a boolean
ItemevaluateItem(XPathContext context)
Evaluate the expression to return a singleton value
ItemTypegetItemType(TypeHierarchy th)
Determine the data type of the items returned by the expression
Expressionoptimize(Optimizer opt, StaticContext env, ItemType contextItemType)
Perform optimisation of an expression and its subexpressions.
voidsetOperator(int operator)
ExpressiontypeCheck(StaticContext env, ItemType contextItemType)
Type-check the expression

Method Detail

computeCardinality

public int computeCardinality()
Determine the static cardinality

computeSpecialProperties

public int computeSpecialProperties()
Determine the special properties of this expression

Returns: NON_CREATIVE.

display

public void display(int level, NamePool pool, PrintStream out)
Diagnostic print of expression structure

effectiveBooleanValue

public boolean effectiveBooleanValue(XPathContext context)
Get the result as a boolean

evaluateItem

public Item evaluateItem(XPathContext context)
Evaluate the expression to return a singleton value

getItemType

public ItemType getItemType(TypeHierarchy th)
Determine the data type of the items returned by the expression

Parameters: th

Returns: Type.BOOLEAN

optimize

public Expression optimize(Optimizer opt, StaticContext env, ItemType contextItemType)
Perform optimisation of an expression and its subexpressions.

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.

Parameters: opt the optimizer in use. This provides access to supporting functions; it also allows different optimization strategies to be used in different circumstances. env the static context of the expression contextItemType 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 ITEM_TYPE

Returns: the original expression, rewritten if appropriate to optimize execution

Throws: net.sf.saxon.trans.StaticError if an error is discovered during this phase (typically a type error)

setOperator

public void setOperator(int operator)

typeCheck

public Expression typeCheck(StaticContext env, ItemType contextItemType)
Type-check the expression