GeneralComparison

java.lang.Object
- net.sf.saxon.expr.Expression
- - net.sf.saxon.expr.BinaryExpression
  - - net.sf.saxon.expr.GeneralComparison

All Implemented Interfaces:

java.io.Serializable, javax.xml.transform.SourceLocator, LocationProvider, SaxonLocator, ComparisonExpression, EvaluableItem, SequenceIterable, InstructionInfo, org.xml.sax.Locator
```
public class GeneralComparison
extends BinaryExpression
implements ComparisonExpression
```
GeneralComparison: a boolean expression that compares two expressions for equals, not-equals, greater-than or less-than. This implements the operators =, !=, <, >, etc. This implementation is not used when in backwards-compatible mode

See Also:

Serialized Form

Field Summary

Fields
Modifier and Type Field Description

protected AtomicComparer comparer

protected int singletonOperator
- Fields inherited from class net.sf.saxon.expr.BinaryExpression
  operand0, operand1, operator
- Fields inherited from class net.sf.saxon.expr.Expression
  EVALUATE_METHOD, ITERATE_METHOD, locationId, PROCESS_METHOD, staticProperties

Fields
Modifier and Type	Field	Description
`protected AtomicComparer`	`comparer`
`protected int`	`singletonOperator`

Constructor Summary

Constructors
Constructor	Description
`GeneralComparison(Expression p0, int op, Expression p1)`	Create a relational expression identifying the two operands and the operator

Method Summary

All Methods Static Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`protected static boolean`	`compare(AtomicValue a1, int operator, AtomicValue a2, AtomicComparer comparer, XPathContext context)`	Compare two atomic values
`int`	`computeCardinality()`	Determine the static cardinality.
`boolean`	`convertsUntypedToOther()`	Determine whether untyped atomic values should be converted to the type of the other operand
`Expression`	`copy()`	Copy an expression.
`protected java.lang.String`	`displayOperator()`
`boolean`	`effectiveBooleanValue(XPathContext context)`	Evaluate the expression in a boolean context
`Item`	`evaluateItem(XPathContext context)`	Evaluate the expression in a given context
`AtomicComparer`	`getAtomicComparer()`	Get the AtomicComparer used to compare atomic values.
`protected GeneralComparison`	`getInverseComparison()`
`ItemType`	`getItemType(TypeHierarchy th)`	Determine the data type of the expression
`int`	`getSingletonOperator()`	Get the primitive (singleton) operator used: one of Token.FEQ, Token.FNE, Token.FLT, Token.FGT, Token.FLE, Token.FGE
`Expression`	`optimize(ExpressionVisitor visitor, ItemType contextItemType)`	Optimize the expression
`Expression`	`typeCheck(ExpressionVisitor visitor, ItemType contextItemType)`	Type-check the expression

Methods inherited from class net.sf.saxon.expr.BinaryExpression
computeSpecialProperties, equals, explain, getOperands, getOperator, hashCode, isAssociative, isCommutative, isInverse, iterateSubExpressions, promote, replaceSubExpression, setFlattened, simplify, toString

Methods inherited from interface net.sf.saxon.expr.ComparisonExpression
getOperands

Methods inherited from class net.sf.saxon.expr.Expression
addToPathMap, adoptChildExpression, checkForUpdatingSubexpressions, checkPermittedContents, computeDependencies, computeStaticProperties, display, doPromotion, dynamicError, evaluateAsString, evaluatePendingUpdates, explain, findParentOf, getCardinality, getColumnNumber, getColumnNumber, getConstructType, getContainer, getDependencies, getExecutable, getHostLanguage, getImplementationMethod, getIntrinsicDependencies, getLineNumber, getLineNumber, getLocationId, getLocationProvider, getObjectName, getProperties, getProperty, getPublicId, getSlotsUsed, getSpecialProperties, getSystemId, getSystemId, hasLoopingSubexpression, implementsStaticTypeCheck, isUpdatingExpression, iterate, iterateEvents, markTailFunctionCalls, process, resetLocalStaticProperties, setContainer, setFiltered, setLocationId, staticTypeCheck, suppressValidation, typeError

Methods inherited from class java.lang.Object
clone, finalize, getClass, notify, notifyAll, wait, wait, wait

- Field Detail
  - singletonOperator
```
protected int singletonOperator
```
  - comparer
```
protected AtomicComparer comparer
```
- Constructor Detail
  - GeneralComparison
```
public GeneralComparison(Expression p0,
                         int op,
                         Expression p1)
```
    Create a relational expression identifying the two operands and the operator
    
    Parameters:
    
    p0 - the left-hand operand
    
    op - the operator, as a token returned by the Tokenizer (e.g. Token.LT)
    
    p1 - the right-hand operand
- Method Detail
  - getAtomicComparer
```
public AtomicComparer getAtomicComparer()
```
    Get the AtomicComparer used to compare atomic values. This encapsulates any collation that is used
    
    Specified by:
    
    getAtomicComparer in interface ComparisonExpression
  - getSingletonOperator
```
public int getSingletonOperator()
```
    Get the primitive (singleton) operator used: one of Token.FEQ, Token.FNE, Token.FLT, Token.FGT, Token.FLE, Token.FGE
    
    Specified by:
    
    getSingletonOperator in interface ComparisonExpression
  - convertsUntypedToOther
```
public boolean convertsUntypedToOther()
```
    Determine whether untyped atomic values should be converted to the type of the other operand
    
    Specified by:
    
    convertsUntypedToOther in interface ComparisonExpression
    
    Returns:
    
    true if untyped values should be converted to the type of the other operand, false if they should be converted to strings.
  - computeCardinality
```
public int computeCardinality()
```
    Determine the static cardinality. Returns [1..1]
    
    Overrides:
    
    computeCardinality in class BinaryExpression
    
    Returns:
    
    the computed cardinality, as one of the values StaticProperty.ALLOWS_ZERO_OR_ONE, StaticProperty.EXACTLY_ONE, StaticProperty.ALLOWS_ONE_OR_MORE, StaticProperty.ALLOWS_ZERO_OR_MORE
  - typeCheck
```
public Expression typeCheck(ExpressionVisitor visitor,
                            ItemType contextItemType)
                     throws XPathException
```
    Type-check the expression
    
    Overrides:
    
    typeCheck in class BinaryExpression
    
    Parameters:
    
    visitor - an expression visitor
    
    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 Type.ITEM_TYPE
    
    Returns:
    
    the checked expression
    
    Throws:
    
    XPathException - if an error is discovered during this phase (typically a type error)
  - optimize
```
public Expression optimize(ExpressionVisitor visitor,
                           ItemType contextItemType)
                    throws XPathException
```
    Optimize the expression
    
    Overrides:
    
    optimize in class BinaryExpression
    
    Parameters:
    
    visitor - an expression visitor
    
    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 Type.ITEM_TYPE
    
    Returns:
    
    the checked expression
    
    Throws:
    
    XPathException - if an error is discovered during this phase (typically a type error)
  - copy
```
public Expression copy()
```
    Copy an expression. This makes a deep copy.
    
    Specified by:
    
    copy in class Expression
    
    Returns:
    
    the copy of the original expression
  - evaluateItem
```
public Item evaluateItem(XPathContext context)
                  throws XPathException
```
    Evaluate the expression in a given context
    
    Specified by:
    
    evaluateItem in interface EvaluableItem
    
    Overrides:
    
    evaluateItem in class Expression
    
    Parameters:
    
    context - the given context for evaluation
    
    Returns:
    
    a BooleanValue representing the result of the numeric comparison of the two operands
    
    Throws:
    
    XPathException - if any dynamic error occurs evaluating the expression
  - effectiveBooleanValue
```
public boolean effectiveBooleanValue(XPathContext context)
                              throws XPathException
```
    Evaluate the expression in a boolean context
    
    Overrides:
    
    effectiveBooleanValue in class Expression
    
    Parameters:
    
    context - the given context for evaluation
    
    Returns:
    
    a boolean representing the result of the numeric comparison of the two operands
    
    Throws:
    
    XPathException - if any dynamic error occurs evaluating the expression
  - compare
```
protected static boolean compare(AtomicValue a1,
                                 int operator,
                                 AtomicValue a2,
                                 AtomicComparer comparer,
                                 XPathContext context)
                          throws XPathException
```
    Compare two atomic values
    
    Parameters:
    
    a1 - the first value
    
    operator - the operator, for example Token.EQUALS
    
    a2 - the second value
    
    comparer - the comparer to be used to perform the comparison
    
    context - the XPath evaluation context
    
    Returns:
    
    true if the comparison succeeds
    
    Throws:
    
    XPathException
  - getItemType
```
public ItemType getItemType(TypeHierarchy th)
```
    Determine the data type of the expression
    
    Specified by:
    
    getItemType in class Expression
    
    Parameters:
    
    th - the type hierarchy cache
    
    Returns:
    
    the value BuiltInAtomicType.BOOLEAN
  - getInverseComparison
```
protected GeneralComparison getInverseComparison()
```
  - displayOperator
```
protected java.lang.String displayOperator()
```
    Overrides:
    
    displayOperator in class BinaryExpression

Class GeneralComparison

Field Summary

Fields inherited from class net.sf.saxon.expr.BinaryExpression

Fields inherited from class net.sf.saxon.expr.Expression

Constructor Summary

Method Summary

Methods inherited from class net.sf.saxon.expr.BinaryExpression

Methods inherited from interface net.sf.saxon.expr.ComparisonExpression

Methods inherited from class net.sf.saxon.expr.Expression

Methods inherited from class java.lang.Object

Field Detail

singletonOperator

comparer

Constructor Detail

GeneralComparison

Method Detail

getAtomicComparer

getSingletonOperator

convertsUntypedToOther

computeCardinality

typeCheck

optimize

copy

evaluateItem

effectiveBooleanValue

compare

getItemType

getInverseComparison

displayOperator