net.sf.saxon.functions

Class Translate

Implemented Interfaces:
EvaluableItem, InstructionInfoProvider, SequenceIterable, Serializable, SourceLocator

public class Translate
extends SystemFunction

Implement the XPath translate() function

Field Summary

Fields inherited from class net.sf.saxon.functions.SystemFunction

operation

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

argument

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

EVALUATE_METHOD, ITERATE_METHOD, PROCESS_METHOD, locationId, staticProperties

Method Summary

Item
evaluateItem(XPathContext context)
Evaluate the function
IntToIntHashMap
getStaticMap()
Get the translation map built at compile time if there is one
static CharSequence
translate(StringValue sv0, StringValue sv1, StringValue sv2)
Perform the translate function
static CharSequence
translateUsingMap(CharSequence in, IntToIntHashMap map)
Implement the translate() function using an index built at compile time
Expression
typeCheck(ExpressionVisitor visitor, ItemType contextItemType)
Perform type checking of an expression and its subexpressions.

Methods inherited from class net.sf.saxon.functions.SystemFunction

addContextDocumentArgument, addDocToPathMap, checkArguments, computeCardinality, computeSpecialProperties, copy, getDetails, getErrorCodeForTypeErrors, getItemType, getRequiredType, makeSystemFunction, optimize, setDetails, useContextItemAsDefault

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

addExternalFunctionCallToPathMap, checkArgumentCount, checkArguments, equals, explain, getArguments, getDisplayName, getFunctionName, getNumberOfArguments, hashCode, iterateSubExpressions, optimize, preEvaluate, promote, replaceSubExpression, setArguments, setFunctionName, simplify, simplifyArguments, toString, typeCheck

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

addToPathMap, adoptChildExpression, checkPermittedContents, computeCardinality, computeDependencies, computeSpecialProperties, computeStaticProperties, copy, display, doPromotion, dynamicError, effectiveBooleanValue, evaluateAsString, evaluateItem, explain, explain, findParentOf, getCardinality, getColumnNumber, getConstructType, getContainer, getDependencies, getExecutable, getHostLanguage, getImplementationMethod, getInstructionInfo, getIntrinsicDependencies, getItemType, getLineNumber, getLocationId, getLocationProvider, getPublicId, getSlotsUsed, getSpecialProperties, getSystemId, hasLoopingSubexpression, implementsStaticTypeCheck, iterate, iterateEvents, iterateSubExpressions, markTailFunctionCalls, optimize, process, promote, replaceSubExpression, resetLocalStaticProperties, setContainer, setFiltered, setFlattened, setLocationId, simplify, staticTypeCheck, suppressValidation, toString, typeCheck, typeError

Method Details

evaluateItem

public Item evaluateItem(XPathContext context)
            throws XPathException
Evaluate the function
Specified by:
evaluateItem in interface EvaluableItem
Overrides:
evaluateItem in interface Expression

getStaticMap

public IntToIntHashMap getStaticMap()
Get the translation map built at compile time if there is one

translate

public static CharSequence translate(StringValue sv0,
                                     StringValue sv1,
                                     StringValue sv2)
Perform the translate function

translateUsingMap

public static CharSequence translateUsingMap(CharSequence in,
                                             IntToIntHashMap map)
Implement the translate() function using an index built at compile time
Parameters:
in - the string to be translated
map - index built at compile time, mapping input characters to output characters. The map returns -1 for a character that is to be deleted from the input string, Integer.MAX_VALUE for a character that is to remain intact
Returns:
the translated character string

typeCheck

public Expression typeCheck(ExpressionVisitor visitor,
                            ItemType contextItemType)
            throws XPathException
Perform 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.

If the implementation returns a value other than "this", then it is required to ensure that the parent pointer and location information in the returned expression have been set up correctly. It should not rely on the caller to do this, although for historical reasons many callers do so.

Overrides:
typeCheck in interface FunctionCall
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 original expression, rewritten to perform necessary run-time type checks, and to perform other type-related optimizations
Throws:
XPathException - if an error is discovered during this phase (typically a type error)