net.sf.saxon.functions

Class Replace

public class Replace extends SystemFunction

This class implements the replace() function for replacing substrings that match a regular expression
Method Summary
static StringcheckReplacement(CharSequence rep)
Check the contents of the replacement string
ItemevaluateItem(XPathContext c)
Evaluate the function in a string context
RegularExpressiongetCompiledRegularExpression()
Get the compiled regular expression if available, otherwise return null
Expressionoptimize(ExpressionVisitor visitor, ItemType contextItemType)
Perform optimisation of an expression and its subexpressions.
Expressionsimplify(ExpressionVisitor visitor)
Simplify and validate.

Method Detail

checkReplacement

public static String checkReplacement(CharSequence rep)
Check the contents of the replacement string

Parameters: rep the replacement string

Returns: null if the string is OK, or an error message if not

evaluateItem

public Item evaluateItem(XPathContext c)
Evaluate the function in a string context

getCompiledRegularExpression

public RegularExpression getCompiledRegularExpression()
Get the compiled regular expression if available, otherwise return null

Returns: the compiled regex, or null

optimize

public Expression optimize(ExpressionVisitor visitor, 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: 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 ITEM_TYPE

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

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

simplify

public Expression simplify(ExpressionVisitor visitor)
Simplify and validate. This is a pure function so it can be simplified in advance if the arguments are known

Parameters: visitor an expression visitor