net.sf.saxon.instruct

Class AnalyzeString

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

public class AnalyzeString
extends Instruction

An xsl:analyze-string element in the stylesheet. New at XSLT 2.0

Field Summary

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

EVALUATE_METHOD, ITERATE_METHOD, PROCESS_METHOD, locationId, staticProperties

Constructor Summary

AnalyzeString(Expression select, Expression regex, Expression flags, Expression matching, Expression nonMatching, RegularExpression pattern)
Construct an AnalyzeString instruction

Method Summary

void
checkPermittedContents(SchemaType parentType, StaticContext env, boolean whole)
Check that any elements and attributes constructed or returned by this expression are acceptable in the content model of a given complex type.
int
computeDependencies()
Compute the dependencies of an expression, as the union of the dependencies of its subexpressions.
Expression
copy()
Copy an expression.
void
explain(ExpressionPresenter out)
Diagnostic print of expression structure.
int
getImplementationMethod()
An implementation of Expression must provide at least one of the methods evaluateItem(), iterate(), or process().
int
getInstructionNameCode()
ItemType
getItemType(TypeHierarchy th)
Get the item type of the items returned by evaluating this instruction
Expression
getMatchingExpression()
Get the expression used to process matching substrings
Expression
getNonMatchingExpression()
Get the expression used to process non-matching substrings
boolean
hasLoopingSubexpression(Expression child)
Given an expression that is an immediate child of this expression, test whether the evaluation of the parent expression causes the child expression to be evaluated repeatedly
SequenceIterator
iterate(XPathContext context)
Return an Iterator to iterate over the values of a sequence.
Iterator
iterateSubExpressions()
Get all the XPath expressions associated with this instruction (in XSLT terms, the expression present on attributes of the instruction, as distinct from the child instructions in a sequence construction)
Expression
optimize(ExpressionVisitor visitor, ItemType contextItemType)
Perform optimisation of an expression and its subexpressions.
TailCall
processLeavingTail(XPathContext context)
ProcessLeavingTail: called to do the real work of this instruction.
protected void
promoteInst(PromotionOffer offer)
Handle promotion offers, that is, non-local tree rewrites.
boolean
replaceSubExpression(Expression original, Expression replacement)
Replace one subexpression by a replacement subexpression
Expression
simplify(ExpressionVisitor visitor)
Simplify an expression.
Expression
typeCheck(ExpressionVisitor visitor, ItemType contextItemType)
Perform type checking of an expression and its subexpressions.

Methods inherited from class net.sf.saxon.instruct.Instruction

assembleParams, assembleTunnelParams, computeCardinality, computeSpecialProperties, createsNewNodes, dynamicError, evaluateAsString, evaluateItem, getImplementationMethod, getInstructionInfo, getInstructionNameCode, getItemType, getSourceLocator, isXSLT, iterate, process, processLeavingTail, promote, promoteInst, simplify

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

Constructor Details

AnalyzeString

public AnalyzeString(Expression select,
                     Expression regex,
                     Expression flags,
                     Expression matching,
                     Expression nonMatching,
                     RegularExpression pattern)
Construct an AnalyzeString instruction
Parameters:
select - the expression containing the input string
regex - the regular expression
flags - the flags parameter
matching - actions to be applied to a matching substring
nonMatching - actions to be applied to a non-matching substring
pattern - the compiled regular expression, if it was known statically

Method Details

checkPermittedContents

public void checkPermittedContents(SchemaType parentType,
                                   StaticContext env,
                                   boolean whole)
            throws XPathException
Check that any elements and attributes constructed or returned by this expression are acceptable in the content model of a given complex type. It's always OK to say yes, since the check will be repeated at run-time. The process of checking element and attribute constructors against the content model of a complex type also registers the type of content expected of those constructors, so the static validation can continue recursively.
Overrides:
checkPermittedContents in interface Expression

computeDependencies

public int computeDependencies()
Compute the dependencies of an expression, as the union of the dependencies of its subexpressions. (This is overridden for path expressions and filter expressions, where the dependencies of a subexpression are not all propogated). This method should be called only once, to compute the dependencies; after that, getDependencies should be used.
Overrides:
computeDependencies in interface Expression
Returns:
the depencies, as a bit-mask

copy

public Expression copy()
Copy an expression. This makes a deep copy.
Overrides:
copy in interface Expression
Returns:
the copy of the original expression

explain

public void explain(ExpressionPresenter out)
Diagnostic print of expression structure. The abstract expression tree is written to the supplied output destination.
Overrides:
explain in interface Expression

getImplementationMethod

public int getImplementationMethod()
An implementation of Expression must provide at least one of the methods evaluateItem(), iterate(), or process(). This method indicates which of these methods is prefered.
Overrides:
getImplementationMethod in interface Instruction

getInstructionNameCode

public int getInstructionNameCode()
Overrides:
getInstructionNameCode in interface Instruction

getItemType

public ItemType getItemType(TypeHierarchy th)
Get the item type of the items returned by evaluating this instruction
Overrides:
getItemType in interface Instruction
Parameters:
th - the type hierarchy cache
Returns:
the static item type of the instruction

getMatchingExpression

public Expression getMatchingExpression()
Get the expression used to process matching substrings
Returns:
the expression used to process matching substrings

getNonMatchingExpression

public Expression getNonMatchingExpression()
Get the expression used to process non-matching substrings
Returns:
the expression used to process non-matching substrings

hasLoopingSubexpression

public boolean hasLoopingSubexpression(Expression child)
Given an expression that is an immediate child of this expression, test whether the evaluation of the parent expression causes the child expression to be evaluated repeatedly
Overrides:
hasLoopingSubexpression in interface Expression
Parameters:
child - the immediate subexpression
Returns:
true if the child expression is evaluated repeatedly

iterate

public SequenceIterator iterate(XPathContext context)
            throws XPathException
Return an Iterator to iterate over the values of a sequence. The value of every expression can be regarded as a sequence, so this method is supported for all expressions. This default implementation handles iteration for expressions that return singleton values: for non-singleton expressions, the subclass must provide its own implementation.
Specified by:
iterate in interface SequenceIterable
Overrides:
iterate in interface Instruction
Parameters:
context - supplies the context for evaluation
Returns:
a SequenceIterator that can be used to iterate over the result of the expression
Throws:
XPathException - if any dynamic error occurs evaluating the expression

iterateSubExpressions

public Iterator iterateSubExpressions()
Get all the XPath expressions associated with this instruction (in XSLT terms, the expression present on attributes of the instruction, as distinct from the child instructions in a sequence construction)
Overrides:
iterateSubExpressions in interface Expression

optimize

public Expression optimize(ExpressionVisitor visitor,
                           ItemType contextItemType)
            throws XPathException
Perform optimisation of an expression and its subexpressions. This is the third and final phase of static optimization.

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.

Overrides:
optimize in interface Expression
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 if appropriate to optimize execution
Throws:
XPathException - if an error is discovered during this phase (typically a type error)

processLeavingTail

public TailCall processLeavingTail(XPathContext context)
            throws XPathException
ProcessLeavingTail: called to do the real work of this instruction. This method must be implemented in each subclass. The results of the instruction are written to the current Receiver, which can be obtained via the Controller.
Specified by:
processLeavingTail in interface TailCallReturner
Overrides:
processLeavingTail in interface Instruction
Parameters:
context - The dynamic context of the transformation, giving access to the current node, the current variables, etc.
Returns:
null if the instruction has completed execution; or a TailCall indicating a function call or template call that is delegated to the caller, to be made after the stack has been unwound so as to save stack space.

promoteInst

protected void promoteInst(PromotionOffer offer)
            throws XPathException
Handle promotion offers, that is, non-local tree rewrites.
Overrides:
promoteInst in interface Instruction
Parameters:
offer - The type of rewrite being offered
Throws:
XPathException -

replaceSubExpression

public boolean replaceSubExpression(Expression original,
                                    Expression replacement)
Replace one subexpression by a replacement subexpression
Overrides:
replaceSubExpression in interface Expression
Parameters:
original - the original subexpression
replacement - the replacement subexpression
Returns:
true if the original subexpression is found

simplify

public Expression simplify(ExpressionVisitor visitor)
            throws XPathException
Simplify an expression. This performs any static optimization (by rewriting the expression as a different expression).
Overrides:
simplify in interface Instruction
Parameters:
visitor - an expression visitor
Returns:
the simplified expression
Throws:
XPathException - if an error is discovered during expression rewriting

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 Expression
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)