com.saxonica.ee.expr

Class ExpressionADJ

java.lang.Object

com.saxonica.ee.pattern.Adjunct

com.saxonica.ee.expr.ExpressionADJ

Direct Known Subclasses:

AxisExpressionADJ, BinaryExpressionADJ, BlockADJ, ContextItemExpressionADJ, StringLiteralADJ, SystemFunctionCallADJ, UnaryExpressionADJ, VariableReferenceADJ, WhichOfADJ

public class ExpressionADJ
extends Adjunct

Field Summary

Fields

Modifier and Type	Field and Description
static ContextItemStaticInfo	ci
Expression	expr

Constructor Summary

Constructors

Constructor and Description
ExpressionADJ(Expression e)

Method Summary

Methods

Modifier and Type	Method and Description
Expression	applyAxis(byte axis) Convert an expression to apply to nodes along a given axis.
Expression	copyLocationInfo(Expression e) Copy location information from this Expression onto another (new) Expression
Expression	evaluateAgainstBoolean(Expression e, PatternOptimizationEE patternOptimization) Given an expression that is known to be true, produce a simplified version of this expression.
void	export(ExpressionPresenter out) Export - in this case export the wrapped expression
Set<Expression>	getOperandPreconditions(PatternOptimizationEE patternOptimization) Get preconditions for the operands of an expression
static Set<Expression>	getOperandPreconditions(PatternOptimizationEE patternOptimization, Expression e) Get preconditions for the operands of an expression
Set<Expression>	getPreconditions(PatternOptimizationEE patternOptimization) Get the preconditions for an expression
static Set<Expression>	getPreconditions(PatternOptimizationEE patternOptimization, Expression e) Get the preconditions for an expression
RetainedStaticContext	getRetainedStaticContext()
ExpressionADJ	important() Return the adjunct that is important for unification
Expression	interpolateVariables(RewriteContext rc) Intepolate variable values into this expression
Expression[]	interpolateVariablesOperands(RewriteContext rc) Interpolate variable values into operands
boolean	isCallOn(Class<? extends SystemFunction> function) Is this expression a specific function call?
Expression	optimizeForContextType(ContextItemStaticInfo contextItemType) Optimize a pattern with respect to a context item type
Expression	optimizeForName(int i) Optimize a pattern with respect to a named node (element or attribute).
Expression	optimizeForType(int type) Optimize a pattern with respect to a typed node.
List<Expression>	optimizeOperandsForContextType(ContextItemStaticInfo contextItemType)
boolean	sameClass(ExpressionADJ adj) Is this expression the same class as another?
Expression	unify(ExpressionADJ source, RewriteContext rc) Unify this expression against another expression
Set<RewriteContext>	unifyingBindings(ExpressionADJ source, RewriteContext rc) Unify this expression against another expression
Set<RewriteContext>	unifyOperandBindings(ExpressionADJ source, RewriteContext rc)
Expression[]	unifyOperands(ExpressionADJ source, RewriteContext rc) Unify the operands of this expression against the operands of another

Methods inherited from class com.saxonica.ee.pattern.Adjunct

getExpressionAdjunct, getNodeTestAdjunct, getPatternAdjunct, index, processRewrites

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

expr

public Expression expr

ci

public static ContextItemStaticInfo ci

Constructor Detail

ExpressionADJ

public ExpressionADJ(Expression e)

Method Detail

getOperandPreconditions

public static Set<Expression> getOperandPreconditions(PatternOptimizationEE patternOptimization,
                                      Expression e)

Get preconditions for the operands of an expression

Parameters:

patternOptimization - controls for the optimization

e - the expression to examine

Returns:

the set of preconditions form all its operands

getPreconditions

public static Set<Expression> getPreconditions(PatternOptimizationEE patternOptimization,
                               Expression e)

Get the preconditions for an expression

Note that as a Pattern is a subclass of Expression, we need different named functions for each type.

Parameters:

patternOptimization - controls for the optimization

e - the expression to examine

Returns:

a set of precondition expressions for this pattern

getRetainedStaticContext

public RetainedStaticContext getRetainedStaticContext()

optimizeForName

public Expression optimizeForName(int i)

Optimize a pattern with respect to a named node (element or attribute). This is usually carried out on the base pattern, to determine if it will match the named node to be matched.

Parameters:

i - the fingerprint of the name of the node to be matched.

Returns:

null if it isn't for this named node, otherwise the pattern itself.

optimizeForType

public Expression optimizeForType(int type)

Optimize a pattern with respect to a typed node. This is usually carried out on the base pattern, to determine if it will match the typed node to be matched.

Parameters:

type - the type of the node to be matched.

Returns:

null if it isn't for this type of node, otherwise the pattern itself.

optimizeForContextType

public Expression optimizeForContextType(ContextItemStaticInfo contextItemType)

Optimize a pattern with respect to a context item type

Parameters:

contextItemType - the type of the context item

Returns:

a modified expression or the expression itself.

optimizeOperandsForContextType

public List<Expression> optimizeOperandsForContextType(ContextItemStaticInfo contextItemType)

applyAxis

public Expression applyAxis(byte axis)

Convert an expression to apply to nodes along a given axis. If appropriate this normally returns a BooleanExpressionPattern containing a suitable FilterExpression

Parameters:

axis - The axis to move this expression to

Returns:

a expression which evaluates the original expression along a given axis.

evaluateAgainstBoolean

public Expression evaluateAgainstBoolean(Expression e,
                                PatternOptimizationEE patternOptimization)

Given an expression that is known to be true, produce a simplified version of this expression. For example, if this expression is A[@x = 3], and the expression known to be true is (@x = 3), then this method might return A.

Parameters:

e - the expression assumed to be true.

patternOptimization -

Returns:

a possibly modified expression.

getPreconditions

public Set<Expression> getPreconditions(PatternOptimizationEE patternOptimization)

Get the preconditions for an expression

Note that as a Pattern is a subclass of Expression, we need different named functions for each type.

Parameters:

patternOptimization -

Returns:

a set of precondition expressions for this expression

getOperandPreconditions

public Set<Expression> getOperandPreconditions(PatternOptimizationEE patternOptimization)

Get preconditions for the operands of an expression

Parameters:

patternOptimization - controls for the optimization

Returns:

the set of preconditions from all its operands

copyLocationInfo

public Expression copyLocationInfo(Expression e)

Copy location information from this Expression onto another (new) Expression

Parameters:

e - the Expression to have location information added

Returns:

the input expression.

isCallOn

public boolean isCallOn(Class<? extends SystemFunction> function)

Is this expression a specific function call?

Parameters:

function - the function to be checked

Returns:

true if the expression is a call on thei given function

sameClass

public boolean sameClass(ExpressionADJ adj)

Is this expression the same class as another?

Parameters:

adj - the adjunct for the comparison expression

Returns:

true if both are the same class of expression

unifyingBindings

public Set<RewriteContext> unifyingBindings(ExpressionADJ source,
                                   RewriteContext rc)

Unify this expression against another expression

Parameters:

source - the expression to be unified against

rc - the evaluation context to use (which may be side-effected)

Returns:

a set of rewrite context bindings if it can unify, otherwise null

unify

public Expression unify(ExpressionADJ source,
               RewriteContext rc)

Unify this expression against another expression

Parameters:

source - the expression to be unified against

rc - the evaluation context to use (which may be side-effected)

Returns:

a unified expression if it can unify, otherwise null

unifyOperands

public Expression[] unifyOperands(ExpressionADJ source,
                         RewriteContext rc)

Unify the operands of this expression against the operands of another

Parameters:

source - the expression to be unified against

rc - the evaluation context to use (which may be side-effected)

Returns:

the unified operands, if all will unify, else null

unifyOperandBindings

public Set<RewriteContext> unifyOperandBindings(ExpressionADJ source,
                                       RewriteContext rc)

interpolateVariablesOperands

public Expression[] interpolateVariablesOperands(RewriteContext rc)

Interpolate variable values into operands

Parameters:

rc -

Returns:

interpolateVariables

public Expression interpolateVariables(RewriteContext rc)

Intepolate variable values into this expression

Parameters:

rc - the evaluation context (which contains any variable bindings)

Returns:

a possibly modified expression with variable values interpolated

important

public ExpressionADJ important()

Return the adjunct that is important for unification

Returns:

this adjunct, or the important adjunct of a child adjunct if this is deemed 'transparent'

export

public void export(ExpressionPresenter out)

Export - in this case export the wrapped expression

Parameters:

out -