Package net.sf.saxon.sort
Class SortKeyDefinition
- java.lang.Object
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- net.sf.saxon.sort.SortKeyDefinition
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- All Implemented Interfaces:
java.io.Serializable
public class SortKeyDefinition extends java.lang.Object implements java.io.Serializable
A SortKeyDefinition defines one component of a sort key.
Note that most attributes defining the sort key can be attribute value templates, and can therefore vary from one invocation to another. We hold them as expressions. As soon as they are all known (which in general is only at run-time), the SortKeyDefinition is replaced by a FixedSortKeyDefinition in which all these values are fixed.- See Also:
- Serialized Form
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Field Summary
Fields Modifier and Type Field Description protected boolean
backwardsCompatible
protected java.lang.String
baseURI
protected Expression
caseOrder
protected StringCollator
collation
protected Expression
collationName
protected Expression
dataTypeExpression
protected boolean
emptyLeast
protected Expression
language
protected Expression
order
protected Expression
sortKey
protected Expression
stable
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Constructor Summary
Constructors Constructor Description SortKeyDefinition()
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Method Summary
All Methods Instance Methods Concrete Methods Modifier and Type Method Description java.lang.String
getBaseURI()
Get the static base URI of the expression.Expression
getCaseOrder()
Get the expression that defines the case order of the sort keys.StringCollator
getCollation()
Get the collation to be usedExpression
getCollationNameExpression()
Get the selected collation name (specifically, an expression which when evaluated returns the collation URI).Expression
getDataTypeExpression()
Get the expression that defines the data type of the sort keysboolean
getEmptyLeast()
Ask whether empty sequence comes before other values or after themAtomicComparer
getFinalComparator()
Get the comparator which is used to compare two values according to this sort key.Expression
getLanguage()
Get the expression that defines the language of the sort keysExpression
getOrder()
Get the expression that defines the order as ascending or descendingExpression
getSortKey()
Get the expression used as the sort keyExpression
getStable()
Ask whether this sort key definition is stableboolean
isBackwardsCompatible()
Ask whether this sort key is evaluated in XSLT 1.0 backwards compatibility modeboolean
isFixed()
Ask whether the sort key definition is fixed, that is, whether all the information needed to create a Comparator is known staticallyAtomicComparer
makeComparator(XPathContext context)
Allocate an AtomicComparer to perform the comparisons described by this sort key component.void
setBackwardsCompatible(boolean compatible)
Set whether this sort key is evaluated in XSLT 1.0 backwards compatibility modevoid
setBaseURI(java.lang.String baseURI)
Set the base URI of the expression.void
setCaseOrder(Expression exp)
Set the case order.void
setCollation(StringCollator collation)
Set the collation to be usedvoid
setCollationNameExpression(Expression collationName)
Set the collation name (specifically, an expression which when evaluated returns the collation URI).void
setDataTypeExpression(Expression exp)
Set the data type.void
setEmptyLeast(boolean emptyLeast)
Set whether empty sequence comes before other values or after themvoid
setFinalComparator(AtomicComparer comp)
Set the comparator which is used to compare two values according to this sort key.void
setLanguage(Expression exp)
Set the language.void
setOrder(Expression exp)
Set the order.void
setSortKey(Expression exp)
Set the expression used as the sort keyvoid
setStable(Expression stable)
Set whether this sort key definition is stableSortKeyDefinition
simplify(ExpressionVisitor visitor)
Simplify this sort key definition
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Field Detail
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sortKey
protected Expression sortKey
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order
protected Expression order
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dataTypeExpression
protected Expression dataTypeExpression
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caseOrder
protected Expression caseOrder
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language
protected Expression language
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collationName
protected Expression collationName
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stable
protected Expression stable
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collation
protected StringCollator collation
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baseURI
protected java.lang.String baseURI
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emptyLeast
protected boolean emptyLeast
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backwardsCompatible
protected boolean backwardsCompatible
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Method Detail
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setSortKey
public void setSortKey(Expression exp)
Set the expression used as the sort key- Parameters:
exp
- the sort key select expression
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getSortKey
public Expression getSortKey()
Get the expression used as the sort key- Returns:
- the sort key select expression
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setOrder
public void setOrder(Expression exp)
Set the order. This is supplied as an expression which must evaluate to "ascending" or "descending". If the order is fixed, supply e.g. new StringValue("ascending"). Default is "ascending".- Parameters:
exp
- the expression that determines the order (always a literal in XQuery, but can be defined by an AVT in XSLT)
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getOrder
public Expression getOrder()
Get the expression that defines the order as ascending or descending- Returns:
- the expression that determines the order (always a literal in XQuery, but can be defined by an AVT in XSLT)
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setDataTypeExpression
public void setDataTypeExpression(Expression exp)
Set the data type. This is supplied as an expression which must evaluate to "text", "number", or a QName. If the data type is fixed, the valus should be supplied using setDataType() and not via this method.- Parameters:
exp
- the expression that defines the data type, as used in XSLT 1.0
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getDataTypeExpression
public Expression getDataTypeExpression()
Get the expression that defines the data type of the sort keys- Returns:
- the expression that defines the data type, as used in XSLT 1.0
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setCaseOrder
public void setCaseOrder(Expression exp)
Set the case order. This is supplied as an expression which must evaluate to "upper-first" or "lower-first" or "#default". If the order is fixed, supply e.g. new StringValue("lower-first"). Default is "#default".- Parameters:
exp
- the expression that defines the case order
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getCaseOrder
public Expression getCaseOrder()
Get the expression that defines the case order of the sort keys.- Returns:
- the expression that defines the case order, whose run-time value will be "upper-first", "lower-first", or "#default".
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setLanguage
public void setLanguage(Expression exp)
Set the language. This is supplied as an expression which evaluates to the language name. If the order is fixed, supply e.g. new StringValue("de").- Parameters:
exp
- the expression that determines the language
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getLanguage
public Expression getLanguage()
Get the expression that defines the language of the sort keys- Returns:
- exp the expression that determines the language
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setCollationNameExpression
public void setCollationNameExpression(Expression collationName)
Set the collation name (specifically, an expression which when evaluated returns the collation URI).- Parameters:
collationName
- the expression that determines the collation name
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getCollationNameExpression
public Expression getCollationNameExpression()
Get the selected collation name (specifically, an expression which when evaluated returns the collation URI).- Returns:
- the expression that determines the collation name
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setCollation
public void setCollation(StringCollator collation)
Set the collation to be used- Parameters:
collation
- A StringCollator, which encapsulates both the collation URI and the collating function
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getCollation
public StringCollator getCollation()
Get the collation to be used- Returns:
- A StringCollator, which encapsulates both the collation URI and the collating function
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setBaseURI
public void setBaseURI(java.lang.String baseURI)
Set the base URI of the expression. This is needed to handle the case where a collation URI evaluated at run-time turns out to be a relative URI.- Parameters:
baseURI
- the static base URI of the expression
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getBaseURI
public java.lang.String getBaseURI()
Get the static base URI of the expression. This is needed to handle the case where a collation URI evaluated at run-time turns out to be a relative URI.- Returns:
- the static base URI of the expression
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setStable
public void setStable(Expression stable)
Set whether this sort key definition is stable- Parameters:
stable
- the expression that determines whether the sort key definition is stable (it evaluates to the string "yes" or "no".
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getStable
public Expression getStable()
Ask whether this sort key definition is stable- Returns:
- the expression that determines whether the sort key definition is stable (it evaluates to the string "yes" or "no".
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setBackwardsCompatible
public void setBackwardsCompatible(boolean compatible)
Set whether this sort key is evaluated in XSLT 1.0 backwards compatibility mode- Parameters:
compatible
- true if backwards compatibility mode is selected
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isBackwardsCompatible
public boolean isBackwardsCompatible()
Ask whether this sort key is evaluated in XSLT 1.0 backwards compatibility mode- Returns:
- true if backwards compatibility mode was selected
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setEmptyLeast
public void setEmptyLeast(boolean emptyLeast)
Set whether empty sequence comes before other values or after them- Parameters:
emptyLeast
- true if () is considered lower than any other value
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getEmptyLeast
public boolean getEmptyLeast()
Ask whether empty sequence comes before other values or after them- Returns:
- true if () is considered lower than any other value
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isFixed
public boolean isFixed()
Ask whether the sort key definition is fixed, that is, whether all the information needed to create a Comparator is known statically- Returns:
- true if all information needed to create a Comparator is known statically
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simplify
public SortKeyDefinition simplify(ExpressionVisitor visitor) throws XPathException
Simplify this sort key definition- Parameters:
visitor
- the expression visitor- Returns:
- the simplified sort key definition
- Throws:
XPathException
- if any failure occurs
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makeComparator
public AtomicComparer makeComparator(XPathContext context) throws XPathException
Allocate an AtomicComparer to perform the comparisons described by this sort key component. This method is called at run-time. The AtomicComparer takes into account not only the collation, but also parameters such as order=descending and handling of empty sequence and NaN (the result of the compare() method of the comparator is +1 if the second item is to sort after the first item)- Parameters:
context
- the dynamic evaluation context- Returns:
- an AtomicComparer suitable for making the sort comparisons
- Throws:
XPathException
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setFinalComparator
public void setFinalComparator(AtomicComparer comp)
Set the comparator which is used to compare two values according to this sort key. The comparator makes the final decision whether one value sorts before or after another: this takes into account the data type, the collation, whether empty comes first or last, whether the sort order is ascending or descending.This method is called at compile time if all these factors are known at compile time. It must not be called at run-time, except to reconstitute a finalComparator that has been lost by virtue of serialization .
- Parameters:
comp
- the Atomic Comparer to be used
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getFinalComparator
public AtomicComparer getFinalComparator()
Get the comparator which is used to compare two values according to this sort key. This method may be called either at compile time or at run-time. If no comparator has been allocated, it returns null. It is then necessary to allocate a comparator using themakeComparator(net.sf.saxon.expr.XPathContext)
method.- Returns:
- the Atomic Comparer to be used
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