net.sf.saxon.value
Class Cardinality
java.lang.Object
net.sf.saxon.value.Cardinality
public final class Cardinality
extends java.lang.Object
This class contains static methods to manipulate the cardinality
property of a type.
Cardinality of expressions is denoted by one of the values ONE_OR_MORE, ZERO_OR_MORE,
ZERO_OR_ONE, EXACTLY_ONE, or EMPTY. These are combinations of the three bit-significant
values ALLOWS_ZERO, ALLOWS_ONE, and ALLOWS_MANY.
static boolean | allowsMany(int cardinality) - Determine whether multiple occurrences are allowed
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static boolean | allowsZero(int cardinality) - Determine whether empty sequence is allowed
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static boolean | expectsMany(Expression expression) - Determine whether multiple occurrences are not only allowed, but likely.
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static String | getOccurrenceIndicator(int cardinality) - Get the occurence indicator representing the cardinality
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static int | multiply(int c1, int c2) - Multiply two cardinalities
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static boolean | subsumes(int c1, int c2) - Test if one cardinality subsumes another.
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static int | sum(int c1, int c2) - Add two cardinalities
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static String | toString(int cardinality) - Display the cardinality as a string
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static int | union(int c1, int c2) - Form the union of two cardinalities.
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allowsMany
public static boolean allowsMany(int cardinality)
Determine whether multiple occurrences are allowed
cardinality
- the cardinality of a sequence
- true if the cardinality allows the sequence to contain more than one item
allowsZero
public static boolean allowsZero(int cardinality)
Determine whether empty sequence is allowed
cardinality
- the cardinality of a sequence
- true if the cardinality allows the sequence to be empty
expectsMany
public static boolean expectsMany(Expression expression)
Determine whether multiple occurrences are not only allowed, but likely.
This returns false for an expression that is the atomization of a singleton
node, since in that case it's quite unusual for the typed value to be a
non-singleton sequence.
expression
- an expression
- true if multiple occurrences are not only allowed, but likely. Return
false if multiple occurrences are unlikely, even though they might be allowed.
This is typically the case for the atomized sequence that is obtained by atomizing
a singleton node.
getOccurrenceIndicator
public static String getOccurrenceIndicator(int cardinality)
Get the occurence indicator representing the cardinality
cardinality
- the cardinality value
- the occurrence indicator, for example "*", "+", "?", "".
multiply
public static int multiply(int c1,
int c2)
Multiply two cardinalities
c1
- the first cardinalityc2
- the second cardinality
- the product of the cardinalities, that is, the cardinality of the sequence
"for $x in S1 return S2", where c1 is the cardinality of S1 and c2 is the cardinality of S2
subsumes
public static boolean subsumes(int c1,
int c2)
Test if one cardinality subsumes another. Cardinality c1 subsumes c2 if every option permitted
by c2 is also permitted by c1.
c1
- a cardinalityc2
- another cardinality
- true if if every option permitted
by c2 is also permitted by c1.
sum
public static int sum(int c1,
int c2)
Add two cardinalities
c1
- the first cardinalityc2
- the second cardinality
- the cardinality of a sequence formed by concatenating the sequences whose cardinalities
are c1 and c2
toString
public static String toString(int cardinality)
Display the cardinality as a string
cardinality
- the cardinality value to be displayed
- the representation as a string, for example "zero or one", "zero or more"
union
public static int union(int c1,
int c2)
Form the union of two cardinalities. The cardinality of the expression "if (c) then e1 else e2"
is the union of the cardinalities of e1 and e2.
c1
- a cardinalityc2
- another cardinality
- the cardinality that allows both c1 and c2