Package org.apache.cassandra.cql3.functions

Class AbstractFunction

java.lang.Object

org.apache.cassandra.cql3.functions.AbstractFunction

All Implemented Interfaces:

AssignmentTestable, Function

Direct Known Subclasses:

NativeFunction, UserFunction

public abstract class AbstractFunction
extends Object
implements Function

Base class for our native/hardcoded functions.

Nested Class Summary

Nested classes/interfaces inherited from interface org.apache.cassandra.cql3.AssignmentTestable

AssignmentTestable.TestResult

Field Summary

Fields

Modifier and Type	Field	Description
protected final List<AbstractType<?>>	argTypes
protected final FunctionName	name
protected final AbstractType<?>	returnType

Fields inherited from interface org.apache.cassandra.cql3.functions.Function

UNRESOLVED

Constructor Summary

Constructors

Modifier	Constructor	Description
protected	AbstractFunction(FunctionName name, List<AbstractType<?>> argTypes, AbstractType<?> returnType)

Method Summary

Modifier and Type	Method	Description
void	addFunctionsTo(List<Function> functions)
List<AbstractType<?>>	argTypes()
List<String>	argumentsList()
String	columnName(List<String> columnNames)	Returns the name of the function to use within a ResultSet.
String	elementKeyspace()
String	elementName()
boolean	equals(Object o)
AbstractType<?>	getCompatibleTypeIfKnown(String keyspace)
int	hashCode()
FunctionName	name()
boolean	referencesUserType(ByteBuffer name)
AbstractType<?>	returnType()
final AssignmentTestable.TestResult	testAssignment(String keyspace, ColumnSpecification receiver)
protected String	toCqlString(AbstractType<?> type)	Converts the specified type into its CQL representation.
String	toString()
boolean	typesMatch(List<AbstractType<?>> types)

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface org.apache.cassandra.cql3.functions.Function

compare, isAggregate, isNative, isPure, newArguments

Field Details

name

protected final FunctionName name

argTypes

protected final List<AbstractType<?>> argTypes

returnType

protected final AbstractType<?> returnType

Constructor Details

AbstractFunction

protected AbstractFunction(FunctionName name,
 List<AbstractType<?>> argTypes,
 AbstractType<?> returnType)

Method Details

name

public FunctionName name()

Specified by:

name in interface Function

argTypes

public List<AbstractType<?>> argTypes()

Specified by:

argTypes in interface Function

returnType

public AbstractType<?> returnType()

Specified by:

returnType in interface Function

argumentsList

public List<String> argumentsList()

equals

public boolean equals(Object o)

Overrides:

equals in class Object

addFunctionsTo

public void addFunctionsTo(List<Function> functions)

Specified by:

addFunctionsTo in interface Function

referencesUserType

public boolean referencesUserType(ByteBuffer name)

Specified by:

referencesUserType in interface Function

hashCode

public int hashCode()

Overrides:

hashCode in class Object

testAssignment

public final AssignmentTestable.TestResult testAssignment(String keyspace,
 ColumnSpecification receiver)

Specified by:

testAssignment in interface AssignmentTestable

Returns:

whether this object can be assigned to the provided receiver. We distinguish between 3 values: - EXACT_MATCH if this object is exactly of the type expected by the receiver - WEAKLY_ASSIGNABLE if this object is not exactly the expected type but is assignable nonetheless - NOT_ASSIGNABLE if it's not assignable Most caller should just call the isAssignable() method on the result, though functions have a use for testing "strong" equality to decide the most precise overload to pick when multiple could match.

getCompatibleTypeIfKnown

public AbstractType<?> getCompatibleTypeIfKnown(String keyspace)

Specified by:

getCompatibleTypeIfKnown in interface AssignmentTestable

Returns:

A data type that can represent this, or null if we can't determine that type. The returned type won't necessarely be the exact type, but one that is compatible with it.

toString

public String toString()

Overrides:

toString in class Object

elementKeyspace

public String elementKeyspace()

elementName

public String elementName()

toCqlString

protected String toCqlString(AbstractType<?> type)

Converts the specified type into its CQL representation.

For user function and aggregates tuples need to be handle in a special way as they are frozen by nature but the frozen keyword should not appear in their CQL definition.

Parameters:

type - the type

Returns:

the CQL representation of the specified type

columnName

public String columnName(List<String> columnNames)

Description copied from interface: Function

Returns the name of the function to use within a ResultSet.

Specified by:

columnName in interface Function

Parameters:

columnNames - the names of the columns used to call the function

Returns:

the name of the function to use within a ResultSet

typesMatch

public boolean typesMatch(List<AbstractType<?>> types)