org.teiid.query.sql.symbol

Class Function

java.lang.Object

org.teiid.query.sql.symbol.Function

All Implemented Interfaces:

Cloneable, LanguageObject, Expression

Direct Known Subclasses:

AggregateSymbol

public class Function
extends Object
implements Expression

Represents a function in a sql statement. A function is a type of expression. Functions have a name and some arguments (0..n). Each argument is also an expression. After resolution, a function should have a type and a function descriptor.

Nested Class Summary

Nested classes/interfaces inherited from interface org.teiid.query.sql.LanguageObject

LanguageObject.Util

Field Summary

Fields

Modifier and Type	Field and Description
protected Class<?>	type

Constructor Summary

Constructors

Constructor and Description
Function(String name, Expression[] args) Construct a function with function name and array of arguments.

Method Summary

Modifier and Type	Method and Description
void	acceptVisitor(LanguageVisitor visitor) Method for accepting a visitor.
Object	clone() Return a deep copy of this object.
boolean	equals(Object obj) Compare for equality
Expression	getArg(int index) Get argument at specified index
Expression[]	getArgs() Get function arguments
FunctionDescriptor	getFunctionDescriptor() Get the function descriptor that this function resolves to.
String	getName() Get name of function
Class<?>	getType() Get type of function, if known
int	hashCode() Compute hash code for the object - based on name and hashcode of first arg (if there is one)
void	insertConversion(int index, FunctionDescriptor functionDescriptor) Insert a conversion function at specified index.
boolean	isAggregate()
boolean	isEval()
boolean	isImplicit() Return true if this function is implicit and should not be shown in SQL representations
void	makeImplicit() Make this function implicit / hidden.
void	setArgs(Expression[] args) Set the function arguments - it is assumed that the args are not null.
void	setEval(boolean eval)
void	setFunctionDescriptor(FunctionDescriptor fd) Set the descriptor for this function.
void	setImplicit(boolean implicit)
void	setName(String name)
void	setType(Class<?> type) Set type of function
String	toString() Return string representation of the function.

Methods inherited from class java.lang.Object

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

Field Detail

type

protected Class<?> type

Constructor Detail

Function

public Function(String name,
                Expression[] args)

Construct a function with function name and array of arguments. For functions that have no args, pass empty array, not null.

Parameters:

name - Name of function

args - Function arguments

Method Detail

getName

public String getName()

Get name of function

Returns:

Name of function

setName

public void setName(String name)

getArgs

public Expression[] getArgs()

Get function arguments

Returns:

Get function arguments

getArg

public Expression getArg(int index)

Get argument at specified index

Parameters:

index - Index of argument

setArgs

public void setArgs(Expression[] args)

Set the function arguments - it is assumed that the args are not null. For no arg functions, use an empty Expression array.

Parameters:

args - Function arguments

makeImplicit

public void makeImplicit()

Make this function implicit / hidden.

isImplicit

public boolean isImplicit()

Return true if this function is implicit and should not be shown in SQL representations

Returns:

True if implicit

setImplicit

public void setImplicit(boolean implicit)

insertConversion

public void insertConversion(int index,
                             FunctionDescriptor functionDescriptor)

Insert a conversion function at specified index. This is a convenience method to insert a conversion into the function tree.

Parameters:

index - Argument index to insert conversion function at

functionDescriptor - Conversion function descriptor

getType

public Class<?> getType()

Get type of function, if known

Specified by:

getType in interface Expression

Returns:

Java class name of type, or null if not yet resolved

setType

public void setType(Class<?> type)

Set type of function

Parameters:

type - New type

getFunctionDescriptor

public FunctionDescriptor getFunctionDescriptor()

Get the function descriptor that this function resolves to.

Returns:

Descriptor or null if resolution has not yet occurred

setFunctionDescriptor

public void setFunctionDescriptor(FunctionDescriptor fd)

Set the descriptor for this function.

Parameters:

fd - Function descriptor

acceptVisitor

public void acceptVisitor(LanguageVisitor visitor)

Description copied from interface: LanguageObject

Method for accepting a visitor. It is the responsibility of the language object to call back on the visitor.

Specified by:

acceptVisitor in interface LanguageObject

Parameters:

visitor - Visitor being used

equals

public boolean equals(Object obj)

Compare for equality

Overrides:

equals in class Object

Parameters:

obj - Other object to compare

Returns:

Return true if objects are equivalent

hashCode

public int hashCode()

Compute hash code for the object - based on name and hashcode of first arg (if there is one)

Overrides:

hashCode in class Object

Returns:

Hash code

clone

public Object clone()

Return a deep copy of this object.

Specified by:

clone in interface LanguageObject

Overrides:

clone in class Object

Returns:

Deep copy of the object

isAggregate

public boolean isAggregate()

toString

public String toString()

Return string representation of the function.

Overrides:

toString in class Object

Returns:

String representation

isEval

public boolean isEval()

setEval

public void setEval(boolean eval)