Package org.apache.pinot.common.request.transform

Class TransformExpressionTree

java.lang.Object

org.apache.pinot.common.request.transform.TransformExpressionTree

public class TransformExpressionTree
extends Object

Class for representing expression trees for transforms.

• A TransformExpressionTree node has either transform function or a column name, or a literal.
• Leaf nodes either have column name or literal, whereas non-leaf nodes have transform function.
• Transform function is applied to its children.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	TransformExpressionTree.ExpressionType

Constructor Summary

Constructors

Constructor	Description
TransformExpressionTree(TransformExpressionTree.ExpressionType expressionType, String value, List<TransformExpressionTree> children)
TransformExpressionTree(AstNode root)

Method Summary

Modifier and Type	Method	Description
static TransformExpressionTree	compileToExpressionTree(String expression)
boolean	equals(Object obj)
List<TransformExpressionTree>	getChildren()	Returns the children of the node.
void	getColumns(Set<String> columns)	Add all columns to the passed in column set.
TransformExpressionTree.ExpressionType	getExpressionType()	Returns the expression type of the node, which can be one of the following: TransformExpressionTree.ExpressionType.FUNCTION TransformExpressionTree.ExpressionType.IDENTIFIER TransformExpressionTree.ExpressionType.LITERAL
static String	getStandardExpression(AstNode astNode)	Converts an AstNode into a standard expression.
String	getValue()	Returns the value of the node.
int	hashCode()
boolean	isColumn()	Returns if the tree represents a column name (ie no expression), false otherwise
boolean	isFunction()
boolean	isLiteral()
void	setValue(String value)	allows value to be set (needed to fix the case)
static String	standardizeExpression(String expression)	Compiles the expression and serializes it back to standard format.
String	toString()

Methods inherited from class java.lang.Object

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

Constructor Detail

TransformExpressionTree

public TransformExpressionTree(AstNode root)

TransformExpressionTree

public TransformExpressionTree(TransformExpressionTree.ExpressionType expressionType,
                               String value,
                               @Nullable
                               List<TransformExpressionTree> children)

Method Detail

compileToExpressionTree

public static TransformExpressionTree compileToExpressionTree(String expression)

standardizeExpression

public static String standardizeExpression(String expression)

Compiles the expression and serializes it back to standard format.

E.g. " foo\t ( bar ('a'\t ,foobar( b, 'c'\t, 123) ) ,d )\t" -> "foo(bar('a',foobar(b,'c','123')),d)"

The standard format expressions will be used in the broker response.

getStandardExpression

public static String getStandardExpression(AstNode astNode)

Converts an AstNode into a standard expression.

getExpressionType

public TransformExpressionTree.ExpressionType getExpressionType()

Returns the expression type of the node, which can be one of the following:

• TransformExpressionTree.ExpressionType.FUNCTION
• TransformExpressionTree.ExpressionType.IDENTIFIER
• TransformExpressionTree.ExpressionType.LITERAL

Returns:

Expression type

getValue

public String getValue()

Returns the value of the node.

Returns:

Function name for FUNCTION; column name for IDENTIFIER; string value for LITERAL

setValue

public void setValue(String value)

allows value to be set (needed to fix the case)

Parameters:

value -

getChildren

public List<TransformExpressionTree> getChildren()

Returns the children of the node.

Returns:

List of children

isColumn

public boolean isColumn()

Returns if the tree represents a column name (ie no expression), false otherwise

Returns:

True if tress represents column, false otherwise.

isFunction

public boolean isFunction()

isLiteral

public boolean isLiteral()

getColumns

public void getColumns(Set<String> columns)

Add all columns to the passed in column set.

Parameters:

columns - Output columns

hashCode

public int hashCode()

Overrides:

hashCode in class Object

equals

public boolean equals(Object obj)

Overrides:

equals in class Object

toString

public String toString()

Overrides:

toString in class Object