com.facebook.presto.sql.tree

Class BindExpression

java.lang.Object

com.facebook.presto.sql.tree.Node

com.facebook.presto.sql.tree.Expression

com.facebook.presto.sql.tree.BindExpression

public class BindExpression
extends Expression

"$INTERNAL$BIND"(value, targetFunction)

When invoked, the returned function inserts the given value as the leading argument to the targetFunction. The other arguments are passed unchanged.

Bind is fundamentally first class, just like function applications. It requires special treatment from the type system. There is no way to write out the type of `bind`. The return type of `bind` is function. Its type looks somewhat like:

• X, (X) -> Y => () -> Y
• X1, (X1, X2) -> Y => (X2) -> Y
• X1, (X1, X2, X3) -> Y => (X2, X3) -> Y
• X1, (X1, X2, X3, X4) -> Y => (X2, X3, X4) -> Y
• ...

Lambda capturing is implemented through desugaring in Presto. This expression facilitates desugaring.

Constructor Summary

Constructors

Constructor and Description
BindExpression(List<Expression> values, Expression function)
BindExpression(NodeLocation location, List<Expression> values, Expression function)

Method Summary

Modifier and Type	Method and Description
<R,C> R	accept(AstVisitor<R,C> visitor, C context) Accessible for AstVisitor, use AstVisitor.process(Node, Object) instead.
boolean	equals(Object o)
List<Node>	getChildren()
Expression	getFunction()
List<Expression>	getValues()
int	hashCode()

Methods inherited from class com.facebook.presto.sql.tree.Expression

toString

Methods inherited from class com.facebook.presto.sql.tree.Node

getLocation

Methods inherited from class java.lang.Object

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

Constructor Detail

BindExpression

public BindExpression(List<Expression> values,
                      Expression function)

BindExpression

public BindExpression(NodeLocation location,
                      List<Expression> values,
                      Expression function)

Method Detail

getValues

public List<Expression> getValues()

getFunction

public Expression getFunction()

accept

public <R,C> R accept(AstVisitor<R,C> visitor,
                      C context)

Description copied from class: Expression

Accessible for AstVisitor, use AstVisitor.process(Node, Object) instead.

Overrides:

accept in class Expression

getChildren

public List<Node> getChildren()

Specified by:

getChildren in class Node

equals

public boolean equals(Object o)

Specified by:

equals in class Node

hashCode

public int hashCode()

Specified by:

hashCode in class Node