org.apache.calcite.interpreter

Class Interpreter.Compiler

java.lang.Object

org.apache.calcite.rel.RelVisitor

org.apache.calcite.interpreter.Interpreter.Compiler

All Implemented Interfaces:

ReflectiveVisitor

Direct Known Subclasses:

Nodes.CoreCompiler

Enclosing class:

Interpreter

public static class Interpreter.Compiler
extends RelVisitor
implements ReflectiveVisitor

Walks over a tree of RelNode and, for each, creates a Node that can be executed in the interpreter.

The compiler looks for methods of the form "visit(XxxRel)". A "visit" method must create an appropriate Node and put it into the node field.

If you wish to handle more kinds of relational expressions, add extra "visit" methods in this or a sub-class, and they will be found and called via reflection.

Field Summary

Fields

Modifier and Type	Field and Description
protected Interpreter	interpreter
protected Node	node
protected RelNode	rel
protected RelNode	rootRel

Method Summary

Methods

Modifier and Type	Method and Description
void	rewrite(RelNode r) Fallback rewrite method.
void	visit(RelNode p, int ordinal, RelNode parent) Visits a node during a traversal.
RelNode	visitRoot(RelNode p)

Methods inherited from class org.apache.calcite.rel.RelVisitor

go, replaceRoot

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

interpreter

protected final Interpreter interpreter

rootRel

protected RelNode rootRel

rel

protected RelNode rel

node

protected Node node

Method Detail

visitRoot

public RelNode visitRoot(RelNode p)

visit

public void visit(RelNode p,
         int ordinal,
         RelNode parent)

Description copied from class: RelVisitor

Visits a node during a traversal.

Overrides:

visit in class RelVisitor

Parameters:

p - Node to visit

ordinal - Ordinal of node within its parent

parent - Parent of the node, or null if it is the root of the traversal

rewrite

public void rewrite(RelNode r)

Fallback rewrite method.

Overriding methods (each with a different sub-class of RelNode as its argument type) sets the rel field if intends to rewrite.