de.ipcon.db.oql

Class ParseTreeNode

java.lang.Object

de.ipcon.db.oql.ParseTreeNode

Direct Known Subclasses:

BinaryExpressionNode, ExplainNode, FromNode, LimitNode, ListNode, LiteralNode, OrderNode, ParameterNode, PathNode, PathPart, QueryExpressionNode, SelectNode, UnaryExpressionNode, WhereNode

public class ParseTreeNode
extends java.lang.Object

A Node in the Parse tree which is generated by the Parser as the tree representation of the OQL Query. Each node has a link back to the parent node (null for the root node), and a list of children. Each node contains the Token which represents that part of the tree. heavily inspired by the work of Nissim Karpenstein from Castor JDO.

Author:

Patric Bechtel

Constructor Summary

Constructors

Constructor and Description
ParseTreeNode()
ParseTreeNode(ParseTreeNode parent, Token token) Creates a new Node with supplied parent and token.
ParseTreeNode(Token token) Creates a new root Node with supplied token.

Method Summary

Modifier and Type	Method and Description
void	addChild(ParseTreeNode child) Adds a new node as a child of this node.
void	appendComments(java.lang.StringBuilder s)
void	appendDebugString(java.lang.StringBuilder s) appends a String representation of this node including it's children to the given StringBuilder
java.lang.String	debugString() returns a String representation of this node including it's children
ParseTreeNode	getChild(int index) Accessor method for individual children of this node.
int	getChildCount() Accessor method for the number of children of this node.
de.ipcon.db.oql.ExpressionResultType	getExpressionResultType()
int	getOperatorPrecedence()
ParseTreeNode	getParent() Accessor method for the parent of this node.
java.lang.Class<?>	getResultClass() Calculates the resulting Java class of this node, which is used if it is part of the select expression.
Token	getToken() Accessor method for the token.
ValueType	getType()
boolean	hasType()
boolean	isLeaf() Specifies whether this node is a leaf.
boolean	isRoot() Specifies whether this node is the root of a tree.
ParseTreeNode	removeChild(int index)
void	renderSQL(java.lang.StringBuilder s, java.lang.Object[] oqlArgs, java.util.List sqlArgs) Renders this node into a StringBuilder as SQL statement, copying arguments from oqlArgs to sqlArgs if needed.
void	setOwnType()
void	setParent(ParseTreeNode parent) Sets the parent of this node.
void	setToken(Token token) Changes the Token data in this node.
void	setType(CBOAttributeTypeI aType)
void	setType(java.lang.String typeName, SchemaI schema)
void	setType(ValueType type)
void	setTypeFromChildren()
void	setTypeFromParent(ValueType type)
java.lang.String	toString() returns a String representation of just this node.

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, wait, wait, wait

Constructor Detail

ParseTreeNode

public ParseTreeNode(ParseTreeNode parent,
                     Token token)

Creates a new Node with supplied parent and token.

Parameters:

parent - The parent of this node (null for root)

token - The token data in this node

ParseTreeNode

public ParseTreeNode(Token token)

Creates a new root Node with supplied token.

Parameters:

token - The token data in this node

ParseTreeNode

public ParseTreeNode()

Method Detail

toString

public java.lang.String toString()

returns a String representation of just this node.

Overrides:

toString in class java.lang.Object

debugString

public java.lang.String debugString()

returns a String representation of this node including it's children

appendDebugString

public void appendDebugString(java.lang.StringBuilder s)

appends a String representation of this node including it's children to the given StringBuilder

appendComments

public void appendComments(java.lang.StringBuilder s)

setParent

public void setParent(ParseTreeNode parent)

Sets the parent of this node.

Parameters:

parent - The new parent.

addChild

public void addChild(ParseTreeNode child)

Adds a new node as a child of this node. Changes the nodes parent to this.

Parameters:

child - The new child

removeChild

public ParseTreeNode removeChild(int index)

isRoot

public boolean isRoot()

Specifies whether this node is the root of a tree.

Returns:

True if the node does not have a parent, otherwise false.

isLeaf

public boolean isLeaf()

Specifies whether this node is a leaf.

Returns:

True if the node does not have any children, otherwise false.

getParent

public ParseTreeNode getParent()

Accessor method for the parent of this node.

Returns:

The parent of this node.

getChild

public ParseTreeNode getChild(int index)

Accessor method for individual children of this node.

Parameters:

index - the index of the child to retrieve.

Returns:

the index child of this node.

getChildCount

public int getChildCount()

Accessor method for the number of children of this node.

Returns:

the number of children of this node.

getToken

public Token getToken()

Accessor method for the token.

Returns:

The token which is the datum of this node.

setToken

public void setToken(Token token)

Changes the Token data in this node.

Parameters:

token - the Token data in this node.

renderSQL

public void renderSQL(java.lang.StringBuilder s,
                      java.lang.Object[] oqlArgs,
                      java.util.List sqlArgs)

Renders this node into a StringBuilder as SQL statement, copying arguments from oqlArgs to sqlArgs if needed.

getExpressionResultType

public de.ipcon.db.oql.ExpressionResultType getExpressionResultType()

getResultClass

public java.lang.Class<?> getResultClass()

Calculates the resulting Java class of this node, which is used if it is part of the select expression. It will return the default Java class of the current type or java.lang.Object if type is null.

Returns:

A non-null Java class of this node, possibly defaulting to java.lang.Object if the type is not known or not applicable.

setType

public void setType(ValueType type)

getType

public ValueType getType()

hasType

public boolean hasType()

setType

public void setType(java.lang.String typeName,
                    SchemaI schema)

setType

public void setType(CBOAttributeTypeI aType)

setOwnType

public void setOwnType()

setTypeFromChildren

public void setTypeFromChildren()

setTypeFromParent

public void setTypeFromParent(ValueType type)

getOperatorPrecedence

public int getOperatorPrecedence()