org.apache.calcite.sql

Class SqlNodeList

java.lang.Object

org.apache.calcite.sql.SqlNode

org.apache.calcite.sql.SqlNodeList

All Implemented Interfaces:

Cloneable, Iterable<SqlNode>

public class SqlNodeList
extends SqlNode
implements Iterable<SqlNode>

A SqlNodeList is a list of SqlNodes. It is also a SqlNode, so may appear in a parse tree.

Field Summary

Fields

Modifier and Type	Field and Description
static SqlNodeList	EMPTY An immutable, empty SqlNodeList.

Fields inherited from class org.apache.calcite.sql.SqlNode

EMPTY_ARRAY, pos

Constructor Summary

Constructors

Constructor and Description
SqlNodeList(Collection<? extends SqlNode> collection, SqlParserPos pos) Creates a SqlNodeList containing the nodes in list.
SqlNodeList(SqlParserPos pos) Creates an empty SqlNodeList.

Method Summary

Methods

Modifier and Type	Method and Description
<R> R	accept(SqlVisitor<R> visitor) Accepts a generic visitor.
void	add(SqlNode node)
SqlNodeList	clone(SqlParserPos pos) Clones a SqlNode with a different position.
boolean	equalsDeep(SqlNode node, boolean fail) Returns whether this node is structurally equivalent to another node.
SqlNode	get(int n)
List<SqlNode>	getList()
static boolean	isEmptyList(SqlNode node)
Iterator<SqlNode>	iterator()
SqlNode	set(int n, SqlNode node)
int	size()
SqlNode[]	toArray()
void	unparse(SqlWriter writer, int leftPrec, int rightPrec) Writes a SQL representation of this node to a writer.
void	validate(SqlValidator validator, SqlValidatorScope scope) Validates this node.
void	validateExpr(SqlValidator validator, SqlValidatorScope scope) Validates this node in an expression context.

Methods inherited from class org.apache.calcite.sql.SqlNode

clone, cloneArray, equalDeep, equalDeep, findValidOptions, getKind, getMonotonicity, getParserPosition, isA, toSqlString, toSqlString, toString

Methods inherited from class java.lang.Object

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

Field Detail

EMPTY

public static final SqlNodeList EMPTY

An immutable, empty SqlNodeList.

Constructor Detail

SqlNodeList

public SqlNodeList(SqlParserPos pos)

Creates an empty SqlNodeList.

SqlNodeList

public SqlNodeList(Collection<? extends SqlNode> collection,
           SqlParserPos pos)

Creates a SqlNodeList containing the nodes in list. The list is copied, but the nodes in it are not.

Method Detail

iterator

public Iterator<SqlNode> iterator()

Specified by:

iterator in interface Iterable<SqlNode>

getList

public List<SqlNode> getList()

add

public void add(SqlNode node)

clone

public SqlNodeList clone(SqlParserPos pos)

Description copied from class: SqlNode

Clones a SqlNode with a different position.

Overrides:

clone in class SqlNode

get

public SqlNode get(int n)

set

public SqlNode set(int n,
          SqlNode node)

size

public int size()

unparse

public void unparse(SqlWriter writer,
           int leftPrec,
           int rightPrec)

Description copied from class: SqlNode

Writes a SQL representation of this node to a writer.

The leftPrec and rightPrec parameters give us enough context to decide whether we need to enclose the expression in parentheses. For example, we need parentheses around "2 + 3" if preceded by "5 *". This is because the precedence of the "*" operator is greater than the precedence of the "+" operator.

The algorithm handles left- and right-associative operators by giving them slightly different left- and right-precedence.

If SqlWriter.isAlwaysUseParentheses() is true, we use parentheses even when they are not required by the precedence rules.

For the details of this algorithm, see SqlCall.unparse(org.apache.calcite.sql.SqlWriter, int, int).

Specified by:

unparse in class SqlNode

Parameters:

writer - Target writer

leftPrec - The precedence of the SqlNode immediately preceding this node in a depth-first scan of the parse tree

rightPrec - The precedence of the SqlNode immediately

validate

public void validate(SqlValidator validator,
            SqlValidatorScope scope)

Description copied from class: SqlNode

Validates this node.

The typical implementation of this method will make a callback to the validator appropriate to the node type and context. The validator has methods such as SqlValidator.validateLiteral(org.apache.calcite.sql.SqlLiteral) for these purposes.

Specified by:

validate in class SqlNode

scope - Validator

accept

public <R> R accept(SqlVisitor<R> visitor)

Description copied from class: SqlNode

Accepts a generic visitor.

Implementations of this method in subtypes simply call the appropriate visit method on the visitor object.

The type parameter R must be consistent with the type parameter of the visitor.

Specified by:

accept in class SqlNode

equalsDeep

public boolean equalsDeep(SqlNode node,
                 boolean fail)

Description copied from class: SqlNode

Returns whether this node is structurally equivalent to another node. Some examples:

• 1 + 2 is structurally equivalent to 1 + 2
• 1 + 2 + 3 is structurally equivalent to (1 + 2) + 3, but not to 1 + (2 + 3), because the '+' operator is left-associative

Specified by:

equalsDeep in class SqlNode

toArray

public SqlNode[] toArray()

isEmptyList

public static boolean isEmptyList(SqlNode node)

validateExpr

public void validateExpr(SqlValidator validator,
                SqlValidatorScope scope)

Description copied from class: SqlNode

Validates this node in an expression context.

Usually, this method does much the same as SqlNode.validate(org.apache.calcite.sql.validate.SqlValidator, org.apache.calcite.sql.validate.SqlValidatorScope), but a SqlIdentifier can occur in expression and non-expression contexts.

Overrides:

validateExpr in class SqlNode