mondrian.olap
Class Literal

java.lang.Object
  mondrian.olap.QueryPart
      mondrian.olap.ExpBase
          mondrian.olap.Literal

All Implemented Interfaces:

Exp, Walkable

public class Literal
extends ExpBase

Represents a constant value, such as a string or number, in a parse tree.

Symbols, such as the ASC keyword in Order([Store].Members, [Measures].[Unit Sales], ASC), are also represented as Literals.

Author:

jhyde, 21 January, 1999

Field Summary

int	category
static Literal	doubleNegativeOne
static Literal	doubleOne
static Literal	doubleZero
static Literal	emptyString
static Literal	negativeOne
static Literal	nullValue
static Literal	one
static Literal	zero

Method Summary

Calc	accept(ExpCompiler compiler) Converts this expression into an a tree of expressions which can be efficiently evaluated.
Object	accept(MdxVisitor visitor) Accepts a visitor to this Exp.
Exp	accept(Validator validator) Validates this expression.
Literal	clone()
static Literal	create(BigDecimal d) Creates a numeric literal.
static Literal	create(Double d) Deprecated. Use create(java.math.BigDecimal)
static Literal	create(Integer i) Deprecated. Use create(java.math.BigDecimal)
static Literal	createString(String s) Creates a string literal.
static Literal	createSymbol(String s) Creates a symbol.
int	getCategory() Returns the Category of the expression.
int	getIntValue()
Type	getType() Returns the type of this expression.
Object	getValue()
void	unparse(PrintWriter pw) Writes a string representation of this parse tree node to the given writer.

Methods inherited from class mondrian.olap.ExpBase

cloneArray, getTypes, unparseList

Methods inherited from class mondrian.olap.QueryPart

explain, getChildren

Methods inherited from class java.lang.Object

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

Field Detail

category

public final int category

nullValue

public static final Literal nullValue

emptyString

public static final Literal emptyString

zero

public static final Literal zero

one

public static final Literal one

negativeOne

public static final Literal negativeOne

doubleZero

public static final Literal doubleZero

doubleOne

public static final Literal doubleOne

doubleNegativeOne

public static final Literal doubleNegativeOne

Method Detail

createString

public static Literal createString(String s)

Creates a string literal.

See Also:

createSymbol(java.lang.String)

createSymbol

public static Literal createSymbol(String s)

Creates a symbol.

See Also:

createString(java.lang.String)

create

public static Literal create(Double d)

Deprecated. Use create(java.math.BigDecimal)

Creates a numeric literal.

create

public static Literal create(Integer i)

Deprecated. Use create(java.math.BigDecimal)

Creates an integer literal.

create

public static Literal create(BigDecimal d)

Creates a numeric literal.

Using a BigDecimal allows us to store the precise value that the user typed. We will have to fit the value into a native double or int later on, but parse time is not the time to be throwing away information.

clone

public Literal clone()

Specified by:

clone in interface Exp

Specified by:

clone in class ExpBase

unparse

public void unparse(PrintWriter pw)

Description copied from class: QueryPart

Writes a string representation of this parse tree node to the given writer.

Specified by:

unparse in interface Exp

Overrides:

unparse in class QueryPart

Parameters:

pw - writer

getCategory

public int getCategory()

Description copied from interface: Exp

Returns the Category of the expression.

getType

public Type getType()

Description copied from interface: Exp

Returns the type of this expression. Never null.

accept

public Exp accept(Validator validator)

Description copied from interface: Exp

Validates this expression. The validator acts in the role of 'visitor' (see Gang of Four 'visitor pattern'), and an expression in the role of 'visitee'.

Parameters:

validator - Validator contains validation context

Returns:

The validated expression; often but not always the same as this expression

accept

public Calc accept(ExpCompiler compiler)

Description copied from interface: Exp

Converts this expression into an a tree of expressions which can be efficiently evaluated.

Specified by:

accept in interface Exp

Overrides:

accept in class ExpBase

Returns:

A compiled expression

accept

public Object accept(MdxVisitor visitor)

Description copied from interface: Exp

Accepts a visitor to this Exp. The implementation should generally dispatches to the MdxVisitor.visit(mondrian.olap.Query) method appropriate to the type of expression.

Parameters:

visitor - Visitor

getValue

public Object getValue()

getIntValue

public int getIntValue()