/*
// $Id: //open/mondrian-release/3.2/src/main/mondrian/olap/Literal.java#1 $
// This software is subject to the terms of the Eclipse Public License v1.0
// Agreement, available at the following URL:
// http://www.eclipse.org/legal/epl-v10.html.
// Copyright (C) 1998-2002 Kana Software, Inc.
// Copyright (C) 2001-2009 Julian Hyde and others
// All Rights Reserved.
// You must accept the terms of that agreement to use this software.
//
// jhyde, 21 January, 1999
*/
package mondrian.olap;
import mondrian.olap.type.*;
import mondrian.calc.*;
import mondrian.calc.impl.ConstantCalc;
import mondrian.mdx.MdxVisitor;
import java.io.PrintWriter;
/**
* Represents a constant value, such as a string or number, in a parse tree.
*
* <p>Symbols, such as the <code>ASC</code> keyword in
* <code>Order([Store].Members, [Measures].[Unit Sales], ASC)</code>, are
* also represented as Literals.
*
* @version $Id: //open/mondrian-release/3.2/src/main/mondrian/olap/Literal.java#1 $
* @author jhyde
*/
public class Literal extends ExpBase {
// Data members.
public final int category;
private final Object o;
// Constants for commonly used literals.
public static final Literal nullValue = new Literal(Category.Null, null);
public static final Literal emptyString = new Literal("", false);
public static final Literal zero = new Literal(0);
public static final Literal one = new Literal(1);
public static final Literal negativeOne = new Literal(-1);
public static final Literal doubleZero = new Literal(0.0);
public static final Literal doubleOne = new Literal(1.0);
public static final Literal doubleNegativeOne = new Literal(-1.0);
/**
* Private constructor.
*
* <p>Use the creation methods {@link #createString(String)} etc.
*/
private Literal(int type, Object o) {
this.category = type;
this.o = o;
}
/**
* Creates a string literal.
* @see #createSymbol
*/
public static Literal createString(String s) {
return (s.equals(""))
? emptyString
: new Literal(s, false);
}
/**
* Creates a symbol.
* @see #createString
*/
public static Literal createSymbol(String s) {
return new Literal(s, true);
}
/**
* Creates a numeric literal.
*/
public static Literal create(Double d) {
double dv = d.doubleValue();
if (dv == 0.0) {
return doubleZero;
} else if (dv == 1.0) {
return doubleOne;
} else if (dv == -1.0) {
return doubleNegativeOne;
} else {
return new Literal(d);
}
}
/**
* Creates an integer literal.
*/
public static Literal create(Integer i) {
switch (i) {
case -1:
return negativeOne;
case 0:
return zero;
case 1:
return one;
default:
return new Literal(i);
}
}
private Literal(String s, boolean isSymbol) {
this.o = s;
this.category = isSymbol ? Category.Symbol : Category.String;
}
private Literal(Double d) {
this.o = d;
this.category = Category.Numeric;
}
private Literal(Integer i) {
this.o = i;
this.category = Category.Numeric;
}
public Literal clone() {
return this;
}
public void unparse(PrintWriter pw) {
switch (category) {
case Category.Symbol:
case Category.Numeric:
pw.print(o);
break;
case Category.String:
pw.print(Util.quoteForMdx((String) o));
break;
case Category.Null:
pw.print("NULL");
break;
default:
throw Util.newInternal("bad literal type " + category);
}
}
public int getCategory() {
return category;
}
public Type getType() {
switch (category) {
case Category.Symbol:
return new SymbolType();
case Category.Numeric:
return new NumericType();
case Category.String:
return new StringType();
case Category.Null:
return new NullType();
default:
throw Category.instance.badValue(category);
}
}
public Exp accept(Validator validator) {
return this;
}
public Calc accept(ExpCompiler compiler) {
return new ConstantCalc(getType(), o);
}
public Object accept(MdxVisitor visitor) {
return visitor.visit(this);
}
public Object getValue() {
return o;
}
public int getIntValue() {
if (o instanceof Number) {
return ((Number) o).intValue();
} else {
throw Util.newInternal("cannot convert " + o + " to int");
}
}
}
// End Literal.java