/*
* Copyright (c) 2007 BUSINESS OBJECTS SOFTWARE LIMITED
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* * Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
*
* * Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* * Neither the name of Business Objects nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/
/*
* CalValue.java
* Created: April 2, 2004
* By: Raymond Cypher
*/
package org.openquark.cal.runtime;
/**
* This is the base class used by CAL for values.
*
* @author RCypher
*/
public abstract class CalValue {
/**
* An enumeration for the underlying value type of an internal value.
*
* @author Joseph Wong
*/
public static enum DataType {
CHAR("char"),
BOOLEAN("boolean"),
BYTE("byte"),
SHORT("short"),
INT("int"),
LONG("long"),
FLOAT("float"),
DOUBLE("double"),
OBJECT("object"),
OTHER("other");
/** A display name for the type. */
private final String name;
/**
* Constructs an {@link CalValue.DataType}.
* @param name a display name for the type.
*/
private DataType(String name) {
this.name = name;
}
/**
* {@inheritDoc}
*/
@Override
public String toString() {
return name;
}
}
/**
* Warning: for debugging use only. Implementations must not modify this CalValue in any way.
* debug_getNChildren and debug_getChild provide an abstract way for traversing the value graph.
*
* See the implementation of DebugSupport.javaStackShowInternal to see the contract that implementers
* of this method must adhere to.
*
* @return the number of children of this node.
*/
public abstract int debug_getNChildren();
/**
* Warning: for debugging use only. Implementations must not modify this CalValue in any way.
* debug_getNChildren and debug_getChild provide an abstract way for traversing the value graph.
*
* See the implementation of DebugSupport.javaStackShowInternal to see the contract that implementers
* of this method must adhere to.
*
* @param childN the zero-based child number
* @return the child at the specified childN index. It is possible for this to be null
* when attempting to view an CalValue that is in the proces of being reduced.
*/
public abstract CalValue debug_getChild(int childN);
/**
* Warning: for debugging use only. Implementations must not modify this CalValue in any way.
*
* See the implementation of DebugSupport.javaStackShowInternal to see the contract that implementers
* of this method must adhere to.
*
* @return the start string for this node. Cannot be null.
*/
public abstract String debug_getNodeStartText();
/**
* Warning: for debugging use only. Implementations must not modify this CalValue in any way.
*
* See the implementation of DebugSupport.javaStackShowInternal to see the contract that implementers
* of this method must adhere to.
*
* @return the end string for this node. Cannot be null.
*/
public abstract String debug_getNodeEndText();
/**
* Warning: for debugging use only. Implementations must not modify this CalValue in any way.
*
* See the implementation of DebugSupport.javaStackShowInternal to see the contract that implementers
* of this method must adhere to.
*
* @param childN
* @return string immediately prior to any text for the child at index childN. Cannot be null.
*/
public abstract String debug_getChildPrefixText(int childN);
/**
* Warning: for debugging use only. Implementations must not modify this CalValue in any way.
*
* Returns true if this node is only an indirection to another node and thus behaves in all respects like that
* other node, masking its own identity. If Java supported memory overwrites, then instead of having indirection
* nodes we could directly update memory to change the type of a node.
*
* This method is mainly intended to support cross-machine debugging.
*
* @return true if this node is an indirection node.
*/
public abstract boolean debug_isIndirectionNode();
/**
* Returns the type of the underlying value associated with this CalValue.
*
* For subclasses that do not represent primitive data types, the value
* {@link CalValue.DataType#OTHER} should be returned.
*
* @return the type of the underlying value associated with this CalValue.
*/
public abstract DataType getDataType();
/**
* @return a string representation of this CalValue for debugging purposes. This representation
* is subject to change and should not be relied upon in production code. Does not do any
* evaluation or modify the CalValue in any way.
*/
@Override
public final String toString() {
return DebugSupport.showInternalGraph(this);
}
/**
* {@inheritDoc}
*/
@Override
public final boolean equals(Object other) {
//we need CalValue.equals() and hashCode to always be based on references so that the DebugSupport classes
//correctly deal with sharing.
//This is why CalValue.equals and hashCode are marked as final, delegating to Object's implementation.
return super.equals(other);
}
/**
* {@inheritDoc}
*/
@Override
public final int hashCode() {
//we need CalValue.equals() and hashCode to always be based on references so that the DebugSupport classes
//correctly deal with sharing.
//This is why CalValue.equals and hashCode are marked as final, delegating to Object's implementation.
return super.hashCode();
}
/**
* @return if this CalValue has type DataType.Object, and the underlying Object is in
* fact a CalValue, then return that CalValue, otherwise just return this value.
*/
public abstract CalValue internalUnwrapOpaque();
/**
* @return the MachineType in which this CalValue was created.
*/
public abstract MachineType debug_getMachineType();
}