/*
* 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.
*/
/*
* ForeignValueNode.java
* Created: 4-Apr-2003
* By: David Mosimann
*/
package org.openquark.cal.valuenode;
import org.openquark.cal.compiler.DataConstructor;
import org.openquark.cal.compiler.SourceModel;
import org.openquark.cal.compiler.SourceModelUtilities;
import org.openquark.cal.compiler.TypeConsApp;
import org.openquark.cal.compiler.TypeConstructor;
import org.openquark.cal.compiler.TypeExpr;
import org.openquark.cal.compiler.io.InputPolicy;
import org.openquark.cal.compiler.io.OutputPolicy;
/**
* A value node designed to hold onto foreign values. The foreign values are held onto by an Object reference
* which can be cast to the appropriate Java object by users of this class.
*/
public final class ForeignValueNode extends OpaqueValueNode {
/**
* A custom ValueNodeProvider for the ForeignValueNode.
* @author Frank Worsley
*/
public static class ForeignValueNodeProvider extends ValueNodeProvider<ForeignValueNode> {
public ForeignValueNodeProvider(ValueNodeBuilderHelper builderHelper) {
super(builderHelper);
}
/**
* @see org.openquark.cal.valuenode.ValueNodeProvider#getValueNodeClass()
*/
@Override
public Class<ForeignValueNode> getValueNodeClass() {
return ForeignValueNode.class;
}
/**
* @see org.openquark.cal.valuenode.ValueNodeProvider#isSpecialLiteralizedValueNode()
*/
@Override
public boolean isSpecialLiteralizedValueNode() {
return false;
}
/**
* {@inheritDoc}
*/
@Override
public ForeignValueNode getNodeInstance(Object value, DataConstructor dataConstructor, TypeExpr typeExpr) {
// Check for handleability.
TypeConsApp typeConsApp = typeExpr.rootTypeConsApp();
TypeConstructor typeCons = typeConsApp != null ? getPerspective().getTypeConstructor(typeConsApp.getName())
: null;
if (typeCons == null || typeCons.getForeignTypeInfo() == null) {
return null;
}
return new ForeignValueNode(value, typeExpr);
}
}
/**
* ForeignValueNode constructor.
* @param foreignValue the value of this value node.
* @param typeExprParam the type expression of this value node. Must be a foreign type.
*/
public ForeignValueNode(Object foreignValue, TypeExpr typeExprParam) {
super(foreignValue, typeExprParam);
TypeConsApp typeConsApp = typeExprParam.rootTypeConsApp();
if (typeConsApp == null || !typeConsApp.usesForeignType()) {
throw new IllegalArgumentException("type expression is not a foreign type: " + typeExprParam);
}
}
/**
* Returns the source model representation of the expression represented by
* this ValueNode.
*
* @return SourceModel.Expr
* @throws UnsupportedOperationException
* foreign values don't have CAL textual representations as
* literals
*/
@Override
public SourceModel.Expr getCALSourceModel() {
SourceModel.Expr expr =
SourceModelUtilities.TextParsing.parseExprIntoSourceModel(String.valueOf(getValue()));
if (expr == null) {
// The string representation of the foreign value is not parsable as CAL
// text, so for the purpose of allowing comparisons of such values by
// ValueNode.sameValue(), we return the string representation of
// the foreign value wrapped in a Prelude.error call. Because
// the implementation of ValueNode.sameValue() implements equality comparison
// by comparing the source text of the two value nodes in question,
// by returning the specifically crafted call to error, we preserve
// the intended semantics of the method for foreign value nodes.
expr = SourceModel.Expr.makeErrorCall("Foreign value: '" + String.valueOf(getValue()) + "'");
}
return expr;
//todoBI this should really be an unsupported operation, but it crashes the GemCutter otherwise when
//running a gem with foreign arguments.
//throw new UnsupportedOperationException("foreign values don't have CAL textual representations as literals");
}
/**
* Makes a copy of this ValueNode, but with another TypeExpr instance (of the same type).
* The foreign object is shared so both value nodes will refer to the same foreign object
* @param newTypeExpr the new type of the copied node.
* @return ValueNode
*/
@Override
public ForeignValueNode copyValueNode(TypeExpr newTypeExpr) {
checkCopyType(newTypeExpr);
return new ForeignValueNode(getValue(), newTypeExpr);
}
/**
* Returns the display text representation of the expression. Since we can't say much about a foreign
* type we simply return String.valueOf() on the value represented by this ValueNode.
* @return String
*/
@Override
public String getTextValue() {
return String.valueOf(getValue());
}
/**
* Return an array of objects which are the values needed by the marshaler
* described by 'getInputPolicy()'.
* @return - an array of Java objects corresponding to the value represented by a value node instance.
*/
@Override
public Object[] getInputJavaValues() {
throw new UnsupportedOperationException();
}
/**
* Return an input policy which describes how to marshal a value represented
* by a value node from Java to CAL.
* @return - the input policy associated with ValueNode instance.
*/
@Override
public InputPolicy getInputPolicy() {
throw new UnsupportedOperationException();
}
/**
* Return an output policy which describes how to marshal a value represented
* by a value node from CAL to Java.
* @return - the output policy associated with the ValueNode instance.
*/
@Override
public OutputPolicy getOutputPolicy() {
return OutputPolicy.DEFAULT_OUTPUT_POLICY;
}
}