/*
* 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.
*/
/*
* Scope.java
* Creation date: Dec 22, 2005.
* By: Joseph Wong
*/
package org.openquark.cal.compiler;
import java.io.IOException;
import org.openquark.cal.internal.serialization.ModuleSerializationTags;
import org.openquark.cal.internal.serialization.RecordInputStream;
import org.openquark.cal.internal.serialization.RecordOutputStream;
import org.openquark.cal.internal.serialization.RecordInputStream.RecordHeaderInfo;
/**
* Models the scope modifier in CAL. Currently allowed scopes are private, protected and public.
* entity scope enum pattern.
* Creation date: (6/4/01 1:12:46 PM)
* @author Bo Ilic
*/
public final class Scope implements Comparable<Scope> {
private static final int serializationSchema = 0;
private static final int PRIVATE_ORDINAL = 0;
private static final int PROTECTED_ORDINAL = 1;
private static final int PUBLIC_ORDINAL = 2;
private final String name;
private final int ordinal;
/**
* private entities are useable only within their module of definition.
*/
public static final Scope PRIVATE = new Scope("private", Scope.PRIVATE_ORDINAL);
/**
* protected entities are useable with their module of definition, as well as within friend modules.
*/
public static final Scope PROTECTED = new Scope("protected", Scope.PROTECTED_ORDINAL);
/**
* public entities are useable with their module of definition, as well as in modules importing
* the module defining the entity.
*/
public static final Scope PUBLIC = new Scope("public", Scope.PUBLIC_ORDINAL);
private Scope(String name, int ordinal) {
this.name = name;
this.ordinal = ordinal;
}
/**
* @return The CAL source form of the scope. Currently one of "private", "protected" or "public".
*/
@Override
public String toString() {
return name;
}
public boolean isPublic() {
return this == PUBLIC;
}
public boolean isProtected() {
return this == PROTECTED;
}
public boolean isPrivate() {
return this == PRIVATE;
}
@Override
public int hashCode() {
//note: it is not necessary to override equals, since Object.equals is correct and efficient for a type-safe enum pattern.
//however, overriding hashCode is efficient.
return ordinal;
}
/**
* The ordering is defined by PRIVATE < PROTECTED < PUBLIC.
* {@inheritDoc}
*/
public int compareTo(Scope other) {
int otherOrdinal = other.ordinal;
return ordinal < otherOrdinal ? -1 : (ordinal == otherOrdinal ? 0 : 1);
}
/**
* @return the most restrictive of the 2 scopes. i.e. the minimum of this scope and the other scope.
*/
Scope min(Scope other) {
if (this.compareTo(other) <= 0) {
return this;
} else {
return other;
}
}
/**
* Write this Scope instance to the RecordOutputStream.
* @param s
* @throws IOException
*/
final void write (RecordOutputStream s) throws IOException {
s.startRecord(ModuleSerializationTags.SCOPE, serializationSchema);
s.writeByte(ordinal);
s.endRecord();
}
/**
* Load a Scope instance from the record input stream.
* The read position is after the record header.
* @param s
* @param moduleName the name of the module being loaded
* @param msgLogger the logger to which to log deserialization messages.
* @return a Scope instance.
* @throws IOException
*/
static final Scope load (RecordInputStream s, ModuleName moduleName, CompilerMessageLogger msgLogger) throws IOException {
RecordHeaderInfo rhi = s.findRecord(ModuleSerializationTags.SCOPE);
if (rhi == null) {
throw new IOException ("Unable to find Scope record header.");
}
DeserializationHelper.checkSerializationSchema(rhi.getSchema(), serializationSchema, moduleName, "Scope", msgLogger);
byte ordinalValue = s.readByte();
s.skipRestOfRecord();
switch (ordinalValue)
{
case PRIVATE_ORDINAL:
return PRIVATE;
case PROTECTED_ORDINAL:
return PROTECTED;
case PUBLIC_ORDINAL:
return PUBLIC;
}
throw new IOException ("Unknown scope ordinal: " + ordinalValue);
}
}