/*
* 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.
*/
/*
* LocalFunctionIdentifier.java
* Creation date: (Mar 10, 2006)
* By: James Wright
*/
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;
/**
* Represents the name of a local function, disambiguated by index within
* a toplevel function.
* <p>
* The index is constructed by a pre-order traversal of a toplevel function's
* local definitions. ie, we process all local function names in a let expression,
* then we recursively process each local function in order.
* So, for example, the following code:
* <pre>
* toplevelFunction =
* let
* foo =
* let
* foo = 10;
* bar = 20;
* in
* foo + bar;
*
* bar =
* let
* foo = 20;
* bar = 25;
* in
* foo + bar;
* in
* foo + bar;
* </pre>
* produces the following LocalFunctionIdentifiers:
* <pre>
* toplevelFunction =
* let
* toplevelFunction@foo@0 =
* let
* toplevelFunction@foo@1 = 10;
* toplevelFunction@bar@1 = 20;
* in
* toplevelFunction@foo@1 + toplevelFunction@bar@1;
*
* toplevelFunction@bar@0 =
* let
* toplevelFunction@foo@2 = 20;
* toplevelFunction@bar@2 = 25;
* in
* toplevelFunction@foo@2 + toplevelFunction@bar@2;
* in
* toplevelFunction@foo@0 + toplevelFunction@foo@0;
* </pre>
* @author James Wright
*/
public final class LocalFunctionIdentifier implements Comparable<LocalFunctionIdentifier> {
private static final int serializationSchema = 0;
/** Name of the toplevel function in which this local function occurs. */
private final QualifiedName toplevelFunctionName;
/** Name of the local function */
private final String localFunctionName;
/**
* 0-based index of local functions with this name in the current toplevel
* function. This is nearly always zero, because very few toplevel functions
* contain local functions that have the same names as each other.
*/
private final int index;
/**
* @param toplevelFunctionName QualifiedName of the toplevel function that the local function is defined within
* @param localFunctionName String name of the local function
* @param index pre-order index of the local function (see class-level comment for details)
*/
LocalFunctionIdentifier(QualifiedName toplevelFunctionName, String localFunctionName, int index) {
if(toplevelFunctionName == null || localFunctionName == null) {
throw new NullPointerException("no null arguments allowed for LocalFunctionIdentifier's constructor");
}
if(index < 0) {
throw new IllegalArgumentException("index must be >= 0");
}
this.toplevelFunctionName = toplevelFunctionName;
this.localFunctionName = localFunctionName;
this.index = index;
}
/** @return QualifiedName of the toplevel function that the local function was declared in */
public QualifiedName getToplevelFunctionName() {
return toplevelFunctionName;
}
/** @return name of the local function */
public String getLocalFunctionName() {
return localFunctionName;
}
/** @return pre-order index of the local function (details on this index are available in LocalFunctionIdentifier's class comment) */
public int getIndex() {
return index;
}
/** {@inheritDoc} */
@Override
public String toString() {
return toplevelFunctionName + "@" + localFunctionName + "@" + index;
}
/** {@inheritDoc} */
@Override
public int hashCode() {
return toString().hashCode();
}
/** {@inheritDoc} */
public int compareTo(LocalFunctionIdentifier other) {
int topLevelRelationship = toplevelFunctionName.compareTo(other.toplevelFunctionName);
if(topLevelRelationship != 0) {
return topLevelRelationship;
}
int localNameRelationship = localFunctionName.compareTo(other.localFunctionName);
if(localNameRelationship != 0) {
return localNameRelationship;
}
if(index < other.index) {
return -1;
}
if(index > other.index) {
return 1;
}
return 0;
}
/** {@inheritDoc} */
@Override
public boolean equals(Object otherObj) {
if(!(otherObj instanceof LocalFunctionIdentifier)) {
return false;
}
return compareTo((LocalFunctionIdentifier)otherObj) == 0;
}
/**
* Write this instance of LocalFunctionIdentifier to the RecordOutputStream.
* @param s
* @throws IOException
*/
final void write (RecordOutputStream s) throws IOException {
s.startRecord(ModuleSerializationTags.LOCAL_FUNCTION_IDENTIFIER, serializationSchema);
s.writeIntCompressed(index);
s.writeUTF(localFunctionName);
s.writeQualifiedName(toplevelFunctionName);
s.endRecord();
}
/**
* Load an instance of LocalFunctionIdentifier from the RecordInputStream.
* Read position will be before the record header.
* @param s
* @param moduleName String name of the module that we are reading the identifier for
* @param msgLogger the logger to which to log deserialization messages.
* @return an instance of LocalFunction, or null if there was a problem resolving classes.
* @throws IOException
*/
static final LocalFunctionIdentifier load (RecordInputStream s, ModuleName moduleName, CompilerMessageLogger msgLogger) throws IOException {
int nErrorsBeforeLoad = msgLogger.getNErrors();
try {
// Look for Record header.
RecordHeaderInfo rhi = s.findRecord(ModuleSerializationTags.LOCAL_FUNCTION_IDENTIFIER);
if (rhi == null) {
throw new IOException("Unable to find LocalFunction record header.");
}
DeserializationHelper.checkSerializationSchema(rhi.getSchema(), serializationSchema, moduleName, "LocalFunction", msgLogger);
int index = s.readIntCompressed();
String localFunctionName = s.readUTF();
QualifiedName toplevelFunctionName = s.readQualifiedName();
s.skipRestOfRecord();
// Check if state would be inconsistent by looking for logger errors.
if (msgLogger.getNErrors() > nErrorsBeforeLoad) {
return null;
}
return new LocalFunctionIdentifier(toplevelFunctionName, localFunctionName, index);
} catch(IOException e) {
throw new IOException("Error loading LocalFunctionIdentifier: " + e.getLocalizedMessage());
}
}
}