/*
* 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.
*/
/*
* RTZeroArityFunction.java
* Creation date: June 7, 2006
* By: Raymond Cypher
*/
package org.openquark.cal.internal.runtime.lecc;
import org.openquark.cal.runtime.CALExecutorException;
import org.openquark.cal.runtime.CalValue;
import org.openquark.cal.runtime.ErrorInfo;
/**
* This is the base class for zero arity functions.
* This is a separate class from RTSupercombinator because
* internally zero arity functions behave differently.
* This class derives from RTResultFunction because we want a
* given instance of a zero arity function to always return the
* same value. A non-zero arity function has no result associated
* with it, since it needs to be applied to some arguments to produce
* a value and the result is associated with the application.
* A zero arity function differs from a CAF (constant applicative form)
* in that each reference to a zero arity function produces a new
* instance of the function class. In contrast a CAF class has instances
* associated with execution contexts.
*/
public abstract class RTZeroArityFunction extends RTResultFunction {
/**
* Reduce this graph.
* @param ec
* @return the reduced graph.
* @throws CALExecutorException
*/
@Override
protected final RTValue reduce(RTExecutionContext ec) throws CALExecutorException {
// This is a reduction with no arguments
// Update and return result
if (result == null || result == this) {
setResult (f(null, ec));
}
return result;
}
/*
* (non-Javadoc)
* @see org.openquark.cal.internal.runtime.lecc.RTResultFunction#clearMembers()
*/
@Override
public final void clearMembers () {
// No members to clear in a CAF.
}
/*
* We override the various versions of apply() so that we can create instances of RTApplicationO
* instead of RTApplication. RTApplicationO knows that it is an oversaturated application and is
* able to perform a more efficient reduction by immediately reducing its left hand side.
*/
@Override
public final RTValue apply(RTValue arg1) {
return new RTApplicationO(this, arg1);
}
@Override
public final RTValue apply(RTValue arg1, RTValue arg2) {
return new RTApplicationO(new RTApplicationO(this, arg1), arg2);
}
@Override
public final RTValue apply(RTValue arg1, RTValue arg2, RTValue arg3) {
return new RTApplicationO (new RTApplicationO (new RTApplicationO(this, arg1), arg2), arg3);
}
@Override
public final RTValue apply(RTValue arg1, RTValue arg2, RTValue arg3, RTValue arg4) {
return new RTApplicationO(new RTApplicationO (new RTApplicationO (new RTApplicationO(this, arg1), arg2), arg3), arg4);
}
/**
* Retrieve the module name for this CAL entity.
* @return the name of the module containing the corresponding CAL entity
*/
abstract public String getModuleName ();
/**
* Retrieve the unqualified name for this CAL entity.
* @return the unqualified name of the corresponding CAL entity.
*/
abstract public String getUnqualifiedName ();
/**
* While this function could simply be implemented in terms of the abstract functions
* getModuleName() and getUnqualifiedName() (i.e. return new StringBuilder(getModuleName()).append('.').append(getUnqualifiedName()).toString();)
* it is made abstract so that generated code can return a literal string value.
* This is more optimial than building up the qualified name string each time.
* @return the fully qualified name as a String e.g. "Cal.Core.Prelude.Left", "Cal.Core.Prelude.Cons".
*/
abstract public String getQualifiedName();
/**
* {@inheritDoc}
*/
@Override
public final int debug_getNChildren() {
if (result != null) {
return super.debug_getNChildren();
}
return 0;
}
/**
* {@inheritDoc}
*/
@Override
public final CalValue debug_getChild(int childN) {
if (result != null) {
return super.debug_getChild(childN);
}
throw new IndexOutOfBoundsException();
}
/**
* {@inheritDoc}
*/
@Override
public final String debug_getNodeStartText() {
if (result != null) {
return super.debug_getNodeStartText();
}
return getQualifiedName();
}
/**
* {@inheritDoc}
*/
@Override
public final String debug_getNodeEndText() {
if (result != null) {
return super.debug_getNodeEndText();
}
return "";
}
/**
* {@inheritDoc}
*/
@Override
public final String debug_getChildPrefixText(int childN) {
if (result != null) {
return super.debug_getChildPrefixText(childN);
}
throw new IndexOutOfBoundsException();
}
/**
* A helper function used to generate the start of the function tracing text.
* This will display the thread name, if tracing thread name is enabled, followed by
* displaying the name of the function being evaluated.
*
* @param $ec
* @return StringBuilder
*/
protected final StringBuilder generateBeginningTraceText(RTExecutionContext $ec) {
if (result != null) {
throw new IllegalStateException();
}
StringBuilder $sb;
if ($ec.traceShowsThreadName()) {
$sb = new StringBuilder(Thread.currentThread().getName()).append("> ");
} else {
$sb = new StringBuilder();
}
return $sb.append(getQualifiedName());
}
/**
* Function called when a switch statement in the generated code
* encounters an invalid index. (i.e. an index which doesn't correspond
* to any data constructor etc.)
* @param errorInfo
* @return nothing since this will always throw an exception.
*/
protected final RTValue badSwitchIndex (ErrorInfo errorInfo) {
return RTValue.badValue (errorInfo, "Illegal fall through to default case in " + getQualifiedName() + ".");
}
/**
* Indicate that we have a bad value by throwing an exception.
* This is used in generated methods that return a boolean.
* @param errorInfo
* @return boolean NEVER RETURNED. This method 'returns' an boolean in order to be usable in
* boolean expressions
*/
protected final boolean badSwitchIndex_boolean (ErrorInfo errorInfo) {
return RTValue.badValue_boolean (errorInfo, "Illegal fall through to default case in " + getQualifiedName() + ".");
}
/**
* Indicate that we have a bad value by throwing an exception.
* This is used in generated methods that return a byte.
* @param errorInfo
* @return byte NEVER RETURNED. This method 'returns' an byte in order to be usable in
* byte expressions
*/
protected final byte badSwitchIndex_byte (ErrorInfo errorInfo) {
return RTValue.badValue_byte (errorInfo, "Illegal fall through to default case in " + getQualifiedName() + ".");
}
/**
* Indicate that we have a bad value by throwing an exception.
* This is used in generated methods that return a char.
* @param errorInfo
* @return char NEVER RETURNED. This method 'returns' an char in order to be usable in
* char expressions
*/
protected final char badSwitchIndex_char (ErrorInfo errorInfo) {
return RTValue.badValue_char (errorInfo, "Illegal fall through to default case in " + getQualifiedName() + ".");
}
/**
* Indicate that we have a bad value by throwing an exception.
* This is used in generated methods that return a double.
* @param errorInfo
* @return double NEVER RETURNED. This method 'returns' an double in order to be usable in
* double expressions
*/
protected final double badSwitchIndex_double (ErrorInfo errorInfo) {
return RTValue.badValue_double (errorInfo, "Illegal fall through to default case in " + getQualifiedName() + ".");
}
/**
* Indicate that we have a bad value by throwing an exception.
* This is used in generated methods that return a float.
* @param errorInfo
* @return float NEVER RETURNED. This method 'returns' an float in order to be usable in
* float expressions
*/
protected final float badSwitchIndex_float (ErrorInfo errorInfo) {
return RTValue.badValue_float(errorInfo, "Illegal fall through to default case in " + getQualifiedName() + ".");
}
/**
* Indicate that we have a bad value by throwing an exception.
* This is used in generated methods that return a int.
* @param errorInfo
* @return int NEVER RETURNED. This method 'returns' an int in order to be usable in
* int expressions
*/
protected final int badSwitchIndex_int (ErrorInfo errorInfo) {
return RTValue.badValue_int (errorInfo, "Illegal fall through to default case in " + getQualifiedName() + ".");
}
/**
* Indicate that we have a bad value by throwing an exception.
* This is used in generated methods that return a long.
* @param errorInfo
* @return long NEVER RETURNED. This method 'returns' an long in order to be usable in
* long expressions
*/
protected final long badSwitchIndex_long (ErrorInfo errorInfo) {
return RTValue.badValue_long (errorInfo, "Illegal fall through to default case in " + getQualifiedName() + ".");
}
/**
* Indicate that we have a bad value by throwing an exception.
* This is used in generated methods that return a Object.
* @param errorInfo
* @return Object NEVER RETURNED. This method 'returns' an Object in order to be usable in
* Object expressions
*/
protected final Object badSwitchIndex_Object (ErrorInfo errorInfo) {
return RTValue.badValue_Object (errorInfo, "Illegal fall through to default case in " + getQualifiedName() + ".");
}
/**
* Indicate that we have a bad value by throwing an exception.
* This is used in generated methods that return a short.
* @param errorInfo
* @return short NEVER RETURNED. This method 'returns' an short in order to be usable in
* short expressions
*/
protected final short badSwitchIndex_short (ErrorInfo errorInfo) {
return RTValue.badValue_short (errorInfo, "Illegal fall through to default case in " + getQualifiedName() + ".");
}
/**
* Function called when a switch statement in the generated code encounters
* an unhandled switch index. i.e. the index is valid (corresponds to a DC)
* but no case was provided.
* @param errorInfo
* @param dcName
* @return nothing because this will always throw an exception. A return type is declared
* to make this function easier to use in generated code.
* @throws CALExecutorException
*/
public final RTValue unhandledSwitchIndex (ErrorInfo errorInfo, String dcName) throws CALExecutorException {
String errorMessage = "Unhandled case for " + dcName + " in " + getQualifiedName() + ".";
CALExecutorException e = new CALExecutorException.ExternalException.PatternMatchFailure(errorInfo, errorMessage, null);
if (System.getProperty(LECCMachineConfiguration.DEBUG_INFO_PROP) != null) {
e.printStackTrace();
}
throw e;
}
}