com::declarativa::interprolog::PrologEngine Class Reference

Inheritance diagram for com::declarativa::interprolog::PrologEngine:

Public Member Functions
	PrologEngine (String startPrologCommand, boolean debug)
abstract void	shutdown ()
File	getJarDirectory ()
void	consultFromPackage (String filename, Object requester)
void	consultRelative (String filename, Object requester)
void	load_dynRelative (String filename, Object requester)
void	interrupt ()
boolean	command (String s)
void	progressMessage (String s)
boolean	isDebug ()
void	setDebug (boolean d)
boolean	teachOneObject (Object example)
boolean	teachMoreObjects (Object[] examples)
boolean	teachMoreObjects (ObjectExamplePair[] examples)
Object[]	deterministicGoal (String G, String OVar, Object[] objectsP, String RVars)
boolean	deterministicGoal (String G)
Object[]	deterministicGoal (String G, String RVars)
boolean	deterministicGoal (String G, String OVar, Object[] objectsP)
synchronized boolean	isIdle ()
synchronized void	abortTasks ()
synchronized void	interruptTasks ()
boolean	isAvailable ()
void	waitUntilAvailable ()
void	waitUntilIdle ()
Object	handleCallback (Object x)
final void	firstJavaMessage ()
ResultFromJava	doCallback (Object x)
int	registerJavaObject (Object x)
Object	makeInvisible (Object x)
Object	getRealJavaObject (InvisibleObject o)
Object	getRealJavaObject (int ID)
Object	getRealJavaObject (Object o)
Static Public Member Functions
static File	getJarDirectory (Class aClass)
static void	printBindings (Object[] b)
static Method	findMethod (Class targetClass, String name, Class[] formalArguments) throws NoSuchMethodException
static Constructor	findConstructor (Class targetClass, Class[] formalArguments) throws NoSuchMethodException
static boolean	assignableType (Class left, Class right)
static String	shortClassName (Class c)
Data Fields
String	startPrologCommand
boolean	interrupting = false
final String	firstJavaMessageName = "firstJavaMessage"
Static Public Attributes
static final String	version = "2.0b1"
static final String	nl = System.getProperty("line.separator")
static final int	MAX_INT_VALUE = 134217727
static final int	MIN_INT_VALUE = -134217728
Protected Member Functions
boolean	isShutingDown ()
void	operationRelative (String operation, String filename, Object requester)
abstract boolean	realCommand (String s)
final void	teachIPobjects (ObjectOutputStream obs) throws IOException
void	teachBasicObjects (ObjectOutputStream obs) throws IOException
GoalFromJava	makeDGoalObject (String G, String OVar, Object[] objectsP, String RVars, int timestamp)
int	incGoalTimestamp ()
synchronized void	scheduleGoal (GoalToExecute g)
synchronized GoalToExecute	moreRecentToExecute ()
synchronized GoalToExecute	forgetGoal (int timestamp)
synchronized void	addMessage (MessageExecuting m)
synchronized void	forgetMessage (MessageExecuting m)
synchronized MessageExecuting	lastMessageRequest ()
Object	doSomething ()
Protected Attributes
long	startTime
File	tempDirectory
ObjectRegistry	knownObjects
boolean	shutingDown = false
boolean	debug = false
boolean	topGoalHasStarted = false
int	goalTimestamp
Static Protected Attributes
static int	numberOfInstances = 0
Package Functions
void	makeTempDirectory ()
File	copyToTemp (String filename, Object requester)
Package Attributes
Vector	goalsToExecute
Vector	messagesExecuting
final Method	getRealJavaObjectMethod

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Detailed Description

The heart of InterProlog; a PrologEngine represents a Prolog abstract machine instance. This is an abstract class; you should use it just to declare variables, but must instantiate only a subclass.

Definition at line 19 of file PrologEngine.java.

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Constructor & Destructor Documentation

com::declarativa::interprolog::PrologEngine::PrologEngine (  String  startPrologCommand, boolean  debug )  [inline]

Create a Prolog executor, possibly spawning it in a different process or loading it into memory, depending on the implementation by our subclass. Parameters: startPrologCommand  File path to Prolog machine, see subclass docs for precise semantics debug  if true, print progress messages to aid debugging Definition at line 63 of file PrologEngine.java. References findMethod(), getRealJavaObjectMethod, goalsToExecute, knownObjects, makeTempDirectory(), messagesExecuting, numberOfInstances, setDebug(), shutdown(), and startTime.

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Member Function Documentation

synchronized void com::declarativa::interprolog::PrologEngine::abortTasks (   )  [inline]

Do not invoke this Definition at line 503 of file PrologEngine.java. Referenced by com::xsb::interprolog::NativeEngine::startTopGoal().

synchronized void com::declarativa::interprolog::PrologEngine::addMessage (  MessageExecuting  m  )  [inline, protected]

Just adds to messagesExecuting Definition at line 482 of file PrologEngine.java.

static boolean com::declarativa::interprolog::PrologEngine::assignableType (  Class  left, Class  right )  [inline, static]

It is OK to assign an expression typed right to a variable typed left. Delegates on isAssignableFrom Definition at line 759 of file PrologEngine.java.

boolean com::declarativa::interprolog::PrologEngine::command (  String  s  )  [inline]

Execute a Prolog "command" Definition at line 224 of file PrologEngine.java. Referenced by com::declarativa::interprolog::gui::ListenerWindow::ListenerWindow(), com::declarativa::interprolog::examples::HelloWorld::main(), and com::xsb::interprolog::NativeEngine::NativeEngine().

void com::declarativa::interprolog::PrologEngine::consultFromPackage (  String  filename, Object  requester )  [inline]

Extracts a Prolog file from the jar file or directory where the requester's class came from, and asks the background Prolog process to consult it. You should use this method only after your program is stable. The Prolog file is extracted to a temporary file, and automatically deleted on exiting the application. Parameters: filename  The Prolog file name, including suffix; if absent ".P" is appended requester  Defines where the Prolog file resides See also: consultRelative(String, Object) load_dynRelative(String, Object) Definition at line 173 of file PrologEngine.java. Referenced by com::declarativa::interprolog::gui::ListenerWindow::ListenerWindow(), and com::xsb::interprolog::NativeEngine::NativeEngine().

void com::declarativa::interprolog::PrologEngine::consultRelative (  String  filename, Object  requester )  [inline]

Consults a Prolog file from the directory where the requester's class would come from if it did not come from a jar file. Adds that directory to the library_directory relation, so modules can be found there Parameters: filename  The Prolog file name, including suffix; if absent ".P" is appended requester  Defines where the Prolog file resides Definition at line 187 of file PrologEngine.java.

boolean com::declarativa::interprolog::PrologEngine::deterministicGoal (  String  G, String  OVar, Object[]  objectsP )  [inline]

Useful when you want to pass objects to Prolog but don't need objects returned. Same as deterministicGoal(G, OVar,objectsP,"[]") Definition at line 444 of file PrologEngine.java.

Object [] com::declarativa::interprolog::PrologEngine::deterministicGoal (  String  G, String  RVars )  [inline]

Useful when you're constructing objects from Prolog, but don't need to pass any from Java. Same as deterministicGoal(G,null,null,RVars) Definition at line 439 of file PrologEngine.java.

boolean com::declarativa::interprolog::PrologEngine::deterministicGoal (  String  G  )  [inline]

A parameterless goal with no result other than success/failure. Same as deterministicGoal(G, null,null,"[]") Definition at line 434 of file PrologEngine.java.

Object [] com::declarativa::interprolog::PrologEngine::deterministicGoal (  String  G, String  OVar, Object[]  objectsP, String  RVars )  [inline]

Synchronously calls a Prolog goal. Only the first solution is considered. G should contain a syntactically correct Prolog term, without the trailing dot (.). Throws an IPAbortedException if a Prolog abort happens, and an IPInterruptedException if the interrupt() method was invoked. See also: deterministicGoal(String) deterministicGoal(String,String) deterministicGoal(String,String,Object[]) Returns: a new array containing an object for each term in the rVars list, or null if goal fails Parameters: G  Prolog goal term OVar  Prolog variable that will be bound to objectsP array objectsP  Array of Java objects to pass to Prolog goal RVars  Prolog list with object specifications, typically containing variables occurring in g. If null a single binding will be returned, containing a TermModel object representing the goal term solution Reimplemented in com::declarativa::interprolog::SubprocessEngine, and com::xsb::interprolog::NativeEngine. Definition at line 405 of file PrologEngine.java. References com::declarativa::interprolog::util::ResultFromProlog::error, com::declarativa::interprolog::util::ResultFromProlog::rVars, com::declarativa::interprolog::util::ResultFromProlog::succeeded, and com::declarativa::interprolog::util::ResultFromProlog::timestamp. Referenced by com::declarativa::interprolog::gui::PrologEventBroker::actionPerformed(), com::declarativa::interprolog::gui::RelationTreeNode::getChild(), com::declarativa::interprolog::gui::RelationTreeNode::getChildCount(), com::declarativa::interprolog::gui::RelationTreeNode::getIndexOfChild(), com::declarativa::interprolog::examples::HelloWindow::HelloWindow(), com::declarativa::interprolog::examples::HelloWorld::main(), com::declarativa::interprolog::examples::BackEnd::main(), com::declarativa::interprolog::gui::TermModelWindow::TermModelWindow(), and com::declarativa::interprolog::gui::RelationTreeNode::toString().

ResultFromJava com::declarativa::interprolog::PrologEngine::doCallback (  Object  x  )  [inline]

Execute a Prolog->Java call Definition at line 604 of file PrologEngine.java. References com::declarativa::interprolog::util::MessageFromProlog::arguments, and com::declarativa::interprolog::util::MessageFromProlog::target. Referenced by com::declarativa::interprolog::util::MessageExecuting::run().

Object com::declarativa::interprolog::PrologEngine::doSomething (   )  [inline, protected]

return result to last javaMessage or pick more recent GoalToExecute Reimplemented in com::declarativa::interprolog::SubprocessEngine. Definition at line 571 of file PrologEngine.java. References com::declarativa::interprolog::util::MessageExecuting::getResult(), and com::declarativa::interprolog::util::MessageExecuting::hasEnded().

static Constructor com::declarativa::interprolog::PrologEngine::findConstructor (  Class  targetClass, Class[]  formalArguments )  throws NoSuchMethodException [inline, static]

Similar to findMethod(), but for constructors rather than regular methods Definition at line 729 of file PrologEngine.java.

static Method com::declarativa::interprolog::PrologEngine::findMethod (  Class  targetClass, String  name, Class[]  formalArguments )  throws NoSuchMethodException [inline, static]

An utility building on the functionality of getMethod(), to provide the javaMessage predicate with method argument polimorphism. If the type signatures do not match exactly, searches all method signatures to see if their arguments are type-compatible. Definition at line 692 of file PrologEngine.java. Referenced by PrologEngine().

final void com::declarativa::interprolog::PrologEngine::firstJavaMessage (   )  [inline]

Dummy method, whose name is used to start the callback thread Definition at line 599 of file PrologEngine.java.

synchronized GoalToExecute com::declarativa::interprolog::PrologEngine::forgetGoal (  int  timestamp  )  [inline, protected]

Currently does a dumb linear search, enough for our scenarios. 2 possibilities: use Hashtable; make ResultFromProlog bring back a reference to GoalFromJava Definition at line 470 of file PrologEngine.java.

static File com::declarativa::interprolog::PrologEngine::getJarDirectory (  Class  aClass  )  [inline, static]

Returns the directory containing the jar with the given class Definition at line 109 of file PrologEngine.java.

File com::declarativa::interprolog::PrologEngine::getJarDirectory (   )  [inline]

Returns the directory containing the jar with the engine class Definition at line 104 of file PrologEngine.java.

Object com::declarativa::interprolog::PrologEngine::getRealJavaObject (  Object  o  )  [inline]

Just returns the object, untouched (but "dereferenced" if called from Prolog). This serves the need to get objects in javaMessage because of the way CallbackHandler.doCallback works. For example: ipPrologEngine(_E), stringArraytoList(_O,[miguel,calejo]), javaMessage(_E,_R,getRealJavaObject(_O)),stringArraytoList(_R,List). ... will bind List to [miguel,calejo] and not to an InvisibleObject specification as ordinarly would happen Definition at line 810 of file PrologEngine.java.

Object com::declarativa::interprolog::PrologEngine::getRealJavaObject (  int  ID  )  [inline]

Same as getRealJavaObject(InvisibleObject), but accepts an integer ID as argument instead Definition at line 800 of file PrologEngine.java.

Object com::declarativa::interprolog::PrologEngine::getRealJavaObject (  InvisibleObject  o  )  [inline]

Get the object referred by the integer in a InvisibleObject wrapper. Parameters: o  An InvisibleObject Returns: The real object denoted by o in the context of this engine See also: InvisibleObject Definition at line 796 of file PrologEngine.java.

Object com::declarativa::interprolog::PrologEngine::handleCallback (  Object  x  )  [inline]

Handling of javaMessages and deterministicGoals. This is where most things happen. Parameters: x  Argument of the callback predicate Definition at line 546 of file PrologEngine.java. References com::declarativa::interprolog::util::GoalToExecute::setResult(), and com::declarativa::interprolog::util::ResultFromProlog::timestamp. Referenced by com::xsb::interprolog::NativeEngine::callback().

void com::declarativa::interprolog::PrologEngine::interrupt (   )  [inline]

Interrupt Prolog and make it return to its top level. This is the equivalent to performing a ctrl+c or similar command when using Prolog under a standard console shell. Definition at line 214 of file PrologEngine.java.

synchronized void com::declarativa::interprolog::PrologEngine::interruptTasks (   )  [inline]

Do not invoke this Definition at line 513 of file PrologEngine.java. Referenced by com::xsb::interprolog::NativeEngine::startTopGoal().

boolean com::declarativa::interprolog::PrologEngine::isAvailable (   )  [inline]

Present implementation is always available, so this always returns true Reimplemented in com::declarativa::interprolog::SubprocessEngine. Definition at line 523 of file PrologEngine.java.

boolean com::declarativa::interprolog::PrologEngine::isDebug (   )  [inline]

Debug messages are being written Definition at line 240 of file PrologEngine.java. Referenced by com::declarativa::interprolog::gui::ListenerWindow::ListenerWindow().

synchronized boolean com::declarativa::interprolog::PrologEngine::isIdle (   )  [inline]

The engine is doing nothing Reimplemented in com::xsb::interprolog::NativeEngine. Definition at line 498 of file PrologEngine.java.

boolean com::declarativa::interprolog::PrologEngine::isShutingDown (   )  [inline, protected]

This implementation returns false Reimplemented in com::declarativa::interprolog::SubprocessEngine. Definition at line 83 of file PrologEngine.java.

Object com::declarativa::interprolog::PrologEngine::makeInvisible (  Object  x  )  [inline]

Register an object with this Engine, so it later can be referred from Prolog without serializing it, and returns an InvisibleObject encapsulating the reference. Parameters: x  Object to be registered Returns: InvisibleObject denoting the object. In Prolog one can then refer to it by using the InvisibleObject class. See also: InvisibleObject Definition at line 787 of file PrologEngine.java. Referenced by com::declarativa::interprolog::examples::HelloWindow::HelloWindow().

static void com::declarativa::interprolog::PrologEngine::printBindings (  Object[]  b  )  [inline, static]

Convenience for debugging Definition at line 245 of file PrologEngine.java.

void com::declarativa::interprolog::PrologEngine::progressMessage (  String  s  )  [inline]

Debugging aid Definition at line 234 of file PrologEngine.java. Referenced by com::xsb::interprolog::NativeEngine::callback(), com::xsb::interprolog::NativeEngine::NativeEngine(), and com::xsb::interprolog::NativeEngine::startTopGoal().

abstract boolean com::declarativa::interprolog::PrologEngine::realCommand (  String  s  )  [protected, pure virtual]

Implementation of a simple parameterless Prolog goal; does not support recursive nor multithreaded operation, use command instead See also: command(String) Implemented in com::declarativa::interprolog::SubprocessEngine, and com::xsb::interprolog::NativeEngine.

int com::declarativa::interprolog::PrologEngine::registerJavaObject (  Object  x  )  [inline]

Register an object with this Engine, so it later can be referred from Prolog without serializing it. Parameters: x  Object to be registered Returns: Integer denoting the object. In Prolog one can then refer to it by using the InvisibleObject class. See also: InvisibleObject Definition at line 777 of file PrologEngine.java. Referenced by com::declarativa::interprolog::gui::PrologEventBroker::actionPerformed(), com::declarativa::interprolog::examples::HelloWindow2::HelloWindow2(), and com::xsb::interprolog::NativeEngine::NativeEngine().

synchronized void com::declarativa::interprolog::PrologEngine::scheduleGoal (  GoalToExecute  g  )  [inline, protected]

Adds goal to pool awaiting execution by Prolog Definition at line 456 of file PrologEngine.java.

abstract void com::declarativa::interprolog::PrologEngine::shutdown (   )  [pure virtual]

Release Prolog engine resources, making it unusable Implemented in com::declarativa::interprolog::SubprocessEngine, and com::xsb::interprolog::NativeEngine. Referenced by PrologEngine().

void com::declarativa::interprolog::PrologEngine::teachBasicObjects (  ObjectOutputStream  obs  )  throws IOException [inline, protected]

Provide Prolog with material to construct special objects that actually represent basic type values, so that Prolog can call (through javaMessage) methods with basic type (non-object) arguments. Also provides material for some other convenience objects Definition at line 302 of file PrologEngine.java. Referenced by com::xsb::interprolog::NativeEngine::NativeEngine().

boolean com::declarativa::interprolog::PrologEngine::teachMoreObjects (  ObjectExamplePair[]  examples  )  [inline]

Send an array of object example pairs to Prolog and generate ipObjectSpec facts. Returns true if this succeeds, false otherwise. Parameters: examples  The examples See also: ObjectExamplePair Definition at line 370 of file PrologEngine.java.

boolean com::declarativa::interprolog::PrologEngine::teachMoreObjects (  Object[]  examples  )  [inline]

Same as teachMoreObjects(ObjectExamplePair[]), but example pairs are constructed with (2) repeated examples for each object See also: teachMoreObjects(ObjectExamplePair[]) Definition at line 357 of file PrologEngine.java. Referenced by com::declarativa::interprolog::gui::ListenerWindow::ListenerWindow().

boolean com::declarativa::interprolog::PrologEngine::teachOneObject (  Object  example  )  [inline]

Same as teachMoreObjects(ObjectExamplePair[]), but the single example pair is constructed repeating the object See also: teachMoreObjects(ObjectExamplePair[]) Definition at line 351 of file PrologEngine.java. Referenced by com::declarativa::interprolog::examples::BackEnd::main().

void com::declarativa::interprolog::PrologEngine::waitUntilIdle (   )  [inline]

Sleeps the current Java thread until this engine is available. If this never happens, we're in trouble. Definition at line 536 of file PrologEngine.java.

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Field Documentation

final String com::declarativa::interprolog::PrologEngine::firstJavaMessageName = "firstJavaMessage"

Name of first message sent to Java Definition at line 49 of file PrologEngine.java. Referenced by com::xsb::interprolog::NativeEngine::startTopGoal().

final Method com::declarativa::interprolog::PrologEngine::getRealJavaObjectMethod [package]

"Constant" used for some special javaMessage handling Definition at line 47 of file PrologEngine.java. Referenced by PrologEngine().

Vector com::declarativa::interprolog::PrologEngine::goalsToExecute [package]

Prolog Goals whose execution has not yet finished or whose results have not yet been returned to their Java clients Definition at line 42 of file PrologEngine.java. Referenced by PrologEngine().

int com::declarativa::interprolog::PrologEngine::goalTimestamp [protected]

goal counter Definition at line 39 of file PrologEngine.java.

boolean com::declarativa::interprolog::PrologEngine::interrupting = false

Prolog is handling an interrupt Definition at line 35 of file PrologEngine.java. Referenced by com::xsb::interprolog::NativeEngine::startTopGoal().

ObjectRegistry com::declarativa::interprolog::PrologEngine::knownObjects [protected]

Table of object references that can be referred from Prolog without being serialized Definition at line 32 of file PrologEngine.java. Referenced by PrologEngine().

final int com::declarativa::interprolog::PrologEngine::MAX_INT_VALUE = 134217727 [static]

Maximum integer value. 28 bits is all we got on XSB Prolog Definition at line 55 of file PrologEngine.java.

Vector com::declarativa::interprolog::PrologEngine::messagesExecuting [package]

javaMessage requests that have started execution and whose results have not yet been returned to Prolog. Definition at line 44 of file PrologEngine.java. Referenced by PrologEngine().

final int com::declarativa::interprolog::PrologEngine::MIN_INT_VALUE = -134217728 [static]

Minimum integer value. Definition at line 57 of file PrologEngine.java.

final String com::declarativa::interprolog::PrologEngine::nl = System.getProperty("line.separator") [static]

Convenience for newline Definition at line 27 of file PrologEngine.java.

String com::declarativa::interprolog::PrologEngine::startPrologCommand

File path to Prolog machine Definition at line 24 of file PrologEngine.java.

File com::declarativa::interprolog::PrologEngine::tempDirectory [protected]

Temporary directory where Prolog files are unjared to. It is automatically declared as a Prolog library_directory Definition at line 29 of file PrologEngine.java. Referenced by com::xsb::interprolog::NativeEngine::NativeEngine().

final String com::declarativa::interprolog::PrologEngine::version = "2.0b1" [static]

InterProlog version Definition at line 22 of file PrologEngine.java.

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The documentation for this class was generated from the following file:

• C:/dev/sandbox/xsb_release/XSB/packages/iprolog/com/declarativa/interprolog/PrologEngine.java

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