JPL

java.lang.Object
- org.jpl7.JPL

```
public class JPL
extends java.lang.Object
```
The jpl.JPL class contains static methods which allow (i) inspection and alteration of the "default" initialisation arguments (ii) explicit initialisation (iii) discovery of whether the Prolog engine is already initialised, and if so, with what arguments. The Prolog engine must be initialized before any queries are made, but this will happen automatically (upon the first call to a Prolog FLI routine) if it has not already been done explicitly.
Copyright (C) 2004 Paul Singleton
Copyright (C) 1998 Fred Dushin
Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met:
1. Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer.
2. 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.
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.

Field Summary

Fields
Modifier and Type	Field and Description
`protected static boolean`	`DEBUG`
`static Term`	`JFALSE`
`static Term`	`JNULL`
`static Term`	`JTRUE`
`static Term`	`JVOID`
`static Atom`	`LIST_NIL`
`protected static Atom`	`LIST_NIL_MODERN`
`protected static Atom`	`LIST_NIL_TRADITIONAL`
`static java.lang.String`	`LIST_PAIR`
`protected static java.lang.String`	`LIST_PAIR_MODERN`
`protected static java.lang.String`	`LIST_PAIR_TRADITIONAL`
`static boolean`	`LIST_TOSTRING_TEXTUAL`
`protected static boolean`	`modeDontTellMe`

Constructor Summary

Constructors
Constructor and Description

JPL()

Constructors
Constructor and Description
`JPL()`

Method Summary

All Methods Static Methods Concrete Methods Deprecated Methods
Modifier and Type	Method and Description
`static java.lang.String[]`	`getActualInitArgs()` Returns, in an array of String, the sequence of command-line arguments that were actually used when the Prolog engine was formerly initialised.
`static java.lang.String[]`	`getDefaultInitArgs()` Returns, in an array of String, the sequence of command-line arguments that would be used if the Prolog engine were to be initialised now.
`static java.lang.String`	`getSyntax()`
`static void`	`halt()` Deprecated.
`static boolean`	`init()` Initialises the Prolog engine using the current default initialisation parameters, and returns 'true' (or 'false' if already initialised).
`static boolean`	`init(java.lang.String[] args)` Initializes the Prolog engine, using the String argument parameters passed.
`protected static boolean`	`isSimpleName(java.lang.String s)` Checks if a string is a simple atom, with no quoting needed
`static java.lang.String`	`jarPath()`
`static void`	`loadNativeLibrary()`
`static void`	`main(java.lang.String[] args)`
`static Term`	`newJRef(java.lang.Object object)`
`protected static java.lang.String`	`quotedName(java.lang.String name)` Returns a quoted (iff necessary) form of the Atom's name, as understood by Prolog read/1
`static void`	`setDefaultInitArgs(java.lang.String[] args)` Specifies, in an array of String, the sequence of command-line arguments that should be used if the Prolog engine is subsequently initialised.
`static void`	`setDTMMode(boolean dtm)` Sets the global "dont-tell-me" mode (default value: true).
`static java.lang.String`	`setNativeLibraryDir(java.lang.String newDir)`
`static java.lang.String`	`setNativeLibraryName(java.lang.String newName)`
`static java.lang.String`	`setNativeLibraryPath(java.lang.String newPath)`
`static void`	`setTraditional()`
`static void`	`setTraditionalAnyway()`
`static java.lang.String`	`version_string()` Returns a String (eg "3.0.0-alpha") identifying this version of JPL.
`static org.jpl7.Version`	`version()` Returns (as a Version) an identification of this version of JPL.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Field Detail
  - DEBUG
```
protected static final boolean DEBUG
```
    See Also:
    
    Constant Field Values
  - JFALSE
```
public static final Term JFALSE
```
  - JTRUE
```
public static final Term JTRUE
```
  - JNULL
```
public static final Term JNULL
```
  - JVOID
```
public static final Term JVOID
```
  - modeDontTellMe
```
protected static boolean modeDontTellMe
```
  - LIST_NIL_MODERN
```
protected static final Atom LIST_NIL_MODERN
```
  - LIST_NIL_TRADITIONAL
```
protected static final Atom LIST_NIL_TRADITIONAL
```
  - LIST_NIL
```
public static Atom LIST_NIL
```
  - LIST_PAIR_MODERN
```
protected static final java.lang.String LIST_PAIR_MODERN
```
    See Also:
    
    Constant Field Values
  - LIST_PAIR_TRADITIONAL
```
protected static final java.lang.String LIST_PAIR_TRADITIONAL
```
    See Also:
    
    Constant Field Values
  - LIST_PAIR
```
public static java.lang.String LIST_PAIR
```
  - LIST_TOSTRING_TEXTUAL
```
public static boolean LIST_TOSTRING_TEXTUAL
```
- Constructor Detail
  - JPL
```
public JPL()
```
- Method Detail
  - setNativeLibraryName
```
public static java.lang.String setNativeLibraryName(java.lang.String newName)
```
  - setNativeLibraryDir
```
public static java.lang.String setNativeLibraryDir(java.lang.String newDir)
```
  - setNativeLibraryPath
```
public static java.lang.String setNativeLibraryPath(java.lang.String newPath)
```
  - loadNativeLibrary
```
public static void loadNativeLibrary()
```
  - jarPath
```
public static java.lang.String jarPath()
```
  - setDTMMode
```
public static void setDTMMode(boolean dtm)
```
    Sets the global "dont-tell-me" mode (default value: true). When 'true', bindings will *not* be returned for any variable (in a Query's goal) whose name begins with an underscore character (except for "anonymous" variables, i.e. those whose name comprises just the underscore character, whose bindings are never returned). When 'false', bindings are returned for *all* variables except anonymous ones; this mode may be useful when traditional top-level interpreter behaviour is wanted, e.g. in a Java-based Prolog IDE or debugger.
    This method should be regarded as experimental, and may subsequently be deprecated in favour of some more general mechanism for setting options, perhaps per-Query and per-call as well as globally.
    
    Parameters:
    
    dtm - new "dont-tell-me" mode value
  - setTraditional
```
public static void setTraditional()
```
  - setTraditionalAnyway
```
public static void setTraditionalAnyway()
```
  - getSyntax
```
public static java.lang.String getSyntax()
```
  - getDefaultInitArgs
```
public static java.lang.String[] getDefaultInitArgs()
```
    Returns, in an array of String, the sequence of command-line arguments that would be used if the Prolog engine were to be initialised now. Returns null if the Prolog VM has already been initialised (in which case the default init args are irrelevant and the actual init args are of interest)
    
    Returns:
    
    current default initialisation arguments, or null if already initialised
    
    See Also:
    
    getActualInitArgs()
  - setDefaultInitArgs
```
public static void setDefaultInitArgs(java.lang.String[] args)
```
    Specifies, in an array of String, the sequence of command-line arguments that should be used if the Prolog engine is subsequently initialised.
    
    Parameters:
    
    args - new default initialization arguments
  - getActualInitArgs
```
public static java.lang.String[] getActualInitArgs()
```
    Returns, in an array of String, the sequence of command-line arguments that were actually used when the Prolog engine was formerly initialised. This method returns null if the Prolog engine has not yet been initialised, and thus may be used to test this condition.
    
    Returns:
    
    actual initialization arguments
  - init
```
public static boolean init(java.lang.String[] args)
```
    Initializes the Prolog engine, using the String argument parameters passed. This method need be called only if you want to both (i) initialise the Prolog engine with parameters other than the default ones and (ii) force initialisation to occur (rather than allow it to occur automatically at the first query). For parameter options, consult your local Prolog documentation. The parameter values are passed directly to initialization routines for the Prolog environment.
    This method must be called before making any queries.
    
    Parameters:
    
    args - Initialization parameter list
    
    Returns:
    
    true iff initialization was new; false if already initialized
  - init
```
public static boolean init()
```
    Initialises the Prolog engine using the current default initialisation parameters, and returns 'true' (or 'false' if already initialised).
    
    Returns:
    
    true if initialization was new, false if already initialized
  - isSimpleName
```
protected static boolean isSimpleName(java.lang.String s)
```
    Checks if a string is a simple atom, with no quoting needed
    
    Parameters:
    
    s - string to check if it is simple name (no quoting needed)
    
    Returns:
    
    whether s is a simple name, i.e. which needs no quoting in source text
  - newJRef
```
public static Term newJRef(java.lang.Object object)
```
    Parameters:
    
    object - the object of interest to get the JREF
    
    Returns:
    
    a new Term instance which canonically represents the given object reference (concrete or null)
  - quotedName
```
protected static java.lang.String quotedName(java.lang.String name)
```
    Returns a quoted (iff necessary) form of the Atom's name, as understood by Prolog read/1
    
    Parameters:
    
    name - the name to quote if needed
    
    Returns:
    
    a quoted form of the Atom's name, as understood by Prolog read/1
  - halt
```
@Deprecated
public static void halt()
```
    Deprecated.
    
    Terminates the Prolog session.
    Note. This method calls the FLI halt() method with a status of 0, but the halt method currently is a no-op in SWI.
  - version
```
public static org.jpl7.Version version()
```
    Returns (as a Version) an identification of this version of JPL.
    
    Returns:
    
    the running version of JPL.
  - version_string
```
public static java.lang.String version_string()
```
    Returns a String (eg "3.0.0-alpha") identifying this version of JPL.
    
    Returns:
    
    a String (eg "3.0.0-alpha") identifying this version of JPL.
  - main
```
public static void main(java.lang.String[] args)
```

Class JPL

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

DEBUG

JFALSE

JTRUE

JNULL

JVOID

modeDontTellMe

LIST_NIL_MODERN

LIST_NIL_TRADITIONAL

LIST_NIL

LIST_PAIR_MODERN

LIST_PAIR_TRADITIONAL

LIST_PAIR

LIST_TOSTRING_TEXTUAL

Constructor Detail

JPL

Method Detail

setNativeLibraryName

setNativeLibraryDir

setNativeLibraryPath

loadNativeLibrary

jarPath

setDTMMode

setTraditional

setTraditionalAnyway

getSyntax

getDefaultInitArgs

setDefaultInitArgs

getActualInitArgs

init

init

isSimpleName

newJRef

quotedName

halt

version

version_string

main