package jp.ac.kobe_u.cs.prolog.compiler;
import java.io.File;
import jp.ac.kobe_u.cs.prolog.lang.ListTerm;
import jp.ac.kobe_u.cs.prolog.lang.Predicate;
import jp.ac.kobe_u.cs.prolog.lang.Prolog;
import jp.ac.kobe_u.cs.prolog.lang.PrologClassLoader;
import jp.ac.kobe_u.cs.prolog.lang.PrologControl;
import jp.ac.kobe_u.cs.prolog.lang.SymbolTerm;
import jp.ac.kobe_u.cs.prolog.lang.Term;
/**
* The <code>Compiler</code> class provides methods for translating Prolog
* programs into Java programs.
*
* The <code>Compiler</code> class supports the following compiler options. All
* of them are set to <code>true</code> in default setting.
* <ul>
* <li>Eliminate disjunctions
* <li>Arithmetic compilation
* <li>Inline expansion
* <li>Optimisation of recursive call
* <li>2nd. level indexing (<code>switch_on_hash</code>)
* </ul>
*
* Let us show a sample session for translating a Prolog program
* <code>$PLCAFEDIR/examples/prolog/list.pl</code> into Java. The
* <code>list.pl</code> contains predicates <code>append/3</code>,
* <code>nrev/2</code>, and <code>range/3</code>.
* <ul>
* <li>From Command line<br>
*
* <pre>
* % java -cp $PLCAFEDIR/plcafe.jar jp.ac.kobe_u.cs.prolog.compiler.Compiler:$CLASSPATH $PLCAFEDIR/examples/prolog/list.pl
* Prolog Cafe X.X.X (YYY)
* Copyright(C) 1997-200X M.Banbara and N.Tamura
* % ls
* PRED_append_3.java PRED_nrev_2.java PRED_range_3.java
* </pre>
*
* <li>From Java program<br>
*
* <pre>
* import jp.ac.kobe_u.cs.prolog.compiler.Compiler;
*
* public class T {
* public static void main(String argv[]) {
* Compiler comp = new Compiler();
* comp.prologToJava(argv[0], ".");
* }
* }
* </pre>
*
* <pre>
* % javac -classpath $PLCAFEDIR/plcafe.jar:$CLASSPATH T.java
* % java -classpath $PLCAFEDIR/plcafe.jar:$CLASSPATH T $PLCAFEDIR/examples/prolog/list.pl
* % ls
* PRED_append_3.java PRED_nrev_2.java PRED_range_3.java
* </pre>
*
* </ul>
*
* It is noted that our Prolog-to-Java translator is originally witten in
* Prolog, and then bootstrapped. Please see the following two Prolog programs
* in details.
* <ul>
* <li><code>$PLCAFEDIR/src/compiler/pl2am.pl</code><br>
* Translates a Prolog program into a WAM-based intermediate code.
* <li><code>$PLCAFEDIR/src/compiler/am2j.pl</code><br>
* Translates a WAM-based intermediate code generated by <code>pl2am.pl</code>
* into Java programs.
* </ul>
*
* @author Mutsunori Banbara (banbara@kobe-u.ac.jp)
* @author Naoyuki Tamura (tamura@kobe-u.ac.jp)
* @version 1.2
*/
public class Compiler {
/** Version information */
public static String VERSION = "Prolog Cafe 1.2.5 (mantis)";
/** Copyright information */
public static String COPYRIGHT = "Copyright(C) 1997-2009 M.Banbara and N.Tamura";
/**
* Compiler option for eliminating disjunctions. Its initial value is
* <code>true</code>
*/
protected boolean eliminateDisjunctions = true;
/**
* Compiler option for arithmetic compilation. Its initial value is
* <code>true</code>
*/
protected boolean arithmeticCompilation = true;
/**
* Compiler option for inline expansion. Its initial value is
* <code>true</code>
*/
protected boolean inlineExpansion = true;
/**
* Compiler option for optimising recursive call. Its initial value is
* <code>true</code>
*/
protected boolean optimiseRecursiveCall = true;
/**
* Compiler option for second-level indexing. Its initial value is
* <code>true</code>
*/
protected boolean switchOnHash = true;
/**
* Non-standard option. Compiler option for closure generation. Its initial
* value is <code>false</code>
*/
protected boolean generateClosure = false;
/**
* Translates a Prolog program into a WAM-based intermediate code.
*
* @param _prolog
* an input Prolog file
* @param _wam
* an output file for WAM-based intermediate code.
* @return <code>true</code> if succeeds, otherwise <code>false</code>.
*/
public boolean prologToWAM(String _prolog, String _wam) {
try {
if (!fileExists(_prolog)) {
System.out.println("**ERROR: file " + _prolog
+ " does not exist");
return false;
}
if (fileExists(_wam)) {
System.out.println("**ERROR: file " + _wam + " already exists");
return false;
}
// Create arguments
Term prolog = SymbolTerm.makeSymbol(_prolog);
Term wam = SymbolTerm.makeSymbol(_wam);
Term op = Prolog.Nil;
if (eliminateDisjunctions) {
op = new ListTerm(SymbolTerm.makeSymbol("ed"), op);
}
if (arithmeticCompilation) {
op = new ListTerm(SymbolTerm.makeSymbol("ac"), op);
}
if (inlineExpansion) {
op = new ListTerm(SymbolTerm.makeSymbol("ie"), op);
}
if (optimiseRecursiveCall) {
op = new ListTerm(SymbolTerm.makeSymbol("rc"), op);
}
if (switchOnHash) {
op = new ListTerm(SymbolTerm.makeSymbol("idx"), op);
}
if (generateClosure) {
op = new ListTerm(SymbolTerm.makeSymbol("clo"), op);
}
Term[] args = { new ListTerm(prolog, new ListTerm(wam,
new ListTerm(op, Prolog.Nil))) };
// Create predicate
Class clazz = new PrologClassLoader().loadPredicateClass(
"jp.ac.kobe_u.cs.prolog.compiler.pl2am", "pl2am", 1, true);
Predicate code = (Predicate) clazz.newInstance();
// Translate Prolog into WAM
PrologControl p = new PrologControl();
p.setPredicate(code, args);
// System.out.println(code);
return p.execute(code, args);
} catch (Exception e) {
e.printStackTrace();
}
return false;
}
/**
* Translates WAM-based intermediate code into Java programs.
*
* @param _wam
* an input file for WAM-based intermediate code.
* @param _dir
* a destination directory for java files. The directory must
* already exist.
* @return <code>true</code> if succeeds, otherwise <code>false</code>.
* @see #prologToWAM(String, String)
*/
public boolean wamToJava(String _wam, String _dir) {
try {
if (!fileExists(_wam)) {
System.out.println("**ERROR: file " + _wam + " does not exist");
return false;
}
if (!fileExists(_dir)) {
System.out.println("**ERROR: directory " + _dir
+ " does not exist");
return false;
}
// Create arguments
Term wam = SymbolTerm.makeSymbol(_wam);
Term dir = SymbolTerm.makeSymbol(_dir);
Term[] args = { new ListTerm(wam, new ListTerm(dir, Prolog.Nil)) };
// Create predicate
// Class clazz =
// PredicateEncoder.getClass("jp.ac.kobe_u.cs.prolog.compiler.am2j",
// "am2j", 1);
Class clazz = new PrologClassLoader().loadPredicateClass(
"jp.ac.kobe_u.cs.prolog.compiler.am2j", "am2j", 1, true);
Predicate code = (Predicate) clazz.newInstance();
// Translate WAM into Java
PrologControl p = new PrologControl();
p.setPredicate(code, args);
// System.out.println(code);
return p.execute(code, args);
} catch (Exception e) {
e.printStackTrace();
}
return false;
}
/**
* Translates a Prolog program into Java programs.
*
* @param prolog
* an input Prolog file
* @param dir
* a destination directory for java files. The directory must
* already exist.
* @return <code>true</code> if succeeds, otherwise <code>false</code>.
* @see #prologToWAM(String, String)
* @see #wamToJava(String, String)
*/
public boolean prologToJava(String prolog, String dir) {
String wam = prolog + ".am";
if (!prologToWAM(prolog, wam)) {
return false;
}
if (!wamToJava(wam, dir)) {
return false;
}
try {
File f = new File(wam);
if (f.exists()) {
f.delete();
}
} catch (SecurityException e) {
}
return true;
}
public static void main(String argv[]) {
try {
System.err.println("\n" + VERSION);
System.err.println(COPYRIGHT);
if (argv.length != 1) {
usage();
System.exit(999);
}
Compiler comp = new Compiler();
if (!comp.prologToJava(argv[0], ".")) {
System.exit(1);
}
System.exit(0);
} catch (Exception e) {
e.printStackTrace();
System.exit(1);
}
}
protected static boolean fileExists(String _file) {
try {
File file = new File(_file);
return file.exists();
} catch (SecurityException e) {
}
return false;
}
/** Shows usage */
protected static void usage() {
String s = "Usage:\n";
s += "java -cp $PLCAFEDIR/plcafe.jar";
s += " jp.ac.kobe_u.cs.prolog.compiler.Compiler prolog_file\n";
System.out.println(s);
}
/**
* Returns the boolean value of <code>eliminateDisjunctions</code>.
*
* @see #eliminateDisjunctions
*/
public boolean getEliminateDisjunctions() {
return eliminateDisjunctions;
}
/**
* The <code>eliminateDisjunctions</code> field is set to <code>b</code>.
*
* @see #eliminateDisjunctions
*/
public void setEliminateDisjunctions(boolean b) {
eliminateDisjunctions = b;
}
/**
* Returns the boolean value of <code>arithmeticCompilation</code>.
*
* @see #arithmeticCompilation
*/
public boolean getArithmeticCompilation() {
return arithmeticCompilation;
}
/**
* The <code>arithmeticCompilation</code> field is set to <code>b</code>.
*
* @see #arithmeticCompilation
*/
public void setArithmeticCompilation(boolean b) {
arithmeticCompilation = b;
}
/**
* Returns the boolean value of <code>inlineExpansion</code>.
*
* @see #inlineExpansion
*/
public boolean getInlineExpansion() {
return inlineExpansion;
}
/**
* The <code>inlineExpansion</code> field is set to <code>b</code>.
*
* @see #inlineExpansion
*/
public void setInlineExpansion(boolean b) {
inlineExpansion = b;
}
/**
* Returns the boolean value of <code>optimiseRecursiveCall</code>.
*
* @see #optimiseRecursiveCall
*/
public boolean getOptimiseRecursiveCall() {
return optimiseRecursiveCall;
}
/**
* The <code>optimiseRecursiveCall</code> field is set to <code>b</code>.
*
* @see #optimiseRecursiveCall
*/
public void setOptimiseRecursiveCall(boolean b) {
optimiseRecursiveCall = b;
}
/**
* Returns the boolean value of <code>switchOnHash</code>.
*
* @see #switchOnHash
*/
public boolean getSwitchOnHash() {
return switchOnHash;
}
/**
* The <code>switchOnHash</code> field is set to <code>b</code>.
*
* @see #switchOnHash
*/
public void setSwitchOnHash(boolean b) {
switchOnHash = b;
}
/**
* Returns the boolean value of <code>generateClosure</code>.
*
* @see #generateClosure
*/
public boolean getGenerateClosure() {
return generateClosure;
}
/**
* The <code>generateClosure</code> field is set to <code>b</code>.
*
* @see #generateClosure
*/
public void setGenerateClosure(boolean b) {
generateClosure = b;
}
}