src/main/java/org/luaj/vm3/lib/PackageLib.java - minecraft/opencomputers - Rivoreo Source Code Repositories

 /*******************************************************************************
 * Copyright (c) 2010-2011 Luaj.org. All rights reserved.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 ******************************************************************************/
 package org.luaj.vm3.lib;

 import java.io.InputStream;

 import org.luaj.vm3.Globals;
 import org.luaj.vm3.LuaFunction;
 import org.luaj.vm3.LuaString;
 import org.luaj.vm3.LuaTable;
 import org.luaj.vm3.LuaValue;
 import org.luaj.vm3.Varargs;

 /**
  * Subclass of {@link LibFunction} which implements the lua standard package and module
  * library functions.
  *
  * <h3>Lua Environment Variables</h3>
  * The following variables are available to lua scrips when this library has been loaded:
  * <ul>
  * <li><code>"package.loaded"</code> Lua table of loaded modules.
  * <li><code>"package.path"</code> Search path for lua scripts.
  * <li><code>"package.preload"</code> Lua table of uninitialized preload functions.
  * <li><code>"package.searchers"</code> Lua table of functions that search for object to load.
  * </ul>
  *
  * <h3>Java Environment Variables</h3>
  * These Java environment variables affect the library behavior:
  * <ul>
  * <li><code>"luaj.package.path"</code> Initial value for <code>"package.path"</code>.  Default value is <code>"?.lua"</code>
  * </ul>
  *
  * <h3>Loading</h3>
  * Typically, this library is included as part of a call to either
  * {@link JsePlatform#standardGlobals()} or {@link JmePlatform#standardGlobals()}
  * <pre> {@code
  * Globals globals = JsePlatform.standardGlobals();
  * System.out.println( globals.get("require").call"foo") );
  * } </pre>
  * <p>
  * To instantiate and use it directly,
  * link it into your globals table via {@link LuaValue#load(LuaValue)} using code such as:
  * <pre> {@code
  * Globals globals = new Globals();
  * globals.load(new JseBaseLib());
  * globals.load(new PackageLib());
  * System.out.println( globals.get("require").call("foo") );
  * } </pre>
  * <h3>Limitations</h3>
  * This library has been implemented to match as closely as possible the behavior in the corresponding library in C.
  * However, the default filesystem search semantics are different and delegated to the bas library
  * as outlined in the {@link BaseLib} and {@link JseBaseLib} documentation.
  * <p>
  * @see LibFunction
  * @see BaseLib
  * @see JseBaseLib
  * @see JsePlatform
  * @see JmePlatform
  * @see <a href="http://www.lua.org/manual/5.2/manual.html#6.3">Lua 5.2 Package Lib Reference</a>
  */
 public class PackageLib extends TwoArgFunction {

 	/** The default value to use for package.path.  This can be set with the system property
 	 * <code>"luaj.package.path"</code>, and is <code>"?.lua"</code> by default. */
 	public static String DEFAULT_LUA_PATH;
 	static {
 		try {
 			DEFAULT_LUA_PATH = System.getProperty("luaj.package.path");
 		} catch (Exception e) {
 			System.out.println(e.toString());
 		}
 		if (DEFAULT_LUA_PATH == null)
 			DEFAULT_LUA_PATH = "?.lua";
 	}

 	private static final LuaString _LOADED      = valueOf("loaded");
 	private static final LuaString _LOADLIB     = valueOf("loadlib");
 	private static final LuaString _PRELOAD     = valueOf("preload");
 	private static final LuaString _PATH        = valueOf("path");
 	private static final LuaString _SEARCHPATH  = valueOf("searchpath");
 	private static final LuaString _SEARCHERS   = valueOf("searchers");

 	/** The globals that were used to load this library. */
 	Globals globals;

 	/** The table for this package. */
 	LuaTable package_;

 	/** Loader that loads from {@link preload} table if found there */
 	public preload_searcher preload_searcher;

 	/** Loader that loads as a lua script using the lua path currently in {@link path} */
 	public lua_searcher lua_searcher;

 	/** Loader that loads as a Java class.  Class must have public constructor and be a LuaValue. */
 	public java_searcher java_searcher;

 	private static final LuaString _SENTINEL   = valueOf("\u0001");

 	private static final String FILE_SEP = System.getProperty("file.separator");

 	public PackageLib() {}

 	public LuaValue call(LuaValue modname, LuaValue env) {
 		globals = env.checkglobals();
 		globals.set("require", new require());
 		package_ = new LuaTable();
 		package_.set(_LOADED, new LuaTable());
 		package_.set(_PRELOAD, new LuaTable());
 		package_.set(_PATH, LuaValue.valueOf(DEFAULT_LUA_PATH));
 		package_.set(_LOADLIB, new loadlib());
 		package_.set(_SEARCHPATH, new searchpath());
 		LuaTable searchers = new LuaTable();
 		searchers.set(1, preload_searcher = new preload_searcher());
 		searchers.set(2, lua_searcher     = new lua_searcher());
 		searchers.set(3, java_searcher    = new java_searcher());
 		package_.set(_SEARCHERS, searchers);
 		package_.get(_LOADED).set("package", package_);
 		env.set("package", package_);
 		globals.package_ = this;
 		return env;
 	}

 	/** Allow packages to mark themselves as loaded */
 	public void setIsLoaded(String name, LuaTable value) {
 		package_.get(_LOADED).set(name, value);
 	}


 	/** Set the lua path used by this library instance to a new value.
 	 * Merely sets the value of {@link path} to be used in subsequent searches. */
 	public void setLuaPath( String newLuaPath ) {
 		package_.set(_PATH, LuaValue.valueOf(newLuaPath));
 	}

 	public String tojstring() {
 		return "package";
 	}

 	// ======================== Package loading =============================

 	/**
 	 * require (modname)
 	 *
 	 * Loads the given module. The function starts by looking into the package.loaded table
 	 * to determine whether modname is already loaded. If it is, then require returns the value
 	 * stored at package.loaded[modname]. Otherwise, it tries to find a loader for the module.
 	 *
 	 * To find a loader, require is guided by the package.searchers sequence.
 	 * By changing this sequence, we can change how require looks for a module.
 	 * The following explanation is based on the default configuration for package.searchers.
 	 *
 	 * First require queries package.preload[modname]. If it has a value, this value
 	 * (which should be a function) is the loader. Otherwise require searches for a Lua loader using
 	 * the path stored in package.path. If that also fails, it searches for a Java loader using
 	 * the classpath, using the public default constructor, and casting the instance to LuaFunction.
 	 *
 	 * Once a loader is found, require calls the loader with two arguments: modname and an extra value
 	 * dependent on how it got the loader. If the loader came from a file, this extra value is the file name.
 	 * If the loader is a Java instance of LuaFunction, this extra value is the environment.
 	 * If the loader returns any non-nil value, require assigns the returned value to package.loaded[modname].
 	 * If the loader does not return a non-nil value and has not assigned any value to package.loaded[modname],
 	 * then require assigns true to this entry.
 	 * In any case, require returns the final value of package.loaded[modname].
 	 *
 	 * If there is any error loading or running the module, or if it cannot find any loader for the module,
 	 * then require raises an error.
 	 */
 	public class require extends OneArgFunction {
 		public LuaValue call( LuaValue arg ) {
 			LuaString name = arg.checkstring();
 			LuaValue loaded = package_.get(_LOADED);
 			LuaValue result = loaded.get(name);
 			if ( result.toboolean() ) {
 				if ( result == _SENTINEL )
 					error("loop or previous error loading module '"+name+"'");
 				return result;
 			}

 			/* else must load it; iterate over available loaders */
 			LuaTable tbl = package_.get(_SEARCHERS).checktable();
 			StringBuffer sb = new StringBuffer();
 			Varargs loader = null;
 			for ( int i=1; true; i++ ) {
 				LuaValue searcher = tbl.get(i);
 				if ( searcher.isnil() ) {
 					error( "module '"+name+"' not found: "+name+sb );
 			    }

 			    /* call loader with module name as argument */
 				loader = searcher.invoke(name);
 				if ( loader.isfunction(1) )
 					break;
 				if ( loader.isstring(1) )
 					sb.append( loader.tojstring(1) );
 			}

 			// load the module using the loader
 			loaded.set(name, _SENTINEL);
 			result = loader.arg1().call(name, loader.arg(2));
 			if ( ! result.isnil() )
 				loaded.set( name, result );
 			else if ( (result = loaded.get(name)) == _SENTINEL )
 				loaded.set( name, result = LuaValue.TRUE );
 			return result;
 		}
 	}

 	public static class loadlib extends VarArgFunction {
 		public Varargs loadlib( Varargs args ) {
 			args.checkstring(1);
 			return varargsOf(NIL, valueOf("dynamic libraries not enabled"), valueOf("absent"));
 		}
 	}

 	public class preload_searcher extends VarArgFunction {
 		public Varargs invoke(Varargs args) {
 			LuaString name = args.checkstring(1);
 			LuaValue val = package_.get(_PRELOAD).get(name);
 			return val.isnil()?
 				valueOf("\n\tno field package.preload['"+name+"']"):
 				val;
 		}
 	}

 	public class lua_searcher extends VarArgFunction {
 		public Varargs invoke(Varargs args) {
 			LuaString name = args.checkstring(1);
 			InputStream is = null;

 			// get package path
 			LuaValue path = package_.get(_PATH);
 			if ( ! path.isstring() )
 				return valueOf("package.path is not a string");

 			// get the searchpath function.
 			Varargs v = package_.get(_SEARCHPATH).invoke(varargsOf(name, path));

 			// Did we get a result?
 			if (!v.isstring(1))
 				return v.arg(2).tostring();
 			LuaString filename = v.arg1().strvalue();

 			// Try to load the file.
 			v = globals.loadfile(filename.tojstring());
 			if ( v.arg1().isfunction() )
 				return LuaValue.varargsOf(v.arg1(), filename);

 			// report error
 			return varargsOf(NIL, valueOf("'"+filename+"': "+v.arg(2).tojstring()));
 		}
 	}

 	public class searchpath extends VarArgFunction {
 		public Varargs invoke(Varargs args) {
 			String name = args.checkjstring(1);
 			String path = args.checkjstring(2);
 			String sep = args.optjstring(3, ".");
 			String rep = args.optjstring(4, FILE_SEP);

 			// check the path elements
 			int e = -1;
 			int n = path.length();
 			StringBuffer sb = null;
 			name = name.replace(sep.charAt(0), rep.charAt(0));
 			while ( e < n ) {

 				// find next template
 				int b = e+1;
 				e = path.indexOf(';',b);
 				if ( e < 0 )
 					e = path.length();
 				String template = path.substring(b,e);

 				// create filename
 				int q = template.indexOf('?');
 				String filename = template;
 				if ( q >= 0 ) {
 					filename = template.substring(0,q) + name + template.substring(q+1);
 				}

 				// try opening the file
 				InputStream is = globals.finder.findResource(filename);
 				if (is != null) {
 					try { is.close(); } catch ( java.io.IOException ioe ) {}
 					return valueOf(filename);
 				}

 				// report error
 				if ( sb == null )
 					sb = new StringBuffer();
 				sb.append( "\n\t"+filename );
 			}
 			return varargsOf(NIL, valueOf(sb.toString()));
 		}
 	}

 	public class java_searcher extends VarArgFunction {
 		public Varargs invoke(Varargs args) {
 			String name = args.checkjstring(1);
 			String classname = toClassname( name );
 			Class c = null;
 			LuaValue v = null;
 			try {
 				c = Class.forName(classname);
 				v = (LuaValue) c.newInstance();
 				if (v.isfunction())
 					((LuaFunction)v).initupvalue1(globals);
 				return varargsOf(v, globals);
 			} catch ( ClassNotFoundException  cnfe ) {
 				return valueOf("\n\tno class '"+classname+"'" );
 			} catch ( Exception e ) {
 				return valueOf("\n\tjava load failed on '"+classname+"', "+e );
 			}
 		}
 	}

 	/** Convert lua filename to valid class name */
 	public static final String toClassname( String filename ) {
 		int n=filename.length();
 		int j=n;
 		if ( filename.endsWith(".lua") )
 			j -= 4;
 		for ( int k=0; k<j; k++ ) {
 			char c = filename.charAt(k);
 			if ( (!isClassnamePart(c)) || (c=='/') || (c=='\\') ) {
 				StringBuffer sb = new StringBuffer(j);
 				for ( int i=0; i<j; i++ ) {
 					c = filename.charAt(i);
 					sb.append(
 							 (isClassnamePart(c))? c:
 							 ((c=='/') || (c=='\\'))? '.': '_' );
 				}
 				return sb.toString();
 			}
 		}
 		return n==j? filename: filename.substring(0,j);
 	}

 	private static final boolean isClassnamePart(char c) {
 		if ( (c>='a'&&c<='z') || (c>='A'&&c<='Z') || (c>='0'&&c<='9') )
 			return true;
 		switch ( c ) {
 		case '.':
 		case '$':
 		case '_':
 			return true;
 		default:
 			return false;
 		}
 	}
 }
	/*******************************************************************************
	* Copyright (c) 2010-2011 Luaj.org. All rights reserved.
	*
	* Permission is hereby granted, free of charge, to any person obtaining a copy
	* of this software and associated documentation files (the "Software"), to deal
	* in the Software without restriction, including without limitation the rights
	* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
	* copies of the Software, and to permit persons to whom the Software is
	* furnished to do so, subject to the following conditions:
	*
	* The above copyright notice and this permission notice shall be included in
	* all copies or substantial portions of the Software.
	*
	* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
	* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
	* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
	* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
	* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
	* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
	* THE SOFTWARE.
	******************************************************************************/
	package org.luaj.vm3.lib;

	import java.io.InputStream;

	import org.luaj.vm3.Globals;
	import org.luaj.vm3.LuaFunction;
	import org.luaj.vm3.LuaString;
	import org.luaj.vm3.LuaTable;
	import org.luaj.vm3.LuaValue;
	import org.luaj.vm3.Varargs;

	/**
	* Subclass of {@link LibFunction} which implements the lua standard package and module
	* library functions.
	*
	* <h3>Lua Environment Variables</h3>
	* The following variables are available to lua scrips when this library has been loaded:
	* <ul>
	* <li><code>"package.loaded"</code> Lua table of loaded modules.
	* <li><code>"package.path"</code> Search path for lua scripts.
	* <li><code>"package.preload"</code> Lua table of uninitialized preload functions.
	* <li><code>"package.searchers"</code> Lua table of functions that search for object to load.
	* </ul>
	*
	* <h3>Java Environment Variables</h3>
	* These Java environment variables affect the library behavior:
	* <ul>
	* <li><code>"luaj.package.path"</code> Initial value for <code>"package.path"</code>. Default value is <code>"?.lua"</code>
	* </ul>
	*
	* <h3>Loading</h3>
	* Typically, this library is included as part of a call to either
	* {@link JsePlatform#standardGlobals()} or {@link JmePlatform#standardGlobals()}
	* <pre> {@code
	* Globals globals = JsePlatform.standardGlobals();
	* System.out.println( globals.get("require").call"foo") );
	* } </pre>
	* <p>
	* To instantiate and use it directly,
	* link it into your globals table via {@link LuaValue#load(LuaValue)} using code such as:
	* <pre> {@code
	* Globals globals = new Globals();
	* globals.load(new JseBaseLib());
	* globals.load(new PackageLib());
	* System.out.println( globals.get("require").call("foo") );
	* } </pre>
	* <h3>Limitations</h3>
	* This library has been implemented to match as closely as possible the behavior in the corresponding library in C.
	* However, the default filesystem search semantics are different and delegated to the bas library
	* as outlined in the {@link BaseLib} and {@link JseBaseLib} documentation.
	* <p>
	* @see LibFunction
	* @see BaseLib
	* @see JseBaseLib
	* @see JsePlatform
	* @see JmePlatform
	* @see <a href="http://www.lua.org/manual/5.2/manual.html#6.3">Lua 5.2 Package Lib Reference</a>
	*/
	public class PackageLib extends TwoArgFunction {

	/** The default value to use for package.path. This can be set with the system property
	* <code>"luaj.package.path"</code>, and is <code>"?.lua"</code> by default. */
	public static String DEFAULT_LUA_PATH;
	static {
	try {
	DEFAULT_LUA_PATH = System.getProperty("luaj.package.path");
	} catch (Exception e) {
	System.out.println(e.toString());
	}
	if (DEFAULT_LUA_PATH == null)
	DEFAULT_LUA_PATH = "?.lua";
	}

	private static final LuaString _LOADED = valueOf("loaded");
	private static final LuaString _LOADLIB = valueOf("loadlib");
	private static final LuaString _PRELOAD = valueOf("preload");
	private static final LuaString _PATH = valueOf("path");
	private static final LuaString _SEARCHPATH = valueOf("searchpath");
	private static final LuaString _SEARCHERS = valueOf("searchers");

	/** The globals that were used to load this library. */
	Globals globals;

	/** The table for this package. */
	LuaTable package_;

	/** Loader that loads from {@link preload} table if found there */
	public preload_searcher preload_searcher;

	/** Loader that loads as a lua script using the lua path currently in {@link path} */
	public lua_searcher lua_searcher;

	/** Loader that loads as a Java class. Class must have public constructor and be a LuaValue. */
	public java_searcher java_searcher;

	private static final LuaString _SENTINEL = valueOf("\u0001");

	private static final String FILE_SEP = System.getProperty("file.separator");

	public PackageLib() {}

	public LuaValue call(LuaValue modname, LuaValue env) {
	globals = env.checkglobals();
	globals.set("require", new require());
	package_ = new LuaTable();
	package_.set(_LOADED, new LuaTable());
	package_.set(_PRELOAD, new LuaTable());
	package_.set(_PATH, LuaValue.valueOf(DEFAULT_LUA_PATH));
	package_.set(_LOADLIB, new loadlib());
	package_.set(_SEARCHPATH, new searchpath());
	LuaTable searchers = new LuaTable();
	searchers.set(1, preload_searcher = new preload_searcher());
	searchers.set(2, lua_searcher = new lua_searcher());
	searchers.set(3, java_searcher = new java_searcher());
	package_.set(_SEARCHERS, searchers);
	package_.get(_LOADED).set("package", package_);
	env.set("package", package_);
	globals.package_ = this;
	return env;
	}

	/** Allow packages to mark themselves as loaded */
	public void setIsLoaded(String name, LuaTable value) {
	package_.get(_LOADED).set(name, value);
	}


	/** Set the lua path used by this library instance to a new value.
	* Merely sets the value of {@link path} to be used in subsequent searches. */
	public void setLuaPath( String newLuaPath ) {
	package_.set(_PATH, LuaValue.valueOf(newLuaPath));
	}

	public String tojstring() {
	return "package";
	}

	// ======================== Package loading =============================

	/**
	* require (modname)
	*
	* Loads the given module. The function starts by looking into the package.loaded table
	* to determine whether modname is already loaded. If it is, then require returns the value
	* stored at package.loaded[modname]. Otherwise, it tries to find a loader for the module.
	*
	* To find a loader, require is guided by the package.searchers sequence.
	* By changing this sequence, we can change how require looks for a module.
	* The following explanation is based on the default configuration for package.searchers.
	*
	* First require queries package.preload[modname]. If it has a value, this value
	* (which should be a function) is the loader. Otherwise require searches for a Lua loader using
	* the path stored in package.path. If that also fails, it searches for a Java loader using
	* the classpath, using the public default constructor, and casting the instance to LuaFunction.
	*
	* Once a loader is found, require calls the loader with two arguments: modname and an extra value
	* dependent on how it got the loader. If the loader came from a file, this extra value is the file name.
	* If the loader is a Java instance of LuaFunction, this extra value is the environment.
	* If the loader returns any non-nil value, require assigns the returned value to package.loaded[modname].
	* If the loader does not return a non-nil value and has not assigned any value to package.loaded[modname],
	* then require assigns true to this entry.
	* In any case, require returns the final value of package.loaded[modname].
	*
	* If there is any error loading or running the module, or if it cannot find any loader for the module,
	* then require raises an error.
	*/
	public class require extends OneArgFunction {
	public LuaValue call( LuaValue arg ) {
	LuaString name = arg.checkstring();
	LuaValue loaded = package_.get(_LOADED);
	LuaValue result = loaded.get(name);
	if ( result.toboolean() ) {
	if ( result == _SENTINEL )
	error("loop or previous error loading module '"+name+"'");
	return result;
	}

	/* else must load it; iterate over available loaders */
	LuaTable tbl = package_.get(_SEARCHERS).checktable();
	StringBuffer sb = new StringBuffer();
	Varargs loader = null;
	for ( int i=1; true; i++ ) {
	LuaValue searcher = tbl.get(i);
	if ( searcher.isnil() ) {
	error( "module '"+name+"' not found: "+name+sb );
	}

	/* call loader with module name as argument */
	loader = searcher.invoke(name);
	if ( loader.isfunction(1) )
	break;
	if ( loader.isstring(1) )
	sb.append( loader.tojstring(1) );
	}

	// load the module using the loader
	loaded.set(name, _SENTINEL);
	result = loader.arg1().call(name, loader.arg(2));
	if ( ! result.isnil() )
	loaded.set( name, result );
	else if ( (result = loaded.get(name)) == _SENTINEL )
	loaded.set( name, result = LuaValue.TRUE );
	return result;
	}
	}

	public static class loadlib extends VarArgFunction {
	public Varargs loadlib( Varargs args ) {
	args.checkstring(1);
	return varargsOf(NIL, valueOf("dynamic libraries not enabled"), valueOf("absent"));
	}
	}

	public class preload_searcher extends VarArgFunction {
	public Varargs invoke(Varargs args) {
	LuaString name = args.checkstring(1);
	LuaValue val = package_.get(_PRELOAD).get(name);
	return val.isnil()?
	valueOf("\n\tno field package.preload['"+name+"']"):
	val;
	}
	}

	public class lua_searcher extends VarArgFunction {
	public Varargs invoke(Varargs args) {
	LuaString name = args.checkstring(1);
	InputStream is = null;

	// get package path
	LuaValue path = package_.get(_PATH);
	if ( ! path.isstring() )
	return valueOf("package.path is not a string");

	// get the searchpath function.
	Varargs v = package_.get(_SEARCHPATH).invoke(varargsOf(name, path));

	// Did we get a result?
	if (!v.isstring(1))
	return v.arg(2).tostring();
	LuaString filename = v.arg1().strvalue();

	// Try to load the file.
	v = globals.loadfile(filename.tojstring());
	if ( v.arg1().isfunction() )
	return LuaValue.varargsOf(v.arg1(), filename);

	// report error
	return varargsOf(NIL, valueOf("'"+filename+"': "+v.arg(2).tojstring()));
	}
	}

	public class searchpath extends VarArgFunction {
	public Varargs invoke(Varargs args) {
	String name = args.checkjstring(1);
	String path = args.checkjstring(2);
	String sep = args.optjstring(3, ".");
	String rep = args.optjstring(4, FILE_SEP);

	// check the path elements
	int e = -1;
	int n = path.length();
	StringBuffer sb = null;
	name = name.replace(sep.charAt(0), rep.charAt(0));
	while ( e < n ) {

	// find next template
	int b = e+1;
	e = path.indexOf(';',b);
	if ( e < 0 )
	e = path.length();
	String template = path.substring(b,e);

	// create filename
	int q = template.indexOf('?');
	String filename = template;
	if ( q >= 0 ) {
	filename = template.substring(0,q) + name + template.substring(q+1);
	}

	// try opening the file
	InputStream is = globals.finder.findResource(filename);
	if (is != null) {
	try { is.close(); } catch ( java.io.IOException ioe ) {}
	return valueOf(filename);
	}

	// report error
	if ( sb == null )
	sb = new StringBuffer();
	sb.append( "\n\t"+filename );
	}
	return varargsOf(NIL, valueOf(sb.toString()));
	}
	}

	public class java_searcher extends VarArgFunction {
	public Varargs invoke(Varargs args) {
	String name = args.checkjstring(1);
	String classname = toClassname( name );
	Class c = null;
	LuaValue v = null;
	try {
	c = Class.forName(classname);
	v = (LuaValue) c.newInstance();
	if (v.isfunction())
	((LuaFunction)v).initupvalue1(globals);
	return varargsOf(v, globals);
	} catch ( ClassNotFoundException cnfe ) {
	return valueOf("\n\tno class '"+classname+"'" );
	} catch ( Exception e ) {
	return valueOf("\n\tjava load failed on '"+classname+"', "+e );
	}
	}
	}

	/** Convert lua filename to valid class name */
	public static final String toClassname( String filename ) {
	int n=filename.length();
	int j=n;
	if ( filename.endsWith(".lua") )
	j -= 4;
	for ( int k=0; k<j; k++ ) {
	char c = filename.charAt(k);
	if ( (!isClassnamePart(c)) \|\| (c=='/') \|\| (c=='\\') ) {
	StringBuffer sb = new StringBuffer(j);
	for ( int i=0; i<j; i++ ) {
	c = filename.charAt(i);
	sb.append(
	(isClassnamePart(c))? c:
	((c=='/') \|\| (c=='\\'))? '.': '_' );
	}
	return sb.toString();
	}
	}
	return n==j? filename: filename.substring(0,j);
	}

	private static final boolean isClassnamePart(char c) {
	if ( (c>='a'&&c<='z') \|\| (c>='A'&&c<='Z') \|\| (c>='0'&&c<='9') )
	return true;
	switch ( c ) {
	case '.':
	case '$':
	case '_':
	return true;
	default:
	return false;
	}
	}
	}