--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/luan/impl/Compiled.java	Sun Dec 29 15:25:07 2019 -0700
@@ -0,0 +1,191 @@
+package luan.impl;
+
+import java.io.OutputStream;
+import java.io.ByteArrayOutputStream;
+import java.io.StringWriter;
+import java.io.File;
+import java.io.FileInputStream;
+import java.io.FileOutputStream;
+import java.io.DataInputStream;
+import java.io.DataOutputStream;
+import java.io.IOException;
+import java.net.URI;
+import java.util.Collections;
+import java.util.Map;
+import java.util.HashMap;
+import java.util.Set;
+import java.util.HashSet;
+import javax.tools.FileObject;
+import javax.tools.JavaFileObject;
+import javax.tools.SimpleJavaFileObject;
+import javax.tools.JavaCompiler;
+import javax.tools.ToolProvider;
+import javax.tools.JavaFileManager;
+import javax.tools.StandardJavaFileManager;
+import javax.tools.ForwardingJavaFileManager;
+import goodjava.logging.Logger;
+import goodjava.logging.LoggerFactory;
+
+
+final class Compiled {
+	private static final Logger logger = LoggerFactory.getLogger(Compiled.class);
+
+	private static class MyJavaFileObject extends SimpleJavaFileObject {
+		final ByteArrayOutputStream baos = new ByteArrayOutputStream();
+
+		MyJavaFileObject() {
+			super(URI.create("whatever"),JavaFileObject.Kind.CLASS);
+		}
+
+		@Override public OutputStream openOutputStream() {
+			return baos;
+		}
+
+		byte[] byteCode(String sourceName) {
+			byte[] byteCode = baos.toByteArray();
+			final int len = sourceName.length();
+			int max = byteCode.length-len-3;
+			outer:
+			for( int i=0; true; i++ ) {
+				if( i > max )
+					throw new RuntimeException("len="+len);
+				if( byteCode[i]==1 && (byteCode[i+1] << 8 | 0xFF & byteCode[i+2]) == len ) {
+					for( int j=i+3; j<i+3+len; j++ ) {
+						if( byteCode[j] != '$' )
+							continue outer;
+					}
+					System.arraycopy(sourceName.getBytes(),0,byteCode,i+3,len);
+					break;
+				}
+			}
+			return byteCode;
+		}
+	}
+
+	static Compiled compile(final String className,final String sourceName,final String code) {
+		final int len = sourceName.length();
+		StringBuilder sb = new StringBuilder(sourceName);
+		for( int i=0; i<len; i++ )
+			sb.setCharAt(i,'$');
+		JavaFileObject sourceFile = new SimpleJavaFileObject(URI.create(sb.toString()),JavaFileObject.Kind.SOURCE) {
+			@Override public CharSequence getCharContent(boolean ignoreEncodingErrors) {
+				return code;
+			}
+			@Override public String getName() {
+				return sourceName;
+			}
+			@Override public boolean isNameCompatible(String simpleName,JavaFileObject.Kind kind) {
+				return true;
+			}
+		};
+		final Map<String,MyJavaFileObject> map = new HashMap<String,MyJavaFileObject>();
+		JavaCompiler compiler = ToolProvider.getSystemJavaCompiler();
+		StandardJavaFileManager sjfm = compiler.getStandardFileManager(null,null,null);
+		ForwardingJavaFileManager fjfm = new ForwardingJavaFileManager(sjfm) {
+			@Override public JavaFileObject getJavaFileForOutput(JavaFileManager.Location location, String className, JavaFileObject.Kind kind, FileObject sibling) throws IOException {
+				if( map.containsKey(className) )
+					throw new RuntimeException(className);
+				MyJavaFileObject classFile = new MyJavaFileObject();
+				map.put(className,classFile);
+				return classFile;
+			}
+		};
+		StringWriter out = new StringWriter();
+		boolean b = compiler.getTask(out, fjfm, null, null, null, Collections.singletonList(sourceFile)).call();
+		if( !b )
+			throw new RuntimeException("\n"+out+"\ncode:\n"+code+"\n");
+		Map<String,byte[]> map2 = new HashMap<String,byte[]>();
+		for( Map.Entry<String,MyJavaFileObject> entry : map.entrySet() ) {
+			map2.put( entry.getKey(), entry.getValue().byteCode(sourceName) );
+		}
+		return new Compiled(className,map2);
+	}
+
+
+	private final String className;
+	private final Map<String,byte[]> map;
+	private final Set<String> set = new HashSet<String>();
+
+	private Compiled(String className,Map<String,byte[]> map) {
+		this.className = className;
+		this.map = map;
+	}
+
+	Class loadClass() {
+		try {
+			ClassLoader cl = new ClassLoader() {
+				@Override protected Class<?> findClass(String name) throws ClassNotFoundException {
+					if( !set.add(name) )
+						logger.error("dup "+name);
+					byte[] byteCode = map.get(name);
+					if( byteCode != null ) {
+						return defineClass(name, byteCode, 0, byteCode.length);
+					}
+					return super.findClass(name);
+				}
+			};
+			return cl.loadClass(className);
+		} catch(ClassNotFoundException e) {
+			throw new RuntimeException(e);
+		}
+	}
+
+
+	private static final int VERSION = 1;
+	private static final File tmpDir;
+	static {
+		File f = new File(System.getProperty("java.io.tmpdir"));
+		tmpDir = new File(f,"luan");
+		tmpDir.mkdir();
+		if( !tmpDir.exists() )
+			throw new RuntimeException();
+	}
+
+	static Compiled load(String fileName,String key) {
+		try {
+			File f = new File(tmpDir,fileName);
+			if( !f.exists() )
+				return null;
+			DataInputStream in = new DataInputStream(new FileInputStream(f));
+			if( in.readInt() != VERSION )
+				return null;
+			if( !in.readUTF().equals(key) )
+				return null;
+			String className = in.readUTF();
+			int n = in.readInt();
+			Map<String,byte[]> map = new HashMap<String,byte[]>();
+			for( int i=0; i<n; i++ ) {
+				String s = in.readUTF();
+				int len = in.readInt();
+				byte[] a = new byte[len];
+				in.readFully(a);
+				map.put(s,a);
+			}
+			in.close();
+			return new Compiled(className,map);
+		} catch(IOException e) {
+			logger.error("load failed",e);
+			return null;
+		}
+	}
+
+	void save(String fileName,String key) {
+		try {
+			File f = new File(tmpDir,fileName);
+			DataOutputStream out = new DataOutputStream(new FileOutputStream(f));
+			out.writeInt(VERSION);
+			out.writeUTF(key);
+			out.writeUTF(className);
+			out.writeInt(map.size());
+			for( Map.Entry<String,byte[]> entry : map.entrySet() ) {
+				out.writeUTF( entry.getKey() );
+				byte[] a = entry.getValue();
+				out.writeInt(a.length);
+				out.write(a,0,a.length);
+			}
+			out.close();
+		} catch(IOException e) {
+			logger.error("save failed",e);
+		}
+	}
+}