typicalcompilerscannerbylolo.java

JAVA在编译原理上的应用。

package lolo.test;

import lolo.Input;
import lolo.Scan;
import lolo.Scan.Action;
import lolo.Scanner;

import lolo.scans.Word;
import lolo.scans.JavaIdentifier;
import lolo.scans.SimpleIdentifier;
import lolo.scans.Int;
import lolo.scans.SimpleWhitespace;
import lolo.scans.JavaWhitespace;
import lolo.scans.Flt;
import lolo.scans.QuotedText;
import lolo.scans.QuotedChar;
import lolo.scans.SlashSlashComment;
import lolo.scans.Set;
import lolo.scans.JavadocComment;

import java.io.StringReader;
import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.io.ObjectOutputStream;
import java.io.ObjectInputStream;
import java.io.FileOutputStream;
import java.io.FileInputStream;
import java.io.FileReader;

/** An example to meassure the scanning time using lolo for typical symbols
 * in compiler construction.
 *
 * @author <a href="http://www.inf.uos.de/bernd" target="_blank">Bernd K&uuml;hl</a>
           (<a href="mailto:[e-mail]">[e-mail]</a>)
 */
public class TypicalCompilerScannerByLolo {
    public static void main(String args[]) throws Exception {
        Action wordAction = new Action () {
            public void action(Scan sender, char [] buffer, int off, int len) {
                PrintTypicalCompilerSymbols.word(new String(buffer, off, len));
            }
        };
        Action commentAction = new Action () {
            public void action(Scan sender, char [] buffer, int off, int len) {
                PrintTypicalCompilerSymbols.comment(new String(buffer, off, len));
            }
        };
        Scanner scanner = new Scanner();
        
        scanner.add(new Word("<=").setAction(wordAction));
        scanner.add(new Word(">=").setAction(wordAction));
        scanner.add(new Word("==").setAction(wordAction));
        scanner.add(new Word("&&").setAction(wordAction));
        scanner.add(new Word("||").setAction(wordAction));

        scanner.add(new Int().setAction(new Action() {
            public void action(Scan sender, char [] buffer, int off, int len) {
                PrintTypicalCompilerSymbols.integer(new String(buffer, off, len));
            }
        }));
        scanner.add(new Flt(false).setAction(new Action() {
            public void action(Scan sender, char [] buffer, int off, int len) {
                PrintTypicalCompilerSymbols.floating(new String(buffer, off, len));
            }
        }));

        scanner.add(new SimpleIdentifier().setAction(new Action() {
            public void action(Scan sender, char [] buffer, int off, int len) {
                PrintTypicalCompilerSymbols.identifier(new String(buffer, off, len));
            }
        }));
        scanner.add(new SimpleWhitespace().setIgnore(false).setAction(new Action() {
            public void action(Scan sender, char [] buffer, int off, int len) {
                PrintTypicalCompilerSymbols.whitespace(new String(buffer, off, len));
            }
        }));
        scanner.add(new QuotedText().setAction(new Action() {
            public void action(Scan sender, char [] buffer, int off, int len) {
                PrintTypicalCompilerSymbols.quotedText(new String(buffer, off, len));
            }
        }));
        scanner.add(new QuotedChar().setAction(new Action() {
            public void action(Scan sender, char [] buffer, int off, int len) {
                PrintTypicalCompilerSymbols.quotedChar(buffer[off]);
            }
        }));
        scanner.add(new Set("+-=/@*/!<>?:;|[]{}().,%&").setAction(new Action() {
            public void action(Scan sender, char [] buffer, int off, int len) {
                PrintTypicalCompilerSymbols.character(buffer[off]);
            }
        }));
        scanner.add(new SlashSlashComment().setAction(commentAction).setIgnore(false));
        scanner.add(new JavadocComment().setAction(commentAction).setIgnore(false));

        if (System.getProperty("TypicalCompilerScannerByLolo.unicode") != null)
            scanner.setUnicode(true);  // forces repack of table
        int bufferSize = 1024;
        try {
            bufferSize = Integer.parseInt(System.getProperty("TypicalCompilerScannerByLolo.bufferSize"));
        } catch (Exception e) {
            System.err.println(e);
        }
        
        scanner.pack();

System.err.println("go (bufferSize "+bufferSize+", unicode "+scanner.getUnicode()+")...");
        long old = System.currentTimeMillis();
System.err.println("start time\t"+old+"...");
        Input input = new Input(args.length != 0 ? new FileReader(args[0]) :new InputStreamReader(System.in), bufferSize);
        while (scanner.scan(input) != null)
            ;
            
        long current = System.currentTimeMillis();
System.err.println("end time\t"+current+"...");
        TimeUtil.printMilliSecons("time: ",current-old, System.err);
    }
}