Split LexGenerator out of Main

jflex-maven-plugin/src/main/java/de/jflex/plugin/maven/JFlexMojo.java

@@ -21,7 +21,7 @@
 import java.util.Arrays;
 import java.util.List;
 import java.util.Objects;
-import jflex.Main;
+import jflex.LexGenerator;
 import jflex.Options;
 import org.apache.maven.plugin.AbstractMojo;
 import org.apache.maven.plugin.MojoExecutionException;
@@ -235,7 +235,7 @@ private void parseLexFile(File lexFile) throws MojoFailureException, MojoExecuti
     }
 
     try {
-      Main.generate(lexFile);
+      LexGenerator.generate(lexFile);
       getLog().info("  generated " + generatedFile);
     } catch (Exception e) {
       throw new MojoExecutionException(e.getMessage(), e);

jflex/src/main/java/jflex/Emitter.java

@@ -408,7 +408,7 @@ private void emitNextInput() {
 
   private void emitHeader() {
     println("// DO NOT EDIT");
-    println("// Generated by JFlex " + Main.version + " http://jflex.de/");
+    println("// Generated by JFlex " + LexGenerator.VERSION + " http://jflex.de/");
     String path = FileUtil.getRelativePath(Options.getRootDirectory(), inputFile);
     if (File.separatorChar == '\\') {
       path = FileUtil.slashify(path);

jflex/src/main/java/jflex/LexGenerator.java

@@ -0,0 +1,130 @@
+/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
+ * JFlex 1.7.1-SNAPSHOT                                                    *
+ * Copyright (C) 1998-2018  Gerwin Klein <[email protected]>                    *
+ * All rights reserved.                                                    *
+ *                                                                         *
+ * License: BSD                                                            *
+ *                                                                         *
+ * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
+
+package jflex;
+
+import static jflex.Options.encoding;
+
+import java.io.File;
+import java.io.IOException;
+import java.io.InputStreamReader;
+import java.io.Reader;
+import java.nio.file.Files;
+import java.nio.file.Paths;
+
+/**
+ * This is the generator of JFlex, controlling the scanner generation process.
+ *
+ * @author Gerwin Klein
+ * @author Régis Décamps
+ * @version JFlex 1.7.1-SNAPSHOT
+ */
+public class LexGenerator {
+
+  /** JFlex version */
+  public static final String VERSION = "1.7.1-SNAPSHOT"; // $NON-NLS-1$
+
+  /**
+   * Generates a scanner for the specified input file.
+   *
+   * @param inputFile a file containing a lexical specification to generate a scanner for.
+   */
+  public static void generate(File inputFile) {
+
+    Out.resetCounters();
+
+    Timer totalTime = new Timer();
+    Timer time = new Timer();
+
+    LexScan scanner = null;
+    LexParse parser = null;
+    Reader inputReader = null;
+
+    totalTime.start();
+
+    try {
+      Out.println(ErrorMessages.READING, inputFile.toString());
+      inputReader =
+          new InputStreamReader(Files.newInputStream(Paths.get(inputFile.toString())), encoding);
+      scanner = new LexScan(inputReader);
+      scanner.setFile(inputFile);
+      parser = new LexParse(scanner);
+    } catch (IOException e) {
+      Out.error(ErrorMessages.CANNOT_OPEN, inputFile.toString());
+      throw new GeneratorException();
+    }
+
+    try {
+      NFA nfa = (NFA) parser.parse().value;
+
+      Out.checkErrors();
+
+      if (Options.dump) Out.dump(ErrorMessages.get(ErrorMessages.NFA_IS) + Out.NL + nfa + Out.NL);
+
+      if (Options.dot) nfa.writeDot(Emitter.normalize("nfa.dot", null)); // $NON-NLS-1$
+
+      Out.println(ErrorMessages.NFA_STATES, nfa.numStates);
+
+      time.start();
+      DFA dfa = nfa.getDFA();
+      time.stop();
+      Out.time(ErrorMessages.DFA_TOOK, time);
+
+      dfa.checkActions(scanner, parser);
+
+      nfa = null;
+
+      if (Options.dump) Out.dump(ErrorMessages.get(ErrorMessages.DFA_IS) + Out.NL + dfa + Out.NL);
+
+      if (Options.dot) dfa.writeDot(Emitter.normalize("dfa-big.dot", null)); // $NON-NLS-1$
+
+      Out.checkErrors();
+
+      time.start();
+      dfa.minimize();
+      time.stop();
+
+      Out.time(ErrorMessages.MIN_TOOK, time);
+
+      if (Options.dump) Out.dump(ErrorMessages.get(ErrorMessages.MIN_DFA_IS) + Out.NL + dfa);
+
+      if (Options.dot) dfa.writeDot(Emitter.normalize("dfa-min.dot", null)); // $NON-NLS-1$
+
+      time.start();
+
+      Emitter e = new Emitter(inputFile, parser, dfa);
+      e.emit();
+
+      time.stop();
+
+      Out.time(ErrorMessages.WRITE_TOOK, time);
+
+      totalTime.stop();
+
+      Out.time(ErrorMessages.TOTAL_TIME, totalTime);
+    } catch (ScannerException e) {
+      Out.error(e.file, e.message, e.line, e.column);
+      throw new GeneratorException();
+    } catch (MacroException e) {
+      Out.error(e.getMessage());
+      throw new GeneratorException();
+    } catch (IOException e) {
+      Out.error(ErrorMessages.IO_ERROR, e.toString());
+      throw new GeneratorException();
+    } catch (OutOfMemoryError e) {
+      Out.error(ErrorMessages.OUT_OF_MEMORY);
+      throw new GeneratorException();
+    } catch (GeneratorException e) {
+      throw new GeneratorException();
+    } catch (Exception e) {
+      e.printStackTrace();
+      throw new GeneratorException();
+    }
+  }
+}

jflex/src/main/java/jflex/Main.java

@@ -10,18 +10,12 @@
 package jflex;
 
 import static jflex.ErrorMessages.NO_ENCODING;
-import static jflex.Options.encoding;
 import static jflex.Options.setEncoding;
 import static jflex.Options.unused_warning;
 import static jflex.Out.error;
 
 import java.io.File;
-import java.io.IOException;
-import java.io.InputStreamReader;
-import java.io.Reader;
 import java.lang.reflect.Field;
-import java.nio.file.Files;
-import java.nio.file.Paths;
 import java.util.ArrayList;
 import java.util.List;
 import java.util.Map;
@@ -36,124 +30,25 @@
 import jflex.unicode.UnicodeProperties;
 
 /**
- * This is the main class of JFlex controlling the scanner generation process. It is responsible for
- * parsing the commandline, getting input files, starting up the GUI if necessary, etc.
+ * This is the command-line interface.
+ *
+ * <p>It is responsible for parsing the commandline, getting input files, starting up the GUI if
+ * necessary, etc. and invokes {@link LexGenerator} accordingly.
  *
  * @author Gerwin Klein
  * @author Régis Décamps
  * @version JFlex 1.7.1-SNAPSHOT
  */
 public class Main {
 
-  /** JFlex version */
-  public static final String version = "1.7.1-SNAPSHOT"; // $NON-NLS-1$
-
-  /**
-   * Generates a scanner for the specified input file.
-   *
-   * @param inputFile a file containing a lexical specification to generate a scanner for.
-   */
-  public static void generate(File inputFile) {
-
-    Out.resetCounters();
-
-    Timer totalTime = new Timer();
-    Timer time = new Timer();
-
-    LexScan scanner = null;
-    LexParse parser = null;
-    Reader inputReader = null;
-
-    totalTime.start();
-
-    try {
-      Out.println(ErrorMessages.READING, inputFile.toString());
-      inputReader =
-          new InputStreamReader(Files.newInputStream(Paths.get(inputFile.toString())), encoding);
-      scanner = new LexScan(inputReader);
-      scanner.setFile(inputFile);
-      parser = new LexParse(scanner);
-    } catch (IOException e) {
-      Out.error(ErrorMessages.CANNOT_OPEN, inputFile.toString());
-      throw new GeneratorException();
-    }
-
-    try {
-      NFA nfa = (NFA) parser.parse().value;
-
-      Out.checkErrors();
-
-      if (Options.dump) Out.dump(ErrorMessages.get(ErrorMessages.NFA_IS) + Out.NL + nfa + Out.NL);
-
-      if (Options.dot) nfa.writeDot(Emitter.normalize("nfa.dot", null)); // $NON-NLS-1$
-
-      Out.println(ErrorMessages.NFA_STATES, nfa.numStates);
-
-      time.start();
-      DFA dfa = nfa.getDFA();
-      time.stop();
-      Out.time(ErrorMessages.DFA_TOOK, time);
-
-      dfa.checkActions(scanner, parser);
-
-      nfa = null;
-
-      if (Options.dump) Out.dump(ErrorMessages.get(ErrorMessages.DFA_IS) + Out.NL + dfa + Out.NL);
-
-      if (Options.dot) dfa.writeDot(Emitter.normalize("dfa-big.dot", null)); // $NON-NLS-1$
-
-      Out.checkErrors();
-
-      time.start();
-      dfa.minimize();
-      time.stop();
-
-      Out.time(ErrorMessages.MIN_TOOK, time);
-
-      if (Options.dump) Out.dump(ErrorMessages.get(ErrorMessages.MIN_DFA_IS) + Out.NL + dfa);
-
-      if (Options.dot) dfa.writeDot(Emitter.normalize("dfa-min.dot", null)); // $NON-NLS-1$
-
-      time.start();
-
-      Emitter e = new Emitter(inputFile, parser, dfa);
-      e.emit();
-
-      time.stop();
-
-      Out.time(ErrorMessages.WRITE_TOOK, time);
-
-      totalTime.stop();
-
-      Out.time(ErrorMessages.TOTAL_TIME, totalTime);
-    } catch (ScannerException e) {
-      Out.error(e.file, e.message, e.line, e.column);
-      throw new GeneratorException();
-    } catch (MacroException e) {
-      Out.error(e.getMessage());
-      throw new GeneratorException();
-    } catch (IOException e) {
-      Out.error(ErrorMessages.IO_ERROR, e.toString());
-      throw new GeneratorException();
-    } catch (OutOfMemoryError e) {
-      Out.error(ErrorMessages.OUT_OF_MEMORY);
-      throw new GeneratorException();
-    } catch (GeneratorException e) {
-      throw new GeneratorException();
-    } catch (Exception e) {
-      e.printStackTrace();
-      throw new GeneratorException();
-    }
-  }
-
   /**
    * parseOptions.
    *
    * @param argv an array of {@link java.lang.String} objects.
    * @return a {@link java.util.List} object.
    * @throws jflex.SilentExit if any.
    */
-  public static List<File> parseOptions(String argv[]) throws SilentExit {
+  private static List<File> parseOptions(String argv[]) throws SilentExit {
     List<File> files = new ArrayList<>();
 
     for (int i = 0; i < argv.length; i++) {
@@ -237,7 +132,7 @@ public static List<File> parseOptions(String argv[]) throws SilentExit {
 
       if (Objects.equals(argv[i], "--version")
           || Objects.equals(argv[i], "-version")) { // $NON-NLS-1$ //$NON-NLS-2$
-        Out.println(ErrorMessages.THIS_IS_JFLEX, version);
+        Out.println(ErrorMessages.THIS_IS_JFLEX, LexGenerator.VERSION);
         throw new SilentExit(0);
       }
 
@@ -377,7 +272,7 @@ private static void printUnicodePropertyValuesAndAliases(String unicodeVersion)
   }
 
   /** Prints the cli usage on stdout. */
-  public static void printUsage() {
+  private static void printUsage() {
     Out.println(""); // $NON-NLS-1$
     Out.println("Usage: jflex <options> <input-files>");
     Out.println("");
@@ -404,7 +299,7 @@ public static void printUsage() {
     Out.println("--help");
     Out.println("-h                 print this message");
     Out.println("");
-    Out.println(ErrorMessages.THIS_IS_JFLEX, version);
+    Out.println(ErrorMessages.THIS_IS_JFLEX, LexGenerator.VERSION);
     Out.println("Have a nice day!");
   }
 
@@ -418,7 +313,9 @@ public static void generate(String argv[]) throws SilentExit {
     List<File> files = parseOptions(argv);
 
     if (files.size() > 0) {
-      for (File file : files) generate(file);
+      for (File file : files) {
+        LexGenerator.generate(file);
+      }
     } else {
       new MainFrame();
     }
@@ -440,4 +337,7 @@ public static void main(String argv[]) {
       System.exit(e.exitCode());
     }
   }
+
+  // Only CLI, not meant for instanciation.
+  private Main() {}
 }

jflex/src/main/java/jflex/Out.java

@@ -403,7 +403,7 @@ public static void printSystemInfo() {
     err("OS version:       " + System.getProperty("os.version"));
     err("Encoding:         " + System.getProperty("file.encoding"));
     err("Unicode versions: " + UnicodeProperties.UNICODE_VERSIONS);
-    err("JFlex version:    " + Main.version);
+    err("JFlex version:    " + LexGenerator.VERSION);
   }
 
   /**

jflex/src/main/java/jflex/anttask/JFlexTask.java

@@ -16,7 +16,7 @@
 import java.io.LineNumberReader;
 import java.util.regex.Matcher;
 import java.util.regex.Pattern;
-import jflex.Main;
+import jflex.LexGenerator;
 import jflex.Options;
 import org.apache.tools.ant.BuildException;
 import org.apache.tools.ant.Task;
@@ -69,7 +69,7 @@ public void execute() throws BuildException {
         File destFile = new File(outputDir, className + ".java");
 
         if (inputFile.lastModified() > destFile.lastModified()) {
-          Main.generate(inputFile);
+          LexGenerator.generate(inputFile);
           if (!Options.verbose) System.out.println("Generated: " + destFile.getName());
         }
       } catch (IOException e1) {

jflex/src/main/java/jflex/gui/GeneratorThread.java

@@ -13,7 +13,7 @@
 import java.util.Objects;
 import jflex.ErrorMessages;
 import jflex.GeneratorException;
-import jflex.Main;
+import jflex.LexGenerator;
 import jflex.Options;
 import jflex.Out;
 
@@ -62,7 +62,7 @@ public void run() {
         if (!Objects.equals(outputDir, "")) {
           Options.setDir(outputDir);
         }
-        Main.generate(new File(inputFile));
+        LexGenerator.generate(new File(inputFile));
         Out.statistics();
         parent.generationFinished(true);
       } catch (GeneratorException e) {