Customizing the error messages

.gitignore

@@ -1,2 +1,3 @@
 *.java
 *.class
+doc/*

Makefile

@@ -1,6 +1,4 @@
-all:
-	javacc pascal.jj
-	javac -cp . Pascal.java
+all: precompile_javacc apply_patches build_precompiled_javacc
 
 lex_test1:
 	echo "========== Lexical Test 1 - Should pass: ===========\n\n\n"
@@ -12,4 +10,13 @@ lex_test3:
 	echo "Lexical Test 3 - Should give an error:"
 
 clean:
-	rm *.java || rm *.class
+	rm *.java && rm *.class
+
+apply_patches:
+	cp patches/* .
+
+precompile_javacc:
+	javacc pascal.jj
+
+build_precompiled_javacc:
+	javac -cp . Pascal.java

examples/lexical/correct1.pas

@@ -3,7 +3,8 @@
   var_1: integer;
   var_2: integer;
   var_3: integer;
-
+
+  %
   var_1 := 1;
   var_2 := 2;
   {var_1 := 3;

patches/TokenMgrError.java

@@ -0,0 +1,145 @@
+/* Generated By:JavaCC: Do not edit this line. TokenMgrError.java Version 5.0 */
+/* JavaCCOptions: */
+/** Token Manager Error. */
+public class TokenMgrError extends Error
+{
+
+  /**
+   * The version identifier for this Serializable class.
+   * Increment only if the <i>serialized</i> form of the
+   * class changes.
+   */
+  private static final long serialVersionUID = 1L;
+
+  /*
+   * Ordinals for various reasons why an Error of this type can be thrown.
+   */
+
+  /**
+   * Lexical error occurred.
+   */
+  static final int LEXICAL_ERROR = 0;
+
+  /**
+   * An attempt was made to create a second instance of a static token manager.
+   */
+  static final int STATIC_LEXER_ERROR = 1;
+
+  /**
+   * Tried to change to an invalid lexical state.
+   */
+  static final int INVALID_LEXICAL_STATE = 2;
+
+  /**
+   * Detected (and bailed out of) an infinite loop in the token manager.
+   */
+  static final int LOOP_DETECTED = 3;
+
+  /**
+   * Indicates the reason why the exception is thrown. It will have
+   * one of the above 4 values.
+   */
+  int errorCode;
+
+  /**
+   * Replaces unprintable characters by their escaped (or unicode escaped)
+   * equivalents in the given string
+   */
+  protected static final String addEscapes(String str) {
+    StringBuffer retval = new StringBuffer();
+    char ch;
+    for (int i = 0; i < str.length(); i++) {
+      switch (str.charAt(i))
+      {
+        case 0 :
+          continue;
+        case '\b':
+          retval.append("\\b");
+          continue;
+        case '\t':
+          retval.append("\\t");
+          continue;
+        case '\n':
+          retval.append("\\n");
+          continue;
+        case '\f':
+          retval.append("\\f");
+          continue;
+        case '\r':
+          retval.append("\\r");
+          continue;
+        case '\"':
+          retval.append("\\\"");
+          continue;
+        case '\'':
+          retval.append("\\\'");
+          continue;
+        case '\\':
+          retval.append("\\\\");
+          continue;
+        default:
+          if ((ch = str.charAt(i)) < 0x20 || ch > 0x7e) {
+            String s = "0000" + Integer.toString(ch, 16);
+            retval.append("\\u" + s.substring(s.length() - 4, s.length()));
+          } else {
+            retval.append(ch);
+          }
+          continue;
+      }
+    }
+    return retval.toString();
+  }
+
+  /**
+   * Returns a detailed message for the Error when it is thrown by the
+   * token manager to indicate a lexical error.
+   * Parameters :
+   *    EOFSeen     : indicates if EOF caused the lexical error
+   *    curLexState : lexical state in which this error occurred
+   *    errorLine   : line number when the error occurred
+   *    errorColumn : column number when the error occurred
+   *    errorAfter  : prefix that was seen before this error occurred
+   *    curchar     : the offending character
+   * Note: You can customize the lexical error message by modifying this method.
+   */
+  protected static String LexicalError(boolean EOFSeen, int lexState, int errorLine, int errorColumn, String errorAfter, char curChar) {
+    return("Erro léxico encontrado na linha " +
+          errorLine + ", coluna " +
+          errorColumn + ".  Encontrado: " +
+          (EOFSeen ? "<EOF> " : ("\"" + addEscapes(String.valueOf(curChar)) + "\"") + " (" + (int)curChar + "), ") +
+          "após : \"" + addEscapes(errorAfter) + "\"");
+  }
+
+  /**
+   * You can also modify the body of this method to customize your error messages.
+   * For example, cases like LOOP_DETECTED and INVALID_LEXICAL_STATE are not
+   * of end-users concern, so you can return something like :
+   *
+   *     "Internal Error : Please file a bug report .... "
+   *
+   * from this method for such cases in the release version of your parser.
+   */
+  public String getMessage() {
+    return super.getMessage();
+  }
+
+  /*
+   * Constructors of various flavors follow.
+   */
+
+  /** No arg constructor. */
+  public TokenMgrError() {
+  }
+
+  /** Constructor with message and reason. */
+  public TokenMgrError(String message, int reason) {
+    super(message);
+    errorCode = reason;
+  }
+
+  /** Full Constructor. */
+  public TokenMgrError(boolean EOFSeen, int lexState, int errorLine, int errorColumn, String errorAfter, char curChar, int reason) {
+    this(LexicalError(EOFSeen, lexState, errorLine, errorColumn, errorAfter, curChar), reason);
+  }
+}
+/* JavaCC - OriginalChecksum=3f827858bf5c87e5502cccca67d9b325 (do not edit this line) */