Throw exceptions (not errors) from lexer

+ Add more data to the exception message

compiler/frontend/buildLexer.xml

@@ -36,6 +36,12 @@
     <target name="lexer">
         <flex flexfile="${home}/src/org/jetbrains/jet/lexer/Jet.flex"
               destdir="${home}/src/org/jetbrains/jet/lexer/"/>
+
+        <!-- This is a hack, but we don't want to alter the skeleton we are using now, because being in sync with IDEA is more important-->
+        <replaceregexp file="${home}/src/org/jetbrains/jet/lexer/_JetLexer.java"
+                       match="throw new KotlinLexerException\(message\);"
+                       replace="throw new KotlinLexerException(message + &quot;\\\\n at '&quot; + yytext() + &quot;'\\\\n&quot; + zzBuffer);"/>
+
         <flex flexfile="${home}/src/org/jetbrains/jet/kdoc/lexer/KDoc.flex"
               destdir="${home}/src/org/jetbrains/jet/kdoc/lexer/"/>
     </target>

compiler/frontend/src/org/jetbrains/jet/kdoc/lexer/_KDocLexer.java

@@ -1,4 +1,4 @@
-/* The following code was generated by JFlex 1.4.3 on 3/6/14 2:29 PM */
+/* The following code was generated by JFlex 1.4.3 on 5/27/14 6:17 PM */
 
 package org.jetbrains.jet.kdoc.lexer;
 
@@ -12,7 +12,7 @@ import java.lang.Character;
 /**
  * This class is a scanner generated by 
  * <a href="http://www.jflex.de/">JFlex</a> 1.4.3
- * on 3/6/14 2:29 PM from the specification file
+ * on 5/27/14 6:17 PM from the specification file
  * <tt>/Users/abreslav/work/kotlin/compiler/frontend/src/org/jetbrains/jet/kdoc/lexer/KDoc.flex</tt>
  */
 class _KDocLexer implements FlexLexer {

compiler/frontend/src/org/jetbrains/jet/lexer/Jet.flex

@@ -5,6 +5,7 @@ import com.intellij.lexer.*;
 import com.intellij.psi.*;
 import com.intellij.psi.tree.IElementType;
 import com.intellij.util.containers.Stack;
+import org.jetbrains.jet.lexer.KotlinLexerException;
 
 import org.jetbrains.jet.lexer.JetTokens;
 
@@ -60,6 +61,8 @@ import org.jetbrains.jet.lexer.JetTokens;
     }
 %}
 
+%scanerror KotlinLexerException
+
 %function advance
 %type IElementType
 %eof{

compiler/frontend/src/org/jetbrains/jet/lexer/KotlinLexerException.java

@@ -0,0 +1,23 @@
+/*
+ * Copyright 2010-2014 JetBrains s.r.o.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.jetbrains.jet.lexer;
+
+public class KotlinLexerException extends RuntimeException {
+    public KotlinLexerException(String message) {
+        super(message);
+    }
+}

compiler/frontend/src/org/jetbrains/jet/lexer/_JetLexer.java

@@ -1,4 +1,4 @@
-/* The following code was generated by JFlex 1.4.3 on 5/14/14 2:02 PM */
+/* The following code was generated by JFlex 1.4.3 on 5/27/14 6:17 PM */
 
 package org.jetbrains.jet.lexer;
 
@@ -7,6 +7,7 @@ import com.intellij.lexer.*;
 import com.intellij.psi.*;
 import com.intellij.psi.tree.IElementType;
 import com.intellij.util.containers.Stack;
+import org.jetbrains.jet.lexer.KotlinLexerException;
 
 import org.jetbrains.jet.lexer.JetTokens;
 
@@ -14,8 +15,8 @@ import org.jetbrains.jet.lexer.JetTokens;
 /**
  * This class is a scanner generated by 
  * <a href="http://www.jflex.de/">JFlex</a> 1.4.3
- * on 5/14/14 2:02 PM from the specification file
- * <tt>/Users/svtk/Kotlin/kotlin/compiler/frontend/src/org/jetbrains/jet/lexer/Jet.flex</tt>
+ * on 5/27/14 6:17 PM from the specification file
+ * <tt>/Users/abreslav/work/kotlin/compiler/frontend/src/org/jetbrains/jet/lexer/Jet.flex</tt>
  */
 class _JetLexer implements FlexLexer {
   /** initial size of the lookahead buffer */
@@ -769,7 +770,7 @@ class _JetLexer implements FlexLexer {
    *
    * @param   errorCode  the code of the errormessage to display
    */
-  private void zzScanError(int errorCode) {
+  private void zzScanError(int errorCode) throws KotlinLexerException {
     String message;
     try {
       message = ZZ_ERROR_MSG[errorCode];
@@ -778,7 +779,7 @@ class _JetLexer implements FlexLexer {
       message = ZZ_ERROR_MSG[ZZ_UNKNOWN_ERROR];
     }
 
-    throw new Error(message);
+    throw new KotlinLexerException(message + "\n at '" + yytext() + "'\n" + zzBuffer);
   }
 
 
@@ -790,7 +791,7 @@ class _JetLexer implements FlexLexer {
    * @param number  the number of characters to be read again.
    *                This number must not be greater than yylength()!
    */
-  public void yypushback(int number)  {
+  public void yypushback(int number)  throws KotlinLexerException {
     if ( number > yylength() )
       zzScanError(ZZ_PUSHBACK_2BIG);
 
@@ -818,7 +819,7 @@ class _JetLexer implements FlexLexer {
    * @return      the next token
    * @exception   java.io.IOException  if any I/O-Error occurs
    */
-  public IElementType advance() throws java.io.IOException {
+  public IElementType advance() throws java.io.IOException, KotlinLexerException {
     int zzInput;
     int zzAction;