#99 antlr4, build is clean

pom.xml

@@ -33,7 +33,7 @@ OF THE POSSIBILITY OF SUCH DAMAGE.
   <parent>
     <groupId>com.jcabi</groupId>
     <artifactId>parent</artifactId>
-    <version>0.50.5</version>
+    <version>0.51.0</version>
   </parent>
   <groupId>com.jcabi.incubator</groupId>
   <artifactId>xembly</artifactId>
@@ -92,10 +92,6 @@ OF THE POSSIBILITY OF SUCH DAMAGE.
       <groupId>org.projectlombok</groupId>
       <artifactId>lombok</artifactId>
     </dependency>
-    <dependency>
-      <groupId>org.antlr</groupId>
-      <artifactId>antlr-runtime</artifactId>
-    </dependency>
     <dependency>
       <groupId>org.mockito</groupId>
       <artifactId>mockito-core</artifactId>

src/main/antlr3/org/xembly/Xembly.g → src/main/antlr4/org/xembly/Xembly.g4

@@ -29,28 +29,14 @@
  */
 grammar Xembly;
 
-@header {
-    package org.xembly;
+@lexer::header {
     import java.util.Collection;
     import java.util.LinkedList;
 }
 
-@lexer::header {
-    package org.xembly;
-}
-
-@lexer::members {
-    @Override
-    public void emitErrorMessage(String msg) {
-        throw new ParsingException(msg);
-    }
-}
-
-@parser::members {
-    @Override
-    public void emitErrorMessage(String msg) {
-        throw new ParsingException(msg);
-    }
+@parser::header {
+    import java.util.Collection;
+    import java.util.LinkedList;
 }
 
 directives returns [Collection<Directive> ret]

src/main/java/org/xembly/SyntaxException.java

@@ -34,7 +34,7 @@
  *
  * @since 0.3
  */
-public final class SyntaxException extends Exception {
+public final class SyntaxException extends RuntimeException {
 
     /**
      * Serialization marker.

src/main/java/org/xembly/Verbs.java

@@ -30,11 +30,12 @@
 package org.xembly;
 
 import java.util.Collection;
-import org.antlr.runtime.ANTLRStringStream;
-import org.antlr.runtime.CharStream;
-import org.antlr.runtime.CommonTokenStream;
-import org.antlr.runtime.RecognitionException;
-import org.antlr.runtime.TokenStream;
+import org.antlr.v4.runtime.ANTLRErrorListener;
+import org.antlr.v4.runtime.BaseErrorListener;
+import org.antlr.v4.runtime.CharStreams;
+import org.antlr.v4.runtime.CommonTokenStream;
+import org.antlr.v4.runtime.RecognitionException;
+import org.antlr.v4.runtime.Recognizer;
 
 /**
  * Directives in plain text.
@@ -59,16 +60,32 @@ final class Verbs {
     /**
      * Parse script.
      * @return Collection of directives
-     * @throws SyntaxException If can't parse
      */
-    public Collection<Directive> directives() throws SyntaxException {
-        final CharStream input = new ANTLRStringStream(this.text);
-        final XemblyLexer lexer = new XemblyLexer(input);
-        final TokenStream tokens = new CommonTokenStream(lexer);
-        final XemblyParser parser = new XemblyParser(tokens);
+    public Collection<Directive> directives() {
+        final ANTLRErrorListener errors = new BaseErrorListener() {
+            // @checkstyle ParameterNumberCheck (10 lines)
+            @Override
+            public void syntaxError(final Recognizer<?, ?> recognizer,
+                final Object symbol, final int line,
+                final int position, final String msg,
+                final RecognitionException error) {
+                throw new SyntaxException(Verbs.this.text, error);
+            }
+        };
+        final XemblyLexer lexer = new XemblyLexer(
+            CharStreams.fromString(this.text)
+        );
+        lexer.removeErrorListeners();
+        lexer.addErrorListener(errors);
+        final XemblyParser parser =
+            new XemblyParser(
+                new CommonTokenStream(lexer)
+            );
+        parser.removeErrorListeners();
+        parser.addErrorListener(errors);
         try {
-            return parser.directives();
-        } catch (final RecognitionException | ParsingException ex) {
+            return parser.directives().ret;
+        } catch (final ParsingException ex) {
             throw new SyntaxException(this.text, ex);
         }
     }