#2231 Broken head in syntax

eo-parser/src/main/antlr4/org/eolang/parser/Program.g4

@@ -34,7 +34,10 @@ objects
 object
   :
   (
-    abstraction
+    (
+      abstraction
+      type?
+    )
     |
     application
   )
@@ -52,10 +55,14 @@ abstraction
   :
   (COMMENT EOL)*
   attributes
-  (
-    (suffix (SPACE SLASH (NAME | QUESTION))?)
-    | htail
-  )?
+  ;
+
+type
+  :
+  suffix
+  SPACE
+  SLASH
+  (NAME | QUESTION)?
   ;
 
 attributes
@@ -133,6 +140,9 @@ application
   head
   version
   |
+  abstraction
+  htail?
+  |
   head
   htail?
   |
@@ -154,7 +164,6 @@ application
   |
   application
   suffix
-  htail?
   ;
 
 htail
@@ -180,6 +189,7 @@ htail
     |
     SPACE
     abstraction
+    suffix?
   )+
   ;
 
@@ -215,8 +225,6 @@ head
     DOT
     |
     data
-    |
-    abstraction
   )
   ;
 

eo-parser/src/main/java/org/eolang/parser/RedundantParentheses.java

@@ -40,7 +40,7 @@ final class RedundantParentheses implements Predicate<String> {
     /**
      * Pattern for string literals.
      */
-    private static final Pattern PATTERN = Pattern.compile("(?ms)\"\"\".*?\"\"\"|\".*?\"");
+    private static final Pattern PATTERN = Pattern.compile("(?ms)#.*?\\n|\"\"\".*?\"\"\"|\".*?\"");
 
     /**
      * The callback that will be called in case if redundant parentheses is found.

eo-parser/src/main/java/org/eolang/parser/XeListener.java

@@ -204,18 +204,29 @@ public void enterAbstraction(final ProgramParser.AbstractionContext ctx) {
             ctx.getStart().getCharPositionInLine()
         );
         this.objects.prop("abstract", "");
+        this.objects.leave();
+    }
+
+    @Override
+    public void exitAbstraction(final ProgramParser.AbstractionContext ctx) {
+        // Nothing here
+    }
+
+    @Override
+    public void enterType(final ProgramParser.TypeContext ctx) {
         if (ctx.SLASH() != null) {
+            this.objects.enter();
             if (ctx.QUESTION() == null) {
                 this.objects.prop("atom", ctx.NAME());
             } else {
                 this.objects.prop("atom", "?");
             }
+            this.objects.leave();
         }
-        this.objects.leave();
     }
 
     @Override
-    public void exitAbstraction(final ProgramParser.AbstractionContext ctx) {
+    public void exitType(final ProgramParser.TypeContext ctx) {
         // Nothing here
     }
 

eo-parser/src/test/java/org/eolang/parser/RedundantParenthesesTest.java

@@ -87,6 +87,7 @@ static Stream<Arguments> testCases() {
             Arguments.of("[] > foo\n  \"Hello\".<.eq (\"Hello\".<)\n", true),
             Arguments.of("[] > foo\n  \"\"\"\n(-_-)\n\"\"\" > x", true),
             Arguments.of("[] > foo\n  add (-4) (-5)", true),
+            Arguments.of("# Comment().\n[] > obj\n", true),
             Arguments.of("[] > foo\n  (1.add (a.add 5) (4)) > x", false),
             Arguments.of("[] > foo\n  (1.add (a.add 5) 4) > x", false),
             Arguments.of("[] > foo\n  (1.add (a.add 5) 4)", false),

eo-parser/src/test/java/org/eolang/parser/SyntaxTest.java

@@ -91,7 +91,7 @@ void printsProperListingEvenWhenSyntaxIsBroken() throws Exception {
                 new String(baos.toByteArray(), StandardCharsets.UTF_8)
             ),
             XhtmlMatchers.hasXPaths(
-                "/program/errors[count(error)=1]",
+                "/program/errors[count(error)=2]",
                 String.format("/program[listing='%s']", src)
             )
         );

eo-parser/src/test/resources/org/eolang/parser/typos/broken-head.yaml

@@ -2,7 +2,6 @@
 #  The syntax below is not supported, but it passes the test and
 #  no typos are detected. We should fix it. Most probably EOL-s
 #  are not detected at the end of objects correctly.
-skip: true
 line: 1
 eo: |
   [] > a [] > b [] > c [] > d hello world

eo-parser/src/test/resources/org/eolang/parser/typos/scoped-application-after-suffix.yaml

@@ -0,0 +1,4 @@
+line: 2
+eo: |
+  [x] > first
+    a > x (b > x)