Fix comments parsing.

tests/comments.rs

@@ -21,5 +21,62 @@ fn test_comments() -> Result<(), Box<EvalAltResult>> {
         42
     );
 
+    assert_eq!(engine.eval::<()>("/* Hello world */")?, ());
+
+    Ok(())
+}
+
+#[cfg(not(feature = "no_function"))]
+#[test]
+fn test_comments_doc() -> Result<(), Box<EvalAltResult>> {
+    let engine = Engine::new();
+
+    let ast = engine.compile(
+        r"
+            /// Hello world
+
+
+            fn foo() {}
+        ",
+    )?;
+
+    assert_eq!(
+        ast.iter_functions().next().unwrap().comments[0],
+        "/// Hello world"
+    );
+
+    assert!(engine
+        .compile(
+            r"
+                /// Hello world
+                let x = 42;
+            "
+        )
+        .is_err());
+
+    let ast = engine.compile(
+        r"
+            /** Hello world
+            ** how are you?
+            **/
+
+            fn foo() {}
+        ",
+    )?;
+
+    assert_eq!(
+        ast.iter_functions().next().unwrap().comments[0],
+        "/** Hello world\n            ** how are you?\n            **/"
+    );
+
+    assert!(engine
+        .compile(
+            r"
+                /** Hello world */
+                let x = 42;
+            "
+        )
+        .is_err());
+
     Ok(())
 }