Adding analyzer feedback for karls language concept exercise (#2722)

* Adding analyzer feedback for karls language concept exercise

* Applying suggestions
Update hints to not say exactly what to do
Update isEmpty name to one that does not says directly what to apply
change the analyzer topic that checks that the students re uses containsLanguage to informative
Add an informative topic if the students uses an if statement on containsLanguage

* Rollbacking rename of method isEmpty

Author: manumafe98

config.json

@@ -80,7 +80,6 @@
         ],
         "prerequisites": [
           "arrays",
-          "for-loops",
           "strings"
         ],
         "status": "active"

exercises/concept/karls-languages/.docs/hints.md

@@ -2,31 +2,32 @@
 
 ## 1. Define a function to check if the language list is empty
 
-- Try using the [`isEmpty()`](https://docs.oracle.com/en/java/javase/11/docs/api/java.base/java/util/List.html#isEmpty()) method.
+- One of the [methods][list] on the List type can be used to check if it is empty.
 
 ## 2. Define a function to add a language to the list
 
-- Try using the [`add(E element)`](https://docs.oracle.com/en/java/javase/11/docs/api/java.base/java/util/List.html#add(E)) method.
+- One of the [methods][list] on the List type can be used to add elements.
 - Reminder: methods that return `void` do not need any `return` statements.
 
 ## 3. Define a function to remove a language from the list
 
-- Try using the [`remove(Object o)`](https://docs.oracle.com/en/java/javase/11/docs/api/java.base/java/util/List.html#remove(java.lang.Object)) method.
+- One of the [methods][list] on the List type can be used to remove elements.
 - Reminder: methods that return `void` do not need any `return` statements.
 
 ## 4. Define a function to return the first item in the list
 
-- Try using the [`get(int index)`](https://docs.oracle.com/en/java/javase/11/docs/api/java.base/java/util/List.html#get(int)) method.
+- One of the [methods][list] on the List type can be used to get elements on a certain index.
 
 ## 5. Define a function to return how many languages are in the list
 
-- Try using the [`size()`](https://docs.oracle.com/en/java/javase/11/docs/api/java.base/java/util/List.html#size()) method.
+- One of the [methods][list] on the List type can be used to get the size of the list.
 
 ## 6. Define a function to determine if a language is in the list
 
-- Try using the [`contains(Object o)`](https://docs.oracle.com/en/java/javase/11/docs/api/java.base/java/util/List.html#contains(java.lang.Object)) method.
+- One of the [methods][list] on the List type can be used to check if an element is contained in the list.
 
 ## 7. Define a function to determine if the list is exciting
 
-- Try using a [for-each loop](https://docs.oracle.com/javase/tutorial/java/nutsandbolts/for.html) through all of the elements, checking each one.
-- Alternatively, try using the `containsLanguage` method from the previous step.
+- Try using a method already defined in the class.
+
+[list]: https://docs.oracle.com/en/java/javase/11/docs/api/java.base/java/util/List.html

exercises/concept/karls-languages/.meta/design.md

@@ -43,6 +43,20 @@ This Concepts Exercise's Concepts are:
 
 This Concept Exercise's prerequisites Concepts are:
 
-- `for-loops`: know how to use a for-loop to iterate over a collection.
 - `arrays`: know of the array collection type and that it has a fixed length.
 - `strings`: data types used in this exercise
+
+## Analyzer
+
+This exercise could benefit from the following rules in the [analyzer]:
+
+- `actionable`: If the solution did not use `contains` in the method `containsLanguage`, instruct the student to do so.
+- `actionable`: If the solution did not use `isEmpty` in the method `isEmpty`, instruct the student to do so.
+- `informative`: If the student did not reuse the implementation of the `containsLanguage` method in the `isExciting` method, instruct them to do so.
+  Explain that reusing existing code instead of copy-pasting can help make code easier to maintain.
+- `informative`: If the solution uses an `if statement` in the `containsLanguage` method, instruct the student to return directly the `contains` method.
+
+If the solution does not receive any of the above feedback, it must be exemplar.
+Leave a `celebratory` comment to celebrate the success!
+
+[analyzer]: https://github.com/exercism/java-analyzer

exercises/concept/karls-languages/.meta/src/reference/java/LanguageList.java

@@ -29,11 +29,6 @@ public boolean containsLanguage(String language) {
     }
 
     public boolean isExciting() {
-        for (String language : languages) {
-            if (language.equals("Java") || language.equals("Kotlin")) {
-                return true;
-            }
-        }
-        return false;
+        return containsLanguage("Java") || containsLanguage("Kotlin");
     }
 }