Merge pull request #1720 from typelevel/fix-334

type classes with only defined laws to guideline
typelevel · Jan 8, 2018 · 3774a19 · 3774a19
2 parents 623e81e + fd21cba
commit 3774a19
Showing 1 changed file with 6 additions and 0 deletions.
diff --git a/docs/src/main/tut/guidelines.md b/docs/src/main/tut/guidelines.md
@@ -111,5 +111,11 @@ abstract class KleisliInstance1 {
 }
 ```
 
+### Type classes that ONLY define laws.
+
+We can introduce new type classes for the sake of adding laws that don't apply to the parent type class, e.g. `CommutativeSemigroup` and 
+`CommutativeArrow`.
+
 #### TODO:
+
 Once we drop 2.10 support, AnyVal-extending class constructor parameters can be marked as private.