fn: breaking - polish Either API

fn/either_test.go

@@ -10,17 +10,17 @@ func TestPropConstructorEliminatorDuality(t *testing.T) {
 		Len := func(s string) int { return len(s) } // smh
 		if isRight {
 			v := ElimEither(
+				NewRight[int, string](s),
 				Iden[int],
 				Len,
-				NewRight[int, string](s),
 			)
 			return v == Len(s)
 		}
 
 		v := ElimEither(
+			NewLeft[int, string](i),
 			Iden[int],
 			Len,
-			NewLeft[int, string](i),
 		)
 		return v == i
 	}
@@ -99,16 +99,16 @@ func TestPropToOptionIdentities(t *testing.T) {
 		if isRight {
 			e = NewRight[int, string](s)
 
-			r2O := e.RightToOption() == Some(s)
+			r2O := e.RightToSome() == Some(s)
 			o2R := e == OptionToRight(Some(s), i)
-			l2O := e.LeftToOption() == None[int]()
+			l2O := e.LeftToSome() == None[int]()
 
 			return r2O && o2R && l2O
 		} else {
 			e = NewLeft[int, string](i)
-			l2O := e.LeftToOption() == Some(i)
+			l2O := e.LeftToSome() == Some(i)
 			o2L := e == OptionToLeft(Some(i), s)
-			r2O := e.RightToOption() == None[string]()
+			r2O := e.RightToSome() == None[string]()
 
 			return l2O && o2L && r2O
 		}