From 06c4e0c2c390ac4406a530f3546b60c36ef45847 Mon Sep 17 00:00:00 2001
From: Sarah Vaupel <>
Date: Wed, 5 Aug 2020 11:39:24 +0200
Subject: [PATCH] refactor(course-visibility): use E.maybe

---
 src/Handler/Allocation/List.hs | 7 ++++---
 src/Utils/Course.hs            | 8 ++++----
 2 files changed, 8 insertions(+), 7 deletions(-)

diff --git a/src/Handler/Allocation/List.hs b/src/Handler/Allocation/List.hs
index de8753751..497879edd 100644
--- a/src/Handler/Allocation/List.hs
+++ b/src/Handler/Allocation/List.hs
@@ -41,9 +41,10 @@ countCourses muid ata now addWhere allocation = E.subSelectCount . E.from $ \all
                  )
                E.||. (E.isJust (allocation E.^. AllocationRegisterFrom)
                    E.&&. allocation E.^. AllocationRegisterFrom E.<=. E.val (Just now)
-                   E.&&. (E.isNothing (allocation E.^. AllocationRegisterTo)
-                       E.||. E.val (Just now) E.<=. allocation E.^. AllocationRegisterTo
-                     )
+                   E.&&. E.maybe 
+                           (E.val True)
+                           (\registerTo -> E.val now E.<=. registerTo)
+                           (allocation E.^. AllocationRegisterTo)
                  )
              )
          )
diff --git a/src/Utils/Course.hs b/src/Utils/Course.hs
index f5ee489b3..18c3db230 100644
--- a/src/Utils/Course.hs
+++ b/src/Utils/Course.hs
@@ -80,10 +80,10 @@ courseIsVisible :: UTCTime -> E.SqlExpr (Entity Course) -> E.SqlExpr (E.Value Bo
 courseIsVisible now course = 
   E.isJust (course E.^. CourseVisibleFrom)
   E.&&. course E.^. CourseVisibleFrom E.<=. E.val (Just now)
-  E.&&. (
-    E.isNothing (course E.^. CourseVisibleTo)
-    E.||. E.val (Just now) E.<=. course E.^. CourseVisibleTo
-  )
+  E.&&. E.maybe
+          (E.val True)
+          (\visibleTo -> E.val now E.<=. visibleTo)
+          (course E.^. CourseVisibleTo)
 
 courseIsVisible' :: UTCTime -> Course -> Bool
 courseIsVisible' now Course{..} = NTop courseVisibleFrom <= now' && now' <= NTop courseVisibleTo