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breadcrumbs: guard refactor

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This commit is contained in:
Tom Sydney Kerckhove 2021-05-21 08:41:42 +02:00
parent 884d937792
commit 0db056534c
1 changed files with 5 additions and 7 deletions
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12
yesod-core/src/Yesod/Core/Class/Breadcrumbs.hs
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@ -16,7 +16,7 @@ class YesodBreadcrumbs site where
-- | Gets the title of the current page and the hierarchy of parent pages,
-- along with their respective titles.
breadcrumbs :: (YesodBreadcrumbs site, Eq (Route site)) => HandlerFor site (Text, [(Route site, Text)])
breadcrumbs :: (YesodBreadcrumbs site, Show (Route site), Eq (Route site)) => HandlerFor site (Text, [(Route site, Text)])
breadcrumbs = do
x <- getCurrentRoute
case x of
@ -27,10 +27,8 @@ breadcrumbs = do
return (title, z)
where
go back Nothing = return back
go back (Just this) = do
(title, next) <- breadcrumb this
if this `elem` map fst back
then
error $ "yesod-core: infinite recursion in breadcrumbs at " ++ show title
else
go back (Just this)
| this `elem` map fst back = error $ "yesod-core: infinite recursion in breadcrumbs at " ++ show this
| otherwise = do
(title, next) <- breadcrumb this
go ((this, title) : back) next