Minimal pagination for git and darcs change log

src/Data/Either/Local.hs

@@ -0,0 +1,30 @@
+{- This file is part of Vervis.
+ -
+ - Written in 2016 by fr33domlover <fr33domlover@riseup.net>.
+ -
+ - ♡ Copying is an act of love. Please copy, reuse and share.
+ -
+ - The author(s) have dedicated all copyright and related and neighboring
+ - rights to this software to the public domain worldwide. This software is
+ - distributed without any warranty.
+ -
+ - You should have received a copy of the CC0 Public Domain Dedication along
+ - with this software. If not, see
+ - <http://creativecommons.org/publicdomain/zero/1.0/>.
+ -}
+
+module Data.Either.Local
+    ( maybeRight
+    , maybeLeft
+    )
+where
+
+import Prelude
+
+maybeRight :: Either a b -> Maybe b
+maybeRight (Left _)  = Nothing
+maybeRight (Right b) = Just b
+
+maybeLeft :: Either a b -> Maybe a
+maybeLeft (Left a)  = Just a
+maybeLeft (Right _) = Nothing

src/Data/Git/Local.hs

@@ -21,6 +21,9 @@ module Data.Git.Local
     , TreeRows
     , PathView (..)
     , viewPath
+      -- * View refs
+    , listBranches
+    , listTags
     )
 where
 
@@ -31,6 +34,7 @@ import Data.Byteable (toBytes)
 import Data.Git
 import Data.Git.Harder
 import Data.Git.Types (GitTime (..))
+import Data.Set (Set)
 import Data.Text (Text)
 import Data.Text.Encoding (decodeUtf8With)
 import Data.Text.Encoding.Error (lenientDecode)
@@ -38,6 +42,8 @@ import System.Directory.Tree
 
 import qualified Data.ByteString as B (ByteString, writeFile)
 import qualified Data.ByteString.Lazy as BL (ByteString)
+import qualified Data.Set as S (mapMonotonic)
+import qualified Data.Text as T (pack)
 
 import Data.EventTime.Local
 import Data.Hourglass.Local ()
@@ -115,3 +121,9 @@ viewPath git root path = do
             case target of
                 Left blob  -> return $ BlobView nameT oid (blobGetContent blob)
                 Right tree -> TreeView nameT oid <$> mkRows tree
+
+listBranches :: Git -> IO (Set Text)
+listBranches git = S.mapMonotonic (T.pack . refNameRaw) <$> branchList git
+
+listTags :: Git -> IO (Set Text)
+listTags git = S.mapMonotonic (T.pack . refNameRaw) <$> tagList git

src/Data/Paginate/Local.hs

@@ -156,4 +156,6 @@ paginate ps ns = do
     curr <- psCurrent ps
     let (offset, limit) = subseq (psPer ps) curr
     (total, items) <- psSelect ps offset limit
-    return (items, navModel ns curr total)
+    let (d, m) = total `divMod` psPer ps
+        pages = if m == 0 then d else d + 1
+    return (items, navModel ns curr pages)