Dedicated module for "time ago"

src/Data/EventTime/Local.hs

@@ -0,0 +1,64 @@
+{- 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.EventTime.Local
+    ( TimeUnit (..)
+    , TimeAgo (..)
+    , EventTime (..)
+    , showEventTime
+    )
+where
+
+import Prelude
+
+import Data.Text (Text, snoc)
+
+import qualified Formatting as F
+
+data TimeUnit = Second | Minute | Hour | Day | Week | Month | Year
+
+showSingle :: TimeUnit -> Text
+showSingle tu =
+    case tu of
+        Second -> "second"
+        Minute -> "minute"
+        Hour   -> "hour"
+        Day    -> "day"
+        Week   -> "week"
+        Month  -> "month"
+        Year   -> "year"
+
+showPlural :: TimeUnit -> Text
+showPlural tu = showSingle tu `snoc` 's'
+
+showTimeUnit :: TimeUnit -> Int -> Text
+showTimeUnit tu 1 = showSingle tu
+showTimeUnit tu _ = showPlural tu
+
+data TimeAgo = TimeAgo
+    { taUnit  :: TimeUnit
+    , taCount :: Int
+    }
+
+showTimeAgo :: TimeAgo -> Text
+showTimeAgo (TimeAgo u n) =
+    F.sformat (F.int F.% " " F.% F.stext F.% " ago") n (showTimeUnit u n)
+
+data EventTime = Now | Ago TimeAgo | Never
+
+showEventTime :: EventTime -> Text
+showEventTime Now      = "Now"
+showEventTime (Ago ta) = showTimeAgo ta
+showEventTime Never    = "Never"

vervis.cabal

@@ -38,6 +38,7 @@ library
                        Data.ByteString.Char8.Local
                        Data.ByteString.Local
                        Data.Char.Local
+                       Data.EventTime.Local
                        Data.Git.Local
                        Data.List.Local
                        Network.SSH.Local