Add style palette module for later use

src/Style.hs

@@ -0,0 +1,71 @@
+{- 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/>.
+ -}
+
+-- | Style component palette for use in page templates, in particular Cassius
+-- files.
+module Style
+    ( -- * Types
+      Color ()
+    , Hue ()
+      -- * Plain Colors
+    , black
+    , white
+      -- * Color Hues
+    , red
+    , green
+    , yellow
+    , blue
+    , magenta
+    , cyan
+    , gray
+      -- * Hue to Color
+    , dark
+    , light
+    )
+where
+
+data Lightness = Light | Dark
+
+data Color
+    = Black
+    | Red Lightness
+    | Green Lightness
+    | Yellow Lightness
+    | Blue Lightness
+    | Magenta Lightness
+    | Cyan Lightness
+    | Gray Lightness
+    | White
+
+newtype Hue = Hue (Lightness -> Color)
+
+black, white :: Color
+black = Black
+white = White
+
+red, green, yellow, blue, magenta, cyan, gray :: Hue
+red     = Hue Red
+green   = Hue Green
+yellow  = Hue Yellow
+blue    = Hue Blue
+magenta = Hue Magenta
+cyan    = Hue Cyan
+gray    = Hue Gray
+
+dark :: Hue -> Color
+dark (Hue h) = h Dark
+
+light :: Hue -> Color
+light (Hue h) = h Light

vervis.cabal

@@ -46,6 +46,7 @@ library
                        Handler.Home
                        Handler.Person
                        Handler.Project
+                       Style
   -- other-modules:       
   default-extensions:  TemplateHaskell
                        QuasiQuotes