Hess is a haskell library to generate css data out of descriptive structure. It give the ability to typecheck your CSS and use the power of variables, functions, etc to define shortcut to your CSS.

= define a CSS chunk

a CSS chunk is a selector, pseudo classes and then a list of properties.

body { margin-top: 15px }

is written in Hess structure

[body] @!> [ marginTop: (15,Px) ]

more examples:

HESS: [a] ?> [Hover] @> [ textColor (Color 0 0 0) ] CSS: a : hover { color : #000 }

HESS: [ID "header"] @!> { display "block" } CSS: #header { display: block }

HESS: [ID "header" Child h1] @!> { fontSize "120%" } CSS: #header > h1 { font-size: 120% }

= standalone program

by add 3 lines to the header of your declarative style sheet, you can make it the file a standalone program.

#!/usr/bin/runhaskell -XExtendedDefaultRules
import Hess.Main
main = defaultMain [definitions...]

= TODO

• make a quasiquoter to shorten the declarative file.