CSS styling engine
e4ad50df — Adrian Cochrane 7 days ago
Inform callers who care that literal text is an inline element.
de0ec27e — Adrian Cochrane 9 days ago
Merge branch 'main' of git.argonaut-constellation.org:~alcinnz/haskell-stylist into main
d2460bd3 — Adrian Cochrane 9 days ago
Fixes for broader dependency bounds.


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#Haskell Stylist

Repository | Issue Tracker | Hackage

Generic CSS style engine for Haskell, intended to aid the development of new browser engines.

Haskell Stylist implements CSS selection and cascade (but not inheritance) independant of the CSS at-rules and properties understood by the caller. It is intended to ease the development of new browser engines, independant of their output targets.

For more interesting projects see: https://argonaut-constellation.org/


The second major number indicates that more of CSS has been implemented within the existing API. Until then the error recovery rules will ensure as yet invalid CSS won't have any effect.

The first major number indicates any other change to the API, and might break your code.


To parse a CSS stylesheet call Data.CSS.Syntax.StyleSheet.parse which returns a variant of the passed in StyleSheet. StyleSheet is a typeclass specifying methods for parsing at-rules (parseAtRule), storing parsed style rules (addRule), and optionally setting the stylesheet's priority (setPriority).

If these ultimately call down into a Data.CSS.Syntax.Style.QueryableStyleSheet you can call queryRules to find all matching style rules organized by psuedoelement. Once you have these style rules (typically by specifying a psuedoelement) you can call cascade' to resolve them into any instance of PropertyParser. To query rules not targetting a psuedoelement, you can either lookup the "" psuedoelement or use the cascade shorthand.

PropertyParser allows to declaratively (via Haskell pattern matching) specify how to parse CSS properties, and how they're impacted by CSS inheritance. It has four methods: longhand and shorthand specify how to parse CSS properties, whilst temp and inherit specifies what the default values should be.


  1. Install ghc and cabal-install. (Debian package names listed here)
  2. From within the git repository, run cabal install. This'll compile Stylist and all it's other dependencies.
  3. Run cabal test after every change you make.


Please send patches to our issue tracker by either:

Whichever you find most convenient.

If you'd prefer to not make your email address public please contact alcinnz@argonaut-constellation.org !