As an exercise I wrote a simple string substitution library that supports "$"-based substitution ala Perl or Python. Example usage:
import qualified Data.ByteString.Lazy.Char8 as B import Text.Template
context = Map.fromList . map packPair where packPair (x, y) = (B.pack x, B.pack y)
helloTemplate = B.pack "Hello, $name! Want some ${fruit}s?" helloContext = context [("name", "Johan"), ("fruit", "banana")]
main = B.putStrLn $ substitute helloTemplate helloContext
Hopefully this is useful for someone who needs something more readable than Text.Printf's "%s"-based substitution or string concatenation for longer strings but less than a full blown templating system like the ones found in most web frameworks. Release: http://www.johantibell.com/template/template-0.1.tar.gz Source: darcs get http://darcs.johantibell.com/template Once we get ByteString literals most of the noise in the above example will disappear. In the mean time it's probably a good idea to write utility function like "context" above when you prefer a convenient String interface to a somewhat faster ByteString interface. It would be great if someone could do a code review and add it to Hackage if it looks OK. I'll really appreciate the feedback. Also, I'm not 100% sure how to make the haddock links work with Hackage so they link to the library docs. Is this something done at upload time? Here are some open issues: * I currently use my own ByteString parser. Data.Binary almost does what I need. Basically I need takeWhile and two chars of look-ahead. * I would like to only depend on base, currently I use State so I depend on mtl. Cheers, Johan