Btw

A lot of the code is taken from glguy's version of the same thing. This was mostly an opportunity to practice parsing and meta programming in Haskell

Example

CSV

Values are digits

[fmt|%d&(,)|]

This will parse 1,2,3,4,5 fine. To allow leading and trailing space we can do the following

[fmt|%d&(( )*,( )*)|]

Now we can parse 1,2, 3,2 , 4 just fine.

Can do much much more things too. Can't be arsed writing it all out atm.

E.g. to parse day 20 of advent of code

parser :: String -> [(String, [String])]
parser = [fmt|(((%y?%s)! -> %s&(, ))%n)*|]