Haskell, while notorious for its extremely powerful parser combinators library, lacks a quick-and-dirty way to parse simple-formatted strings in a one-liner. This is especially frustrating for Advent of Code, where the input to some puzzles, which is in other languages fairly painless to parse, requires some overly convoluted, hacky and noncompact solution.
Envious of Python's parse package, I decided to write my own,
very stripped down version, in Haskell. This package provides a way to create a "template" for how
strings should look, and parse them accodringly. While inspired by Python format strings, the
content of each field is returned as a string. If you so desire, you can read them manually.
Examples:
>>> parse "It's {}, I love it!" "It's spam, I love it!" :: String
"spam"
>>> parse "{} + {} = {}" "3.1415926535 + 2.7182818284 = 5.8598744819" :: (String, String, String)
("3.1415926535","2.7182818284","5.8598744819")You can also return the parsed fields as a list, instead of a tuple (for long lists, or ones you
intend to use as a Functor.)
>>> map read $ parseList "{}, {}, {}, {}, {}, {}, {}, {}, {}, {}" "2, 3, 5, 7, 11, 13, 17, 19, 23, 29" :: [Int]
[2,3,5,7,11,13,17,19,23,29]Safe versions of each function are provided alongside them.
It should be noted that this package lacks most of the features supplied by parse, instead providing only basic parsing functionality. This may or may not change in the future.
Also, the parsing method used is slow. It is not intended for parsing large quantities of data.