# Food Chain Generate the lyrics of the song 'I Know an Old Lady Who Swallowed a Fly'. While you could copy/paste the lyrics, or read them from a file, this problem is much more interesting if you approach it algorithmically. This is a [cumulative song](http://en.wikipedia.org/wiki/Cumulative_song) of unknown origin. This is one of many common variants. ```plain I know an old lady who swallowed a fly. I don't know why she swallowed the fly. Perhaps she'll die. I know an old lady who swallowed a spider. It wriggled and jiggled and tickled inside her. She swallowed the spider to catch the fly. I don't know why she swallowed the fly. Perhaps she'll die. I know an old lady who swallowed a bird. How absurd to swallow a bird! She swallowed the bird to catch the spider that wriggled and jiggled and tickled inside her. She swallowed the spider to catch the fly. I don't know why she swallowed the fly. Perhaps she'll die. I know an old lady who swallowed a cat. Imagine that, to swallow a cat! She swallowed the cat to catch the bird. She swallowed the bird to catch the spider that wriggled and jiggled and tickled inside her. She swallowed the spider to catch the fly. I don't know why she swallowed the fly. Perhaps she'll die. I know an old lady who swallowed a dog. What a hog, to swallow a dog! She swallowed the dog to catch the cat. She swallowed the cat to catch the bird. She swallowed the bird to catch the spider that wriggled and jiggled and tickled inside her. She swallowed the spider to catch the fly. I don't know why she swallowed the fly. Perhaps she'll die. I know an old lady who swallowed a goat. Just opened her throat and swallowed a goat! She swallowed the goat to catch the dog. She swallowed the dog to catch the cat. She swallowed the cat to catch the bird. She swallowed the bird to catch the spider that wriggled and jiggled and tickled inside her. She swallowed the spider to catch the fly. I don't know why she swallowed the fly. Perhaps she'll die. I know an old lady who swallowed a cow. I don't know how she swallowed a cow! She swallowed the cow to catch the goat. She swallowed the goat to catch the dog. She swallowed the dog to catch the cat. She swallowed the cat to catch the bird. She swallowed the bird to catch the spider that wriggled and jiggled and tickled inside her. She swallowed the spider to catch the fly. I don't know why she swallowed the fly. Perhaps she'll die. I know an old lady who swallowed a horse. She's dead, of course! ``` ## Hints This exercise is about [code refactoring](https://en.wikipedia.org/wiki/Refactoring), so we are providing you with a solution that already passes the tests. The challenge is to rewrite it until you are proud of it, and learn something in the process. If you don't know where to start, here are some ideas: - Try to reduce repetition to a minimum. - Try to make the code readable. - Generalize your solution, allowing the lady to swallow other things. Take your time. Change one thing at a time and check if your solution still passes the tests. Have fun! ## Getting Started For installation and learning resources, refer to the [exercism help page](http://exercism.io/languages/haskell). ## Running the tests To run the test suite, execute the following command: ```bash stack test ``` #### If you get an error message like this... ``` No .cabal file found in directory ``` You are probably running an old stack version and need to upgrade it. #### Otherwise, if you get an error message like this... ``` No compiler found, expected minor version match with... Try running "stack setup" to install the correct GHC... ``` Just do as it says and it will download and install the correct compiler version: ```bash stack setup ``` ## Running *GHCi* If you want to play with your solution in GHCi, just run the command: ```bash stack ghci ``` ## Feedback, Issues, Pull Requests The [exercism/haskell](https://github.com/exercism/haskell) repository on GitHub is the home for all of the Haskell exercises. If you have feedback about an exercise, or want to help implementing a new one, head over there and create an issue. We'll do our best to help you! ## Source Wikipedia [http://en.wikipedia.org/wiki/There_Was_an_Old_Lady_Who_Swallowed_a_Fly](http://en.wikipedia.org/wiki/There_Was_an_Old_Lady_Who_Swallowed_a_Fly) ## Submitting Incomplete Solutions It's possible to submit an incomplete solution so you can see how others have completed the exercise.