Grade School in Haskell
Given students' names along with the grade that they are in, create a roster for the school
exercism fetch haskell grade-school
Given students' names along with the grade that they are in, create a roster for the school.
In the end, you should be able to:
- Add a student's name to the roster for a grade
- "Add Jim to grade 2."
- Get a list of all students enrolled in a grade
- "Which students are in grade 2?"
- "We've only got Jim just now."
- Get a sorted list of all students in all grades. Grades should sort
as 1, 2, 3, etc., and students within a grade should be sorted
alphabetically by name.
- "Who all is enrolled in school right now?"
- "Grade 1: Anna, Barb, and Charlie. Grade 2: Alex, Peter, and Zoe. Grade 3…"
Note that all our students only have one name. (It's a small town, what do you want?)
For bonus points
Did you get the tests passing and the code clean? If you want to, these are some additional things you could try:
- If you're working in a language with mutable data structures and your implementation allows outside code to mutate the school's internal DB directly, see if you can prevent this. Feel free to introduce additional tests.
Then please share your thoughts in a comment on the submission. Did this experiment make the code better? Worse? Did you learn anything from it?
To complete this exercise you need to create the data type
and implement the following functions:
You will find a dummy data declaration and type signatures already in place, but it is up to you to define the functions and create a meaningful data type, newtype or type synonym.
For installation and learning resources, refer to the exercism help page.
Running the tests
To run the test suite, execute the following command:
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:
If you want to play with your solution in GHCi, just run the command:
Feedback, Issues, Pull Requests
The 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!
A pairing session with Phil Battos at gSchool http://gschool.it
Submitting Incomplete Solutions
It's possible to submit an incomplete solution so you can see how others have completed the exercise.