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:
Note that all our students only have one name. (It's a small town, what do you want?)
For installation and learning resources, refer to the exercism help page.
To work on the exercises, you will need
Core. Consult opam website for instructions on how to install
opam for your OS. Once
opam is installed open a terminal window and run the following command to install core:
opam install core
To run the tests you will need
OUnit. Install it using
opam install ounit
A Makefile is provided with a default target to compile your solution and run the tests. At the command line, type:
utop is a command line program which allows you to run Ocaml code interactively. The easiest way to install it is via opam:
opam install utop
Consult utop for more detail.
The exercism/ocaml repository on GitHub is the home for all of the Ocaml 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
It's possible to submit an incomplete solution so you can see how others have completed the exercise.
open OUnit2 open Grade_school let assert_lists_equal exp got _ctx = let printer = String.concat ";" in assert_equal exp got ~printer let tests = [ "an empty school has no children in grade 1" >:: assert_lists_equal  (grade 1 empty_school); "an empty school has Emma in grade 1 after she's been added to grade 1" >::( let s = add "Emma" 1 empty_school in assert_lists_equal ["Emma"] (grade 1 s) ); "an empty school does not have Emma in grade 1 after she's been added to grade 2" >::( let s = add "Emma" 2 empty_school in assert_lists_equal  (grade 1 s) ); "an empty school has Emma, Timmy, Bob and Becky in grade 1 after they've been added to grade 1" >::( let s = empty_school |> add "Emma" 1 |> add "Timmy" 1 |> add "Bob" 1 |> add "Becky" 1 in assert_lists_equal ["Becky"; "Bob"; "Emma"; "Timmy"] (grade 1 s |> List.sort compare) ); "a sorted school has Emma, Timmy, Bob and Becky in grade 1 in sorted order" >::( let s = empty_school |> add "Emma" 1 |> add "Timmy" 1 |> add "Bob" 1 |> add "Becky" 1 |> sorted in assert_lists_equal ["Becky"; "Bob"; "Emma"; "Timmy"] (grade 1 s) ); ] let () = run_test_tt_main ("grade-school tests" >::: tests)
(** Grade-school exercise *) open Base module GradeMap = Map.M(Int) type student = string type school = student list GradeMap.t let empty_school = Map.empty (module Int) (** Add a student to a school *) let add student grade school = let rec insert student = function |  -> [student] | other::rest -> if String.compare student other <= 0 then student :: other :: rest else other :: insert student rest in Map.update school grade ~f:(Option.value_map ~default:[student] ~f:(insert student)) (** Get all the students from a grade *) let grade n school = Map.find school n |> Option.value ~default: (** Sort the list of students in a grade, if necessary *) let sorted = Fn.id
A huge amount can be learned from reading other people’s code. This is why we wanted to give exercism users the option of making their solutions public.
Here are some questions to help you reflect on this solution and learn the most from it.