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MokuHazushi's solution

to Grade School in the OCaml Track

Published at Nov 22 2019 · 0 comments
Instructions
Test suite
Solution

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:

  • Start with an empty school.
  • Add a student's name to the roster for a grade
    • "Add Jim to grade 2."
    • "OK."
  • 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?)

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Source

A pairing session with Phil Battos at gSchool http://gschool.it

test.ml

(* grade-school - 1.0.0 *)
open OUnit2
open Grade_school

let assert_lists_equal exp got _ctx =
  let printer = String.concat ";" in
  assert_equal exp got ~printer

let tests = [
  "Adding a student adds them to the sorted roster" >:: (
    let school = empty_school |> add "Aimee" 2 in
    assert_lists_equal ["Aimee"] (roster school)
  );
  "Adding more student adds them to the sorted roster" >:: (
    let school = empty_school |> add "Blair" 2 |> add "James" 2 |> add "Paul" 2 in
    assert_lists_equal ["Blair"; "James"; "Paul"] (roster school)
  );
  "Adding students to different grades adds them to the same sorted roster" >:: (
    let school = empty_school |> add "Chelsea" 3 |> add "Logan" 7 in
    assert_lists_equal ["Chelsea"; "Logan"] (roster school)
  );
  "Roster returns an empty list if there are no students enrolled" >:: (
    let school = empty_school in
    assert_lists_equal [] (roster school)
  );
  "Student names with grades are displayed in the same sorted roster" >:: (
    let school = empty_school
                 |> add "Peter" 2
                 |> add "Anna" 1
                 |> add "Barb" 1
                 |> add "Zoe" 2
                 |> add "Alex" 2
                 |> add "Jim" 3
                 |> add "Charlie" 1 in
    assert_lists_equal ["Anna"; "Barb"; "Charlie"; "Alex"; "Peter"; "Zoe"; "Jim"] (roster school)
  );
  "Grade returns the students in that grade in alphabetical order" >:: (
    let school = empty_school |> add "Franklin" 5 |> add "Bradley" 5 |> add "Jeff" 1 in
    assert_lists_equal ["Bradley"; "Franklin"] (grade 5 school)
  );
  "Grade returns an empty list if there are no students in that grade" >:: (
    let school = empty_school in
    assert_lists_equal [] (grade 1 school)
  );
  "Adding a student adds them to the sorted roster" >:: (
    let school = empty_school |> add "Aimee" 2 in
    assert_lists_equal ["Aimee"] (roster school)
  );
  "Adding more student adds them to the sorted roster" >:: (
    let school = empty_school |> add "Blair" 2 |> add "James" 2 |> add "Paul" 2 in
    assert_lists_equal ["Blair"; "James"; "Paul"] (roster school)
  );
  "Adding students to different grades adds them to the same sorted roster" >:: (
    let school = empty_school |> add "Chelsea" 3 |> add "Logan" 7 in
    assert_lists_equal ["Chelsea"; "Logan"] (roster school)
  );
  "Roster returns an empty list if there are no students enrolled" >:: (
    let school = empty_school in
    assert_lists_equal [] (roster school)
  );
  "Student names with grades are displayed in the same sorted roster" >:: (
    let school = empty_school
                 |> add "Peter" 2
                 |> add "Anna" 1
                 |> add "Barb" 1
                 |> add "Zoe" 2
                 |> add "Alex" 2
                 |> add "Jim" 3
                 |> add "Charlie" 1 in
    assert_lists_equal ["Anna"; "Barb"; "Charlie"; "Alex"; "Peter"; "Zoe"; "Jim"] (roster school)
  );
  "Grade returns the students in that grade in alphabetical order" >:: (
    let school = empty_school |> add "Franklin" 5 |> add "Bradley" 5 |> add "Jeff" 1 in
    assert_lists_equal ["Bradley"; "Franklin"] (grade 5 school)
  );
  "Grade returns an empty list if there are no students in that grade" >:: (
    let school = empty_school in
    assert_lists_equal [] (grade 1 school)
  );
  "Adding a student adds them to the sorted roster" >:: (
    let school = empty_school |> add "Aimee" 2 in
    assert_lists_equal ["Aimee"] (roster school)
  );
  "Adding more student adds them to the sorted roster" >:: (
    let school = empty_school |> add "Blair" 2 |> add "James" 2 |> add "Paul" 2 in
    assert_lists_equal ["Blair"; "James"; "Paul"] (roster school)
  );
  "Adding students to different grades adds them to the same sorted roster" >:: (
    let school = empty_school |> add "Chelsea" 3 |> add "Logan" 7 in
    assert_lists_equal ["Chelsea"; "Logan"] (roster school)
  );
  "Roster returns an empty list if there are no students enrolled" >:: (
    let school = empty_school in
    assert_lists_equal [] (roster school)
  );
  "Student names with grades are displayed in the same sorted roster" >:: (
    let school = empty_school
                 |> add "Peter" 2
                 |> add "Anna" 1
                 |> add "Barb" 1
                 |> add "Zoe" 2
                 |> add "Alex" 2
                 |> add "Jim" 3
                 |> add "Charlie" 1 in
    assert_lists_equal ["Anna"; "Barb"; "Charlie"; "Alex"; "Peter"; "Zoe"; "Jim"] (roster school)
  );
  "Grade returns the students in that grade in alphabetical order" >:: (
    let school = empty_school |> add "Franklin" 5 |> add "Bradley" 5 |> add "Jeff" 1 in
    assert_lists_equal ["Bradley"; "Franklin"] (grade 5 school)
  );
  "Grade returns an empty list if there are no students in that grade" >:: (
    let school = empty_school in
    assert_lists_equal [] (grade 1 school)
  );
  "Adding a student adds them to the sorted roster" >:: (
    let school = empty_school |> add "Aimee" 2 in
    assert_lists_equal ["Aimee"] (roster school)
  );
  "Adding more student adds them to the sorted roster" >:: (
    let school = empty_school |> add "Blair" 2 |> add "James" 2 |> add "Paul" 2 in
    assert_lists_equal ["Blair"; "James"; "Paul"] (roster school)
  );
  "Adding students to different grades adds them to the same sorted roster" >:: (
    let school = empty_school |> add "Chelsea" 3 |> add "Logan" 7 in
    assert_lists_equal ["Chelsea"; "Logan"] (roster school)
  );
  "Roster returns an empty list if there are no students enrolled" >:: (
    let school = empty_school in
    assert_lists_equal [] (roster school)
  );
  "Student names with grades are displayed in the same sorted roster" >:: (
    let school = empty_school
                 |> add "Peter" 2
                 |> add "Anna" 1
                 |> add "Barb" 1
                 |> add "Zoe" 2
                 |> add "Alex" 2
                 |> add "Jim" 3
                 |> add "Charlie" 1 in
    assert_lists_equal ["Anna"; "Barb"; "Charlie"; "Alex"; "Peter"; "Zoe"; "Jim"] (roster school)
  );
  "Grade returns the students in that grade in alphabetical order" >:: (
    let school = empty_school |> add "Franklin" 5 |> add "Bradley" 5 |> add "Jeff" 1 in
    assert_lists_equal ["Bradley"; "Franklin"] (grade 5 school)
  );
  "Grade returns an empty list if there are no students in that grade" >:: (
    let school = empty_school in
    assert_lists_equal [] (grade 1 school)
  );
  "Adding a student adds them to the sorted roster" >:: (
    let school = empty_school |> add "Aimee" 2 in
    assert_lists_equal ["Aimee"] (roster school)
  );
  "Adding more student adds them to the sorted roster" >:: (
    let school = empty_school |> add "Blair" 2 |> add "James" 2 |> add "Paul" 2 in
    assert_lists_equal ["Blair"; "James"; "Paul"] (roster school)
  );
  "Adding students to different grades adds them to the same sorted roster" >:: (
    let school = empty_school |> add "Chelsea" 3 |> add "Logan" 7 in
    assert_lists_equal ["Chelsea"; "Logan"] (roster school)
  );
  "Roster returns an empty list if there are no students enrolled" >:: (
    let school = empty_school in
    assert_lists_equal [] (roster school)
  );
  "Student names with grades are displayed in the same sorted roster" >:: (
    let school = empty_school
                 |> add "Peter" 2
                 |> add "Anna" 1
                 |> add "Barb" 1
                 |> add "Zoe" 2
                 |> add "Alex" 2
                 |> add "Jim" 3
                 |> add "Charlie" 1 in
    assert_lists_equal ["Anna"; "Barb"; "Charlie"; "Alex"; "Peter"; "Zoe"; "Jim"] (roster school)
  );
  "Grade returns the students in that grade in alphabetical order" >:: (
    let school = empty_school |> add "Franklin" 5 |> add "Bradley" 5 |> add "Jeff" 1 in
    assert_lists_equal ["Bradley"; "Franklin"] (grade 5 school)
  );
  "Grade returns an empty list if there are no students in that grade" >:: (
    let school = empty_school in
    assert_lists_equal [] (grade 1 school)
  );
  "Adding a student adds them to the sorted roster" >:: (
    let school = empty_school |> add "Aimee" 2 in
    assert_lists_equal ["Aimee"] (roster school)
  );
  "Adding more student adds them to the sorted roster" >:: (
    let school = empty_school |> add "Blair" 2 |> add "James" 2 |> add "Paul" 2 in
    assert_lists_equal ["Blair"; "James"; "Paul"] (roster school)
  );
  "Adding students to different grades adds them to the same sorted roster" >:: (
    let school = empty_school |> add "Chelsea" 3 |> add "Logan" 7 in
    assert_lists_equal ["Chelsea"; "Logan"] (roster school)
  );
  "Roster returns an empty list if there are no students enrolled" >:: (
    let school = empty_school in
    assert_lists_equal [] (roster school)
  );
  "Student names with grades are displayed in the same sorted roster" >:: (
    let school = empty_school
                 |> add "Peter" 2
                 |> add "Anna" 1
                 |> add "Barb" 1
                 |> add "Zoe" 2
                 |> add "Alex" 2
                 |> add "Jim" 3
                 |> add "Charlie" 1 in
    assert_lists_equal ["Anna"; "Barb"; "Charlie"; "Alex"; "Peter"; "Zoe"; "Jim"] (roster school)
  );
  "Grade returns the students in that grade in alphabetical order" >:: (
    let school = empty_school |> add "Franklin" 5 |> add "Bradley" 5 |> add "Jeff" 1 in
    assert_lists_equal ["Bradley"; "Franklin"] (grade 5 school)
  );
  "Grade returns an empty list if there are no students in that grade" >:: (
    let school = empty_school in
    assert_lists_equal [] (grade 1 school)
  );
  "Adding a student adds them to the sorted roster" >:: (
    let school = empty_school |> add "Aimee" 2 in
    assert_lists_equal ["Aimee"] (roster school)
  );
  "Adding more student adds them to the sorted roster" >:: (
    let school = empty_school |> add "Blair" 2 |> add "James" 2 |> add "Paul" 2 in
    assert_lists_equal ["Blair"; "James"; "Paul"] (roster school)
  );
  "Adding students to different grades adds them to the same sorted roster" >:: (
    let school = empty_school |> add "Chelsea" 3 |> add "Logan" 7 in
    assert_lists_equal ["Chelsea"; "Logan"] (roster school)
  );
  "Roster returns an empty list if there are no students enrolled" >:: (
    let school = empty_school in
    assert_lists_equal [] (roster school)
  );
  "Student names with grades are displayed in the same sorted roster" >:: (
    let school = empty_school
                 |> add "Peter" 2
                 |> add "Anna" 1
                 |> add "Barb" 1
                 |> add "Zoe" 2
                 |> add "Alex" 2
                 |> add "Jim" 3
                 |> add "Charlie" 1 in
    assert_lists_equal ["Anna"; "Barb"; "Charlie"; "Alex"; "Peter"; "Zoe"; "Jim"] (roster school)
  );
  "Grade returns the students in that grade in alphabetical order" >:: (
    let school = empty_school |> add "Franklin" 5 |> add "Bradley" 5 |> add "Jeff" 1 in
    assert_lists_equal ["Bradley"; "Franklin"] (grade 5 school)
  );
  "Grade returns an empty list if there are no students in that grade" >:: (
    let school = empty_school in
    assert_lists_equal [] (grade 1 school)
  );
  (* "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)
open Base

module Int_map = Map.M(Int)
type school = string list Int_map.t

let empty_school = Map.empty (module Int)

let add (student: string) (grade: int) (my_school: school) : school =
        let student_list = Map.find my_school grade in
        match student_list with
        | None -> Map.add_exn my_school grade [student]
        | Some l -> Map.set my_school ~key:grade ~data:(List.sort (student::l) String.compare)
;;

let grade (grade: int) (my_school: school) : string list =
        let student_list = Map.find my_school grade in
        match student_list with
        | None -> []
        | Some l -> l
;;

let sorted (my_school: school) : school =
        Map.map my_school (fun student_list -> List.sort student_list String.compare)
;;

let roster (my_school: school) : string list =
        let key_list = List.sort (Map.keys my_school) Int.compare in
        List.fold key_list ~init:[] ~f:(fun acc key -> List.append acc (grade key my_school))
;;

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