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elm/exercises/grade-school/GradeSchool.example

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module GradeSchool exposing (..)
import Dict exposing (..)
type alias Grade =
Int
type alias Student =
String
type alias School =
Dict Int (List Student)
empty : School
empty =
Dict.empty
addStudent : Grade -> Student -> School -> School
addStudent grade student school =
Dict.insert grade (List.sort (student :: (studentsInGrade grade school))) school
studentsInGrade : Grade -> School -> List Student
studentsInGrade grade school =
case (Dict.get grade school) of
Just list ->
list
Nothing ->
[]
allStudents : School -> List ( Grade, List Student )
allStudents school =
Dict.toList school |> List.sortBy fst