haskell example in ruby

grade_parser.rb

#first stab
h=Hash.new
(File.read "grades.txt").split("\n").each do |pair|
    (person, grade)=pair.split ' '
    if h[person]
        h[person] << grade.to_i
    else
        h[person]=[grade.to_i]
    end
end

(h.sort).to_h.each_pair do |key,value|
    print "#{key} #{value} Average: #{value.reduce(:+)/(value.length).to_f}\n"
end

#second attempt
h=Hash.new
(File.read "grades.txt").
    split("\n").
    map {|ele| ele.split}.
    sort.each do |pair| 
        h[pair.first] ? 
            h[pair.first] << pair.last.to_i : 
            h[pair.first]=[pair.last.to_i]
    end

h.each_pair do |key,value|
    print "#{key} #{value} Average: #{value.reduce(:+)/(value.length).to_f}\n"
end

#third
h=Hash.new
(File.read "grades.txt").
    split("\n").
    map {|ele| ele.split}.
    sort.
    each do |pair|
     (person,grade)=pair 
        h[person] ? 
            h[person] << grade.to_i : 
            h[person]=[grade.to_i]
    end


h.each_pair do |key,value|
    print "#{key} #{value} Average: #{value.reduce(:+)/(value.length).to_f}\n"
end

#fourth

(File.open("grades.txt") do |file|
  file
  .map {|line| {person: line.split[0], grade: line.split[1]}}
  .group_by {|record| record[:person] }
  .each {|person,record| record.map! {|r| r[:grade]}}
end)
.sort
.each_pair do |key,value|
    print "#{key} #{value} Average: #{value.reduce(:+)/(value.length).to_f}\n"
end

  

#Alonzo [70] Average: 70.0
#Bob [80] Average: 80.0
#Eugenio [69] Average: 69.0
#Henk [79, 90] Average: 84.5
#Nick [90, 98, 100] Average: 96.0
#Oleg [77] Average: 77.0
#Philip [73, 73] Average: 73.0
#Shlomo [90, 92, 95] Average: 92.33333333333333
#Simor [94] Average: 94.0
#Vered [100] Average: 100.0

grades.txt

Shlomo 90
Nick 90
Vered 100
Alonzo 70
Henk 79
Simor 94
Philip 73
Nick 98
Shlomo 92
Eugenio 69
Bob 80
Shlomo 95
Henk 90
Oleg 77
Philip 73
Nick 100