2016 Update

Task/Letter-frequency/00DESCRIPTION

@@ -1,4 +1,6 @@
+;Task:
 Open a text file and count the occurrences of each letter.
 
 Some of these programs count all characters (including punctuation),
 but some only count letters A to Z.
+<br><br>

Task/Letter-frequency/Elixir/letter-frequency.elixir

@@ -1,11 +1,9 @@
 file = hd(System.argv)
 
-case File.read(file) do
-  {:ok, binary} -> String.upcase(binary)
-                   |> String.codepoints
-                   |> Enum.filter(fn c -> c =~ ~r/[A-Z]/ end)
-                   |> Enum.reduce(Map.new, fn c,acc -> Dict.update(acc, c, 1, &(&1+1)) end)
-                   |> Enum.sort_by(fn {_k,v} -> -v end)
-                   |> Enum.each(fn {k,v} -> IO.puts "#{k}  #{v}" end)
-  {:error, reason} -> IO.inspect reason
-end
+File.read!(file)
+|> String.upcase
+|> String.graphemes
+|> Enum.filter(fn c -> c =~ ~r/[A-Z]/ end)
+|> Enum.reduce(Map.new, fn c,acc -> Map.update(acc, c, 1, &(&1+1)) end)
+|> Enum.sort_by(fn {_k,v} -> -v end)
+|> Enum.each(fn {k,v} -> IO.puts "#{k}  #{v}" end)

Task/Letter-frequency/Julia/letter-frequency.julia

@@ -1,5 +1,5 @@
 function freq(file)
   h = Dict{Char, Integer}()
-  for x in open(readchomp,file) h[x] = get(h,x,0)+1 end
+  for x in open(readstring ,file) h[x] = get(h,x,0)+1 end
   sort(collect(h))
 end

Task/Letter-frequency/OCaml/letter-frequency-2.ocaml

@@ -0,0 +1,10 @@
+open Batteries
+
+let frequency file =
+  let freq = Hashtbl.create 52 in
+    File.with_file_in file
+      (Enum.iter (fun c -> Hashtbl.modify_def 1 c succ freq) % Text.chars_of);
+    List.iter (fun (k,v) -> Text.write_text stdout k;
+                            Printf.printf " %d\n" v)
+    @@ List.sort (fun (_,v) (_,v') -> compare v v')
+    @@ Hashtbl.fold (fun k v l -> (Text.of_uchar k,v) :: l) freq []

Task/Letter-frequency/PowerShell/letter-frequency.psh

@@ -0,0 +1,9 @@
+function frequency ($string) {
+    $arr = $string.ToUpper().ToCharArray() |where{$_ -match '[A-KL-Z]'}
+    $n = $arr.count
+    $arr | group | foreach{
+        [pscustomobject]@{letter = "$($_.name)"; frequency  = "$([math]::round($($_.Count/$n),5))"; count = "$($_.count)"}
+    } | sort letter
+}
+$file = "$($MyInvocation.MyCommand.Name )" #Put the name of your file here
+frequency $(get-content $file -Raw)