Isogram

Challenge Overview

Determine if a word or phrase is an isogram.

Visit the isogram exercise on Exercism to read the full instructions and download the exercise files.

Community Solutions

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The following are the top 3 community solutions by stars:

Solution 1 by @marionebl (⭐ 4) — View on Exercism
Solution 2 by @rmunn (⭐ 13) — View on Exercism
Solution 3 by @damienstanton (⭐ 2) — View on Exercism

Source: Exercism fsharp/isogram

💡 View Solution

module Isogram

let isIsogram (str: string) =
    str
    |> Seq.filter Char.IsLetter
    |> Seq.countBy Char.ToLower
    |> Seq.forall (fun (_, c) -> c = 1)