Anagram Solutions

anagram.clj

(ns anagram
  (:require [clojure.string :refer [lower-case split]]))

(defn- duplicate? [a b]
  (= (lower-case a) (lower-case b)))

(defn- unique-candidates [source candidates]
  (remove #(duplicate? % source) candidates))

(defn- canonicalize [word]
  (frequencies (lower-case word)))

(defn- is_anagram? [canonical_source candidate]
  (= canonical_source (canonicalize candidate)))

(defn anagrams-for [source, candidates]
  (->>
    (unique-candidates source candidates)
    (filter #(is_anagram? (canonicalize source) %))))

anagram.exs

defmodule Anagram do
  defp duplicate?(a, b) do
    String.downcase(a) == String.downcase(b)
  end

  defp unique_words(source, candidates) do
    Enum.reject(candidates, duplicate?(&1, source))
  end

  defp canonical(string) do
    String.downcase(string) |> String.graphemes |> Enum.sort
  end

  defp is_anagram?(canonical_source, candidate) do
    canonical_source == canonical(candidate)
  end

  def match(source, candidates) do
    unique_words(source, candidates)
     |> Enum.filter(is_anagram?(canonical(source), &1))
  end
end