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alisdair's solution

to Anagram in the Clojure Track

Published at Jul 13 2018 · 2 comments
Instructions
Test suite
Solution

Given a word and a list of possible anagrams, select the correct sublist.

Given "listen" and a list of candidates like "enlists" "google" "inlets" "banana" the program should return a list containing "inlets".

Source

Inspired by the Extreme Startup game https://github.com/rchatley/extreme_startup

Submitting Incomplete Solutions

It's possible to submit an incomplete solution so you can see how others have completed the exercise.

anagram_test.clj

(ns anagram-test
  (:require [clojure.test :refer [deftest is]]
            anagram))

(deftest no-matches
  (is (= []
         (anagram/anagrams-for "diaper" ["hello" "world" "zombies" "pants"]))))

(deftest detect-simple-anagram
  (is (= ["tan"] (anagram/anagrams-for "ant" ["tan" "stand" "at"]))))

(deftest does-not-confuse-different-duplicates
  (is (= [] (anagram/anagrams-for "galea" ["eagle"]))))

(deftest eliminate-anagram-subsets
  (is (= [] (anagram/anagrams-for "good" ["dog" "goody"]))))

(deftest detect-anagram
  (is (= ["inlets"]
         (let [coll ["enlists" "google" "inlets" "banana"]]
           (anagram/anagrams-for "listen" coll)))))

(deftest multiple-anagrams
  (is (= ["gallery" "regally" "largely"]
         (let [coll ["gallery" "ballerina" "regally"
                     "clergy"  "largely"   "leading"]]
           (anagram/anagrams-for "allergy" coll)))))

(deftest case-insensitive-anagrams
  (is (= ["Carthorse"]
         (let [coll ["cashregister" "Carthorse" "radishes"]]
           (anagram/anagrams-for "Orchestra" coll)))))

(deftest word-is-not-own-anagram
  (is (= [] (anagram/anagrams-for "banana" ["banana"]))))

(deftest capital-word-is-not-own-anagram
  (is (= [] (anagram/anagrams-for "BANANA" ["banana"]))))
(ns anagram)

(defn- sorted-lowered [s]
  (apply str (sort (clojure.string/lower-case s))))

(defn- is-anagram [s w]
  (and
    (not= s w)
    (= (sorted-lowered s) (sorted-lowered w))))

(defn anagrams-for [s words]
  (filter (partial is-anagram s) words))

Community comments

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Avatar of alisdair
alisdair
Solution Author
commented about 6 years ago

I'm not really happy with this. Seems more complex than it should be.

I'm aware that this recomputes sorted-lowered s multiple times, but I'm more concerned with code clarity than efficiency at this point.

Avatar of geofflane

I think it's pretty easy to understand. It's good functional decomposition which makes each of the levels of abstraction pretty clear.

You don't need to convert the sorted-lowered back to a string. The = will compare lists as well.

It's pretty common in Clojure to end predicates like is-anagram with a question mark indicating it returns a boolean result.

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