Avatar of NobbZ

NobbZ's solution

to Anagram in the LFE Track

Published at Jul 13 2018 · 3 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".


For installation and learning resources, refer to the exercism help page.

To run the provided tests, you will need make. Open a terminal window and run the following from the exercise directory:

make test

You should now be able to see the results of the test suite for the exercise.

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-tests.lfe

(defmodule anagram-tests
  (behaviour ltest-unit)
  (export all))

(include-lib "ltest/include/ltest-macros.lfe")

(deftest no-matches
  (is-equal () (anagram:find "diaper" '("hello" "world" "zombies" "pants"))))

(deftest detect-simple-anagram
  (is-equal '("tan") (anagram:find "ant" '("tan" "stand" "at"))))

(deftest does-not-confuse-different-duplicates
  (is-equal () (anagram:find "galea" '("eagle"))))

(deftest eliminate-angram-subsets
  (is-equal () (anagram:find "good" '("dog" "goody"))))

(deftest detect-anagram
  (is-equal
    '("inlets")
    (anagram:find "listen" '("enlists" "google" "inlets" "banana"))))

(deftest multiple-anagrams
  (is-equal
    '("gallery" "regally" "largely")
    (anagram:find
      "allergy"
      '("gallery" "ballerina" "regally" "clergy" "largely" "leading"))))

(deftest case-insensitive-subject
  (is-equal
    '("carthorse")
    (anagram:find "Orchestra" '("cashregister" "carthorse" "radishes"))))

(deftest case-insensitive-candidate
  (is-equal
    '("Carthorse")
    (anagram:find "Orchestra" '("cashregister" "Carthorse" "radishes"))))

(deftest does-not-detect-a-word-as-its-own-anagram
  (is-equal
    '("cron")
    (anagram:find "corn" '("corn" "dark" "Corn" "rank" "CORN" "cron" "park"))))
;; -*- mode: lisp -*-

(defmodule anagram
  (export (find 2)))

(defun find (original wordlist)
  (let* ((lower-original (string:to_lower original))
         (sorted-lower-original (lists:sort lower-original)))
    (lists:filter (lambda (word)
                    (let* ((lower-word (string:to_lower word))
                           (sorted-lower-word (lists:sort lower-word)))
                      (and (== sorted-lower-word sorted-lower-original)
                           (/= lower-word lower-original))))
                  wordlist)))

Community comments

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Avatar of yurrriq

I'd love to see another iteration with the same separation of responsibilities as your other submissions :)

Avatar of yurrriq

Also, and does not short circuit while andalso does, so you could rewrite your filter function to be lazier.

Avatar of NobbZ

You are right, I really need to learn to choose more carefully anong lazy/strict and/or versions… That's a problem I have in erlang as well (but I tend to overuse shortcutting versions there)

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