Anagram Project

Background

Pyschology researchers are investigating subjects' ability to solve anagrams. As such, they need a way of generating and verifying the solution to anagrams.

Definitions

For the purpose of this project, let the following definitions hold:

• Word: One of the set of standard Unix words.
• Anagram: a word or sequence of words formed by rearranging the letters of another string, such as rant creep, formed from carpenter.
• Anagram Puzzle: a string which is not a word but is an anagram.
• Anagram Solution: a word made of the same letters of a given anagram.
• Unsolvable Anagram: a string which is neither a word nor an anagram (bit of misnomer, eh?).

Requirements

The solution must:

• Be a clojure library...
• That can generate anagram puzzles..
• Of varying difficulty...
• And verify that a given word is the solution to a given anagram...
• While being fast enough to use interactively at the REPL.

Prior Art

Internet Anagram Server by Wordsmith

Wordsmith's service sports an impressive number of knobs you can turn to create great anagrams. This thing is awesome. So tempted to just make client library for their api and be done...

Scrable

https://en.wikipedia.org/wiki/Scrabble_letter_distributions Who would have ever thought

The Anagram Dictionary https://en.wikipedia.org/wiki/Anagram_dictionary

http://norvig.com/mayzner.html - Really good explanations, updates to bigram tables https://stackoverflow.com/a/12477976 - basic algorithm for finding single word anagrams http://pi.math.cornell.edu/~mec/2003-2004/cryptography/subs/digraphs.html - Bigram table I'm using https://web.stanford.edu/class/cs9/sample_probs/Anagrams.pdf - good explanation of algorithm http://www.ssynth.co.uk/~gay/anagabout.html - implementation, but with shoddy details

https://stackoverflow.com/a/881367 - inspiration

Thanks to @seancorfield, @dpsutton, and @porkostomus for help with the partial anagram algorithm!

The Difficulty with Difficulty

How the heck do you measure anagram difficulty? It turns out this is a subject of much academic research and debate. I'm a

Questions and Answers

• Are we going to deal with Anagram phrases (multiword anagrams)?
  • Every definition I've read so far defines an anagram as a "word, phrase, or name". While I'm not excited about the added complexity multi-word anagrams will add (orders of magnitude more), I think they have to be handled to stay true to the problem.
• What are we going to do to optimize for speed?
  • As little as possible. Premature optimization and all that.
• How are we going to measure "difficulty"?
  • With contrived but convincing standards, of course. After all, this is science. But really, we're going to define the difficulty of an anagram by the