Thursday, April 30, 2015

April 2015 1HaskellADay Problems and Solutions

April 2015
  • April 30th, 2015: "SHOW ME DA MONAY!" for today's #haskell problem 
    Simple? Sure! Solution? Yes.
  • April 29th, 2015: We take stock of the Stochastic Oscillator for today's #haskell problem #trading We are so partially stoched for a partial solution for the Stochastic Oscillator 
  • April 28th, 2015: Today's #haskell puzzle as a ken-ken solver a solution (beyond my ... ken) is defined at
  • April 27th, 2015: Rainy days and Mondays do not stop the mail, nor today's #haskell problem! The solution posted at … shows us view-patterns and how to spell the word 'intercalate'.
  • April 24th, 2015: Bidirectionally (map) yours! for today's #haskell problem A solution to this problem is posted at 
  • April 23rd, 2015: Today's #haskell problem looks impossible! So this looks like this is a job for ... KIM POSSIBLE! YAY! @sheshanaag offers a solution at .
  • April 22nd, 2015: "I need tea." #BritishProblems "I need clean data" #EveryonesPipeDream "Deletia" today's #haskell problem Deletia solution? Solution deleted? Here ya go!
  • April 21st, 2015: In which we learn about Tag-categories, and then Levenshtein distances between them for today's #haskell problem Okay, wait: is it a group of categories or a category of groups? me confused! A solution to today's #haskell at
  • April 20th, 2015: Today we can't see the forest for the trees, so let's change that A solution to our first day in the tag-forest ... make sure you're marking your trail with breadcrumbs!
  • April 17th, 2015: No. Wait. You wanted line breaks with that, too? Well, why didn't you say so in the first place? Have some curry with a line-breaky solution at
  • April 16th, 2015: "more then." #okaythen Sry, not sry, but here's today's #haskell problem: I can't even. lolz. rofl. lmao. whatevs. And a big-ole-blob-o-words is given as the solution for today's #haskell problem. It ain't pretty, but... there it is
  • April 15th, 2015: Poseidon's trident or Andrew's Pitchfork analysis, if you prefer, for today's #haskell problem
  • April 14th, 2015: Refining the SMA-trend-ride for today's #haskell problem. Trending and throttling doesn't ... quite get us there, but ... solution:
  • April 13th, 2015: In today's #haskell problem we learn zombies are comonadic, and like eating SMA-brains. Yeah. That. Hold the zombies, please! (Or: when $40k net profit is not enough by half!)
  • April 10th, 2015: Today's #haskell problem delivered with much GRAVITAS, boils down to: don't be a dumb@$$ when investing #KeepinItReal The SMA-advisor is REALLY chatty, but how good is it? TBD, but here's a very simple advisor: Backtesting for this strategy is posted at (or: how a not so good buy/sell strategy give you not so good results!)
  • April 9th, 2015: A bit of analysis of historical stock data for today's #haskell problem A solution to the SMA-analyses part is posted at 
  • April 8th, 2015: MOAR! MOAR! You clamor for MOAR real-world #haskell problems, and how can I say no? Downloading stock screens Hint: get the screens from a web service; look at, e.g.: A 'foldrM'-solution to this problem is posted at
  • April 7th, 2015: Looking at a bit of real-world #haskell for today's stock (kinda-)screen-scraping problem at Hint: perhaps you'd like to solve this problem using tagsoup? *GASP* You mean ... it actually ... works? A MonadWriter-y tagsoup-y Monoidial-MultiMap-y solution
  • April 6th, 2015: What do three men teaching all of high school make, beside today's #haskell problem? Tired men, of course! Thanks, George Boole! Three Men and a High School, SOLVED!
  • April 3rd, 2015: reverseR that list like a Viking! Rrrrr! for today's problem … #haskell Totes cheated to get you the solution used a library that I wrote, so, like, yeah, totes cheated! ;)
  • April 2nd, 2015: We're breaking new ground for today's #haskell problem: let's reverse lists... relationally. And tag-type some values After several fits and starts @geophf learns how to reverse a list... relationally and can count to the nr 5, as well
  • April 1st, 2015: Take a drink of today's #haskell problem: love potion nr9 because, after all: all we need is love, la-di-dah-di-da! A solution can be found au shaque d'amour posted at

Wednesday, April 1, 2015

March 2015 1HaskellADay Problems and Solutions

March 2015
  • March 31st, 2015: Today's #haskell exercise has us looking for a really big pandigital prime ... like: REALLY big. Maybe.
  • March 30th, 2015: A little math-problem to ease us into the week, suggested by @jamestanton 3 consecutive integers that are co-composed
  • March 27th, 2015: Today's #haskell problem is unification of multiple free variables We find this to be 'CoSimple.' 34 lines (and a new n-to-1 data mapping-type) defining not a 'CoSimple' unifier but now an 'UnSimple' one. Ugh!
  • March 26th, 2015: Unification is interesting! (Functional Unification paper) Let's look at the unification-problem for today's #haskell problem We define simple unification (of up to one free logic variable) in a module called unification.simple, oddly enough.
  • March 25th, 2015: In Old Norse, words end with 'R' (not all). For today's #Haskell problem, relations end with 'R' Where I learn to speak Old Norse with a slightly better accent: unifying lists with headR and tailR with unifyLists
  • March 24th, 2015: For today's #haskell problem we learn that 'kayso' is a word, and we edge a bit more toward pure relational calculus A solution to this relational-calculus problem that is defined over Data/Control logic modules:
  • March 23rd, 2015: WHO KNEW a chance meeting with @webyrd at the POPL06 would lead to today's #haskell problem? μBikini I mean: μKanren And the solution implies that monadic-list states are logic programming? Perhaps.
  • March 19th, 2015: We now learn signal spreads ... like ... margarine! for today's #haskell problem
  • March 18th, 2015: For today's #haskell problem we learn that Jupiter's moon Europa is made from Froyo, and custard! Mmmm!
  • March 17th, 2015: No quaternions were harmed in today's #haskell π-problem IN SPACE!
  • March 16th, 2105: In space, no one can here you scream "@NASA" (nor anything else for that matter. Today's #haskell problem
  • March 14th, 2015: Happy π day! A plain-text version of these NASA π-in-space puzzles are available at
  • March 13th, 2015: Okay, ladies and gentlemen, today, in honor of tomorrow being π day, let's take a #coercive #logic break and π it up!
  • March 12th, 2015: I wonder if the suitor's surname is Quine for today's #haskell problem #coercive #logic
  • March 10th, 2015: For today's #haskell problem, we wonder if Balikaya is Aharmanite or Mazdaysian #scheherazade #coercive #logic
  • March 9th, 2015: In which Iskandar is asked Kamar's Children's ages in Scheherazade's #haskell metapuzzle #coercive #logic 
  • March 6th, 2015: Champernowne's constant for today's #haskell problem Please let me know if you can NOT access this problem: I've marked it private as previous ones are being modified in place. DON'T DO THAT!  In which we show @geophf triumphs with brütish-forcisms for today's #haskell solution
  • March 5th, 2015: For today's #haskell problem, we ponder why they aren't calledLEFT-triangles. Is it a plot? Leftist triangles are subject to the (IO) State (monad) ... geddit? #sigh never mind anyway, solution: Or, put another way: in which we see @geophf can not have a function type that includes -> Int -> ... AND, we really need MapReduce here!
  • March 4th, 2015: Truncatable primes (11 in all) are asking to be solved in today's #haskell problem This @1HaskellADay problem turned into a _TWO_day solution! Worth it? Why, yes, after redesigning _TWO_ libraries!
  • March 3rd, 2015: There's more than a 1-in-a-million chance there are 'sum' double palindromic numbers in today's #haskell problem The solution was not too hard, M. Euler!
  • March 2nd, 2015: What-what! abcde * fghij is equal to ... well, something, it appears. and the prob1, prob2 winners are ... A solution to today's #haskell problem.