Typed Logic

Wednesday, September 2, 2020

September 2020 Haskell Problems and Solutions

2020-09-09: Today's #haskell exercise is to compile our book-word-net into a Haskell module. The #haskell solution compiled the August 2020 Gutenberg top 100 read books into Haskell terms.
2020-09-08: Data analytics on our top 100 gutenberg books is today's #haskell exercise. Did you know that there approximately 2000 English words in common usage? Today's #haskell solution: "Sounds about right."
2020-09-01: Today's #haskell problem is reducing a map of mapping of information to maps to a map. HOW HASKELL-Y! Yesterday's #haskell solution updated both problem and solution and made some data-discoveries along the way. Neat-o!

Tuesday, September 1, 2020

February 2019 Haskell 1-liners

February 18th, 2019:
Define ext :: (Maybe a, b) -> Maybe (a,b)
e.g.: ext (Just 5, "Hi") = Just (5, "Hi")

Al͜l ̸͑ha͂͟il̶! @TechnoEmpress \o/
cλementd @clementd `fmap swap. sequenceA . swap` :-)
Raveline @Raveline bisequence . second pure
Alexey Radkov @sheshanaag uncurry (flip $ fmap . flip (,))
a fool @fresheyeball ext = \case (Just x, y) -> Just (x, y); _ -> Nothing

September 2020 Haskell 1-liners

2020-09-08: given
```
removeInfreqs :: Set String -> Ontology -> Ontology
removeInfreqs infrequentWords ont = 
   Map.map (\wordcounts -> foldl (flip ri') wordcounts infrequentWords) ont
```
where Ontology is a map-of-maps.
1. remove flip to get the same functional result.
2. curry away ont from the function removeInfreqs
3. curry away wordcounts from the map-lambda function.
4. curry away infrequentWords from the function removeInfreqs
  
  n.b.: This curry may not be as straightforward as the other curries.
2020-09-01: Given all of the above, and now that you've curried the above lambda to [SPOILER]:

\key -> const (not (Set.member key stoppers))
Curry away key from this new lambda.

Wednesday, August 26, 2020

August 2020 1HaskellADay 1Liners

2020-08-31:

#Haskell #BetterWithCurry #1Liner For:
```
>>> :t Map.filterWithKey 
Map.filterWithKey :: (k -> a -> Bool) -> Map k a -> Map k a
```
we have this filtering function: \key _val -> not (Set.member key stoppers)

_val is unused. Curry it away.
2020-08-28:
rmFront :: Set Char -> String -> StringrmFront weirds str = dropWhile (flip Set.member weirds) str
Simple currying questions: can this function-implementation be simplified with currying? Can it be simplified ... MORE? Answers: yes, and yes. Show your implementation.
2020-08-26: We have this: \info -> importBook info >>= return . (info,) There are way too many info-references. What's a better way to write this expression?

Five solutions from @noaheasterly:

runKleisli (id &&& Kleisli importBook)
liftA2 (liftA2 (,)) return importBook
liftA2 (fmap . (,)) id importBook
traverse importBook . join (,)
traverse importBook . (id &&& id)

Monday, August 3, 2020

August 2020 1HaskellADay Problems and Solutions

2020-08-31: For today's #haskell problem we learn the nature of the words "the" and "yesterday." Fundamental things. SCROOGE! Yesterday's #haskell solution shows us that "scrooge" was the most-written word in "A Christmas Carol." Fancy that!
2020-08-28: Today's #haskell problem: a word-frequency analysis, ... a CLEAN-word-frequency analysis. Today's #haskell solution. Amazing, isn't it, that the word Charles Dickens wrote the most, by far, was 'the'. #writerslife
2020-08-27: We're looking at 'weird characters' and 'weird words' for today's #haskell problem. We found words, weird words, and the weird characters in those weird words in today's #haskell solution.
2020-08-26: For today's #haskell problem, let's download the top-100 books from project gutenberg! For today's #haskell solution, we have the top-100 gutenberg books, downloaded and ready for analysis!
2020-08-25: "Project Gutenberg, here I come!" is my battle-cry for today's #Haskell problem. We have an index to book indices for yesterday's #haskell solution.
2020-08-24: Multiplication using cosines is called ... Prosthaphaeresis... and also called: "today's #haskell problem."
2020-08-21: Gimme a hint? ... or two? Today's #haskell problem is to find words in dictionaries with the help of supplied hints. "Alien." The word was "alien" for today's #Haskell solution (because it's always the aliens) (I didn't say that.) I, FOR ONE, WELCOME OUR NEW ALIEN OVERLORDS!
2020-08-20: Yesterday we did word-lookups from provided dictionaries. Today's #haskell problem is a little analysis (a word histogram) of those word-dictionaries.
"fromList [(1,234371)]" That, there, them's alotta words, yup. Yesterday's #haskell solution.
2020-08-19: SKRIBBL.io! (A part of) SKRIBBL.io is the #Haskell challenge for today. And the #haskell solution, monad-style!
2020-08-10: HEAPS! Luv me sum HEAPS! Today's #haskell problem is to define the Heap collection and its operations.
2020-08-03: Today's #haskell problem is to generate random permutation of active team members. So, yeah: random permutes down low on the team members, d'#Haskell

Thursday, July 2, 2020

July 2020 1HaskellADay Problems and Solutions

2020-07-31: Well, that's random. Generating random numbers and sequences is today's #Haskell problem. Today's #haskell solution shows that I can (<*>) that monad, first go, without even looking it up or anything. So, yeah, I'm walking pretty tall right now.
2020-07-30: Kate and Shoaib are going on vacation. Commander Adama in Star Wars tells us that for today's #haskell problem, we are to "Make it so, Number one." And: there they go! Shoaib and Kate, going on a vacay, havin' fun, and type-safely, at that, because of the #haskell solution 'n stuff.
2020-07-29: "How many days until ...?" A date calculator for today's #haskell problem. When I say: "Compute the date," I'm not talking fig trees, here. The solution to today's #Haskell problem.
2020-07-28: Today's #haskell problem involves passing arguments to and verifying results from an external application. 'frankenfurters.' That's what we're trying to sum here. 'frankenfurters.' 'Fault Tolerance'? We've got that with today's #haskell solution.
2020-07-27: Today's #Haskell exercise makes us realize that ... "All, in all, you're just a ... nother brick in THE WALL. :/" A solution pour vous, s'il vous plaît.
2020-07-24: Today's #haskell problem explores the result of processed images from, in this case, Amazon's Rekognition. Today's #haskell solution: BIRDz! ... Cardinals, in fact.
2020-07-23: For today's #haskell problem, let's read in a JPG (o' FLAH'z!) and write it out as a TIFF ... for, you know, like: an image processing/classification exercise, at some later date. Ooh! TIFFY! TIFF saved from loaded JPEG image.
2020-07-22: For today's #haskell problem we extract data from JSON returned from a REST endpoint. The #haskell solution is declarative/functional-composition goodness to parse data from JSON returned from a REST endpoint.
2020-07-21: We ping a public API REST endpoint for today's #Haskell problem. For today's #haskell solution, simpleHttp in Network.HTTP.Conduit does the trick!
2020-07-20: For today's #haskell problem we read a file that contains a JSON message and parse it.
2020-07-17: Oops! Where has the time gone? That's today's ... I mean, YESTERDAY's, #haskell problem.
2020-07-16: And now, for something completely different: today's #haskell problem has us reading a file, parsing the data, and ranking the results. #haskell solution to which level is most recruit-efficient for a dark chest.
2020-07-15: For today's #haskell problem, we pull what we've done so far all together and compute today's pairings, given historical context.
2020-07-14: For today's #haskell problem, we pull what we've done so far all together and compute today's pairings, given historical context.
2020-07-14: For today's #Haskell problem, we look at using our historical context of pairings to answer questions for future pairings.
2020-07-13: Now that we've selected pairings for today, let's store those pairings into an historical context for today's #haskell problem.
2020-07-08: Pairing and ... 'Mobbing' (?) ... okay, really??? is our game for today's #haskell problem. A solution to the simple pairing-problem.
2020-07-07: For today's #haskell problem, we lay a foundation for building a team-pairing app. This day's problem addresses a History-type to provide context to the pairing-algorithm.
2020-07-06: For today's #haskell problem, we look at finding the spanning trees of a graph.
2020-07-02: Today's #haskell exercise finds us (acyclic) pathing though a simpler, yet-not-fully connected, graph.
2020-07-01: For today's #haskell problem we find cycles in graphs, ... MOTORcycles in graphs! AHA! AND MAKE MINE A DUCATI! ON FYE-YARRRR! 🔥 ... no ... wait ... Oh, well. #GraphTheory