I don’t know yet even anything about monads, same comment about type classes. Using VSCode adding function signatures look often veird compared to Elm. Anyway, it’s still fun to learn and write some code in Haskell. Here is the latest example for which I used ca. two months creating five differen…

nice, learning is always good. the 3 instances of read $ show $ _ should probably be a call to fromIntegral

Awesome! I would actually have some use for SolarCurrent: I need to take some action when the sun rises above -7 degrees below the horizon and again take some action when the sun sinks below this threshold. (I’ve been using Python ephem for that.) Being no astronomer, I can not make enough sense of…

[image] eldritch-cookie: the 3 instances of read $ show $ _ should probably be a call to fromIntegral Not in this case, as I don’t care about milliseconds of the read posix-seconds, so I round the Double to Integer and it works ok and it’s easy to calculate using the function mod the hours, m…

Python’s name ephem must be from ephemeris, meaning: A table giving the coordinates of a celestial body at a number of specific times during a given period. Well, I’ll look at it. I agree, a good documentation is important, so I’ll check haddock. My module SolarCurrent contains exactly the same c…

[image] polarit: ghci> hours = read $ show $ mod (div ps 3600) 24 hours :: Read a => a This read/show business really is something to be avoided. You’re turning a number into a string and then back into a number for no apparent reason. This is also the reason you’re unable to print the result…

[image] polarit: Btw, the limit -7 degrees below horizon is near the common civil twilight limit -6 degr below horizon Indeed that’s what it is, possibly corrected for atmospheric aberration? Civil twilight is what our local regulatory authorities deem the activity period of predatory birds, …

There are a few numeric type classes that allow conversions in Haskell: -- embeds the integer in any 'Num' type. -- used by the compiler for integer literals in source code fromInteger :: Num a => Integer -> a -- careful: overflows without warning! -- >>> fromIntegral (1000 :: Int) :: Word8 -- 23…

[image] rhendric: What problems do you encounter with ghci> hours = mod (div ps 3600) 24 hours :: Integral a => a ghci> hours 20 it :: Integral a => a No problems within ghci. The following happend as I replaced the lines using read show with the new ones without conversions: main = do …

[image] polarit: Maybe there is a function in Data.Time getting the local time with the given timezone from the current UTC time utcToLocalTime ? Also, the error looks like it’s because ps is a Double, but round expects to return an Int or other integral type. You can do ps = fromInteger $ ro…

I have just uploaded the latest improved version which has no read $ show $ sequences anymore. The old version mod instructions are replaced with a function found from stackoverflow.com It can be used for remainders of non-integer division. nonIntRem :: RealFrac a => a -> a -> a nonIntRem x y = x…

A little progress each day

Learn

polarit October 10, 2024, 8:50pm 14

Yes, I have now tried haddock and I enjoy it!
It looks nice really.

local run-example
MainV1 source
SolarlibV1 source