yes, it looks all good, until you want to change it. For instance, to make the file name a CLI parameter, you need to understand things like type classes, specifically Monad, Functor and Applicative. You may need a long time to be at ease with these things and a superficial understanding will not take you very far. In Python, it'll take you a few minutes to do the same thing.
What do you mean by "long time"? Why wouldn't it apply just the same to some Python file that defines a Maybe with a bit of unwrap and bind and orElse or whatever?
Instead of things going boom and spewing a stack sometimes they just go Nothing instead, you don't need much more understanding than that. There is a lot of syntax in Haskell that is somewhat hard to understand at first but you don't actually need it to write stuff yourself.
This idea that you need to talk a particular way and be able to teach CS theory at uni and whatnot to build stuff in Haskell is probably not very healthy.
Long time, I mean possibly several weeks of full-time studying for an intermediate Python or C++ programmer.
I'm not saying you need any CS theory to write Haskell or that it's super hard. But I think the learning curve is pretty steep, and it's hard to write code without a good understanding of the concepts. Just tweaking until it type checks isn't going to cut it.
Consider this code. Generated from ChatGPT. This is supposed to be a simple command line option parsing. I don't think it's obvious what all the operators mean.
Sure, you can try to reuse this, and extend it. But I think sooner than later you'll be stuck with some undecipherable error messages and you'll have to sit down and understand what it all means.
data Options = Options
{ optVerbose :: Bool
, optInput :: String
} deriving Show
optionsParser :: Parser Options
optionsParser = Options
<$> switch
( long "verbose"
<> short 'v'
<> help "Enable verbose mode" )
<\*> strOption
( long "input"
<> short 'i'
<> metavar "FILENAME"
<> help "Input file name" )
This is a really good point. I have coworkers that don't really code, but can use ChatGPT to help them put together a Python app that does what they need with some common sense changes. I don't think I could even do the same with Haskell with a fair amount of coding experience+ reading up a lot on Haskell over the years. It may be obvious to those select few who are drawn to Haskell, but I think they greatly underestimate the challenges for the average person. That's the essence of what I've been saying to the parent thread that believes a subset of Haskell will become popular some day. I could be wrong, but just can't see it.
It is obvious, as long as you know what Functors and Semigroups for custom data types are. If you don't know it, you can still use it freely without fully understanding the meaning of `<>` and `<$>`, because they are written almost as plain bullet points of components to treat as a single whole.
