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This approach doesn't remove boilerplate, the initial version is 8 lines, the final version is 6 lines. Except the final version has a lot of code hidden in hel

This approach doesn't remove boilerplate, the initial version is 8 lines, the final version is 6 lines. Except the final version has a lot of code hidden in helper methods, making it impossible to understand at first glance without reading those helper methods. (LiftA2, chain, Left, Right, Lodash helper methods). The initial version is also very clear, we have a set of method calls that execute sequentially, and if any of them fail, we go to the catch block and call showError. This indicates that all functions in the try block can throw an error. The final version goes through a lot more trouble yet I don't get any extra information by reading the code. Now I don't even know which functions are error prone because everything is a mix of weird functions like map, chain, and liftA2. The second version also seems to promote more cognitive load. Try-Catch is simple, it doesn't require any brain cells to understand. This approach required an entire blog post. It seems better to dedicate mental energy to more important decisions rather than a simple function that processes CSVs. I think I understand the benefits of functional programming when one is writing a compiler, but this seems to be a misuse of functional techniques.

nine_k 7y ago
The article's example is a toy example. In a real-world example of the same approach, like this piece of highly non-idiomatic Python that still reads much like plain English [1]. > Try-Catch is simple, it doesn't require any brain cells to understand ...because you have already spent the effort to learn it. Equally, monadic code can be quite compact and simple, once you have have spent the effort to learn a new approach. Also, a catch clause does not give you an idea what data cause the crash, only what line. The Either-based approach allows every place to report all relevant local info; the linked code has complete error reporting. Everything is non-idiomatic until it is. If you write JS and use Promises and `await`, you already use monadic behavior and an analog of Haskell's "do notation". Some might think that callbacks are more intuitive, though. [1]: https://pastebin.com/wY8ZC0mP https://pastebin.com/wY8ZC0mP

nine_k 7y ago

The article's example is a toy example. In a real-world example of the same approach, like this piece of highly non-idiomatic Python that still reads much like plain English [1]. > Try-Catch is simple, it doesn't require any brain cells to understand ...because you have already spent the effort to learn it. Equally, monadic code can be quite compact and simple, once you have have spent the effort to learn a new approach. Also, a catch clause does not give you an idea what data cause the crash, only what line. The Either-based approach allows every place to report all relevant local info; the linked code has complete error reporting. Everything is non-idiomatic until it is. If you write JS and use Promises and `await`, you already use monadic behavior and an analog of Haskell's "do notation". Some might think that callbacks are more intuitive, though. [1]: https://pastebin.com/wY8ZC0mP https://pastebin.com/wY8ZC0mP