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re: Why you are scared of Functional Programming VIEW POST


Anybody doing imperative programming can start using the functional constructs of their current language. It's the lowest learning curve to being introduced to a new paradigm.


Sure, but some of them make it really difficult to do so or don’t have features to support really common practices of the paradigm. Like in C#, I can do partial application, but it’s awkward without curried functions. Also functions can be values, but I frequently have to make long type declarations to make that happen. It’s annoying enough to be discouraging because the language doesn’t support me in it.


Why would this be a problem? You'll still be learning a functional paradigm, but comfortably in your current language. You can also use it on your current project, thus you can learn it at work. It's a great way for somebody to expose themselves to something new and spark their interest.

Partial application is easy with lambda functions. You don't need currying for that. var in C#, auto in C++, and perhaps even implicit typing in Rust, also remove a lot of the need for long declarations.

You definitely have a point about applying the principles to whatever language you are using. I certainly try to when I am working in our legacy systems which are in other languages. You don't have to have currying and partial application and whatnot to write pure functions and well-structured functional programs.

But at the end of the day, not having those features provides a lot of resistance to using the paradigm, and can actually be more work than using the language's default paradigm. I learned this the hard way when I tried to implement error handling in C#, like I was using in F# (which also has to handle exceptions from framework/ecosystem libraries). Some things will simply not be worth fighting the resistance (and if talking about doing it in a team using OO, won't make code review), and so you won't get to learn them.

As far as implicit typing, give it a try and see. It doesn't work well for functions (in C# anyway). Example: var addOne = x => x + 1; gives compile error "Cannot assign lambda expression to an implicitly typed variable." That was a great disappointment to me. I was used to being the consumer where the function was already defined like list.Where(x => x.IsTrue). But when you are the one defining the functions, not just plugging them in, it gets painful quickly.

I'll admit that isn't nice in C#. Maybe I was thinking more C++ where auto and template arguments remove a lot of the need for typing. Or in Python where the dynamic types also remove the need for typing.

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