My usage can be divided into the following 5 categories. 1. interface 2. modularity 3. legibility 4. brevity 5. tricks If the variant type is only internal to the module, I use regular variants, because as you said they are compiled more efficiently. If the variant type is exported in the interface and I feel … Read more
There are some differences feature-wise, as well as semantically. Features SML supports but not OCaml: transparent signature ascription module-level let symmetric sharing constraints syntactic sugar for functors over types and values Features OCaml 4 has but not SML: higher-order functors recursive modules local modules nested signatures modules as first-class values general module sharing (sig with … Read more
OCaml has two ways of specifying types, they can be done inline: let intEq (x : int) (y : int) : bool = … or they can be placed in an interface file, as you have done: val intEq : int -> int -> bool I believe the latter is preferred, since it more cleanly … Read more
When you define a semantics of function definition, as a language designer, you have choices: either to make the name of the function visible in the scope of its own body, or not. Both choices are perfectly legal, for example C-family languages being far from functional, still do have names of definitions visible in their … Read more
The semantics for this is the same as in F# (probably because F# is based on OCaml): function allows the use of pattern matching (i.e. |), but consequently it can be passed only one argument. function p_1 -> exp_1 | … | p_n -> exp_n is equivalent to fun exp -> match exp with p_1 … Read more
The implementation of such a library is possible outside the compiler, thanks to the ffi support of the language. The library must be split in two parts: the native ocaml source part, and the C runtime part. the OCaml source must contain the datatype declaration, as well as the declaration of all the imported functions. … Read more
Well, having both available instead of only one gives the programmer tighter control on the scope. With let x = e1 in e2, the binding is only present in e2‘s environment, while with let rec x = e1 in e2 the binding is present in both e1 and e2‘s environments. (Edit: I want to emphasize … Read more
Do you want fast or do you want easy? If you want fast, you should use C++, even if you’re using FP principles to aid in correctness. Since timing is crucial, the support for soft (and hard, if need be) real-time programming will be important. You can decide exactly how and when you have time … Read more
From a practical standpoint, you can think of “functors” in OCaml and Haskell as unrelated. As you said, in Haskell a functor is any type that allows you to map a function over it. In OCaml, a functor is a module parametrized by another module. In Functional Programming, what is a functor? has a good … Read more
Why password validation rules are bad? Our very own Jeff Atwood (blogger of Coding Horror and co-founder of Stack Overflow and Stack Exchange) wrote a blog about password rules back in March of 2017 titled Password Rules are Bullshit. If you haven’t read this post, I would urge you to do so as it greatly … Read more