RishabhRD / functional

Some functional programming abstractions for C++

Functional

This library contains some functional programming abstractions for C++. The library is based on C++20 and may contain some abstractions that are part of C++23 too.

Table of contents

rd::compose

Composes 2 functions as:

auto gof = rd::compose(g, f); // g.f

Here f would be applied before g. f can accept any number of arguments. g can accept only one argument whose type is type of output of f. gof can accept same arguments as f.

Thanks to @tartanllama's ranges implementation.

rd::bind_back

Bind arguments to last of function and returns the new function:

auto sum = [](auto a, auto b, auto c){
  return a + b + c;
};

auto sum_1 = rd::bind_back(2, 3);
sum_1(1);

So, how it looks like:

F :: (Arg1..., Arg2...) -> R

Then,

G = rd::bind_back(F, arg2...) :: G(Arg1...) -> R

rd::curried

Makes a given function curried.

auto sum = rd::curried([](auto a, auto b){
  return a + b;
});

auto sum_with_1 = sum(1);
// sum_with_1(2) == 3;

rd::pipeable

Makes a function pipeable and reverse curried as well.

auto f = rd::pipeable([](auto a, auto b, auto c){
  // ...
});

auto fc = f(c);
// call fc(a, b)

auto fbc = f(b);

int main(){
  a | f(b, c);
  a | fc(b);
  a | fbc();
  a | fbc;
}

rd::flip

Returns a function such that last argument to given function is first argument to returned function.

F(a, b...) => G(b..., a)