Re: Recursion, Yo

On Wed, 10 Apr 2024 11:18:12 +0200, David Brown wrote:

Basically, anything you could do with a nested function in gcc C you can
do in C++:

Has anybody suggested adding coroutines to C++ yet?

E.g. Python equivalent to the permute function that uses a recursive
generator:

    def permute(seq) :
        if len(seq) == 0 :
            yield ()
        else :
            for i in range(len(seq)) :
                for rest in permute(seq[:i] + seq[i + 1:]) :
                    yield (seq[i],) + rest
                #end for
            #end for
        #end if
    #end permute

Example use:

    for x in permute(("a", "b", "c")) :
        print(x)
    #end for

Output:

    ('a', 'b', 'c')
    ('a', 'c', 'b')
    ('b', 'a', 'c')
    ('b', 'c', 'a')
    ('c', 'a', 'b')
    ('c', 'b', 'a')

And then there’s the fun you can have with async/await ...