add const function

[wcbeard]

I haven't found a function in toolz to replicate Haskell's const function, that creates a function that returns a constant value.

Example usage would be

def const(v):
    return lambda *x, **k: v

f = const(5)
f(2)  # 5
f(3.14, [1, 3], a='whatever')  # 5

Unless I'm missing an existing function, would it be worthwhile to add something similar to the library?

[llllllllll]

👍 I also commonly have a use for the const function. Do you think it should accept *args, **kwargs or just one positional arg? I think there is a case for either.

[wcbeard]

Hmm, good question. I think I'd prefer the more general *args, **kwargs style, just to avoid more TypeErrors at runtime.

It seems like it could generalize to more uses, but I guess I don't have a strong opinion.

[llllllllll]

I also think the *args, **kwargs is more general. I just wanted to bring it up in case someone had a strong reason to not allow it.