`_.permutation` and `_.combination` support for arrays

[bdkent]

It would be really useful to support the standard permutation/combination functions on arrays.

Something like:

_.permutations([0, 1], ['a', 'b']) => [ [0, 'a'], [0, 'b'], [1, 'a'], [1, 'b'] ];

_.combinations([1, 2, 3, 4], 2) => [ [1, 2], [1, 3], [1, 4], [2, 3], [2, 4], [3, 4] ];

These additions have already (and I think unfortunately) been rejected from lodash proper:
lodash/lodash#1191
lodash/lodash#1032

I very frequently find the need for them, so I think they belong in lodash-contrib.

Thanks!

[refack]

Accepted as an enhancement. Do you have a PR for this?

[jdalton]

@bdkent You should also 👍 the lodash issues.
This helps me keep tabs on user demand for such methods.

[mathpere]

👍

[frostme]

👍

[wassname]

Here is an implementation for arrays strings and object. It's similar to pythons itertools.product.

Let me know if you want me to make it a PR (and which category it fits into?).

[ericmarkmartin]

👍

[TWiStErRob]

Long-standing...

[o0x2a]

👍

[devhyunjae]

👍 Any updates in here?

[wassname]

I made this into a PR see #56

[electic]

Any plans to merge this?