Added map and join methods. Also made negative indices work for get

[dfellis]

Hi, thanks for getting this project started for a circular buffer with an Array interface!

For my own usage, I needed map and join, so at first I just did a toArray() and did them, but would prefer eliminating the extra temporary object, so I've implemented the parts I need and wrote tests for them.

While writing the tests I noticed that the get function doesn't allow negative indexing, which seems useful for Circular Buffers in a way that it wouldn't be for a normal Array, so I also added a negative-capable modulus function and used it there.

[dfellis]

...and I just realized you're using tabs, let me fix the formatting.

[bubbakk]

Good morning.
Thank you for this implementation: really useful, reach of methods and well implemented!

I needed a little improvement to last() method: maybe you can like it.
Now last() accepts an optional argument: if passed returns last n inserted values, not only one.
I tried to conform added code to your coding style.

Here it is:

last : function (arg) {
  if (typeof arg === 'undefined' || arg === 1)
    return this.data[this.end];
  else if (typeof arg === 'number') {
    arg = Math.abs(parseInt(arg));
    let result = new Array(arg);
    for (let index = 0; index < arg; index++) {
      let idx = this.end - index;
      if ( idx >= 0 ) result[index] = this.data[idx];
      if ( idx < 0 ) result[index] = this.data[this.size - 1 + ((idx + 1) % this.size)];
    }
    return result;
  }
},

[dfellis]

Hi @bubbakk it appears this repository has been abandoned (I wrote this PR over 2 years ago) and I removed the usage of the library, even with these improvements, from the repository that was depending on it.

If you're willing to maintain the codebase yourself, I would recommend forking off of this repository or my fork and then you can add your function there and refactor the code style to be more to your liking.

I left the PR up because @trevnorris does seem to still be active and this is the #1 repository listed on his Github page: https://github.com/trevnorris so I thought he might notice it when taking a trip down memory lane.

[trevnorris]

@dfellis It's been a while. Didn't realize people still used this library. Thanks for the PR. It's now been squashed and merged.