NathanKleekamp

const fib = (count, result = [0, 1]) => {
  if (count <= 2 || count === 0) {
    return result;
  }
  const { length } = result;
  return fib(count - 1, result.concat(result[length - 1] + result[length - 2]));
};

const fib5 = fib(5) // [0, 1, 1, 2, 3]
const fib10 = fib(10) // [0, 1, 1, 2, 3, 5, 8, 13, 21, 34]

NathanKleekamp

// With a loop O(n)
const sumSequenceLoop = (seq) => seq.reduce((accum, current) => accum + current);
console.log(sumSequenceLoop([1, 2, 3, 4])) // 10
console.log(sumSequenceLoop([2, 4, 6])) // 12
console.log(sumSequenceLoop([3, 6, 9, 12])); // 30

// With Gauss's formula O(1)
const sumSequence = (seq) => seq.length * (seq[0] + seq[seq.length - 1]) / 2;
console.log(sumSequence([1, 2, 3, 4])) // 10
console.log(sumSequence([2, 4, 6])) // 12

NathanKleekamp

Using git-submodules to version-control Vim plugins

If you work across many computers (and even otherwise!), it's a good idea to keep a copy of your setup on the cloud, preferably in a git repository, and clone it on another machine when you need. Thus, you should keep the .vim directory along with your .vimrc version-controlled.

But when you have plugins installed inside .vim/bundle (if you use pathogen), or inside .vim/pack (if you use Vim 8's packages), keeping a copy where you want to be able to update the plugins (individual git repositories), as well as your vim-configuration as a whole, requires you to use git submodules.

Creating the repository

Initialize a git repository inside your .vim directory, add everything (including the vimrc), commit and push to a GitHub/BitBucket/GitLab repository:

cd ~/.vim

NathanKleekamp

Keybase proof

I hereby claim:

• I am nathankleekamp on github.
• I am nkleekamp (https://keybase.io/nkleekamp) on keybase.
• I have a public key ASDv_4O70JdjPRxKu2xc0i5F93E1IPeLEZt-EZ1SV14vzgo

To claim this, I am signing this object:

NathanKleekamp

From the Archives: Code Quarterly's 2011 Q&A with Rich Hickey

Rich Hickey is frequently quoted as saying:

You can reach a point with Lisp where, between the conceptual simplicity, the large libraries, and the customization of macros, you are able to write only code that matters. And, once there, you are able to achieve a very high degree of focus, such as you would when playing Go, or playing a musical instrument, or meditating. And then, as with those activities, there can be a feeling of elation that accompanies that mental state of focus.

NathanKleekamp

# Remove the submodule entry from .git/config
git submodule deinit -f path/to/submodule

# Remove the submodule directory from the superproject's .git/modules directory
rm -rf .git/modules/path/to/submodule

# Remove the entry in .gitmodules and remove the submodule directory located at path/to/submodule
git rm -f path/to/submodule

# Taken from https://stackoverflow.com/a/36593218

NathanKleekamp

// const rest = array => array.slice(1, array.length);
const rest = ([first, ...rest]) => rest

const testArray = [1, 2, 3, 4, 5];
rest(testArray) // [2, 3, 4, 5];

rest([]).length === 0; // true
Array.isArray(rest([])); // true

NathanKleekamp

const last = array => array.slice(-1);

const testArray = [0, 1, 2, 3];
last(testArray); // [3]

NathanKleekamp

const complement = fn => (...args) => !fn.apply(null, args);
const isEven = x => x % 2 === 0;
const isOdd = complement(isEven);

isEven(2); // false
isEven(1); // true
isEven(0); // false

NathanKleekamp

const isEven = x => x % 2 === 0;

isEven(2); // true
isEven(1); // false
isEven(0); // true