joshwcomeau

const flipMatrix = matrix => (
  matrix[0].map((column, index) => (
    matrix.map(row => row[index])
  ))
);

const rotateMatrix = matrix => (
  flipMatrix(matrix.reverse())
);

joshwcomeau

const flipMatrix = matrix => (
  matrix[0].map((column, index) => (
    matrix.map(row => row[index])
  ))
);

const rotateMatrix = matrix => (
  flipMatrix(matrix.reverse())
);

joshwcomeau

const rotateMatrix = matrix => (
  matrix[0].map((column, index) => (
    [...matrix].reverse().map(row => row[index])
  ))
);

const flipMatrixCounterClockwise = matrix => (
  rotateMatrix(matrix).reverse()
);

joshwcomeau

const flipMatrix = matrix => (
  matrix[0].map((column, index) => (
    matrix.map(row => row[index])
  ))
);

joshwcomeau

.drawer {
  position: absolute;
  z-index: 10;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  overflow: hidden;

  .backdrop {

joshwcomeau

////// Fun with ES2015 Generators & Fibonacci Sequence //////
//
// Generators are awesome for lazy calculations, but they're less 
// than ideal for certain use-cases (give me the result of the
// 1000th iteration).
//
// This is an experiment where I try to have my cake and eat it too, 
// by wrapping a generator with a factory function.
//
//// Note: This is the comment-free version!

joshwcomeau

////// Fun with ES2015 Generators & Fibonacci Sequence //////
//
// Generators are awesome for lazy calculations, but they're less 
// than ideal for certain use-cases (give me the result of the
// 1000th iteration).
//
// This is an experiment where I try to have my cake and eat it too, 
// by wrapping a generator with a factory function.
//
//// Note: This is the annotated version!

joshwcomeau

  app.post('/process-upload', upload.single('image'), (req, res) => {
    // Define some helper methods that provide semantic names to the
    // actions in our route.
    const resizeAndConvert = buffer => (
      imConvertPromise({
        srcData: buffer,
        width: 32,
        height: 16,
        format: 'PNG'
      })

joshwcomeau

// If the function does not take an 'errback' callback, we can still wrap our 
// functions. Let's use a fictional method:
fictionalMethod(data, successCallback, failureCallback) {
  fictionalAsyncOperation(data, result => {
    if ( !result ) {
      return failureCallback(new Error('Result not found'))
    } else {
      return successCallback(result);
    }
  })

joshwcomeau

class LetterDemo extends Component {
  constructor(props) { ... }

  componentWillMount() { ... }

  componentWillUnmount() { ... }

  onStart({entering, leaving}, node) {
    if (entering) {
      node.classList.add('enter');