danielgtaylor

Moving to ES6 from CoffeeScript

I fell in love with CoffeeScript a couple of years ago. Javascript has always seemed something of an interesting curiosity to me and I was happy to see the meteoric rise of Node.js, but coming from a background of Python I really preferred a cleaner syntax.

In any fast moving community it is inevitable that things will change, and so today we see a big shift toward ES6, the new version of Javascript. It incorporates a handful of the nicer features from CoffeeScript and is usable today through tools like Babel. Here are some of my thoughts and issues on moving away from CoffeeScript in favor of ES6.

While reading I suggest keeping open a tab to Babel's learning ES6 page. The examples there are great.

Punctuation

Holy punctuation, Batman! Say goodbye to your whitespace and hello to parenthesis, curly braces, and semicolons again. Even with the advanced ES6 syntax you'll find yourself writing a lot more punctuatio

yurydelendik

function getHightlightCoords() {
var pageIndex = PDFViewerApplication.pdfViewer.currentPageNumber - 1; 
var page = PDFViewerApplication.pdfViewer.getPageView(pageIndex);
var pageRect = page.canvas.getClientRects()[0];
var selectionRects = window.getSelection().getRangeAt(0).getClientRects();
var viewport = page.viewport;
var selected = selectionRects.map(function (r) {
  return viewport.convertToPdfPoint(r.left - pageRect.x, r.top - pageRect.y).concat(
     viewport.convertToPdfPoint(r.right - pageRect.x, r.bottom - pageRect.y)); 
});

lest

SELECT
    table_name,
    pg_size_pretty(table_size) AS table_size,
    pg_size_pretty(indexes_size) AS indexes_size,
    pg_size_pretty(total_size) AS total_size
FROM (
    SELECT
        table_name,
        pg_table_size(table_name) AS table_size,
        pg_indexes_size(table_name) AS indexes_size,

antonio

build_package_combined_patch() {
  local package_name="$1"

  {
    curl https://raw.github.com/gist/3721565/falcon.patch | patch -p1
    autoconf
    ./configure --prefix="$PREFIX_PATH" $CONFIGURE_OPTS
    make -j 8
    make install
  } >&4 2>&1

piscisaureus

Locate the section for your github remote in the .git/config file. It looks like this:

[remote "origin"]
	fetch = +refs/heads/*:refs/remotes/origin/*
	url = git@github.com:joyent/node.git

Now add the line fetch = +refs/pull/*/head:refs/remotes/origin/pr/* to this section. Obviously, change the github url to match your project's URL. It ends up looking like this:

lest

# rails command
_script_rails() {
  local check_dir=$PWD
  while [ "$(dirname $check_dir)" != "/" ]; do
    if [ -f "$check_dir/script/rails" ]; then
      "$check_dir/script/rails" $@
      return
    fi
    check_dir="$(dirname $check_dir)"
  done

lest

import Data.Word

freq = 0.3
spread = 8.0

unbase :: Integral int => int -> Word8 -> Word8 -> Word8 -> int
unbase base r g b = (fi r*base+fi g)*base+fi b
    where fi = fromIntegral

-- | Approximate a 24-bit Rgb colour with a colour in the xterm256 6x6x6 colour cube, returning its index.

lest

[ -f $HOME/.profile ] && . $HOME/.profile

HISTSIZE=2000
SAVEHIST=$HISTSIZE
HISTFILE=$HOME/.zsh_history
setopt append_history
setopt inc_append_history
setopt extended_history
setopt hist_find_no_dups
setopt hist_ignore_all_dups