coffeescript-notes.md

Fat arrows and skinny arrows

Take care! The -> and => operators look similar, but they have different meanings.

The -> symbol creates a function.

The => symbol binds a function.

Splat arguments

Here's a function that takes splat arguments:

generatePath = (origin, coordinates...) ->
  points = ["M #{coords[origin].x} #{coords[origin].y}"]
  for point in coordinates
    points.push("L #{coords[point].x} #{coords[point].y}")
  points.join("")

Calling the function is a little confusing at first. These don't work:

hexagon = ['s2','t3','t4','s4','b4','b3','s2']
c = paper.path(generatePath(hexagon))

c = paper.path(generatePath(['s2','t3','t4','s4','b4','b3','s2']))

But all of the following all work:

hexagon = ['s2','t3','t4','s4','b4','b3','s2']
c = paper.path(generatePath(hexagon...))

c = paper.path(generatePath('s2','t3','t4','s4','b4','b3','s2'))

c = paper.path(generatePath(['s2','t3','t4','s4','b4','b3','s2']...))

hexagon = ['s2','t3','t4','s4','b4','b3','s2']...
c = paper.path(generatePath(hexagon))