CoffeeScript输入意外结束

Question

I've started a little game in CoffeScript using canvas. My problem is this error:

coffee -c -o lib/ src/
/src/interface.coffee:8:48: error: unexpected end of input
    @ctx.clearRect 0, 0, @size[0], @size[1]
                                           ^

I've rewrote it many times but it still don't want to compile. Here is the code:

class Interface:
    constructor : (id) ->
        @canvas = document.getElementById "#{id}"
        @ctx = @canvas.getContext "2d"
        @size = [@canvas.width, @canvas.height]

    clear : () ->
        @ctx.clearRect 0, 0, @size[0], @size[1]

Oh, and can someone tell me what exactly this error means?

Thank you in advance.

Answer 1

Its the colon after Interface. An easy way to debug that error for future reference:

Step 1: paste problem code into the 'Try CoffeeScript' part of the coffeescript website to repro the error.

Step 2: erase or comment-out lines until the error goes away and the code compiles

Step 3: the last line you erased was the error.

Step 4: find the error(s) in that line and fix.

Step 5: repeat as necessary.

This is how I figured out what the problem was. This process also works well for the 'Unmatched Outdent' error.