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Conway's Game of Life in CoffeeScript

willbailey.name

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Re: Conway's Game of Life in CoffeeScript

#11

Post by ggchappell »

d0m wrote: post #6

Pretty clean code! A small suggestion: cell.live = false if count 3 cell.live = true if count == 3 Could become: cell.live = count 3 cell.live = count == 3 since it's a bit redundant to write "true" since it's already a boolean expression. It's a little bit like saying: if a == true: return true else: return false instead of: return a // Agreed that a could be a "truth" value without being the real "true". Still: ret…

Nope. The point of those if's is that the value of cell.live remains unchanged if the condition is false. Your code does not do that.

What should happen is that, if count is 3, then cell.live becomes true. If count is 2, then cell.live retains its previous value. For all other values of count, cell.live becomes false.

Re: Conway's Game of Life in CoffeeScript

#12

Post by heimidal »

alttab wrote: post #9
pan69 wrote: post #5

Earlier quoted context omitted.

I really like how that is done. It would be great to be able to annotate source code like this within your IDE.

the newest version of vim has this seamlessly integrated :)

For real? If so, how do you access it?

Re: Conway's Game of Life in CoffeeScript

#14

Post by amirshim »

I love CoffeeScript, except that it makes me hate writing javascript code now :) Thanks @jashkenas for an amazing language.

I personally like code like this:

  countNeighbors: (cell) ->
    neighbors = 0
    neighbors += @isAlive cell.row+x, cell.col+y for x in [-1..1] when x || y for y in [-1..1]
    neighbors 
  isAlive: (row, col) -> if @world[row] and @world[row][col] and @world[row][col].live then 1 else 0
but you have to be careful, since putting a space before the "+x" will cause some bad stuff to happen. Maybe I shouldn't drop so many parenthesis.

@jashkenas can you fix [-10..10] (constant boundary) loops to not check for increasing/decreasing :) I can't think of an edge case that breaks it.

Re: Conway's Game of Life in CoffeeScript

#17

Post by jacobolus »

amirshim wrote: post #14

I love CoffeeScript, except that it makes me hate writing javascript code now :) Thanks @jashkenas for an amazing language. I personally like code like this: countNeighbors: (cell) -> neighbors = 0 neighbors += @isAlive cell.row+x, cell.col+y for x in [-1..1] when x || y for y in [-1..1] neighbors isAlive: (row, col) -> if @world[row] and @world[row][col] and @world[row][col].live then 1 else 0 but you have to be car…

If you add a space after the + also, it’ll be fine (indeed, better).

But to be honest, I hate code that tries to do 5 bits of logic on one 100-character-long line, instead of just breaking into two more readable lines. [Edit: looks like that was fixed in the version at http://willbailey.name/conway/docs/conway.html]

Also, can’t your isAlive function look like:

  isAlive: (row, col) -> @world[row]?[col]?.live

Re: Conway's Game of Life in CoffeeScript

#20

Post by abarrett »

ggchappell wrote: post #10
jashkenas wrote: post #7

Earlier quoted context omitted.

Or simply: cell.live = count is 3 no?

No. You aren't handling the case when count is 2 correctly. In that case, cell.live should remain unchanged, while you are setting it to false. (Note, however, that the code in the comment you are replying to is also incorrect. And does the same thing as your code. So you posted a correct transformation of incorrect code, that keeps it incorrect.)

The original version still contains redundancy. It would be:

    cell.live = count == 3 if count != 2
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