@nicolai, Thx for the cool tip. #eightNeighbors is new to me and I
was curious to try it. So below is one way to have Life with it.
For conciseness of this post, please excuse that I've roughly used
booleans directly as grid elements rather a nicely encapsulated Cell
object.
Object subclass: #LifeGrid
instanceVariableNames: 'size cellsAlive'
LifeGrid >> initialize
size := 4.
cellsAlive := Dictionary new.
1 to: size do: [:x|
1 to: size do: [:y|
cellsAlive at: (x@y) put: false ] ]
LifeGrid >> turnAliveAt: location
cellsAlive at: location put: true
LifeGrid >> aliveAt: location
^ cellsAlive at: location ifPresent: [ :isAlive | isAlive ]
ifAbsent: [ false ]
LifeGrid >> countNeighboursAt: location
^ (location eightNeighbors select: [ :neighbour | self aliveAt:
neighbour ]) size
Testing from Playground...
grid := LifeGrid new.
grid countNeighboursAt: 2@2. "==>0"
grid turnAliveAt: 1@1.
grid countNeighboursAt: 2@2. "==>1"
grid turnAliveAt: 3@3.
grid countNeighboursAt: 2@2. "==>2"
grid countNeighboursAt: 1@2. "==>1"
cheers -ben
On 16 January 2018 at 05:47, Nicolai Hess <nicolaih...@gmail.com> wrote:
>
>
> 2018-01-15 18:04 GMT+01:00 Photon <nico-br...@live.de>:
>>
>> when I call the countNeighbours method i get an error: the block wants two
>> arguments but I pass only one.
>> This is probally because i want to pass x y but only really pass x wich
>> ends
>> up being a cell and not the index.
>>
>> I still have trouble thinking it trough. The indicieDo: method seems to
>> make
>> the matrix bigger?! I don`t quite understand it.
>
>
> It should not, and looking at the implementation, it just iterates with two
> loops 1 to number of rows times 1 to number of columns and calls your
> block argument with the pair of indexes.
>
>>
>>
>> There must be an easy way to to figure out if the suroundings are alive or
>> not. I mean its all there what I need and in my mind its so easy to
>> discribe
>> it with normal words. But to tell the machine witth syntax is another
>> thing
>> really :/
>
>
> About the surroundings, there is a nice method in Point
> Point>>eightNeighbors, that gives you the coordinates of the eight
> surrounding fields
> for example:
> (5@7) eightNeighbors "{(6@7). (6@8). (5@8). (4@8). (4@7). (4@6). (5@6).
> (6@6)}"
>
> with this method and if you iterate through all pairs of indices of the
> matrix, you can
> do your computation for every point, but you have to take care about the
> points that don't
> have valid matrix indices for some of their neighbours (like 0@0, the left
> and top neighbours
> may actually "on the other side of the matrix"). But you can take a look at
> SequenceableCollection>>atWrap: how it deals with "wrapping around".
>
>
>
>>
>>
>> what if i selected only one element with do:[] and let its tell me its
>> idices. I store them in a temp object and then I check outside the block
>> the
>> neighbours and add to the counter. Once this is done I repeat as many
>> times
>> as their elements in the matrix?
