To find neighbours

Lets suppose that we have an array which looks like this:


#(#(O O O O)
  #(O O X O)
  #(O O O O))

How would I go about to find the neighbours of 'X
without using loads of if-else ?

>>27
In Scheme, parenthesis and rectangular brackets are exchangeable. Racketeers in particular prefer to use the latter in certain positions to enhance readability. Particularly in expressions like let where you would otherwise end up with a salad of parenthesis when nesting them.