erlang-list-comprehension.erl

% Simple comprehensions (notice the similarity to map?)
  % increment
  [ X+1 || X <- [1,2,3,4] ].
  % powers of two
  [ math:pow(2,X) || X <- [1,2,3,4] ].

% Comprehension with list of tuples
  CityWeathers = [{cloudy, chicago}, {sunny, florida}, {raining, london}, {cloudy, durham}].
  [ case Weather of cloudy -> io:format("~p is cloudy\n", [City]); _ -> false end || {Weather, City} <- CityWeathers ].
  % Almost the same thing: using a filter instead of case
  [ io:format("~p is cloudy\n", [City]) || {Weather, City} <- CityWeathers, Weather =:= cloudy ].
  % Even better: anything that doesn't match the pattern gets ignored
  [ io:format("~p is cloudy\n", [City]) || {cloudy, City} <- CityWeathers ].

% Multiple generators
  ChessBoard = [ {X, Y} || X <- lists:seq(1,8), Y <- lists:seq(1,8) ].