Iterate over multiple arrays

nested.rb

x_coords = [...]
y_coords = [...]

x_coords.each do |x|
  y_coords.each do |y|
    do_point x, y
  end
end

product.rb

x_coords = [...]
y_coords = [...]

x_coords.product(y_coords).each do |x, y|
  do_point x, y
end

# edit even better:
points = x_coords.product y_coords
points.each do |x, y|
  do_point x, y
end

i'd prefer the second. language features are there to be used.

and if this can be optimized then it is more likely that a builtin .product gets optimized than the parser detecting that a nested .each can be optimized.

greetings, eMBee