$num_elements = 4;
@_ = ( list,of,elements,to,splice );

@spliced_list =
  # This map operates on the list of splices.
  # the left side of || should test something
  # most likely something in $_ and return
  # something (or call a sub) if the test is
  # successful, and if the test fails, it should
  # failover to the right side of the || which
  # returns ().  
  map { func1($_) }

  # This map operates on the spliced elements.
  # Splicing the list removes those elements
  # from the list as a side affect.
  map { func2( [ splice(@_, 0, $num_elements) ] ) }

  # Since this snippet shows how to fold an array,
  # we only need to iterate over the count of
  # new elements.
  0 .. (@_ / $num_elements);