Bottle.List.is_list_with_length

You're seeing just the macro is_list_with_length, go back to Bottle.List module for more information.
Link to this macro

is_list_with_length(sub, expected_length)

View Source (macro)

Guard that passes for a list of a specific length

Examples

iex> is_list_with_length([], 0)
true

iex> is_list_with_length([:foo], 1)
true

iex> is_list_with_length([:foo], 2)
false