module/paths

    array
    boot.janet on line 2523, column 1

    The list of paths to look for modules, templated for 
    module/expand-path. Each element is a two-element tuple, containing 
    the path template and a keyword :source, :native, or :image 
    indicating how require should load files found at these paths.

    A tuple can also contain a third element, specifying a filter that 
    prevents module/find from searching that path template if the 
    filter doesn't match the input path. The filter can be a string or 
    a predicate function, and is often a file extension, including the 
    period.