searchablelist -- a list whose elements inherit from hasEquals
In contrast to searchableList, this uses choice type 'list' and not ref
type 'Sequence', so it is more efficient.
create a list from this searchablelist.
create a list from this Sequence.
A list is immutable, so it can be reused and shared between threads.
Compared to a stream, a list may require more (heap) allocation.
Default implementation uses asStream. Heirs must redefine at least
one of asList or asStream.
get the number of non-overlapping matches of l within this
get the index of l within this list or nil if it does not exist
replace all occurances of f by r