Several elixir functions – namely meld(), reindent(), and
translate() – take an argument rules which assists those functions in
interpreting their arguments.
Details
In all cases, rules can either be a character string identifying a set of
built-in rules for a specific language or purpose – currently, elixir
accepts "C", "C++", "Lua", or "R" – or a list with elements
required for interpretation.
elixir:::ruleset contains the built-in rules. Passing an empty list() as
the rules argument to an elixir function will cause it to complain about
the missing components, which is one way of discerning what is needed for
a given function, but usually these error messages do not quite cover all
details of what is needed.