In addition to the standard #open and #close directives, Caml Light provides three additional directives.
#infix " id "+. The notation prefix id can be used to refer to the
identifier id itself. Expressions of the form expr1 id expr2 are
parsed as the application prefix id expr1 expr2. The argument to
the #infix directive must be an identifier, that is, a sequence of
letters, digits and underscores starting with a letter; otherwise, the
#infix declaration has no effect. Example:
#infix "union";;
let prefix union = fun x y -> ... ;;
[1,2] union [3,4];;
#uninfix " id "#infix " id " directive.
#directory " dir-name "