module Flags_intf:sig..end
module Flags implements Unix-style sets of flags that are represented as
an int with various bits set, one bit for each flag. E.g. Linux_ext.Epoll.Flag.
Flags defines a module type Flags.S, the interface for a flags, and a functor
Flags.Make for creating a flags implementation.
module Flags implements Unix-style sets of flags that are represented as
an int with various bits set, one bit for each flag. E.g. Linux_ext.Epoll.Flag.
Flags defines a module type Flags.S, the interface for a flags, and a functor
Flags.Make for creating a flags implementation.
module Int63: Core_int63module type S =sig..end
module type S is the interface for a set of flags.
module type Make_arg =sig..end
module type Flags =sig..end
module Flags implements Unix-style sets of flags that are represented as
an int with various bits set, one bit for each flag. E.g. Linux_ext.Epoll.Flag.
Flags defines a module type Flags.S, the interface for a flags, and a functor
Flags.Make for creating a flags implementation.
module type S is the interface for a set of flags. Values of type t are set of
flags, and the various functions operate on sets of flags. There is a finite universe
of flags (in particular 63 flags, one for each bit).
sexp_of_t and t_of_sexp use the flag names supplied to Flags.Make.
consistent with subset
An entry flag, name in known means that the bit(s) in flag is (are) called
name; i.e. if bit_and flags flag = flag, then the bit(s) is (are) set and name
will appear in sexp_of_t flags. known is only used to make sexp_of_t's output
human readable.
The flags in the output of sexp_of_t will occur in the same order as they appear
in known.
It is allowed to have a single flag with multiple bits set.
It is an error if different flags intersect, and allow_intersecting = false.
allow_intersecting says whether to allow intersecting known flags. It is
common to do allow_intersecting = false, however in some situations, e.g.
Unix open flags, the flags intersect.
should_print_error says whether to print an error message if there is an error in
the known flags. It is typical to use should_print_error = true because
Flags.Make is applied at the module level, where the exception raised isn't
displayed nicely.
create ~bit:n creates a flag with the nth bit set. n must be between 0 and
62.
Typically a flag has one bit set; create is useful in exactly those cases. For
flags with multiple bits one can either define the Int63.t directly or create it in
terms of simpler flags, using + and -.
Flags.Make builds a new flags module. If there is an error in the known flags,
it behaves as per on_error.
We expose type t = int in the result of Flags.Make so that one can easily use
flag constants as values of the flag type without having to coerce them. It is
typical to hide the t = int in another signature S.