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.
val __pa_ounit_275876e34cf609db118f3d84b799a790 : string
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: Int63
module 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
uses the flag names supplied to Flags.Make
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 n
th 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
.