.TH LIBNORMALFORM_ANY 3 LIBNORMALFORM
.SH NAME
libnormalform_any \- Existential qualifier

.SH SYNOPSIS
.nf
#include <libnormalform.h>

struct libnormalform_mapping {
        void *\fIkey\fP;
        void *\fIvalue\fP;
};

struct libnormalform_map {
        struct libnormalform_mapping *\fImappings\fP;
        size_t \fInmappings\fP;
        void *\fIuser_data\fP;
        const char *\fIidentifier\fP;
        struct libnormalform_map *\fIcopy_for_clone\fP;
};

LIBNORMALFORM_SENTENCE *
libnormalform_any(struct libnormalform_map *\fId\fP, LIBNORMALFORM_SENTENCE *\fIk\fP, LIBNORMALFORM_SENTENCE *\fIv\fP);

LIBNORMALFORM_SENTENCE *
libnormalform_exists(struct libnormalform_map *\fId\fP, LIBNORMALFORM_SENTENCE *\fIk\fP);

LIBNORMALFORM_SENTENCE *
libnormalform_nexists(struct libnormalform_map *\fId\fP, LIBNORMALFORM_SENTENCE *\fIk\fP);

LIBNORMALFORM_SENTENCE *
libnormalform_existentially(struct libnormalform_map *\fId\fP, LIBNORMALFORM_SENTENCE *\fIv\fP);

LIBNORMALFORM_SENTENCE *
libnormalform_empty(struct libnormalform_map *\fId\fP);

LIBNORMALFORM_SENTENCE *
libnormalform_nonempty(struct libnormalform_map *\fId\fP);
.fi
.PP
Link with
.IR -lnormalform .

.SH DESCRIPTION
The
.BR libnormalform_any ()
function creates a sentence that is true
when and only when the sentence
.I v
is true for the
.I .value
for at least one element in
.I d
for which
.I k
is also true for the
.I .key
of the element.
.PP
The
.BR libnormalform_exists ()
function creates a sentence that is true
when and only when the sentence
.I k
is true for the
.I .key
of at least one element in
.IR d .
.PP
The
.BR libnormalform_nexists ()
function creates a sentence that is true
when and only when the sentence
.I k
is false for the
.I .key
of every element in
.IR d .
.PP
The
.BR libnormalform_existentially ()
function creates a sentence that is true
when and only when the sentence
.I v
is true for the
.I .value
of at least one element in
.IR d .
.PP
The
.BR libnormalform_empty ()
function creates a sentence that is true
when and only when
.IR d
contains no elements.
.PP
The
.BR libnormalform_nonempty ()
function creates a sentence that is true
when and only when
.IR d
contains at least one element.
.PP
.I d->mappings
and
.I d->nmappings
is used only be the
.BR libnormalform_evaluate (3)
function and must be set before
.BR libnormalform_evaluate (3)
is called, but need not be set
earlier.
.I d->nmappings
shall be set to number of elements in
the qualifers domain of interest, and
.I d->mappings
shall be set to the list of elements
in the domain. Each element shall have its
.I .key
set to the value the antecedent formula
.RI ( k )
is tested on, and
.I .value
set to the value the predicate formula
.RI ( v )
is tested on; these fields may be
.IR NULL ,
and are ultimately evaluated via
arguments passed to the
.BR libnormalform_function (3)
function but may undergo transformation
via arguments passed to the
.BR libnormalform_transformation (3)
function on the way.
.PP
The values
.I d->mappings
and
.I d->nmappings
may be set differently every time the
.BR libnormalform_evaluate (3)
is called.
.PP
Although unused, the
.BR libnormalform_empty ()
and
.BR libnormalform_nonempty ()
functions require that
.I d->mappings
is properly set up (although the values
in it can all be
.IR NULL )
before the
.BR libnormalform_evaluate (3)
function is called.
.PP
See
.BR libnormalform_to_string (3)
for the purpose of
.IR d->identifier ,
it need not be set before the
.BR libnormalform_to_string (3)
function is called.
.PP
See
.BR libnormalform_clone (3)
for the purpose of
.IR d->copy_for_clone ,
it need not be set before the
.BR libnormalform_clone (3)
function is called.
.PP
The application can set
.I d->user_data
set freely, and can opt to leave it
unset. It is never used or reference
by the library, but it could be used
by the application to identify the
domain.
.PP
.I d
must not be
.IR NULL .
.PP
The returned pointer shall either be
deallocated with the
.BR libnormalform_free (3)
function or be relinquished by being
used as part of another sentence.
.PP
These functions adopt the ownership of any
.I LIBNORMALFORM_SENTENCE *
passed into it. Therefore, the user shall
not attempt to deallocate input sentences.
This holds even on failure: if the function
fails, input sentences are deallocated.

.SH RETURN VALUE
Upon successful completion, the
.BR libnormalform_any (),
.BR libnormalform_exists (),
.BR libnormalform_nexists (),
.BR libnormalform_existentially (),
.BR libnormalform_empty (),
and
.BR libnormalform_nonempty (),
functions return an object representing
the sentence; otherwise, the functions
return
.I NULL
and set
.I errno
to indicate the error.

.SH ERRORS
The
.BR libnormalform_any (),
.BR libnormalform_exists (),
.BR libnormalform_nexists (),
.BR libnormalform_existentially (),
.BR libnormalform_empty (),
and
.BR libnormalform_nonempty (),
functions fail if:
.TP
.B ENOMEM
Insufficient memory was available to
create the sentence object.
.PP
These functions will also fail without setting
.I errno
if
.I k
or
.I v
is
.IR NULL .

.SH ATTRIBUTES
For an explanation of the terms used in this
section, see
.BR attributes (7)
and
.IR "info \(dq(libc)POSIX Safety Concepts\(dq" .
.TS
allbox;
lb lb lb
l l l.
Interface	Attribute	Value
T{
.BR libnormalform_any (),
.br
.BR libnormalform_exists (),
.br
.BR libnormalform_nexists (),
.br
.BR libnormalform_existentially ()
T}	Thread safety	MT-Safe race:\fIk\fP,\fIv\fP
T{
.BR libnormalform_empty (),
.br
.BR libnormalform_nonempty ()
T}	Thread safety	MT-Safe
T{
.BR libnormalform_any (),
.br
.BR libnormalform_exists (),
.br
.BR libnormalform_nexists (),
.br
.BR libnormalform_existentially (),
.br
.BR libnormalform_empty (),
.br
.BR libnormalform_nonempty ()
T}	Async-signal safety	AS-Unsafe heap
T{
.BR libnormalform_any (),
.br
.BR libnormalform_exists (),
.br
.BR libnormalform_nexists (),
.br
.BR libnormalform_existentially (),
.br
.BR libnormalform_empty (),
.br
.BR libnormalform_nonempty ()
T}	Async-cancel safety	AC-Safe mem, AC-Unsafe heap
.TE

.SH SEE ALSO
.BR libnormalform (7),
.BR libnormalform_function (3)