prop_number(3) - NetBSD Manual Pages

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PROP_NUMBER(3)          NetBSD Library Functions Manual         PROP_NUMBER(3)


NAME

     prop_number, prop_number_create_integer,
     prop_number_create_unsigned_integer, prop_number_copy, prop_number_size,
     prop_number_unsigned, prop_number_integer_value,
     prop_number_unsigned_integer_value, prop_number_equals,
     prop_number_equals_integer, prop_number_equals_unsigned_integer --
     numeric value property object


LIBRARY

     Property Container Object Library (libprop, -lprop)


SYNOPSIS

     #include <prop/proplib.h>

     prop_number_t
     prop_number_create_integer(int64_t val);

     prop_number_t
     prop_number_create_unsigned_integer(uint64_t val);

     prop_number_t
     prop_number_copy(prop_number_t number);

     int
     prop_number_size(prop_number_t number);

     bool
     prop_number_unsigned(prop_number_t number);

     int64_t
     prop_number_integer_value(prop_number_t number);

     uint64_t
     prop_number_unsigned_integer_value(prop_number_t number);

     bool
     prop_number_equals(prop_number_t num1, prop_number_t num2);

     bool
     prop_number_equals_integer(prop_number_t number, int64_t val);

     bool
     prop_number_equals_unsigned_integer(prop_number_t number, uint64_t val);


DESCRIPTION

     The prop_number family of functions operate on a numeric value property
     object type.  Values are either signed or unsigned, and promoted to a
     64-bit type (int64_t or uint64_t, respectively).

     It is possible to compare number objects that differ in sign.  Such com-
     parisons first test to see if each object is within the valid number
     range of the other:

     ·   Signed numbers that are greater than or equal to 0 can be compared to
         unsigned numbers.

     ·   Unsigned numbers that are less than or equal to the largest signed
         64-bit value (INT64_MAX) can be compared to signed numbers.

     Number objects have a different externalized representation depending on
     their sign:

     ·   Signed numbers are externalized in base-10 (decimal).

     ·   Unsigned numbers are externalized in base-16 (hexadecimal).

     When numbers are internalized, the sign of the resulting number object
     (and thus its valid range) is determined by a set of rules evaluated in
     the following order:

     ·   If the first character of the number is a `-' then the number is
         signed.

     ·   If the first two characters of the number are `0x' then the number is
         unsigned.

     ·   If the number value fits into the range of a signed number then the
         number is signed.

     ·   In all other cases, the number is unsigned.

     prop_number_create_integer(int64_t val)
            Create a numeric value object with the signed value val.  Returns
            NULL on failure.

     prop_number_create_unsigned_integer(uint64_t val)
            Create a numeric value object with the unsigned value val.
            Returns NULL on failure.

     prop_number_copy(prop_number_t number)
            Copy a numeric value object.  If the supplied object isn't a
            numeric value, NULL is returned.

     prop_number_size(prop_number_t number)
            Returns 8, 16, 32, or 64, representing the number of bits required
            to hold the value of the object.  If the supplied object isn't a
            numeric value, NULL is returned.

     prop_number_unsigned(prop_number_t number)
            Returns true if the numeric value object has an unsigned value.

     prop_number_integer_value(prop_number_t number)
            Returns the signed integer value of the numeric value object.  If
            the supplied object isn't a numeric value, zero is returned.
            Thus, it is not possible to distinguish between ``not a
            prop_number_t'' and ``prop_number_t has a value of 0''.

     prop_number_unsigned_integer_value(prop_number_t number)
            Returns the unsigned integer value of the numeric value object.
            If the supplied object isn't a numeric value, zero is returned.
            Thus, it is not possible to distinguish between ``not a
            prop_number_t'' and ``prop_number_t has a value of 0''.

     prop_number_equals(prop_number_t num1, prop_number_t num2)
            Returns true if the two numeric value objects are equivalent.  If
            at least one of the supplied objects isn't a numeric value, false
            is returned.

     prop_number_equals_integer(prop_number_t number, int64_t val)
            Returns true if the object's value is equivalent to the signed
            value val.  If the supplied object isn't a numerical value or if
            val exceeds INT64_MAX, false is returned.

     prop_number_equals_unsigned_integer(prop_number_t number, uint64_t val)
            Returns true if the object's value is equivalent to the unsigned
            value val.  If the supplied object isn't a numerical value or if
            val exceeds INT64_MAX, false is returned.


SEE ALSO

     prop_array(3), prop_bool(3), prop_data(3), prop_dictionary(3),
     prop_object(3), prop_string(3), proplib(3)


HISTORY

     The proplib property container object library first appeared in
     NetBSD 4.0.

NetBSD 6.0                     January 21, 2008                     NetBSD 6.0