- Documentation
- Reference manual
- Foreign Language Interface
- The Foreign Include File
- Analysing Terms via the Foreign Interface
- Reading data from a term
- PL_get_atom()
- PL_get_atom_chars()
- PL_get_string_chars()
- PL_get_chars()
- PL_get_list_chars()
- PL_get_integer()
- PL_get_long()
- PL_get_int64()
- PL_get_uint64()
- PL_get_intptr()
- PL_get_bool()
- PL_get_pointer()
- PL_get_float()
- PL_get_functor()
- PL_get_name_arity()
- PL_get_compound_name_arity()
- PL_get_module()
- PL_get_arg()
- PL_get_dict_key()
- Reading data from a term
- Analysing Terms via the Foreign Interface
- The Foreign Include File
- Foreign Language Interface
- Packages
- Reference manual
Availability:C-language interface function
BUF_STACK implies, if the data is not static (as from an
atom), that the data is pushed on a stack. If BUF_MALLOC is used, the
data must be freed using PL_free()
when no longer needed.
With the introduction of wide characters (see section
2.19.1), not all atoms can be converted into a char*.
This function fails if t is of the wrong type, but also if
the text cannot be represented. See the REP_* flags below
for details. See also PL_get_wchars()
and PL_get_nchars().
- CVT_ATOM
- Convert if term is an atom.
- CVT_STRING
- Convert if term is a string.
- CVT_LIST
- Convert if term is a list of of character codes.
- CVT_INTEGER
- Convert if term is an integer.
- CVT_RATIONAL
- Convert if term is an rational number. The number is written as <num>r<den>.
- CVT_XINTEGER
- Convert if term is an integer to hexadecimal notation. May be combined
with
CVT_RATIONALto represent rational numbers using hexadecimal notation. Hexadecimal notation is notably useful for transferring big integers to other programming environments if the target system can read hexadecimal notation because the result is both more compact and faster to write and read. - CVT_FLOAT
- Convert if term is a float. The characters returned are the same as write/1 would write for the floating point number.
- CVT_NUMBER
- Convert if term is an integer, rational number or or float. Equivalent
to
CVT_INTEGER|CVT_RATIONAL|CVT_FLOAT - CVT_ATOMIC
- Convert if term is atomic.
- CVT_VARIABLE
- Convert variable to print-name
- CVT_WRITE
- Convert any term that is not converted by any of the other flags using
write/1.
If no
BUF_*is provided,BUF_STACKis implied. - CVT_WRITE_CANONICAL
- As
CVT_WRITE, but using write_canonical/2. - CVT_WRITEQ
- As
CVT_WRITE, but using writeq/2. - CVT_ALL
- Convert if term is any of the above, except for
CVT_VARIABLEandCVT_WRITE*. - CVT_EXCEPTION
- If conversion fails due to a type error, raise a Prolog type error exception in addition to failure
- BUF_DISCARDABLE
- Data must copied immediately.
- BUF_STACK
- Data is stored on a stack. The older
BUF_RINGis an alias forBUF_STACK. See section 12.4.14. - BUF_MALLOC
- Data is copied to a new buffer returned by PL_malloc(3). When no longer needed the user must call PL_free() on the data.
- REP_ISO_LATIN_1
- Text is in ISO Latin-1 encoding and the call fails if text cannot be represented. This flag has the value 0 and is thus the default.
- REP_UTF8
- Convert the text to a UTF-8 string. This works for all text.
- REP_MB
- Convert to default locale-defined 8-bit string. Success depends on the locale. Conversion is done using the wcrtomb() C library function.