I would like to do unformatted, or binary, input and output of CL
objects (arrays, structures, numbers, etc.). Symbolics CL has a
function dump-forms-to-file which allows you to dump an object to a
file that can be reloaded later. Is there anything in CL that is
analogous? I have seen CLOS's make-load-form, but it appears one must
define it, and I don't see how to do that.
A related but slightly different question is, can I read/write a
machine-native datum such as a floating point number such that it can
be read/written unformatted in another language like Fortran.
I am using CMUCL on an SGI but I would prefer a portable solution if
possible. Thanks for any help.
--
Liam Healy
··········@nrl.navy.mil
·····@apogee.nrl.navy.mil (Liam Healy) writes:
>I would like to do unformatted, or binary, input and output of CL
>objects (arrays, structures, numbers, etc.). Symbolics CL has a
>function dump-forms-to-file which allows you to dump an object to a
>file that can be reloaded later. Is there anything in CL that is
>analogous? I have seen CLOS's make-load-form, but it appears one must
>define it, and I don't see how to do that.
A portable solution would be to write the data to a file, compile that
and load it later. Loading such a data structure is four times as fast
as loading the Ascii representation (for my applications), but
still not comparable to the speed of loading structes in C.
You can use (read-sequence ...) and (write-sequence ...) when
provided. Those can work in constant space and can be very fast.
>A related but slightly different question is, can I read/write a
>machine-native datum such as a floating point number such that it can
>be read/written unformatted in another language like Fortran.
>I am using CMUCL on an SGI but I would prefer a portable solution if
>possible. Thanks for any help.
Most compilers use tagged formats for direct values (ints, doubles),
so their internal representation is incompatible with those of the
native machine.
If you have to tangle with such problems often, you should consider
using C functions to do your I/O.
Martin
--
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