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/* Copyright (C) 2000, 2001, 2006, 2008, 2009, 2011-2013, 2016, 2018
* Free Software Foundation, Inc.
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public License
* as published by the Free Software Foundation; either version 3 of
* the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
* 02110-1301 USA
*/
#ifdef HAVE_CONFIG_H
# include <config.h>
#endif
#include "libguile/_scm.h"
#include "libguile/eval.h"
#include "libguile/feature.h"
#include "libguile/gc.h"
#include "libguile/numbers.h"
#include "libguile/ports.h"
#include "libguile/strings.h"
#include "libguile/struct.h"
#include "libguile/validate.h"
#include "libguile/values.h"
SCM scm_values_vtable;
/* OBJ must be a values object containing exactly two values.
scm_i_extract_values_2 puts those two values into *p1 and *p2. */
void
scm_i_extract_values_2 (SCM obj, SCM *p1, SCM *p2)
{
SCM values;
SCM_ASSERT_TYPE (SCM_VALUESP (obj), obj, SCM_ARG1,
"scm_i_extract_values_2", "values");
values = scm_struct_ref (obj, SCM_INUM0);
if (scm_ilength (values) != 2)
scm_wrong_type_arg_msg
("scm_i_extract_values_2", SCM_ARG1, obj,
"a values object containing exactly two values");
*p1 = SCM_CAR (values);
*p2 = SCM_CADR (values);
}
static SCM
print_values (SCM obj, SCM pwps)
{
SCM values = scm_struct_ref (obj, SCM_INUM0);
SCM port = SCM_PORT_WITH_PS_PORT (pwps);
scm_print_state *ps = SCM_PRINT_STATE (SCM_PORT_WITH_PS_PS (pwps));
scm_puts ("#<values ", port);
scm_iprin1 (values, port, ps);
scm_puts (">", port);
return SCM_UNSPECIFIED;
}
size_t
scm_c_nvalues (SCM obj)
{
if (SCM_LIKELY (SCM_VALUESP (obj)))
return scm_ilength (scm_struct_ref (obj, SCM_INUM0));
else
return 1;
}
SCM
scm_c_value_ref (SCM obj, size_t idx)
{
if (SCM_LIKELY (SCM_VALUESP (obj)))
{
SCM values = scm_struct_ref (obj, SCM_INUM0);
size_t i = idx;
while (SCM_LIKELY (scm_is_pair (values)))
{
if (i == 0)
return SCM_CAR (values);
values = SCM_CDR (values);
i--;
}
}
else if (idx == 0)
return obj;
scm_error (scm_out_of_range_key,
"scm_c_value_ref",
"Too few values in ~S to access index ~S",
scm_list_2 (obj, scm_from_size_t (idx)),
scm_list_1 (scm_from_size_t (idx)));
}
SCM_DEFINE (scm_values, "values", 0, 0, 1,
(SCM args),
"Delivers all of its arguments to its continuation. Except for\n"
"continuations created by the @code{call-with-values} procedure,\n"
"all continuations take exactly one value. The effect of\n"
"passing no value or more than one value to continuations that\n"
"were not created by @code{call-with-values} is unspecified.")
#define FUNC_NAME s_scm_values
{
long n;
SCM result;
SCM_VALIDATE_LIST_COPYLEN (1, args, n);
if (n == 1)
result = SCM_CAR (args);
else
result = scm_c_make_struct (scm_values_vtable, 0, 1, SCM_UNPACK (args));
return result;
}
#undef FUNC_NAME
SCM
scm_c_values (SCM *base, size_t nvalues)
{
SCM ret, *walk;
if (nvalues == 1)
return *base;
for (ret = SCM_EOL, walk = base + nvalues - 1; walk >= base; walk--)
ret = scm_cons (*walk, ret);
return scm_values (ret);
}
void
scm_init_values (void)
{
SCM print = scm_c_define_gsubr ("%print-values", 2, 0, 0, print_values);
scm_values_vtable = scm_make_vtable (scm_from_utf8_string ("pr"), print);
scm_add_feature ("values");
#include "libguile/values.x"
}
/*
Local Variables:
c-file-style: "gnu"
End:
*/
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