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/*
Copyright (C) 2020 Fredrik Johansson
This file is part of FLINT.
FLINT is free software: you can redistribute it and/or modify it under
the terms of the GNU Lesser General Public License (LGPL) as published
by the Free Software Foundation; either version 3 of the License, or
(at your option) any later version. See <https://www.gnu.org/licenses/>.
*/
#include "ca.h"
void
ca_re(ca_t res, const ca_t x, ca_ctx_t ctx)
{
if (CA_IS_SPECIAL(x))
{
if (CA_IS_UNKNOWN(x))
ca_unknown(res, ctx);
else
ca_undefined(res, ctx);
}
else if (CA_IS_QQ(x, ctx))
{
ca_set(res, x, ctx);
}
else if (CA_IS_QQ_I(x, ctx))
{
const fmpz *n, *d;
fmpq_t t;
n = QNF_ELEM_NUMREF(CA_NF_ELEM(x));
d = QNF_ELEM_DENREF(CA_NF_ELEM(x));
fmpq_init(t);
fmpq_set_fmpz_frac(t, n, d);
ca_set_fmpq(res, t, ctx);
fmpq_clear(t);
}
else if (ca_check_is_real(x, ctx) == T_TRUE) /* todo: avoid duplicate computations with is_real/is_imaginary */
{
ca_set(res, x, ctx);
}
else if (ca_check_is_imaginary(x, ctx) == T_TRUE)
{
ca_zero(res, ctx);
}
else
{
_ca_make_field_element(res, _ca_ctx_get_field_fx(ctx, CA_Re, x), ctx);
fmpz_mpoly_q_gen(CA_MPOLY_Q(res), 0, CA_MCTX_1(ctx));
}
}