Ejemplo n.º 1
0
Scheme_Object *scheme_complex_normalize(const Scheme_Object *o)
{
  Scheme_Complex *c = (Scheme_Complex *)o;

  if (c->i == zero)
    return c->r;
  if (c->r == zero) {
    /* No coercions */
    return (Scheme_Object *)c; 
  }

  /* Coercions: Exact -> float -> double
     If the complex contains a float and an exact, we coerce the exact
     to a float, etc. */

#ifdef MZ_USE_SINGLE_FLOATS
  if (SCHEME_FLTP(c->i)) {
    if (!SCHEME_FLTP(c->r)) {
      Scheme_Object *v;
      if (SCHEME_DBLP(c->r)) {
        v = scheme_make_double(SCHEME_FLT_VAL(c->i));
        c->i = v;
      } else {
        v = scheme_make_float(scheme_get_val_as_float(c->r));
	c->r = v;
      }
    }
  } else if (SCHEME_FLTP(c->r)) {
    Scheme_Object *v;
    /* Imag part can't be a float, or we'd be in the previous case */
    if (SCHEME_DBLP(c->i)) {
      v = scheme_make_double(SCHEME_FLT_VAL(c->r));
      c->r = v;
    } else {
      v = scheme_make_float(scheme_get_val_as_float(c->i));
      c->i = v;
    }
  } else
#endif

  if (SCHEME_DBLP(c->i)) {
    if (!SCHEME_DBLP(c->r)) {
      Scheme_Object *r;
      r = scheme_make_double(scheme_get_val_as_double(c->r));
      c->r = r;
    }
  } else if (SCHEME_DBLP(c->r)) {
    Scheme_Object *i;
    i = scheme_make_double(scheme_get_val_as_double(c->i));
    c->i = i;
  }

  return (Scheme_Object *)c;
}
Ejemplo n.º 2
0
Scheme_Object *
scheme_abs(int argc, Scheme_Object *argv[])
{
  Scheme_Type t;
  Scheme_Object *o;

  o = argv[0];

  if (SCHEME_INTP(o)) {
    intptr_t n = SCHEME_INT_VAL(o);
    return scheme_make_integer_value(ABS(n));
  } 
  t = _SCHEME_TYPE(o);
#ifdef MZ_USE_SINGLE_FLOATS
  if (t == scheme_float_type)
    return scheme_make_float(fabs(SCHEME_FLT_VAL(o)));
#endif
  if (t == scheme_double_type)
    return scheme_make_double(fabs(SCHEME_DBL_VAL(o)));
  if (t == scheme_bignum_type) {
    if (SCHEME_BIGPOS(o))
      return o;
    return scheme_bignum_negate(o);
  }
  if (t == scheme_rational_type) {
    if (scheme_is_rational_positive(o))
      return o;
    else
      return scheme_rational_negate(o);
  }

  NEED_REAL(abs);

  ESCAPED_BEFORE_HERE;
}
Ejemplo n.º 3
0
static Scheme_Object *
minus (int argc, Scheme_Object *argv[])
{
  Scheme_Object *ret, *v;

  ret = argv[0];
  if (!SCHEME_NUMBERP(ret)) {
    scheme_wrong_contract("-", "number?", 0, argc, argv);
    ESCAPED_BEFORE_HERE;
  }
  if (argc == 1) {
    if (SCHEME_FLOATP(ret)) {
#ifdef MZ_USE_SINGLE_FLOATS
      if (SCHEME_FLTP(ret))
	return scheme_make_float(-SCHEME_FLT_VAL(ret));
#endif
      return scheme_make_double(-SCHEME_DBL_VAL(ret));
    }
    return scheme_bin_minus(zeroi, ret);
  }
  if (argc == 2) {
    v = argv[1];
    if (!SCHEME_NUMBERP(v)) {
      scheme_wrong_contract("-", "number?", 1, argc, argv);
      ESCAPED_BEFORE_HERE;
    } 
    return scheme_bin_minus(ret, v);
  }
  return minus_slow(ret, argc, argv);
}
Ejemplo n.º 4
0
Scheme_Object *
scheme_sub1 (int argc, Scheme_Object *argv[])
{
  Scheme_Type t;
  Scheme_Object *o = argv[0];

  if (SCHEME_INTP(o)) {
    intptr_t v;
    v = SCHEME_INT_VAL(o);
    if (v > -(0x3FFFFFFF))
      return scheme_make_integer(SCHEME_INT_VAL(o) - 1);
    else {
      Small_Bignum b;
      return scheme_bignum_sub1(scheme_make_small_bignum(v, &b));
    }
  }
  t = _SCHEME_TYPE(o);
#ifdef MZ_USE_SINGLE_FLOATS
  if (t == scheme_float_type)
    return scheme_make_float(SCHEME_FLT_VAL(o) - 1.0f);
#endif
  if (t == scheme_double_type)
    return scheme_make_double(SCHEME_DBL_VAL(o) - 1.0);
  if (t == scheme_bignum_type)
    return scheme_bignum_sub1(o);
  if (t == scheme_rational_type)
    return scheme_rational_sub1(o);
  if (t == scheme_complex_type)
    return scheme_complex_sub1(o);
  
  NEED_NUMBER(sub1);

  ESCAPED_BEFORE_HERE;
}
Ejemplo n.º 5
0
Scheme_Object *scheme_rational_power(const Scheme_Object *o, const Scheme_Object *p)
{
  double b, e, v;

  if (((Scheme_Rational *)p)->denom == one) {
    Scheme_Object *a[2], *n;
    a[0] = ((Scheme_Rational *)o)->num;
    a[1] = ((Scheme_Rational *)p)->num;
    n = scheme_expt(2, a);
    a[0] = ((Scheme_Rational *)o)->denom;
    return make_rational(n, scheme_expt(2, a), 0);
  }

  if (scheme_is_rational_positive(o)) {
    b = scheme_rational_to_double(o);
    e = scheme_rational_to_double(p);

    v = pow(b, e);

#ifdef USE_SINGLE_FLOATS_AS_DEFAULT
    return scheme_make_float(v);
#else
    return scheme_make_double(v);
#endif
  } else {
    return scheme_complex_power(scheme_real_to_complex(o),
				scheme_real_to_complex(p));
  }
}
Ejemplo n.º 6
0
Scheme_Object *scheme_complex_power(const Scheme_Object *base, const Scheme_Object *exponent)
{
    Scheme_Complex *cb = (Scheme_Complex *)base;
    Scheme_Complex *ce = (Scheme_Complex *)exponent;
    double a, b, c, d, bm, ba, nm, na, r1, r2;
    int d_is_zero;

    if ((ce->i == zero) && !SCHEME_FLOATP(ce->r)) {
        if (SCHEME_INTP(ce->r) || SCHEME_BIGNUMP(ce->r))
            return scheme_generic_integer_power(base, ce->r);
    }

    a = scheme_get_val_as_double(cb->r);
    b = scheme_get_val_as_double(cb->i);
    c = scheme_get_val_as_double(ce->r);
    d = scheme_get_val_as_double(ce->i);
    d_is_zero = (ce->i == zero);

    bm = sqrt(a * a + b * b);
    ba = atan2(b, a);

    /* New mag & angle */
    nm = scheme_double_expt(bm, c) * exp(-(ba * d));
    if (d_is_zero) /* precision here can avoid NaNs */
        na = ba * c;
    else
        na = log(bm) * d + ba * c;

    r1 = nm * cos(na);
    r2 = nm * sin(na);

#ifdef MZ_USE_SINGLE_FLOATS
    /* Coerce to double or float? */
#ifdef USE_SINGLE_FLOATS_AS_DEFAULT
    if (!SCHEME_DBLP(cb->r) && !SCHEME_DBLP(cb->i)
            && !SCHEME_DBLP(ce->r) && !SCHEME_DBLP(ce->i))
#else
    if (SCHEME_FLTP(cb->r) && SCHEME_FLTP(cb->i)
            && SCHEME_FLTP(ce->r) && SCHEME_FLTP(ce->i))
#endif
        return scheme_make_complex(scheme_make_float((float)r1),
                                   scheme_make_float((float)r2));
#endif

    return scheme_make_complex(scheme_make_double(r1),
                               scheme_make_double(r2));
}
Ejemplo n.º 7
0
Scheme_Object *scheme_complex_sqrt(const Scheme_Object *o)
{
    Scheme_Complex *c = (Scheme_Complex *)o;
    Scheme_Object *r, *i, *ssq, *srssq, *nrsq, *prsq, *nr, *ni;

    r = c->r;
    i = c->i;

    if (scheme_is_zero(i)) {
        /* Special case for x+0.0i: */
        r = scheme_sqrt(1, &r);
        if (!SCHEME_COMPLEXP(r))
            return scheme_make_complex(r, i);
        else {
            c = (Scheme_Complex *)r;
            if (SAME_OBJ(c->r, zero)) {
                /* need an inexact-zero real part: */
#ifdef MZ_USE_SINGLE_FLOATS
                if (SCHEME_FLTP(c->i))
                    r = scheme_make_float(0.0);
                else
#endif
                    r = scheme_make_double(0.0);
                return scheme_make_complex(r, c->i);
            } else
                return r;
        }
    }

    ssq = scheme_bin_plus(scheme_bin_mult(r, r),
                          scheme_bin_mult(i, i));

    srssq = scheme_sqrt(1, &ssq);

    if (SCHEME_FLOATP(srssq)) {
        /* We may have lost too much precision, if i << r.  The result is
           going to be inexact, anyway, so switch to using expt. */
        Scheme_Object *a[2];
        a[0] = (Scheme_Object *)o;
        a[1] = scheme_make_double(0.5);
        return scheme_expt(2, a);
    }

    nrsq = scheme_bin_div(scheme_bin_minus(srssq, r),
                          scheme_make_integer(2));

    nr = scheme_sqrt(1, &nrsq);
    if (scheme_is_negative(i))
        nr = scheme_bin_minus(zero, nr);

    prsq = scheme_bin_div(scheme_bin_plus(srssq, r),
                          scheme_make_integer(2));

    ni = scheme_sqrt(1, &prsq);

    return scheme_make_complex(ni, nr);
}
Ejemplo n.º 8
0
Scheme_Object *scheme_rational_sqrt(const Scheme_Object *o)
{
  Scheme_Rational *r = (Scheme_Rational *)o;
  Scheme_Object *n, *d;
  double v;

  n = scheme_integer_sqrt(r->num);
  if (!SCHEME_DBLP(n)) {
    d = scheme_integer_sqrt(r->denom);
    if (!SCHEME_DBLP(d))
      return make_rational(n, d, 0);
  }

  v = sqrt(scheme_rational_to_double(o));

#ifdef USE_SINGLE_FLOATS_AS_DEFAULT
  return scheme_make_float(v);
#else
  return scheme_make_double(v);
#endif
}
Ejemplo n.º 9
0
static Scheme_Object *
rem_mod (int argc, Scheme_Object *argv[], char *name, int first_sign)
{
  Scheme_Object *n1, *n2, *r;
  int negate;

  n1 = argv[0];
  n2 = argv[1];

  if (!scheme_is_integer(n1))
    scheme_wrong_contract(name, "integer?", 0, argc, argv);
  if (!scheme_is_integer(n2))
    scheme_wrong_contract(name, "integer?", 1, argc, argv);

  if (SCHEME_INTP(n2) && !SCHEME_INT_VAL(n2))
    scheme_raise_exn(MZEXN_FAIL_CONTRACT_DIVIDE_BY_ZERO,
		     "%s: undefined for 0", name);
  if (
#ifdef MZ_USE_SINGLE_FLOATS
      (SCHEME_FLTP(n2) && (SCHEME_FLT_VAL(n2) == 0.0f)) ||
#endif
      (SCHEME_DBLP(n2) && (SCHEME_DBL_VAL(n2) == 0.0))) {
    int neg;
    neg = scheme_minus_zero_p(SCHEME_FLOAT_VAL(n2));
    scheme_raise_exn(MZEXN_FAIL_CONTRACT_DIVIDE_BY_ZERO,
		     "%s: undefined for %s0.0",
		     name,
		     neg ? "-" : "");
  }

  if (SCHEME_INTP(n1) && !SCHEME_INT_VAL(n1))
    return zeroi;

  if (SCHEME_INTP(n1) && SCHEME_INTP(n2)) {
    intptr_t a, b, na, nb, v;
    int neg1, neg2;

    a = SCHEME_INT_VAL(n1);
    b = SCHEME_INT_VAL(n2);
    na =  (a < 0) ? -a : a;
    nb =  (b < 0) ? -b : b;

    v = na % nb;

    if (v) {
      if (first_sign) {
	if (a < 0)
	  v = -v;
      } else {
	neg1 = (a < 0);
	neg2 = (b < 0);
	
	if (neg1 != neg2)
	  v = nb - v;
	
	if (neg2)
	  v = -v;
      }
    }

    return scheme_make_integer(v);
  }

  if (SCHEME_FLOATP(n1) || SCHEME_FLOATP(n2)) {
    double a, b, na, nb, v;
#ifdef MZ_USE_SINGLE_FLOATS
    int was_single = !(SCHEME_DBLP(n1) || SCHEME_DBLP(n2));
#endif

    if (SCHEME_INTP(n1))
      a = SCHEME_INT_VAL(n1);
#ifdef MZ_USE_SINGLE_FLOATS
    else if (SCHEME_FLTP(n1))
      a = SCHEME_FLT_VAL(n1);
#endif
    else if (SCHEME_DBLP(n1))
      a = SCHEME_DBL_VAL(n1);
    else
      a = scheme_bignum_to_double(n1);

    if (SCHEME_INTP(n2))
      b = SCHEME_INT_VAL(n2);
#ifdef MZ_USE_SINGLE_FLOATS
    else if (SCHEME_FLTP(n2))
      b = SCHEME_FLT_VAL(n2);
#endif
    else if (SCHEME_DBLP(n2))
      b = SCHEME_DBL_VAL(n2);
    else
      b = scheme_bignum_to_double(n2);

    if (a == 0.0) {
      /* Avoid sign problems. */
#ifdef MZ_USE_SINGLE_FLOATS
      if (was_single)
	return scheme_zerof;
#endif
      return scheme_zerod;
    }

    na =  (a < 0) ? -a : a;
    nb =  (b < 0) ? -b : b;

    if (MZ_IS_POS_INFINITY(nb))
      v = na;
    else if (MZ_IS_POS_INFINITY(na)) {
#ifdef MZ_USE_SINGLE_FLOATS
      if (was_single)
	return scheme_zerof;
#endif
      return scheme_zerod;
    } else {
      v = fmod(na, nb);

#ifdef FMOD_CAN_RETURN_NEG_ZERO
      if (v == 0.0)
	v = 0.0;
#endif
    }

    if (v) {
      if (first_sign) {
        /* remainder */
	if (a < 0)
	  v = -v;
      } else {
        /* modulo */
	int neg1, neg2;
	
	neg1 = (a < 0);
	neg2 = (b < 0);
	
	if (neg1 != neg2)
	  v = nb - v;
	
	if (neg2)
	  v = -v;
      }
    }

#ifdef MZ_USE_SINGLE_FLOATS
    if (was_single)
      return scheme_make_float((float)v);
#endif

    return scheme_make_double(v);
  }

  n1 = scheme_to_bignum(n1);
  n2 = scheme_to_bignum(n2);

  scheme_bignum_divide(n1, n2, NULL, &r, 1);

  negate = 0;

  if (!SCHEME_INTP(r) || SCHEME_INT_VAL(r)) {
    /* Easier if we can assume 'r' is positive: */
    if (SCHEME_INTP(r)) {
      if (SCHEME_INT_VAL(r) < 0)
	r = scheme_make_integer(-SCHEME_INT_VAL(r));
    } else if (!SCHEME_BIGPOS(r))
      r = scheme_bignum_negate(r);

    if (first_sign) {
      if (!SCHEME_BIGPOS(n1))
	negate = 1;
    } else {
      int neg1, neg2;
      
      neg1 = !SCHEME_BIGPOS(n1);
      neg2 = !SCHEME_BIGPOS(n2);
      
      if (neg1 != neg2) {
	if (neg2)
	  r = scheme_bin_plus(n2, r);
	else
	  r = scheme_bin_minus(n2, r);
      } else if (neg2)
	negate = 1;
    }
    
    if (negate) {
      if (SCHEME_INTP(r))
	r = scheme_make_integer(-SCHEME_INT_VAL(r));
      else
	r = scheme_bignum_negate(r);
    }
  }

  return r;
}
Ejemplo n.º 10
0
Scheme_Object *
do_bin_quotient(const char *name, const Scheme_Object *n1, const Scheme_Object *n2, Scheme_Object **bn_rem)
{
  Scheme_Object *q;

  if (!scheme_is_integer(n1)) {
    Scheme_Object *a[2];
    a[0] = (Scheme_Object *)n1;
    a[1] = (Scheme_Object *)n2;
    scheme_wrong_contract(name, "integer?", 0, 2, a);
  }
  if (!scheme_is_integer(n2)) {
    Scheme_Object *a[2];
    a[0] = (Scheme_Object *)n1;
    a[1] = (Scheme_Object *)n2;
    scheme_wrong_contract(name, "integer?", 1, 2, a);
  }

  if (SCHEME_INTP(n2) && !SCHEME_INT_VAL(n2))
    scheme_raise_exn(MZEXN_FAIL_CONTRACT_DIVIDE_BY_ZERO,
		     "%s: undefined for 0", name);
  if (
#ifdef MZ_USE_SINGLE_FLOATS
      (SCHEME_FLTP(n2) && (SCHEME_FLT_VAL(n2) == 0.0f)) ||
#endif
      (SCHEME_DBLP(n2) && (SCHEME_DBL_VAL(n2) == 0.0)))
    scheme_raise_exn(MZEXN_FAIL_CONTRACT_DIVIDE_BY_ZERO,
		     "%s: undefined for 0.0", name);

  if (SCHEME_INTP(n1) && SCHEME_INTP(n2)) {
    /* Beware that most negative fixnum divided by -1
       isn't a fixnum: */
    return (scheme_make_integer_value(SCHEME_INT_VAL(n1) / SCHEME_INT_VAL(n2)));
  }
  if (SCHEME_DBLP(n1) || SCHEME_DBLP(n2)) {
    Scheme_Object *r;
    double d, d2;

    r = scheme_bin_div(n1, n2); /* could be exact 0 ... */
    if (SCHEME_DBLP(r)) {
      d = SCHEME_DBL_VAL(r);
      
      if (d > 0)
	d2 = floor(d);
      else
	d2 = ceil(d);
      
      if (d2 == d)
	return r;
      else
	return scheme_make_double(d2);
    } else
      return r;
  }
#ifdef MZ_USE_SINGLE_FLOATS
  if (SCHEME_FLTP(n1) || SCHEME_FLTP(n2)) {
    Scheme_Object *r;
    float d, d2;

    r = scheme_bin_div(n1, n2); /* could be exact 0 ... */
    if (SCHEME_FLTP(r)) {
      d = SCHEME_FLT_VAL(r);
      
      if (d > 0)
	d2 = floor(d);
      else
	d2 = ceil(d);
      
      if (d2 == d)
	return r;
      else
	return scheme_make_float(d2);
    } else
      return r;
  }
#endif

#if 0
  /* I'm pretty sure this isn't needed, but I'm keeping the code just
     in case... 03/19/2000 */
  if (SCHEME_RATIONALP(n1))
    wrong_contract(name, "integer?", n1);
  if (SCHEME_RATIONALP(n2))
    wrong_contract(name, "integer?", n2);
#endif
  
  n1 = scheme_to_bignum(n1);
  n2 = scheme_to_bignum(n2);

  scheme_bignum_divide(n1, n2, &q, bn_rem, 1);
  return q;
}
Ejemplo n.º 11
0
Scheme_Object *scheme_places_deep_copy_worker(Scheme_Object *so, Scheme_Hash_Table *ht)
{
  Scheme_Object *new_so = so;
  if (SCHEME_INTP(so)) {
    return so;
  }
  if (ht) {
    Scheme_Object *r; 
    if ((r = scheme_hash_get(ht, so))) {
      return r;
    }
  }

  switch (so->type) {
    case scheme_true_type:
    case scheme_false_type:
    case scheme_null_type:
    case scheme_void_type:
    /* place_bi_channels are allocated in the master and can be passed along as is */
    case scheme_place_bi_channel_type:
      new_so = so;
      break;
    case scheme_place_type:
      new_so = ((Scheme_Place *) so)->channel;
      break;
    case scheme_char_type:
      new_so = scheme_make_char(SCHEME_CHAR_VAL(so));
      break;
    case scheme_rational_type:
      {
        Scheme_Object *n;
        Scheme_Object *d;
        n = scheme_rational_numerator(so);
        d = scheme_rational_denominator(so);
        n = scheme_places_deep_copy_worker(n, ht);
        d = scheme_places_deep_copy_worker(d, ht);
        new_so = scheme_make_rational(n, d);
      }
      break;
    case scheme_float_type:
      new_so = scheme_make_float(SCHEME_FLT_VAL(so));
      break;
    case scheme_double_type:
      new_so = scheme_make_double(SCHEME_DBL_VAL(so));
      break;
    case scheme_complex_type:
      {
        Scheme_Object *r;
        Scheme_Object *i;
        r = scheme_complex_real_part(so);
        i = scheme_complex_imaginary_part(so);
        r = scheme_places_deep_copy_worker(r, ht);
        i = scheme_places_deep_copy_worker(i, ht);
        new_so = scheme_make_complex(r, i);
      }
      break;
    case scheme_char_string_type:
      new_so = scheme_make_sized_offset_char_string(SCHEME_CHAR_STR_VAL(so), 0, SCHEME_CHAR_STRLEN_VAL(so), 1);
      break;
    case scheme_byte_string_type:
      if (SHARED_ALLOCATEDP(so)) {
        new_so = so;
      }
      else {
        new_so = scheme_make_sized_offset_byte_string(SCHEME_BYTE_STR_VAL(so), 0, SCHEME_BYTE_STRLEN_VAL(so), 1);
      }
      break;
    case scheme_unix_path_type:
      new_so = scheme_make_sized_offset_path(SCHEME_BYTE_STR_VAL(so), 0, SCHEME_BYTE_STRLEN_VAL(so), 1);
      break;
    case scheme_symbol_type:
      if (SCHEME_SYM_UNINTERNEDP(so)) {
        scheme_log_abort("cannot copy uninterned symbol");
        abort();
      } else {
        new_so = scheme_make_sized_offset_byte_string(SCHEME_SYM_VAL(so), 0, SCHEME_SYM_LEN(so), 1);
        new_so->type = scheme_serialized_symbol_type;
      }
      break;
    case scheme_serialized_symbol_type:
        new_so = scheme_intern_exact_symbol(SCHEME_BYTE_STR_VAL(so), SCHEME_BYTE_STRLEN_VAL(so));
      break;
    case scheme_pair_type:
      {
        Scheme_Object *car;
        Scheme_Object *cdr;
        Scheme_Object *pair;
        car = scheme_places_deep_copy_worker(SCHEME_CAR(so), ht);
        cdr = scheme_places_deep_copy_worker(SCHEME_CDR(so), ht);
        pair = scheme_make_pair(car, cdr);
        new_so = pair;
      }
      break;
    case scheme_vector_type:
      {
        Scheme_Object *vec;
        intptr_t i;
        intptr_t size = SCHEME_VEC_SIZE(so);
        vec = scheme_make_vector(size, 0);
        for (i = 0; i <size ; i++) {
          Scheme_Object *tmp;
          tmp = scheme_places_deep_copy_worker(SCHEME_VEC_ELS(so)[i], ht);
          SCHEME_VEC_ELS(vec)[i] = tmp;
        }
        SCHEME_SET_IMMUTABLE(vec);
        new_so = vec;
      }
      break;
    case scheme_fxvector_type:
      if (SHARED_ALLOCATEDP(so)) {
        new_so = so;
      }
      else {
        Scheme_Vector *vec;
        intptr_t i;
        intptr_t size = SCHEME_FXVEC_SIZE(so);
        vec = scheme_alloc_fxvector(size);

        for (i = 0; i < size; i++) {
          SCHEME_FXVEC_ELS(vec)[i] = SCHEME_FXVEC_ELS(so)[i];
        }
        new_so = (Scheme_Object *) vec;
      }
      break;
    case scheme_flvector_type:
      if (SHARED_ALLOCATEDP(so)) {
        new_so = so;
      }
      else {
        Scheme_Double_Vector *vec;
        intptr_t i;
        intptr_t size = SCHEME_FLVEC_SIZE(so);
        vec = scheme_alloc_flvector(size);

        for (i = 0; i < size; i++) {
          SCHEME_FLVEC_ELS(vec)[i] = SCHEME_FLVEC_ELS(so)[i];
        }
        new_so = (Scheme_Object *) vec;
      }
      break;
    case scheme_structure_type:
      {
        Scheme_Structure *st = (Scheme_Structure*)so;
        Scheme_Serialized_Structure *nst;
        Scheme_Struct_Type *stype = st->stype;
        Scheme_Struct_Type *ptype = stype->parent_types[stype->name_pos - 1];
        Scheme_Object *nprefab_key;
        intptr_t size = stype->num_slots;
        int local_slots = stype->num_slots - (ptype ? ptype->num_slots : 0);
        int i = 0;

        if (!stype->prefab_key) {
          scheme_log_abort("cannot copy non prefab structure");
          abort();
        }
        {
          for (i = 0; i < local_slots; i++) {
            if (!stype->immutables || stype->immutables[i] != 1) {
              scheme_log_abort("cannot copy mutable prefab structure");
              abort();
            }
          }
        }
        nprefab_key = scheme_places_deep_copy_worker(stype->prefab_key, ht);
        nst = (Scheme_Serialized_Structure*) scheme_make_serialized_struct_instance(nprefab_key, size);
        for (i = 0; i <size ; i++) {
          Scheme_Object *tmp;
          tmp = scheme_places_deep_copy_worker((Scheme_Object*) st->slots[i], ht);
          nst->slots[i] = tmp;
        }
        new_so = (Scheme_Object*) nst;
      }
      break;

    case scheme_serialized_structure_type:
      {
        Scheme_Serialized_Structure *st = (Scheme_Serialized_Structure*)so;
        Scheme_Struct_Type *stype;
        Scheme_Structure *nst;
        intptr_t size;
        int i = 0;
      
        size = st->num_slots;
        stype = scheme_lookup_prefab_type(SCHEME_CDR(st->prefab_key), size);
        nst = (Scheme_Structure*) scheme_make_blank_prefab_struct_instance(stype);
        for (i = 0; i <size ; i++) {
          Scheme_Object *tmp;
          tmp = scheme_places_deep_copy_worker((Scheme_Object*) st->slots[i], ht);
          nst->slots[i] = tmp;
        }
        new_so = (Scheme_Object*)nst;
      }
      break;

    case scheme_resolved_module_path_type:
    default:
      printf("places deep copy cannot copy object of type %hi at %p\n", so->type, so);
      scheme_log_abort("places deep copy cannot copy object");
      abort();
      break;
  }
  if (ht) {
    scheme_hash_set(ht, so, new_so);
  }
  return new_so;
}