Ejemplo n.º 1
0
Archivo: bool.c Proyecto: SamB/racket
int is_equal (Scheme_Object *obj1, Scheme_Object *obj2, Equal_Info *eql)
{
  Scheme_Type t1, t2;
  int cmp;

 top:
  if (eql->next_next) {
    if (eql->next) {
      Scheme_Object *a[2];
      a[0] = obj1;
      a[1] = obj2;
      obj1 = _scheme_apply(eql->next, 2, a);
      return SCHEME_TRUEP(obj1);
    }
    eql->next = eql->next_next;
  }

  cmp = is_eqv(obj1, obj2);
  if (cmp > -1)
    return cmp;

  if (eql->for_chaperone 
      && SCHEME_CHAPERONEP(obj1)
      && (!(SCHEME_CHAPERONE_FLAGS((Scheme_Chaperone *)obj1) & SCHEME_CHAPERONE_IS_IMPERSONATOR)
          || (eql->for_chaperone > 1))) {
    obj1 = ((Scheme_Chaperone *)obj1)->prev;
    goto top;
  }

  t1 = SCHEME_TYPE(obj1);
  t2 = SCHEME_TYPE(obj2);

  if (NOT_SAME_TYPE(t1, t2)) {
    if (!eql->for_chaperone) {
      if (SCHEME_CHAPERONEP(obj1)) {
        obj1 = ((Scheme_Chaperone *)obj1)->val;
        goto top;
      }
      if (SCHEME_CHAPERONEP(obj2)) {
        obj2 = ((Scheme_Chaperone *)obj2)->val;
        goto top;
      }
    }
    return 0;
  } else if (t1 == scheme_pair_type) {
#   include "mzeqchk.inc"
    if ((eql->car_depth > 2) || !scheme_is_list(obj1)) {
      if (union_check(obj1, obj2, eql))
        return 1;
    }
    eql->car_depth += 2;
    if (is_equal(SCHEME_CAR(obj1), SCHEME_CAR(obj2), eql)) {
      eql->car_depth -= 2;
      obj1 = SCHEME_CDR(obj1);
      obj2 = SCHEME_CDR(obj2);
      goto top;
    } else
      return 0;
  } else if (t1 == scheme_mutable_pair_type) {
#   include "mzeqchk.inc"
    if (eql->for_chaperone == 1)
      return 0;
    if (union_check(obj1, obj2, eql))
      return 1;
    if (is_equal(SCHEME_CAR(obj1), SCHEME_CAR(obj2), eql)) {
      obj1 = SCHEME_CDR(obj1);
      obj2 = SCHEME_CDR(obj2);
      goto top;
    } else
      return 0;
  } else if ((t1 == scheme_vector_type)
             || (t1 == scheme_fxvector_type)) {
#   include "mzeqchk.inc"
    if ((eql->for_chaperone == 1) && (!SCHEME_IMMUTABLEP(obj1)
                                      || !SCHEME_IMMUTABLEP(obj2)))
      return 0;
    if (union_check(obj1, obj2, eql))
      return 1;
    return vector_equal(obj1, obj2, eql);
  } else if (t1 == scheme_flvector_type) {
    intptr_t l1, l2, i;
    l1 = SCHEME_FLVEC_SIZE(obj1);
    l2 = SCHEME_FLVEC_SIZE(obj2);
    if (l1 == l2) {
      for (i = 0; i < l1; i++) {
        if (!double_eqv(SCHEME_FLVEC_ELS(obj1)[i],
                        SCHEME_FLVEC_ELS(obj2)[i]))
          return 0;
      }
      return 1;
    }
    return 0;
  } else if ((t1 == scheme_byte_string_type)
             || ((t1 >= scheme_unix_path_type) 
                 && (t1 <= scheme_windows_path_type))) {
    intptr_t l1, l2;
    if ((eql->for_chaperone == 1) && (!SCHEME_IMMUTABLEP(obj1)
                                      || !SCHEME_IMMUTABLEP(obj2)))
      return 0;
    l1 = SCHEME_BYTE_STRTAG_VAL(obj1);
    l2 = SCHEME_BYTE_STRTAG_VAL(obj2);
    return ((l1 == l2)
	    && !memcmp(SCHEME_BYTE_STR_VAL(obj1), SCHEME_BYTE_STR_VAL(obj2), l1));
  } else if (t1 == scheme_char_string_type) {
    intptr_t l1, l2;
    if ((eql->for_chaperone == 1) && (!SCHEME_IMMUTABLEP(obj1)
                                      || !SCHEME_IMMUTABLEP(obj2)))
      return 0;
    l1 = SCHEME_CHAR_STRTAG_VAL(obj1);
    l2 = SCHEME_CHAR_STRTAG_VAL(obj2);
    return ((l1 == l2)
	    && !memcmp(SCHEME_CHAR_STR_VAL(obj1), SCHEME_CHAR_STR_VAL(obj2), l1 * sizeof(mzchar)));
  } else if (t1 == scheme_regexp_type) {
    if (scheme_regexp_is_byte(obj1) != scheme_regexp_is_byte(obj2))
      return 0;
    if (scheme_regexp_is_pregexp(obj1) != scheme_regexp_is_pregexp(obj2))
      return 0;
    obj1 = scheme_regexp_source(obj1);
    obj2 = scheme_regexp_source(obj2);
    goto top;
  } else if ((t1 == scheme_structure_type)
             || (t1 == scheme_proc_struct_type)) {
    Scheme_Struct_Type *st1, *st2;
    Scheme_Object *procs1, *procs2;

    st1 = SCHEME_STRUCT_TYPE(obj1);
    st2 = SCHEME_STRUCT_TYPE(obj2);

    if (eql->for_chaperone == 1)
      procs1 = NULL;
    else
      procs1 = scheme_struct_type_property_ref(scheme_impersonator_of_property, (Scheme_Object *)st1);
    if (procs1)
      procs1 = apply_impersonator_of(eql->for_chaperone, procs1, obj1);
    if (eql->for_chaperone)
      procs2 = NULL;
    else {
      procs2 = scheme_struct_type_property_ref(scheme_impersonator_of_property, (Scheme_Object *)st2);
      if (procs2)
        procs2 = apply_impersonator_of(eql->for_chaperone, procs2, obj2);
    }

    if (procs1 || procs2) {
      /* impersonator-of property trumps other forms of checking */
      if (procs1) obj1 = procs1;
      if (procs2) obj2 = procs2;
      goto top;
    } else {
      procs1 = scheme_struct_type_property_ref(scheme_equal_property, (Scheme_Object *)st1);
      if (procs1 && (st1 != st2)) {
        procs2 = scheme_struct_type_property_ref(scheme_equal_property, (Scheme_Object *)st2);
        if (!procs2
            || !SAME_OBJ(SCHEME_VEC_ELS(procs1)[0], SCHEME_VEC_ELS(procs2)[0]))
          procs1 = NULL;
      }

      if (procs1) {
        /* Has an equality property: */
        Scheme_Object *a[3], *recur;
        Equal_Info *eql2;
#     include "mzeqchk.inc"

        if (union_check(obj1, obj2, eql))
          return 1;

        /* Create/cache closure to use for recursive equality checks: */
        if (eql->recur) {
          recur = eql->recur;
          eql2 = (Equal_Info *)SCHEME_PRIM_CLOSURE_ELS(recur)[0];
        } else {
          eql2 = (Equal_Info *)scheme_malloc(sizeof(Equal_Info));
          a[0] = (Scheme_Object *)eql2;
          recur = scheme_make_prim_closure_w_arity(equal_recur,
                                                   1, a,
                                                   "equal?/recur",
                                                   2, 2);
          eql->recur = recur;
        }
        memcpy(eql2, eql, sizeof(Equal_Info));

        a[0] = obj1;
        a[1] = obj2;
        a[2] = recur;

        procs1 = SCHEME_VEC_ELS(procs1)[1];

        recur = _scheme_apply(procs1, 3, a);

        memcpy(eql, eql2, sizeof(Equal_Info));

        return SCHEME_TRUEP(recur);
      } else if (st1 != st2) {
        return 0;
      } else if ((eql->for_chaperone == 1)
                 && !(MZ_OPT_HASH_KEY(&st1->iso) & STRUCT_TYPE_ALL_IMMUTABLE)) {
        return 0;
      } else {
        /* Same types, but doesn't have an equality property
           (or checking for chaperone), so check transparency: */
        Scheme_Object *insp;
        insp = scheme_get_param(scheme_current_config(), MZCONFIG_INSPECTOR);
        if (scheme_inspector_sees_part(obj1, insp, -2)
            && scheme_inspector_sees_part(obj2, insp, -2)) {
#       include "mzeqchk.inc"
          if (union_check(obj1, obj2, eql))
            return 1;
          return struct_equal(obj1, obj2, eql);
        } else
          return 0;
      }
    }
  } else if (t1 == scheme_box_type) {
    SCHEME_USE_FUEL(1);
    if ((eql->for_chaperone == 1) && (!SCHEME_IMMUTABLEP(obj1)
                                      || !SCHEME_IMMUTABLEP(obj2)))
      return 0;
    if (union_check(obj1, obj2, eql))
      return 1;
    obj1 = SCHEME_BOX_VAL(obj1);
    obj2 = SCHEME_BOX_VAL(obj2);
    goto top;
  } else if (t1 == scheme_hash_table_type) {
#   include "mzeqchk.inc"
    if (eql->for_chaperone == 1) 
      return 0;
    if (union_check(obj1, obj2, eql))
      return 1;
    return scheme_hash_table_equal_rec((Scheme_Hash_Table *)obj1, (Scheme_Hash_Table *)obj2, eql);
  } else if (t1 == scheme_hash_tree_type) {
#   include "mzeqchk.inc"
    if (union_check(obj1, obj2, eql))
      return 1;
    return scheme_hash_tree_equal_rec((Scheme_Hash_Tree *)obj1, (Scheme_Hash_Tree *)obj2, eql);
  } else if (t1 == scheme_bucket_table_type) {
#   include "mzeqchk.inc"
    if (eql->for_chaperone == 1) 
      return 0;
    if (union_check(obj1, obj2, eql))
      return 1;
    return scheme_bucket_table_equal_rec((Scheme_Bucket_Table *)obj1, (Scheme_Bucket_Table *)obj2, eql);
  } else if (t1 == scheme_cpointer_type) {
    return (((char *)SCHEME_CPTR_VAL(obj1) + SCHEME_CPTR_OFFSET(obj1))
            == ((char *)SCHEME_CPTR_VAL(obj2) + SCHEME_CPTR_OFFSET(obj2)));
  } else if (t1 == scheme_wrap_chunk_type) {
    return vector_equal(obj1, obj2, eql);
  } else if (t1 == scheme_resolved_module_path_type) {
    obj1 = SCHEME_PTR_VAL(obj1);
    obj2 = SCHEME_PTR_VAL(obj2);
    goto top;
  } else if (t1 == scheme_place_bi_channel_type) {
    Scheme_Place_Bi_Channel *bc1, *bc2;
    bc1 = (Scheme_Place_Bi_Channel *)obj1;
    bc2 = (Scheme_Place_Bi_Channel *)obj2;
   return (SAME_OBJ(bc1->recvch, bc2->recvch)
           && SAME_OBJ(bc1->sendch, bc2->sendch));
  } else if (!eql->for_chaperone && ((t1 == scheme_chaperone_type)
                                     || (t1 == scheme_proc_chaperone_type))) {
    /* both chaperones */
    obj1 = ((Scheme_Chaperone *)obj1)->val;
    obj2 = ((Scheme_Chaperone *)obj2)->val;
    goto top;
  } else {
    Scheme_Equal_Proc eqlp = scheme_type_equals[t1];
    if (eqlp) {
      if (union_check(obj1, obj2, eql))
        return 1;
      return eqlp(obj1, obj2, eql);
    } else
      return 0;
  }
}
Ejemplo n.º 2
0
int is_equal (Scheme_Object *obj1, Scheme_Object *obj2, Equal_Info *eql)
{
  Scheme_Type t1, t2;
  int cmp;
  Scheme_Object *orig_obj1, *orig_obj2;

 top:
  orig_obj1 = obj1;
  orig_obj2 = obj2;

  if (eql->next_next) {
    if (eql->next) {
      Scheme_Object *a[2];
      a[0] = obj1;
      a[1] = obj2;
      obj1 = _scheme_apply(eql->next, 2, a);
      return SCHEME_TRUEP(obj1);
    }
    eql->next = eql->next_next;
  }

 top_after_next:
  cmp = is_fast_equal(obj1, obj2, eql->for_chaperone == 1);
  if (cmp > -1)
    return cmp;

  if (eql->for_chaperone 
      && SCHEME_CHAPERONEP(obj2)
      && scheme_is_noninterposing_chaperone(obj2)) {
    obj2 = ((Scheme_Chaperone *)obj2)->prev;
    goto top_after_next;
  }

  if (eql->for_chaperone 
      && SCHEME_CHAPERONEP(obj1)
      && (!(SCHEME_CHAPERONE_FLAGS((Scheme_Chaperone *)obj1) & SCHEME_CHAPERONE_IS_IMPERSONATOR)
          || (eql->for_chaperone > 1))) {
    /* `obj1` and `obj2` are not eq, otherwise is_fast_equal()
       would have returned true */
    if (SCHEME_CHAPERONEP(obj2)) {
      /* for immutable hashes, it's ok for the two objects to not be eq,
         as long as the interpositions are the same and the underlying
         values are `{impersonator,chaperone}-of?`: */
      if (SCHEME_HASHTRP(((Scheme_Chaperone *)obj1)->val)
          && SCHEME_HASHTRP(((Scheme_Chaperone *)obj2)->val)
          /* eq redirects means redirects were propagated: */
          && SAME_OBJ(((Scheme_Chaperone *)obj1)->redirects,
                      ((Scheme_Chaperone *)obj2)->redirects))
        obj2 = ((Scheme_Chaperone *)obj2)->prev;
    }
    obj1 = ((Scheme_Chaperone *)obj1)->prev;
    goto top_after_next;
  }

  t1 = SCHEME_TYPE(obj1);
  t2 = SCHEME_TYPE(obj2);

  if (NOT_SAME_TYPE(t1, t2)) {
    if (!eql->for_chaperone) {
      if (SCHEME_CHAPERONEP(obj1)) {
        obj1 = ((Scheme_Chaperone *)obj1)->val;
        goto top_after_next;
      } else if (t1 == scheme_hash_tree_indirection_type) {
        obj1 = (Scheme_Object *)scheme_hash_tree_resolve_placeholder((Scheme_Hash_Tree *)obj1);
        goto top_after_next;
      }
      if (SCHEME_CHAPERONEP(obj2)) {
        obj2 = ((Scheme_Chaperone *)obj2)->val;
        goto top_after_next;
      } else if (t2 == scheme_hash_tree_indirection_type) {
        obj2 = (Scheme_Object *)scheme_hash_tree_resolve_placeholder((Scheme_Hash_Tree *)obj2);
        goto top_after_next;
      }
    }
    return 0;
  } else {
    switch (t1) {
    case scheme_pair_type:
      {
#   include "mzeqchk.inc"
        if ((eql->car_depth > 2) || !scheme_is_list(obj1)) {
          if (union_check(obj1, obj2, eql))
            return 1;
        }
        eql->car_depth += 2;
        if (is_equal(SCHEME_CAR(obj1), SCHEME_CAR(obj2), eql)) {
          eql->car_depth -= 2;
          obj1 = SCHEME_CDR(obj1);
          obj2 = SCHEME_CDR(obj2);
          goto top;
        } else
          return 0;
      }
    case scheme_mutable_pair_type:
      {
#   include "mzeqchk.inc"
        if (eql->for_chaperone == 1)
          return 0;
        if (union_check(obj1, obj2, eql))
          return 1;
        if (is_equal(SCHEME_CAR(obj1), SCHEME_CAR(obj2), eql)) {
          obj1 = SCHEME_CDR(obj1);
          obj2 = SCHEME_CDR(obj2);
          goto top;
        } else
          return 0;
      }
    case scheme_vector_type:
    case scheme_fxvector_type:
      {
#   include "mzeqchk.inc"
        if ((eql->for_chaperone == 1) && (!SCHEME_IMMUTABLEP(obj1)
                                          || !SCHEME_IMMUTABLEP(obj2)))
          return 0;
        if (union_check(obj1, obj2, eql))
          return 1;
        return vector_equal(obj1, orig_obj1, obj2, orig_obj2, eql);
      }
    case scheme_byte_string_type:
    case scheme_unix_path_type:
    case scheme_windows_path_type:
      {
        intptr_t l1, l2;
        if ((eql->for_chaperone == 1) && (!SCHEME_IMMUTABLEP(obj1)
                                          || !SCHEME_IMMUTABLEP(obj2)))
          return 0;
        l1 = SCHEME_BYTE_STRTAG_VAL(obj1);
        l2 = SCHEME_BYTE_STRTAG_VAL(obj2);
        return ((l1 == l2)
                && !memcmp(SCHEME_BYTE_STR_VAL(obj1), SCHEME_BYTE_STR_VAL(obj2), l1));
      }
    case scheme_char_string_type:
      {
        intptr_t l1, l2;
        if ((eql->for_chaperone == 1) && (!SCHEME_IMMUTABLEP(obj1)
                                          || !SCHEME_IMMUTABLEP(obj2)))
          return 0;
        l1 = SCHEME_CHAR_STRTAG_VAL(obj1);
        l2 = SCHEME_CHAR_STRTAG_VAL(obj2);
        return ((l1 == l2)
                && !memcmp(SCHEME_CHAR_STR_VAL(obj1), SCHEME_CHAR_STR_VAL(obj2), l1 * sizeof(mzchar)));
      }
    case scheme_regexp_type:
      {
        if (scheme_regexp_is_byte(obj1) != scheme_regexp_is_byte(obj2))
          return 0;
        if (scheme_regexp_is_pregexp(obj1) != scheme_regexp_is_pregexp(obj2))
          return 0;
        obj1 = scheme_regexp_source(obj1);
        obj2 = scheme_regexp_source(obj2);
        goto top;
      }
    case scheme_structure_type:
    case scheme_proc_struct_type:
      {
        Scheme_Struct_Type *st1, *st2;
        Scheme_Object *procs1, *procs2;

        st1 = SCHEME_STRUCT_TYPE(obj1);
        st2 = SCHEME_STRUCT_TYPE(obj2);

        if (eql->for_chaperone == 1)
          procs1 = NULL;
        else
          procs1 = scheme_struct_type_property_ref(scheme_impersonator_of_property, (Scheme_Object *)st1);
        if (procs1)
          procs1 = scheme_apply_impersonator_of(eql->for_chaperone, procs1, obj1);
        if (eql->for_chaperone)
          procs2 = NULL;
        else {
          procs2 = scheme_struct_type_property_ref(scheme_impersonator_of_property, (Scheme_Object *)st2);
          if (procs2)
            procs2 = scheme_apply_impersonator_of(eql->for_chaperone, procs2, obj2);
        }

        if (procs1 || procs2) {
          /* impersonator-of property trumps other forms of checking */
          if (procs1) { obj1 = procs1; orig_obj1 = obj1; }
          if (procs2) { obj2 = procs2; orig_obj2 = obj2; }
          goto top_after_next;
        } else {
          procs1 = scheme_struct_type_property_ref(scheme_equal_property, (Scheme_Object *)st1);
          if (procs1 && (st1 != st2)) {
            procs2 = scheme_struct_type_property_ref(scheme_equal_property, (Scheme_Object *)st2);
            if (!procs2
                || !SAME_OBJ(SCHEME_VEC_ELS(procs1)[0], SCHEME_VEC_ELS(procs2)[0]))
              procs1 = NULL;
          }

          if (procs1) {
            /* Has an equality property: */
            Scheme_Object *a[3], *recur;
            Equal_Info *eql2;
#     include "mzeqchk.inc"

            if (union_check(obj1, obj2, eql))
              return 1;

            /* Create/cache closure to use for recursive equality checks: */
            if (eql->recur) {
              recur = eql->recur;
              eql2 = (Equal_Info *)SCHEME_PRIM_CLOSURE_ELS(recur)[0];
            } else {
              eql2 = (Equal_Info *)scheme_malloc(sizeof(Equal_Info));
              a[0] = (Scheme_Object *)eql2;
              recur = scheme_make_prim_closure_w_arity(equal_recur,
                                                       1, a,
                                                       "equal?/recur",
                                                       2, 2);
              eql->recur = recur;
            }
            memcpy(eql2, eql, sizeof(Equal_Info));

            a[0] = orig_obj1;
            a[1] = orig_obj2;
            a[2] = recur;

            procs1 = SCHEME_VEC_ELS(procs1)[1];

            recur = _scheme_apply(procs1, 3, a);

            memcpy(eql, eql2, sizeof(Equal_Info));

            return SCHEME_TRUEP(recur);
          } else if (st1 != st2) {
            return 0;
          } else if ((eql->for_chaperone == 1)
                     && !(MZ_OPT_HASH_KEY(&st1->iso) & STRUCT_TYPE_ALL_IMMUTABLE)) {
            return 0;
          } else {
            /* Same types, but doesn't have an equality property
               (or checking for chaperone), so check transparency: */
            Scheme_Object *insp;
            if (scheme_struct_is_transparent(obj1))
              insp = NULL;
            else {
              insp = scheme_get_param(scheme_current_config(), MZCONFIG_INSPECTOR);
            }
            if (!insp || scheme_inspector_sees_part(obj1, insp, -2)) {
#       include "mzeqchk.inc"
              if (union_check(obj1, obj2, eql))
                return 1;
              return struct_equal(obj1, orig_obj1, obj2, orig_obj2, eql);
            } else
              return 0;
          }
        }
      }
    case scheme_box_type:
      {
        SCHEME_USE_FUEL(1);
        if ((eql->for_chaperone == 1) && (!SCHEME_IMMUTABLEP(obj1)
                                          || !SCHEME_IMMUTABLEP(obj2)))
          return 0;
        if (union_check(obj1, obj2, eql))
          return 1;
        if (SAME_OBJ(obj1, orig_obj1))
          obj1 = SCHEME_BOX_VAL(obj1);
        else
          obj1 = scheme_unbox(orig_obj1);
        if (SAME_OBJ(obj2, orig_obj2))
          obj2 = SCHEME_BOX_VAL(obj2);
        else
          obj2 = scheme_unbox(orig_obj2);
        goto top;
      }
    case scheme_hash_table_type:
      {
#   include "mzeqchk.inc"
        if (eql->for_chaperone == 1) 
          return 0;
        if (union_check(obj1, obj2, eql))
          return 1;
        return scheme_hash_table_equal_rec((Scheme_Hash_Table *)obj1, orig_obj1, 
                                           (Scheme_Hash_Table *)obj2, orig_obj2,
                                           eql);
      }
    case scheme_hash_tree_type:
    case scheme_eq_hash_tree_type:
    case scheme_eqv_hash_tree_type:
    case scheme_hash_tree_indirection_type:
      {
#   include "mzeqchk.inc"
        if (union_check(obj1, obj2, eql))
          return 1;
        return scheme_hash_tree_equal_rec((Scheme_Hash_Tree *)obj1, orig_obj1,
                                          (Scheme_Hash_Tree *)obj2, orig_obj2,
                                          eql);
      } 
    case scheme_bucket_table_type:
      {
#   include "mzeqchk.inc"
        if (eql->for_chaperone == 1) 
          return 0;
        if (union_check(obj1, obj2, eql))
          return 1;
        return scheme_bucket_table_equal_rec((Scheme_Bucket_Table *)obj1, orig_obj1,
                                             (Scheme_Bucket_Table *)obj2, orig_obj2,
                                             eql);
      }
    case scheme_wrap_chunk_type: {
      return vector_equal(obj1, obj1, obj2, obj2, eql);
    }
    case scheme_resolved_module_path_type:
      {
        obj1 = SCHEME_PTR_VAL(obj1);
        obj2 = SCHEME_PTR_VAL(obj2);
        goto top;
      }
    case scheme_module_index_type:
      {
        Scheme_Modidx *midx1, *midx2;
#   include "mzeqchk.inc"
        midx1 = (Scheme_Modidx *)obj1;
        midx2 = (Scheme_Modidx *)obj2;
        if (eql->eq_for_modidx
            && (SCHEME_FALSEP(midx1->path)
                || SCHEME_FALSEP(midx2->path)))
          return 0;
        else if (is_equal(midx1->path, midx2->path, eql)) {
          obj1 = midx1->base;
          obj2 = midx2->base;
          goto top;
        }
      }
    case scheme_scope_table_type:
      {
        Scheme_Scope_Table *mt1 = (Scheme_Scope_Table *)obj1;
        Scheme_Scope_Table *mt2 = (Scheme_Scope_Table *)obj2;
        if (!is_equal((Scheme_Object *)mt1->simple_scopes, (Scheme_Object *)mt2->simple_scopes, eql))
          return 0;
        obj1 = mt1->multi_scopes;
        obj2 = mt2->multi_scopes;
        goto top;
      }
    default:
      if (!eql->for_chaperone && ((t1 == scheme_chaperone_type)
                                  || (t1 == scheme_proc_chaperone_type))) {
        /* both chaperones */
        obj1 = ((Scheme_Chaperone *)obj1)->val;
        obj2 = ((Scheme_Chaperone *)obj2)->val;
        goto top_after_next;
      } else {
        Scheme_Equal_Proc eqlp = scheme_type_equals[t1];
        if (eqlp) {
          if (union_check(obj1, obj2, eql))
            return 1;
          return eqlp(obj1, obj2, eql);
        } else
          return 0;
      }
    }
  }
}