libguile/pairs.h

   1 /* classes: h_files */
   2
   3 #ifndef SCM_PAIRS_H
   4 #define SCM_PAIRS_H
   5
   6 /* Copyright (C) 1995,1996,2000,2001, 2004, 2006, 2008, 2009, 2010, 2012 Free Software Foundation, Inc.
   7  *
   8  * This library is free software; you can redistribute it and/or
   9  * modify it under the terms of the GNU Lesser General Public License
  10  * as published by the Free Software Foundation; either version 3 of
  11  * the License, or (at your option) any later version.
  12  *
  13  * This library is distributed in the hope that it will be useful, but
  14  * WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  16  * Lesser General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU Lesser General Public
  19  * License along with this library; if not, write to the Free Software
  20  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
  21  * 02110-1301 USA
  22  */
  23
  24 \f
  25
  26 #include "libguile/__scm.h"
  27
  28 #include "libguile/gc.h"
  29
  30 \f
  31
  32 #if (SCM_DEBUG_PAIR_ACCESSES == 1)
  33 # define SCM_VALIDATE_PAIR(cell, expr) \
  34     ((!scm_is_pair (cell) ? scm_error_pair_access (cell), 0 : 0), (expr))
  35 #else
  36 # define SCM_VALIDATE_PAIR(cell, expr) (expr)
  37 #endif
  38
  39 /*
  40  * Use scm_is_null_and_not_nil if it's important (for correctness)
  41  * that #nil must NOT be considered null.
  42  */
  43 #define scm_is_null_and_not_nil(x)     (scm_is_eq ((x), SCM_EOL))
  44
  45 /*
  46  * Use scm_is_null_assume_not_nil if
  47 #nil will never be tested,
  48  * for increased efficiency.
  49  */
  50 #define scm_is_null_assume_not_nil(x)  (scm_is_eq ((x), SCM_EOL))
  51
  52 /*
  53  * See the comments preceeding the definitions of SCM_BOOL_F and
  54  * SCM_MATCHES_BITS_IN_COMMON in tags.h for more information on
  55  * how the following macro works.
  56  */
  57 #define scm_is_null_or_nil(x)  \
  58   (SCM_MATCHES_BITS_IN_COMMON ((x), SCM_ELISP_NIL, SCM_EOL))
  59
  60
  61 \f
  62
  63 /* Older spellings for these null, nil, and pair predicates. */
  64 #define SCM_NILP(x) (scm_is_eq ((x), SCM_ELISP_NIL))
  65 #define SCM_NULL_OR_NIL_P(x) (scm_is_null_or_nil (x))
  66 #define SCM_NULLP(x) (scm_is_null (x))
  67 #define SCM_NNULLP(x) (!scm_is_null (x))
  68 #define SCM_CONSP(x)            (scm_is_pair (x))
  69 #define SCM_NCONSP(x)           (!SCM_CONSP (x))
  70
  71
  72 \f
  73
  74 /* #nil is null. */
  75 #define scm_is_null(x)          (scm_is_null_or_nil(x))
  76
  77 #define SCM_CAR(x)              (SCM_VALIDATE_PAIR (x, SCM_CELL_OBJECT_0 (x)))
  78 #define SCM_CDR(x)              (SCM_VALIDATE_PAIR (x, SCM_CELL_OBJECT_1 (x)))
  79
  80 #define SCM_SETCAR(x, v)        (SCM_VALIDATE_PAIR (x, SCM_SET_CELL_OBJECT_0 ((x), (v))))
  81 #define SCM_SETCDR(x, v)        (SCM_VALIDATE_PAIR (x, SCM_SET_CELL_OBJECT_1 ((x), (v))))
  82
  83 #define SCM_CAAR(OBJ)           SCM_CAR (SCM_CAR (OBJ))
  84 #define SCM_CDAR(OBJ)           SCM_CDR (SCM_CAR (OBJ))
  85 #define SCM_CADR(OBJ)           SCM_CAR (SCM_CDR (OBJ))
  86 #define SCM_CDDR(OBJ)           SCM_CDR (SCM_CDR (OBJ))
  87
  88 #define SCM_CAAAR(OBJ)          SCM_CAR (SCM_CAR (SCM_CAR (OBJ)))
  89 #define SCM_CDAAR(OBJ)          SCM_CDR (SCM_CAR (SCM_CAR (OBJ)))
  90 #define SCM_CADAR(OBJ)          SCM_CAR (SCM_CDR (SCM_CAR (OBJ)))
  91 #define SCM_CDDAR(OBJ)          SCM_CDR (SCM_CDR (SCM_CAR (OBJ)))
  92 #define SCM_CAADR(OBJ)          SCM_CAR (SCM_CAR (SCM_CDR (OBJ)))
  93 #define SCM_CDADR(OBJ)          SCM_CDR (SCM_CAR (SCM_CDR (OBJ)))
  94 #define SCM_CADDR(OBJ)          SCM_CAR (SCM_CDR (SCM_CDR (OBJ)))
  95 #define SCM_CDDDR(OBJ)          SCM_CDR (SCM_CDR (SCM_CDR (OBJ)))
  96
  97 #define SCM_CAAAAR(OBJ)         SCM_CAR (SCM_CAR (SCM_CAR (SCM_CAR (OBJ))))
  98 #define SCM_CDAAAR(OBJ)         SCM_CDR (SCM_CAR (SCM_CAR (SCM_CAR (OBJ))))
  99 #define SCM_CADAAR(OBJ)         SCM_CAR (SCM_CDR (SCM_CAR (SCM_CAR (OBJ))))
 100 #define SCM_CDDAAR(OBJ)         SCM_CDR (SCM_CDR (SCM_CAR (SCM_CAR (OBJ))))
 101 #define SCM_CAADAR(OBJ)         SCM_CAR (SCM_CAR (SCM_CDR (SCM_CAR (OBJ))))
 102 #define SCM_CDADAR(OBJ)         SCM_CDR (SCM_CAR (SCM_CDR (SCM_CAR (OBJ))))
 103 #define SCM_CADDAR(OBJ)         SCM_CAR (SCM_CDR (SCM_CDR (SCM_CAR (OBJ))))
 104 #define SCM_CDDDAR(OBJ)         SCM_CDR (SCM_CDR (SCM_CDR (SCM_CAR (OBJ))))
 105 #define SCM_CAAADR(OBJ)         SCM_CAR (SCM_CAR (SCM_CAR (SCM_CDR (OBJ))))
 106 #define SCM_CDAADR(OBJ)         SCM_CDR (SCM_CAR (SCM_CAR (SCM_CDR (OBJ))))
 107 #define SCM_CADADR(OBJ)         SCM_CAR (SCM_CDR (SCM_CAR (SCM_CDR (OBJ))))
 108 #define SCM_CDDADR(OBJ)         SCM_CDR (SCM_CDR (SCM_CAR (SCM_CDR (OBJ))))
 109 #define SCM_CAADDR(OBJ)         SCM_CAR (SCM_CAR (SCM_CDR (SCM_CDR (OBJ))))
 110 #define SCM_CDADDR(OBJ)         SCM_CDR (SCM_CAR (SCM_CDR (SCM_CDR (OBJ))))
 111 #define SCM_CADDDR(OBJ)         SCM_CAR (SCM_CDR (SCM_CDR (SCM_CDR (OBJ))))
 112 #define SCM_CDDDDR(OBJ)         SCM_CDR (SCM_CDR (SCM_CDR (SCM_CDR (OBJ))))
 113
 114 \f
 115
 116 #if (SCM_DEBUG_PAIR_ACCESSES == 1)
 117 SCM_API void scm_error_pair_access (SCM);
 118 #endif
 119
 120 SCM_INLINE int scm_is_pair (SCM x);
 121 SCM_INLINE SCM scm_cons (SCM x, SCM y);
 122 SCM_INLINE SCM scm_car (SCM x);
 123 SCM_INLINE SCM scm_cdr (SCM x);
 124
 125 #if SCM_CAN_INLINE || defined SCM_INLINE_C_IMPLEMENTING_INLINES
 126 /* Return a newly allocated pair whose car is @var{x} and whose cdr is
 127    @var{y}.  The pair is guaranteed to be different (in the sense of
 128    @code{eq?}) from every previously existing object.  */
 129 SCM_INLINE_IMPLEMENTATION SCM
 130 scm_cons (SCM x, SCM y)
 131 {
 132   return scm_cell (SCM_UNPACK (x), SCM_UNPACK (y));
 133 }
 134
 135 SCM_INLINE_IMPLEMENTATION int
 136 scm_is_pair (SCM x)
 137 {
 138   /* The following "workaround_for_gcc_295" avoids bad code generated by
 139      i386 gcc 2.95.4 (the Debian packaged 2.95.4-24 at least).
 140
 141      Under the default -O2 the inlined SCM_I_CONSP test gets "optimized" so
 142      the fetch of the tag word from x is done before confirming it's a
 143      non-immediate (SCM_NIMP).  Needless to say that bombs badly if x is a
 144      immediate.  This was seen to afflict scm_srfi1_split_at and something
 145      deep in the bowels of ceval().  In both cases segvs resulted from
 146      deferencing a random immediate value.  srfi-1.test exposes the problem
 147      through a short list, the immediate being SCM_EOL in that case.
 148      Something in syntax.test exposed the ceval() problem.
 149
 150      Just "volatile SCM workaround_for_gcc_295 = lst" is enough to avoid the
 151      problem, without even using that variable.  The "w=w" is just to
 152      prevent a warning about it being unused.
 153      */
 154 #if defined (__GNUC__) && __GNUC__ == 2 && __GNUC_MINOR__ == 95
 155   volatile SCM workaround_for_gcc_295 = x;
 156   workaround_for_gcc_295 = workaround_for_gcc_295;
 157 #endif
 158
 159   return SCM_I_CONSP (x);
 160 }
 161
 162 SCM_INLINE_IMPLEMENTATION SCM
 163 scm_car (SCM x)
 164 {
 165   if (SCM_UNLIKELY (!scm_is_pair (x)))
 166     scm_wrong_type_arg_msg ("car", 0, x, "pair");
 167   return SCM_CAR (x);
 168 }
 169
 170 SCM_INLINE_IMPLEMENTATION SCM
 171 scm_cdr (SCM x)
 172 {
 173   if (SCM_UNLIKELY (!scm_is_pair (x)))
 174     scm_wrong_type_arg_msg ("cdr", 0, x, "pair");
 175   return SCM_CDR (x);
 176 }
 177 #endif
 178
 179 SCM_API SCM scm_cons2 (SCM w, SCM x, SCM y);
 180 SCM_API SCM scm_pair_p (SCM x);
 181 SCM_API SCM scm_set_car_x (SCM pair, SCM value);
 182 SCM_API SCM scm_set_cdr_x (SCM pair, SCM value);
 183
 184 SCM_API SCM scm_cddr (SCM x);
 185 SCM_API SCM scm_cdar (SCM x);
 186 SCM_API SCM scm_cadr (SCM x);
 187 SCM_API SCM scm_caar (SCM x);
 188 SCM_API SCM scm_cdddr (SCM x);
 189 SCM_API SCM scm_cddar (SCM x);
 190 SCM_API SCM scm_cdadr (SCM x);
 191 SCM_API SCM scm_cdaar (SCM x);
 192 SCM_API SCM scm_caddr (SCM x);
 193 SCM_API SCM scm_cadar (SCM x);
 194 SCM_API SCM scm_caadr (SCM x);
 195 SCM_API SCM scm_caaar (SCM x);
 196 SCM_API SCM scm_cddddr (SCM x);
 197 SCM_API SCM scm_cdddar (SCM x);
 198 SCM_API SCM scm_cddadr (SCM x);
 199 SCM_API SCM scm_cddaar (SCM x);
 200 SCM_API SCM scm_cdaddr (SCM x);
 201 SCM_API SCM scm_cdadar (SCM x);
 202 SCM_API SCM scm_cdaadr (SCM x);
 203 SCM_API SCM scm_cdaaar (SCM x);
 204 SCM_API SCM scm_cadddr (SCM x);
 205 SCM_API SCM scm_caddar (SCM x);
 206 SCM_API SCM scm_cadadr (SCM x);
 207 SCM_API SCM scm_cadaar (SCM x);
 208 SCM_API SCM scm_caaddr (SCM x);
 209 SCM_API SCM scm_caadar (SCM x);
 210 SCM_API SCM scm_caaadr (SCM x);
 211 SCM_API SCM scm_caaaar (SCM x);
 212
 213 SCM_INTERNAL void scm_init_pairs (void);
 214
 215 #endif  /* SCM_PAIRS_H */
 216
 217 /*
 218   Local Variables:
 219   c-file-style: "gnu"
 220   End:
 221 */