git.distorted.org.uk Git - u/mdw/catacomb/blob - field.c

   1 /* -*-c-*-
   2  *
   3  * $Id$
   4  *
   5  * Abstract field operations
   6  *
   7  * (c) 2001 Straylight/Edgeware
   8  */
   9
  10 /*----- Licensing notice --------------------------------------------------*
  11  *
  12  * This file is part of Catacomb.
  13  *
  14  * Catacomb is free software; you can redistribute it and/or modify
  15  * it under the terms of the GNU Library General Public License as
  16  * published by the Free Software Foundation; either version 2 of the
  17  * License, or (at your option) any later version.
  18  *
  19  * Catacomb is distributed in the hope that it will be useful,
  20  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  21  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  22  * GNU Library General Public License for more details.
  23  *
  24  * You should have received a copy of the GNU Library General Public
  25  * License along with Catacomb; if not, write to the Free
  26  * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
  27  * MA 02111-1307, USA.
  28  */
  29
  30 /*----- Header files ------------------------------------------------------*/
  31
  32 #include "field.h"
  33 #include "mp.h"
  34
  35 /*----- Main code ---------------------------------------------------------*/
  36
  37 /* --- @field_id@ --- *
  38  *
  39  * Arguments:   @field *f@ = pointer to a field
  40  *              @mp *d@ = a destination element
  41  *              @mp *x@ = a source element
  42  *
  43  * Returns:     The result element.
  44  *
  45  * Use:         An identity operation which can be used if your field has no
  46  *              internal representation.
  47  */
  48
  49 mp *field_id(field *f, mp *d, mp *x)
  50   { x = MP_COPY(x); if (d) MP_DROP(d); return (x); }
  51
  52 /* --- @field_samep@ --- *
  53  *
  54  * Arguments:   @field *f, *g@ = two fields
  55  *
  56  * Returns:     Nonzero if the fields are identical (not just isomorphic).
  57  *
  58  * Use:         Checks for sameness of fields.  This function does the full
  59  *              check, not just the field-type-specific check done by the
  60  *              @sampep@ field operation.
  61  */
  62
  63 int field_samep(field *f, field *g)
  64   { return (f == g || (f->ops == g->ops && F_SAMEP(f, g))); }
  65
  66 /* --- @field_stdsamep@ --- *
  67  *
  68  * Arguments:   @field *f, *g@ = two fields
  69  *
  70  * Returns:     Nonzero if the fields are identical (not just isomorphic).
  71  *
  72  * Use:         Standard sameness check, based on equality of the @m@
  73  *              member.
  74  */
  75
  76 int field_stdsamep(field *f, field *g) { return (MP_EQ(f->m, g->m)); }
  77
  78 /*----- That's all, folks -------------------------------------------------*/