pstoraster/zmisc3.c

   1 /* Copyright (C) 1997, 1998 Aladdin Enterprises.  All rights reserved.
   2
   3   This file is part of GNU Ghostscript.
   4
   5   GNU Ghostscript is distributed in the hope that it will be useful, but
   6   WITHOUT ANY WARRANTY.  No author or distributor accepts responsibility
   7   to anyone for the consequences of using it or for whether it serves any
   8   particular purpose or works at all, unless he says so in writing.  Refer
   9   to the GNU General Public License for full details.
  10
  11   Everyone is granted permission to copy, modify and redistribute GNU
  12   Ghostscript, but only under the conditions described in the GNU General
  13   Public License.  A copy of this license is supposed to have been given
  14   to you along with GNU Ghostscript so you can know your rights and
  15   responsibilities.  It should be in a file named COPYING.  Among other
  16   things, the copyright notice and this notice must be preserved on all
  17   copies.
  18
  19   Aladdin Enterprises supports the work of the GNU Project, but is not
  20   affiliated with the Free Software Foundation or the GNU Project.  GNU
  21   Ghostscript, as distributed by Aladdin Enterprises, does not require any
  22   GNU software to build or run it.
  23 */
  24
  25 /*$Id$ */
  26 /* Miscellaneous LanguageLevel 3 operators */
  27 #include "ghost.h"
  28 #include "gsclipsr.h"
  29 #include "oper.h"
  30 #include "igstate.h"
  31 #include "store.h"
  32
  33 /* - clipsave - */
  34 private int
  35 zclipsave(os_ptr op)
  36 {
  37     return gs_clipsave(igs);
  38 }
  39
  40 /* - cliprestore - */
  41 private int
  42 zcliprestore(os_ptr op)
  43 {
  44     return gs_cliprestore(igs);
  45 }
  46
  47 /* <proc1> <proc2> .eqproc <bool> */
  48 /*
  49  * Test whether two procedures are equal to depth 10.
  50  * This is the equality test used by idiom recognition in 'bind'.
  51  */
  52 #define MAX_DEPTH 10            /* depth is per Adobe specification */
  53 typedef struct ref2_s {
  54     ref proc1, proc2;
  55 } ref2_t;
  56 private int
  57 zeqproc(register os_ptr op)
  58 {
  59     ref2_t stack[MAX_DEPTH + 1];
  60     ref2_t *top = stack;
  61
  62     make_array(&stack[0].proc1, 0, 1, op - 1);
  63     make_array(&stack[0].proc2, 0, 1, op);
  64     for (;;) {
  65         long i;
  66
  67         if (r_size(&top->proc1) == 0) {
  68             /* Finished these arrays, go up to next level. */
  69             if (top == stack) {
  70                 /* We're done matching: it succeeded. */
  71                 make_true(op - 1);
  72                 pop(1);
  73                 return 0;
  74             }
  75             --top;
  76             continue;
  77         }
  78         /* Look at the next elements of the arrays. */
  79         i = r_size(&top->proc1) - 1;
  80         array_get(&top->proc1, i, &top[1].proc1);
  81         array_get(&top->proc2, i, &top[1].proc2);
  82         r_dec_size(&top->proc1, 1);
  83         ++top;
  84         /*
  85          * Amazingly enough, the objects' executable attributes are not
  86          * required to match.  This means { x load } will match { /x load },
  87          * even though this is clearly wrong.
  88          */
  89 #if 0
  90         if (r_has_attr(&top->proc1, a_executable) !=
  91             r_has_attr(&top->proc2, a_executable)
  92             )
  93             break;
  94 #endif
  95         if (obj_eq(&top->proc1, &top->proc2)) {
  96             /* Names don't match strings. */
  97             if (r_type(&top->proc1) != r_type(&top->proc2) &&
  98                 (r_type(&top->proc1) == t_name ||
  99                  r_type(&top->proc2) == t_name)
 100                 )
 101                 break;
 102             --top;              /* no recursion */
 103             continue;
 104         }
 105         if (r_is_array(&top->proc1) && r_is_array(&top->proc2) &&
 106             r_size(&top->proc1) == r_size(&top->proc2) &&
 107             top < stack + (MAX_DEPTH - 1)
 108             ) {
 109             /* Descend into the arrays. */
 110             continue;
 111         }
 112         break;
 113     }
 114     /* An exit from the loop indicates that matching failed. */
 115     make_false(op - 1);
 116     pop(1);
 117     return 0;
 118 }
 119
 120 /* ------ Initialization procedure ------ */
 121
 122 const op_def zmisc3_op_defs[] =
 123 {
 124     op_def_begin_ll3(),
 125     {"0cliprestore", zcliprestore},
 126     {"0clipsave", zclipsave},
 127     {"2.eqproc", zeqproc},
 128     op_def_end(0)
 129 };