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   1 /* -*-c-*-
   2  *
   3  * $Id: mptext.c,v 1.1 1999/11/17 18:02:16 mdw Exp $
   4  *
   5  * Textual representation of multiprecision numbers
   6  *
   7  * (c) 1999 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 /*----- Revision history --------------------------------------------------*
  31  *
  32  * $Log: mptext.c,v $
  33  * Revision 1.1  1999/11/17 18:02:16  mdw
  34  * New multiprecision integer arithmetic suite.
  35  *
  36  */
  37
  38 /*----- Header files ------------------------------------------------------*/
  39
  40 #include <ctype.h>
  41 #include <stdio.h>
  42
  43 #include <mLib/darray.h>
  44
  45 #include "mp.h"
  46 #include "mptext.h"
  47
  48 /*----- Data structures ---------------------------------------------------*/
  49
  50 #ifndef CHARV
  51    DA_DECL(charv, char);
  52 #  define CHARV
  53 #endif
  54
  55 /*----- Main code ---------------------------------------------------------*/
  56
  57 /* --- @mp_read@ --- *
  58  *
  59  * Arguments:   @mp *m@ = destination multiprecision number
  60  *              @int radix@ = base to assume for data (or zero to guess)
  61  *              @const mptext_ops *ops@ = pointer to operations block
  62  *              @void *p@ = data for the operations block
  63  *
  64  * Returns:     The integer read, or zero if it didn't work.
  65  *
  66  * Use:         Reads an integer from some source.  If the @radix@ is
  67  *              specified, the number is assumed to be given in that radix,
  68  *              with the letters `a' (either upper- or lower-case) upwards
  69  *              standing for digits greater than 9.  Otherwise, base 10 is
  70  *              assumed unless the number starts with `0' (octal), `0x' (hex)
  71  *              or `nnn_' (base `nnn').  An arbitrary amount of whitespace
  72  *              before the number is ignored.
  73  */
  74
  75 mp *mp_read(mp *m, int radix, const mptext_ops *ops, void *p)
  76 {
  77   int r;
  78   int ch;
  79   unsigned f = 0;
  80
  81   enum {
  82     f_neg = 1u,
  83     f_ok = 2u
  84   };
  85
  86   /* --- Initialize the destination number --- */
  87
  88   MP_MODIFY(m, 16);
  89   m->vl = m->v;
  90   m->f &= ~MP_UNDEF;
  91
  92   /* --- Read an initial character --- */
  93
  94   ch = ops->get(p);
  95   while (isspace(ch))
  96     ch = ops->get(p);
  97
  98   /* --- Handle an initial sign --- */
  99
 100   if (ch == '-') {
 101     f |= f_neg;
 102     ch = ops->get(p);
 103     while (isspace(ch))
 104       ch = ops->get(p);
 105   }
 106
 107   /* --- If the radix is zero, look for leading zeros --- */
 108
 109   if (radix)
 110     r = -1;
 111   else if (ch != '0') {
 112     radix = 10;
 113     r = 0;
 114   } else {
 115     ch = ops->get(p);
 116     if (ch == 'x') {
 117       ch = ops->get(p);
 118       radix = 16;
 119     } else {
 120       radix = 8;
 121       f |= f_ok;
 122     }
 123     r = -1;
 124   }
 125
 126   /* --- Time to start --- */
 127
 128   for (;; ch = ops->get(p)) {
 129     int x;
 130
 131     /* --- An underscore indicates a numbered base --- */
 132
 133     if (ch == '_' && r > 0 && r <= 36) {
 134       radix = r;
 135       m->vl = m->v;
 136       r = -1;
 137       f &= ~f_ok;
 138       continue;
 139     }
 140
 141     /* --- Check that the character is a digit and in range --- */
 142
 143     if (!isalnum(ch))
 144       break;
 145     if (ch >= '0' && ch <= '9')
 146       x = ch - '0';
 147     else {
 148       ch = tolower(ch);
 149       if (ch >= 'a' && ch <= 'z')       /* ASCII dependent! */
 150         x = ch - 'a' + 10;
 151       else
 152         break;
 153     }
 154
 155     /* --- Sort out what to do with the character --- */
 156
 157     if (x >= 10 && r >= 0)
 158       r = -1;
 159     if (x >= radix)
 160       break;
 161
 162     if (r >= 0)
 163       r = r * 10 + x;
 164
 165     /* --- Stick the character on the end of my integer --- */
 166
 167     MP_ENSURE(m, MP_LEN(m) + 1);
 168     MPX_UMULN(m->v, m->vl, m->v, m->vl - 1, radix);
 169     MPX_UADDN(m->v, m->vl, x);
 170     MP_SHRINK(m);
 171     f |= f_ok;
 172   }
 173
 174   ops->unget(ch, p);
 175
 176   /* --- Bail out if the number was bad --- */
 177
 178   if (!(f & f_ok)) {
 179     MP_DROP(m);
 180     return (0);
 181   }
 182
 183   /* --- Set the sign and return --- */
 184
 185   m->f = 0;
 186   if (f & f_neg)
 187     m->f |= MP_NEG;
 188   return (m);
 189 }
 190
 191 /* --- @mp_write@ --- *
 192  *
 193  * Arguments:   @mp *m@ = pointer to a multi-precision integer
 194  *              @int radix@ = radix to use when writing the number out
 195  *              @const mptext_ops *ops@ = pointer to an operations block
 196  *              @void *p@ = data for the operations block
 197  *
 198  * Returns:     Zero if it worked, nonzero otherwise.
 199  *
 200  * Use:         Writes a large integer in textual form.
 201  */
 202
 203 int mp_write(mp *m, int radix, const mptext_ops *ops, void *p)
 204 {
 205   charv v = DA_INIT;
 206   mpw b = radix;
 207   mp bb;
 208
 209   /* --- Set various things up --- */
 210
 211   m = MP_COPY(m);
 212   mp_build(&bb, &b, &b + 1);
 213
 214   /* --- If the number is negative, sort that out --- */
 215
 216   if (m->f & MP_NEG) {
 217     if (ops->put("-", 1, p))
 218       return (EOF);
 219     MP_SPLIT(m);
 220     m->f &= ~MP_NEG;
 221   }
 222
 223   /* --- Write digits to a temporary array --- */
 224
 225   do {
 226     mp *q = MP_NEW, *r = MP_NEW;
 227     int ch;
 228     mpw x;
 229
 230     mp_div(&q, &r, m, &bb);
 231     x = r->v[0];
 232     if (x < 10)
 233       ch = '0' + x;
 234     else
 235       ch = 'a' + x - 10;
 236     DA_UNSHIFT(&v, ch);
 237     MP_DROP(m);
 238     MP_DROP(r);
 239     m = q;
 240   } while (MP_CMP(m, !=, MP_ZERO));
 241
 242   /* --- Finished that --- */
 243
 244   MP_DROP(m);
 245
 246   {
 247     int rc = ops->put(DA(&v), DA_LEN(&v), p);
 248     DA_DESTROY(&v);
 249     return (rc ? EOF : 0);
 250   }
 251 }
 252
 253 /*----- Test rig ----------------------------------------------------------*/
 254
 255 #ifdef TEST_RIG
 256
 257 #include <mLib/testrig.h>
 258
 259 static int verify(dstr *v)
 260 {
 261   int ok = 1;
 262   int ib = *(int *)v[0].buf, ob = *(int *)v[2].buf;
 263   dstr d = DSTR_INIT;
 264   mp *m = mp_readdstr(MP_NEW, &v[1], 0, ib);
 265   if (m) {
 266     if (!ob) {
 267       fprintf(stderr, "*** unexpected successful parse\n"
 268                       "*** input [%i] = %s\n",
 269               ib, v[1].buf);
 270       mp_writedstr(m, &d, 10);
 271       fprintf(stderr, "*** (value = %s)\n", d.buf);
 272       ok = 0;
 273     } else {
 274       mp_writedstr(m, &d, ob);
 275       if (d.len != v[3].len || memcmp(d.buf, v[3].buf, d.len) != 0) {
 276         fprintf(stderr, "*** failed read or write\n"
 277                         "*** input [%i]    = %s\n"
 278                         "*** output [%i]   = %s\n"
 279                         "*** expected [%i] = %s\n",
 280                 ib, v[1].buf, ob, d.buf, ob, v[3].buf);
 281         ok = 0;
 282       }
 283     }
 284     mp_drop(m);
 285   } else {
 286     if (ob) {
 287       fprintf(stderr, "*** unexpected parse failure\n"
 288                       "*** input [%i] = %s\n"
 289                       "*** expected [%i] = %s\n",
 290               ib, v[1].buf, ob, v[3].buf);
 291       ok = 0;
 292     }
 293   }
 294
 295   dstr_destroy(&d);
 296   return (ok);
 297 }
 298
 299 static test_chunk tests[] = {
 300   { "mptext", verify,
 301     { &type_int, &type_string, &type_int, &type_string, 0 } },
 302   { 0, 0, { 0 } }
 303 };
 304
 305 int main(int argc, char *argv[])
 306 {
 307   sub_init();
 308   test_run(argc, argv, tests, SRCDIR "/tests/mptext");
 309   return (0);
 310 }
 311
 312 #endif
 313
 314 /*----- That's all, folks -------------------------------------------------*/