libguile/read.c

   1 /* Copyright (C) 1995,1996,1997,1999,2000,2001,2003, 2004 Free Software
   2  * Foundation, Inc.
   3  *
   4  * This library is free software; you can redistribute it and/or
   5  * modify it under the terms of the GNU Lesser General Public
   6  * License as published by the Free Software Foundation; either
   7  * version 2.1 of the License, or (at your option) any later version.
   8  *
   9  * This library is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12  * Lesser General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU Lesser General Public
  15  * License along with this library; if not, write to the Free Software
  16  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  17  */
  18
  19
  20 \f
  21
  22 #include <stdio.h>
  23 #include "libguile/_scm.h"
  24 #include "libguile/chars.h"
  25 #include "libguile/eval.h"
  26 #include "libguile/unif.h"
  27 #include "libguile/keywords.h"
  28 #include "libguile/alist.h"
  29 #include "libguile/srcprop.h"
  30 #include "libguile/hashtab.h"
  31 #include "libguile/hash.h"
  32 #include "libguile/ports.h"
  33 #include "libguile/root.h"
  34 #include "libguile/strings.h"
  35 #include "libguile/strports.h"
  36 #include "libguile/vectors.h"
  37 #include "libguile/validate.h"
  38 #include "libguile/srfi-4.h"
  39
  40 #include "libguile/read.h"
  41
  42 \f
  43
  44 SCM_GLOBAL_SYMBOL (scm_sym_dot, ".");
  45 SCM_SYMBOL (scm_keyword_prefix, "prefix");
  46
  47 scm_t_option scm_read_opts[] = {
  48   { SCM_OPTION_BOOLEAN, "copy", 0,
  49     "Copy source code expressions." },
  50   { SCM_OPTION_BOOLEAN, "positions", 0,
  51     "Record positions of source code expressions." },
  52   { SCM_OPTION_BOOLEAN, "case-insensitive", 0,
  53     "Convert symbols to lower case."},
  54   { SCM_OPTION_SCM, "keywords", SCM_UNPACK (SCM_BOOL_F),
  55     "Style of keyword recognition: #f or 'prefix."}
  56 #if SCM_ENABLE_ELISP
  57   ,
  58   { SCM_OPTION_BOOLEAN, "elisp-vectors", 0,
  59     "Support Elisp vector syntax, namely `[...]'."},
  60   { SCM_OPTION_BOOLEAN, "elisp-strings", 0,
  61     "Support `\\(' and `\\)' in strings."}
  62 #endif
  63 };
  64
  65 /*
  66   Give meaningful error messages for errors
  67
  68   We use the format
  69
  70   FILE:LINE:COL: MESSAGE
  71   This happened in ....
  72
  73   This is not standard GNU format, but the test-suite likes the real
  74   message to be in front.
  75
  76  */
  77
  78
  79 void
  80 scm_i_input_error (char const *function,
  81                    SCM port, const char *message, SCM arg)
  82 {
  83   SCM fn = (scm_is_string (SCM_FILENAME(port))
  84             ? SCM_FILENAME(port)
  85             : scm_from_locale_string ("#<unknown port>"));
  86
  87   SCM string_port = scm_open_output_string ();
  88   SCM string = SCM_EOL;
  89   scm_simple_format (string_port,
  90                      scm_from_locale_string ("~A:~S:~S: ~A"),
  91                      scm_list_4 (fn,
  92                                  scm_from_int (SCM_LINUM (port) + 1),
  93                                  scm_from_int (SCM_COL (port) + 1),
  94                                  scm_from_locale_string (message)));
  95
  96   string = scm_get_output_string (string_port);
  97   scm_close_output_port (string_port);
  98   scm_error_scm (scm_from_locale_symbol ("read-error"),
  99                  function? scm_from_locale_string (function) : SCM_BOOL_F,
 100                  string,
 101                  arg,
 102                  SCM_BOOL_F);
 103 }
 104
 105
 106 SCM_DEFINE (scm_read_options, "read-options-interface", 0, 1, 0,
 107             (SCM setting),
 108             "Option interface for the read options. Instead of using\n"
 109             "this procedure directly, use the procedures @code{read-enable},\n"
 110             "@code{read-disable}, @code{read-set!} and @code{read-options}.")
 111 #define FUNC_NAME s_scm_read_options
 112 {
 113   SCM ans = scm_options (setting,
 114                          scm_read_opts,
 115                          SCM_N_READ_OPTIONS,
 116                          FUNC_NAME);
 117   if (SCM_COPY_SOURCE_P)
 118     SCM_RECORD_POSITIONS_P = 1;
 119   return ans;
 120 }
 121 #undef FUNC_NAME
 122
 123 /* An association list mapping extra hash characters to procedures.  */
 124 static SCM *scm_read_hash_procedures;
 125
 126 SCM_DEFINE (scm_read, "read", 0, 1, 0,
 127             (SCM port),
 128             "Read an s-expression from the input port @var{port}, or from\n"
 129             "the current input port if @var{port} is not specified.\n"
 130             "Any whitespace before the next token is discarded.")
 131 #define FUNC_NAME s_scm_read
 132 {
 133   int c;
 134   SCM tok_buf, copy;
 135
 136   if (SCM_UNBNDP (port))
 137     port = scm_cur_inp;
 138   SCM_VALIDATE_OPINPORT (1, port);
 139
 140   c = scm_flush_ws (port, (char *) NULL);
 141   if (EOF == c)
 142     return SCM_EOF_VAL;
 143   scm_ungetc (c, port);
 144
 145   tok_buf = scm_c_make_string (30, SCM_UNDEFINED);
 146   return scm_lreadr (&tok_buf, port, &copy);
 147 }
 148 #undef FUNC_NAME
 149
 150
 151
 152 char *
 153 scm_grow_tok_buf (SCM *tok_buf)
 154 {
 155   size_t oldlen = scm_i_string_length (*tok_buf);
 156   const char *olddata = scm_i_string_chars (*tok_buf);
 157   char *newdata;
 158   SCM newstr = scm_i_make_string (2 * oldlen, &newdata);
 159   size_t i;
 160
 161   for (i = 0; i != oldlen; ++i)
 162     newdata[i] = olddata[i];
 163
 164   *tok_buf = newstr;
 165   return newdata;
 166 }
 167
 168 /* Consume an SCSH-style block comment.  Assume that we've already
 169    read the initial `#!', and eat characters until we get a
 170    exclamation-point/sharp-sign sequence.
 171 */
 172
 173 static void
 174 skip_scsh_block_comment (SCM port)
 175 {
 176   int bang_seen = 0;
 177
 178   for (;;)
 179     {
 180       int c = scm_getc (port);
 181
 182       if (c == EOF)
 183         scm_i_input_error ("skip_block_comment", port,
 184                            "unterminated `#! ... !#' comment", SCM_EOL);
 185
 186       if (c == '!')
 187         bang_seen = 1;
 188       else if (c == '#' && bang_seen)
 189         return;
 190       else
 191         bang_seen = 0;
 192     }
 193 }
 194
 195 int
 196 scm_flush_ws (SCM port, const char *eoferr)
 197 {
 198   register int c;
 199   while (1)
 200     switch (c = scm_getc (port))
 201       {
 202       case EOF:
 203       goteof:
 204         if (eoferr)
 205           {
 206             scm_i_input_error (eoferr,
 207                                port,
 208                                "end of file",
 209                                SCM_EOL);
 210           }
 211         return c;
 212       case ';':
 213       lp:
 214         switch (c = scm_getc (port))
 215           {
 216           case EOF:
 217             goto goteof;
 218           default:
 219             goto lp;
 220           case SCM_LINE_INCREMENTORS:
 221             break;
 222           }
 223         break;
 224       case '#':
 225         switch (c = scm_getc (port))
 226           {
 227           case EOF:
 228             eoferr = "read_sharp";
 229             goto goteof;
 230           case '!':
 231             skip_scsh_block_comment (port);
 232             break;
 233           default:
 234             scm_ungetc (c, port);
 235             return '#';
 236           }
 237         break;
 238       case SCM_LINE_INCREMENTORS:
 239       case SCM_SINGLE_SPACES:
 240       case '\t':
 241         break;
 242       default:
 243         return c;
 244       }
 245 }
 246
 247
 248
 249 int
 250 scm_casei_streq (char *s1, char *s2)
 251 {
 252   while (*s1 && *s2)
 253     if (scm_c_downcase((int)*s1) != scm_c_downcase((int)*s2))
 254       return 0;
 255     else
 256       {
 257         ++s1;
 258         ++s2;
 259       }
 260   return !(*s1 || *s2);
 261 }
 262
 263 static int
 264 scm_i_casei_streq (const char *s1, const char *s2, size_t len2)
 265 {
 266   while (*s1 && len2 > 0)
 267     if (scm_c_downcase((int)*s1) != scm_c_downcase((int)*s2))
 268       return 0;
 269     else
 270       {
 271         ++s1;
 272         ++s2;
 273         --len2;
 274       }
 275   return !(*s1 || len2 > 0);
 276 }
 277
 278 /* recsexpr is used when recording expressions
 279  * constructed by read:sharp.
 280  */
 281 static SCM
 282 recsexpr (SCM obj, long line, int column, SCM filename)
 283 {
 284   if (!scm_is_pair(obj)) {
 285     return obj;
 286   } else {
 287     SCM tmp = obj, copy;
 288     /* If this sexpr is visible in the read:sharp source, we want to
 289        keep that information, so only record non-constant cons cells
 290        which haven't previously been read by the reader. */
 291     if (scm_is_false (scm_whash_lookup (scm_source_whash, obj)))
 292       {
 293         if (SCM_COPY_SOURCE_P)
 294           {
 295             copy = scm_cons (recsexpr (SCM_CAR (obj), line, column, filename),
 296                              SCM_UNDEFINED);
 297             while ((tmp = SCM_CDR (tmp)) && scm_is_pair (tmp))
 298               {
 299                 SCM_SETCDR (copy, scm_cons (recsexpr (SCM_CAR (tmp),
 300                                                       line,
 301                                                       column,
 302                                                       filename),
 303                                             SCM_UNDEFINED));
 304                 copy = SCM_CDR (copy);
 305               }
 306             SCM_SETCDR (copy, tmp);
 307           }
 308         else
 309           {
 310             recsexpr (SCM_CAR (obj), line, column, filename);
 311             while ((tmp = SCM_CDR (tmp)) && scm_is_pair (tmp))
 312               recsexpr (SCM_CAR (tmp), line, column, filename);
 313             copy = SCM_UNDEFINED;
 314           }
 315         scm_whash_insert (scm_source_whash,
 316                           obj,
 317                           scm_make_srcprops (line,
 318                                              column,
 319                                              filename,
 320                                              copy,
 321                                              SCM_EOL));
 322       }
 323     return obj;
 324   }
 325 }
 326
 327
 328 static SCM scm_get_hash_procedure(int c);
 329 static SCM scm_i_lreadparen (SCM *, SCM, char *, SCM *, char);
 330
 331 static char s_list[]="list";
 332 static char s_vector[]="vector";
 333
 334 SCM
 335 scm_lreadr (SCM *tok_buf, SCM port, SCM *copy)
 336 #define FUNC_NAME "scm_lreadr"
 337 {
 338   int c;
 339   size_t j;
 340   SCM p;
 341
 342  tryagain:
 343   c = scm_flush_ws (port, s_scm_read);
 344   switch (c)
 345     {
 346     case EOF:
 347       return SCM_EOF_VAL;
 348
 349     case '(':
 350       return SCM_RECORD_POSITIONS_P
 351         ? scm_lreadrecparen (tok_buf, port, s_list, copy)
 352         : scm_i_lreadparen (tok_buf, port, s_list, copy, ')');
 353     case ')':
 354       scm_i_input_error (FUNC_NAME, port,"unexpected \")\"", SCM_EOL);
 355       goto tryagain;
 356
 357 #if SCM_ENABLE_ELISP
 358     case '[':
 359       if (SCM_ELISP_VECTORS_P)
 360         {
 361           p = scm_i_lreadparen (tok_buf, port, s_vector, copy, ']');
 362           return scm_is_null (p) ? scm_nullvect : scm_vector (p);
 363         }
 364       goto read_token;
 365 #endif
 366     case '\'':
 367       p = scm_sym_quote;
 368       goto recquote;
 369     case '`':
 370       p = scm_sym_quasiquote;
 371       goto recquote;
 372     case ',':
 373       c = scm_getc (port);
 374       if ('@' == c)
 375         p = scm_sym_uq_splicing;
 376       else
 377         {
 378           scm_ungetc (c, port);
 379           p = scm_sym_unquote;
 380         }
 381     recquote:
 382       p = scm_cons2 (p,
 383                      scm_lreadr (tok_buf, port, copy),
 384                      SCM_EOL);
 385       if (SCM_RECORD_POSITIONS_P)
 386         scm_whash_insert (scm_source_whash,
 387                           p,
 388                           scm_make_srcprops (SCM_LINUM (port),
 389                                              SCM_COL (port) - 1,
 390                                              SCM_FILENAME (port),
 391                                              SCM_COPY_SOURCE_P
 392                                              ? (*copy = scm_cons2 (SCM_CAR (p),
 393                                                                    SCM_CAR (SCM_CDR (p)),
 394                                                                    SCM_EOL))
 395                                              : SCM_UNDEFINED,
 396                                              SCM_EOL));
 397       return p;
 398     case '#':
 399       c = scm_getc (port);
 400
 401       {
 402         /* Check for user-defined hash procedure first, to allow
 403            overriding of builtin hash read syntaxes.  */
 404         SCM sharp = scm_get_hash_procedure (c);
 405         if (scm_is_true (sharp))
 406           {
 407             int line = SCM_LINUM (port);
 408             int column = SCM_COL (port) - 2;
 409             SCM got;
 410
 411             got = scm_call_2 (sharp, SCM_MAKE_CHAR (c), port);
 412             if (scm_is_eq (got, SCM_UNSPECIFIED))
 413               goto handle_sharp;
 414             if (SCM_RECORD_POSITIONS_P)
 415               return *copy = recsexpr (got, line, column,
 416                                        SCM_FILENAME (port));
 417             else
 418               return got;
 419           }
 420       }
 421     handle_sharp:
 422       switch (c)
 423         {
 424           /* Vector, arrays, both uniform and not are handled by this
 425              one function.  It also disambiguates between '#f' and
 426              '#f32' and '#f64'.
 427           */
 428         case '0': case '1': case '2': case '3': case '4':
 429         case '5': case '6': case '7': case '8': case '9':
 430         case 'u': case 's': case 'f':
 431         case '@':
 432         case '(':
 433 #if SCM_ENABLE_DEPRECATED
 434           /* See below for 'i' and 'e'. */
 435         case 'a':
 436         case 'c':
 437         case 'y':
 438         case 'h':
 439         case 'l':
 440 #endif
 441           return scm_i_read_array (port, c);
 442
 443         case 't':
 444         case 'T':
 445           return SCM_BOOL_T;
 446
 447         case 'F':
 448           /* See above for lower case 'f'. */
 449           return SCM_BOOL_F;
 450
 451
 452         case 'i':
 453         case 'e':
 454 #if SCM_ENABLE_DEPRECATED
 455           {
 456             /* When next char is '(', it really is an old-style
 457                uniform array. */
 458             int next_c = scm_getc (port);
 459             if (next_c != EOF)
 460               scm_ungetc (next_c, port);
 461             if (next_c == '(')
 462               return scm_i_read_array (port, c);
 463             /* Fall through. */
 464           }
 465 #endif
 466         case 'b':
 467         case 'B':
 468         case 'o':
 469         case 'O':
 470         case 'd':
 471         case 'D':
 472         case 'x':
 473         case 'X':
 474         case 'I':
 475         case 'E':
 476           scm_ungetc (c, port);
 477           c = '#';
 478           goto num;
 479
 480         case '!':
 481           /* should never happen, #!...!# block comments are skipped
 482              over in scm_flush_ws. */
 483           abort ();
 484
 485         case '*':
 486           j = scm_read_token (c, tok_buf, port, 0);
 487           p = scm_istr2bve (scm_c_substring_shared (*tok_buf, 1, j));
 488           if (scm_is_true (p))
 489             return p;
 490           else
 491             goto unkshrp;
 492
 493         case '{':
 494           j = scm_read_token (c, tok_buf, port, 1);
 495           return scm_string_to_symbol (scm_c_substring_copy (*tok_buf, 0, j));
 496
 497         case '\\':
 498           c = scm_getc (port);
 499           j = scm_read_token (c, tok_buf, port, 0);
 500           if (j == 1)
 501             return SCM_MAKE_CHAR (c);
 502           if (c >= '0' && c < '8')
 503             {
 504               /* Dirk:FIXME::  This type of character syntax is not R5RS
 505                * compliant.  Further, it should be verified that the constant
 506                * does only consist of octal digits.  Finally, it should be
 507                * checked whether the resulting fixnum is in the range of
 508                * characters.  */
 509               p = scm_i_mem2number (scm_i_string_chars (*tok_buf), j, 8);
 510               if (SCM_I_INUMP (p))
 511                 return SCM_MAKE_CHAR (SCM_I_INUM (p));
 512             }
 513           for (c = 0; c < scm_n_charnames; c++)
 514             if (scm_charnames[c]
 515                 && (scm_i_casei_streq (scm_charnames[c],
 516                                        scm_i_string_chars (*tok_buf), j)))
 517               return SCM_MAKE_CHAR (scm_charnums[c]);
 518           scm_i_input_error (FUNC_NAME, port, "unknown character name ~a",
 519                              scm_list_1 (scm_c_substring (*tok_buf, 0, j)));
 520
 521           /* #:SYMBOL is a syntax for keywords supported in all contexts.  */
 522         case ':':
 523           return scm_symbol_to_keyword (scm_read (port));
 524
 525         default:
 526         callshrp:
 527           {
 528             SCM sharp = scm_get_hash_procedure (c);
 529
 530             if (scm_is_true (sharp))
 531               {
 532                 int line = SCM_LINUM (port);
 533                 int column = SCM_COL (port) - 2;
 534                 SCM got;
 535
 536                 got = scm_call_2 (sharp, SCM_MAKE_CHAR (c), port);
 537                 if (scm_is_eq (got, SCM_UNSPECIFIED))
 538                   goto unkshrp;
 539                 if (SCM_RECORD_POSITIONS_P)
 540                   return *copy = recsexpr (got, line, column,
 541                                            SCM_FILENAME (port));
 542                 else
 543                   return got;
 544               }
 545           }
 546         unkshrp:
 547         scm_i_input_error (FUNC_NAME, port, "Unknown # object: ~S",
 548                            scm_list_1 (SCM_MAKE_CHAR (c)));
 549         }
 550
 551     case '"':
 552       j = 0;
 553       while ('"' != (c = scm_getc (port)))
 554         {
 555           if (c == EOF)
 556             str_eof: scm_i_input_error (FUNC_NAME, port,
 557                                         "end of file in string constant",
 558                                         SCM_EOL);
 559
 560           while (j + 2 >= scm_i_string_length (*tok_buf))
 561             scm_grow_tok_buf (tok_buf);
 562
 563           if (c == '\\')
 564             switch (c = scm_getc (port))
 565               {
 566               case EOF:
 567                 goto str_eof;
 568               case '"':
 569               case '\\':
 570                 break;
 571 #if SCM_ENABLE_ELISP
 572               case '(':
 573               case ')':
 574                 if (SCM_ESCAPED_PARENS_P)
 575                   break;
 576                 goto bad_escaped;
 577 #endif
 578               case '\n':
 579                 continue;
 580               case '0':
 581                 c = '\0';
 582                 break;
 583               case 'f':
 584                 c = '\f';
 585                 break;
 586               case 'n':
 587                 c = '\n';
 588                 break;
 589               case 'r':
 590                 c = '\r';
 591                 break;
 592               case 't':
 593                 c = '\t';
 594                 break;
 595               case 'a':
 596                 c = '\007';
 597                 break;
 598               case 'v':
 599                 c = '\v';
 600                 break;
 601               case 'x':
 602                 {
 603                   int a, b;
 604                   a = scm_getc (port);
 605                   if (a == EOF) goto str_eof;
 606                   b = scm_getc (port);
 607                   if (b == EOF) goto str_eof;
 608                   if      ('0' <= a && a <= '9') a -= '0';
 609                   else if ('A' <= a && a <= 'F') a = a - 'A' + 10;
 610                   else if ('a' <= a && a <= 'f') a = a - 'a' + 10;
 611                   else goto bad_escaped;
 612                   if      ('0' <= b && b <= '9') b -= '0';
 613                   else if ('A' <= b && b <= 'F') b = b - 'A' + 10;
 614                   else if ('a' <= b && b <= 'f') b = b - 'a' + 10;
 615                   else goto bad_escaped;
 616                   c = a * 16 + b;
 617                   break;
 618                 }
 619               default:
 620               bad_escaped:
 621                 scm_i_input_error(FUNC_NAME, port,
 622                                   "illegal character in escape sequence: ~S",
 623                                   scm_list_1 (SCM_MAKE_CHAR (c)));
 624               }
 625           scm_c_string_set_x (*tok_buf, j, SCM_MAKE_CHAR (c));
 626           ++j;
 627         }
 628       if (j == 0)
 629         return scm_nullstr;
 630
 631       /* Change this to scm_c_substring_read_only when
 632          SCM_STRING_CHARS has been removed.
 633       */
 634       return scm_c_substring_copy (*tok_buf, 0, j);
 635
 636     case '0': case '1': case '2': case '3': case '4':
 637     case '5': case '6': case '7': case '8': case '9':
 638     case '.':
 639     case '-':
 640     case '+':
 641     num:
 642       j = scm_read_token (c, tok_buf, port, 0);
 643       if (j == 1 && (c == '+' || c == '-'))
 644         /* Shortcut:  Detected symbol '+ or '- */
 645         goto tok;
 646
 647       p = scm_i_mem2number (scm_i_string_chars (*tok_buf), j, 10);
 648       if (scm_is_true (p))
 649         return p;
 650       if (c == '#')
 651         {
 652           if ((j == 2) && (scm_getc (port) == '('))
 653             {
 654               scm_ungetc ('(', port);
 655               c = scm_i_string_chars (*tok_buf)[1];
 656               goto callshrp;
 657             }
 658           scm_i_input_error (FUNC_NAME, port, "unknown # object", SCM_EOL);
 659         }
 660       goto tok;
 661
 662     case ':':
 663       if (scm_is_eq (SCM_PACK (SCM_KEYWORD_STYLE), scm_keyword_prefix))
 664         return scm_symbol_to_keyword (scm_read (port));
 665
 666       /* fallthrough */
 667     default:
 668 #if SCM_ENABLE_ELISP
 669     read_token:
 670 #endif
 671       j = scm_read_token (c, tok_buf, port, 0);
 672       /* fallthrough */
 673
 674     tok:
 675       return scm_string_to_symbol (scm_c_substring (*tok_buf, 0, j));
 676     }
 677 }
 678 #undef FUNC_NAME
 679
 680
 681 #ifdef _UNICOS
 682 _Pragma ("noopt");              /* # pragma _CRI noopt */
 683 #endif
 684
 685 size_t
 686 scm_read_token (int ic, SCM *tok_buf, SCM port, int weird)
 687 {
 688   size_t j;
 689   int c;
 690
 691   c = (SCM_CASE_INSENSITIVE_P ? scm_c_downcase(ic) : ic);
 692
 693   if (weird)
 694     j = 0;
 695   else
 696     {
 697       j = 0;
 698       while (j + 2 >= scm_i_string_length (*tok_buf))
 699         scm_grow_tok_buf (tok_buf);
 700       scm_c_string_set_x (*tok_buf, j, SCM_MAKE_CHAR (c));
 701       ++j;
 702     }
 703
 704   while (1)
 705     {
 706       while (j + 2 >= scm_i_string_length (*tok_buf))
 707         scm_grow_tok_buf (tok_buf);
 708       c = scm_getc (port);
 709       switch (c)
 710         {
 711         case '(':
 712         case ')':
 713 #if SCM_ENABLE_ELISP
 714         case '[':
 715         case ']':
 716 #endif
 717         case '"':
 718         case ';':
 719         case SCM_WHITE_SPACES:
 720         case SCM_LINE_INCREMENTORS:
 721           if (weird
 722 #if SCM_ENABLE_ELISP
 723               || ((!SCM_ELISP_VECTORS_P) && ((c == '[') || (c == ']')))
 724 #endif
 725               )
 726             goto default_case;
 727
 728           scm_ungetc (c, port);
 729         case EOF:
 730         eof_case:
 731           return j;
 732         case '\\':
 733           if (!weird)
 734             goto default_case;
 735           else
 736             {
 737               c = scm_getc (port);
 738               if (c == EOF)
 739                 goto eof_case;
 740               else
 741                 goto default_case;
 742             }
 743         case '}':
 744           if (!weird)
 745             goto default_case;
 746
 747           c = scm_getc (port);
 748           if (c == '#')
 749             {
 750               return j;
 751             }
 752           else
 753             {
 754               scm_ungetc (c, port);
 755               c = '}';
 756               goto default_case;
 757             }
 758
 759         default:
 760         default_case:
 761           {
 762             c = (SCM_CASE_INSENSITIVE_P ? scm_c_downcase(c) : c);
 763             scm_c_string_set_x (*tok_buf, j, SCM_MAKE_CHAR (c));
 764             ++j;
 765           }
 766
 767         }
 768     }
 769 }
 770
 771 #ifdef _UNICOS
 772 _Pragma ("opt");                /* # pragma _CRI opt */
 773 #endif
 774
 775 static SCM
 776 scm_i_lreadparen (SCM *tok_buf, SCM port, char *name, SCM *copy, char term_char)
 777 #define FUNC_NAME "scm_i_lreadparen"
 778 {
 779   SCM tmp;
 780   SCM tl;
 781   SCM ans;
 782   int c;
 783
 784   c = scm_flush_ws (port, name);
 785   if (term_char == c)
 786     return SCM_EOL;
 787   scm_ungetc (c, port);
 788   if (scm_is_eq (scm_sym_dot, (tmp = scm_lreadr (tok_buf, port, copy))))
 789     {
 790       ans = scm_lreadr (tok_buf, port, copy);
 791     closeit:
 792       if (term_char != (c = scm_flush_ws (port, name)))
 793         scm_i_input_error (FUNC_NAME, port, "missing close paren", SCM_EOL);
 794       return ans;
 795     }
 796   ans = tl = scm_cons (tmp, SCM_EOL);
 797   while (term_char != (c = scm_flush_ws (port, name)))
 798     {
 799       scm_ungetc (c, port);
 800       if (scm_is_eq (scm_sym_dot, (tmp = scm_lreadr (tok_buf, port, copy))))
 801         {
 802           SCM_SETCDR (tl, scm_lreadr (tok_buf, port, copy));
 803           goto closeit;
 804         }
 805       SCM_SETCDR (tl, scm_cons (tmp, SCM_EOL));
 806       tl = SCM_CDR (tl);
 807     }
 808   return ans;
 809 }
 810 #undef FUNC_NAME
 811
 812
 813 SCM
 814 scm_lreadrecparen (SCM *tok_buf, SCM port, char *name, SCM *copy)
 815 #define FUNC_NAME "scm_lreadrecparen"
 816 {
 817   register int c;
 818   register SCM tmp;
 819   register SCM tl, tl2 = SCM_EOL;
 820   SCM ans, ans2 = SCM_EOL;
 821   /* Need to capture line and column numbers here. */
 822   int line = SCM_LINUM (port);
 823   int column = SCM_COL (port) - 1;
 824
 825   c = scm_flush_ws (port, name);
 826   if (')' == c)
 827     return SCM_EOL;
 828   scm_ungetc (c, port);
 829   if (scm_is_eq (scm_sym_dot, (tmp = scm_lreadr (tok_buf, port, copy))))
 830     {
 831       ans = scm_lreadr (tok_buf, port, copy);
 832       if (')' != (c = scm_flush_ws (port, name)))
 833         scm_i_input_error (FUNC_NAME, port, "missing close paren", SCM_EOL);
 834       return ans;
 835     }
 836   /* Build the head of the list structure. */
 837   ans = tl = scm_cons (tmp, SCM_EOL);
 838   if (SCM_COPY_SOURCE_P)
 839     ans2 = tl2 = scm_cons (scm_is_pair (tmp)
 840                            ? *copy
 841                            : tmp,
 842                            SCM_EOL);
 843   while (')' != (c = scm_flush_ws (port, name)))
 844     {
 845       SCM new_tail;
 846
 847       scm_ungetc (c, port);
 848       if (scm_is_eq (scm_sym_dot, (tmp = scm_lreadr (tok_buf, port, copy))))
 849         {
 850           SCM_SETCDR (tl, tmp = scm_lreadr (tok_buf, port, copy));
 851           if (SCM_COPY_SOURCE_P)
 852             SCM_SETCDR (tl2, scm_cons (scm_is_pair (tmp)
 853                                        ? *copy
 854                                        : tmp,
 855                                        SCM_EOL));
 856           if (')' != (c = scm_flush_ws (port, name)))
 857             scm_i_input_error (FUNC_NAME, port,
 858                                "missing close paren", SCM_EOL);
 859           goto exit;
 860         }
 861
 862       new_tail = scm_cons (tmp, SCM_EOL);
 863       SCM_SETCDR (tl, new_tail);
 864       tl = new_tail;
 865
 866       if (SCM_COPY_SOURCE_P)
 867         {
 868           SCM new_tail2 = scm_cons (scm_is_pair (tmp) ? *copy : tmp, SCM_EOL);
 869           SCM_SETCDR (tl2, new_tail2);
 870           tl2 = new_tail2;
 871         }
 872     }
 873 exit:
 874   scm_whash_insert (scm_source_whash,
 875                     ans,
 876                     scm_make_srcprops (line,
 877                                        column,
 878                                        SCM_FILENAME (port),
 879                                        SCM_COPY_SOURCE_P
 880                                        ? *copy = ans2
 881                                        : SCM_UNDEFINED,
 882                                        SCM_EOL));
 883   return ans;
 884 }
 885 #undef FUNC_NAME
 886
 887
 888 \f
 889
 890 /* Manipulate the read-hash-procedures alist.  This could be written in
 891    Scheme, but maybe it will also be used by C code during initialisation.  */
 892 SCM_DEFINE (scm_read_hash_extend, "read-hash-extend", 2, 0, 0,
 893             (SCM chr, SCM proc),
 894             "Install the procedure @var{proc} for reading expressions\n"
 895             "starting with the character sequence @code{#} and @var{chr}.\n"
 896             "@var{proc} will be called with two arguments:  the character\n"
 897             "@var{chr} and the port to read further data from. The object\n"
 898             "returned will be the return value of @code{read}.")
 899 #define FUNC_NAME s_scm_read_hash_extend
 900 {
 901   SCM this;
 902   SCM prev;
 903
 904   SCM_VALIDATE_CHAR (1, chr);
 905   SCM_ASSERT (scm_is_false (proc)
 906               || scm_is_eq (scm_procedure_p (proc), SCM_BOOL_T),
 907               proc, SCM_ARG2, FUNC_NAME);
 908
 909   /* Check if chr is already in the alist.  */
 910   this = *scm_read_hash_procedures;
 911   prev = SCM_BOOL_F;
 912   while (1)
 913     {
 914       if (scm_is_null (this))
 915         {
 916           /* not found, so add it to the beginning.  */
 917           if (scm_is_true (proc))
 918             {
 919               *scm_read_hash_procedures =
 920                 scm_cons (scm_cons (chr, proc), *scm_read_hash_procedures);
 921             }
 922           break;
 923         }
 924       if (scm_is_eq (chr, SCM_CAAR (this)))
 925         {
 926           /* already in the alist.  */
 927           if (scm_is_false (proc))
 928             {
 929               /* remove it.  */
 930               if (scm_is_false (prev))
 931                 {
 932                   *scm_read_hash_procedures =
 933                     SCM_CDR (*scm_read_hash_procedures);
 934                 }
 935               else
 936                 scm_set_cdr_x (prev, SCM_CDR (this));
 937             }
 938           else
 939             {
 940               /* replace it.  */
 941               scm_set_cdr_x (SCM_CAR (this), proc);
 942             }
 943           break;
 944         }
 945       prev = this;
 946       this = SCM_CDR (this);
 947     }
 948
 949   return SCM_UNSPECIFIED;
 950 }
 951 #undef FUNC_NAME
 952
 953 /* Recover the read-hash procedure corresponding to char c.  */
 954 static SCM
 955 scm_get_hash_procedure (int c)
 956 {
 957   SCM rest = *scm_read_hash_procedures;
 958
 959   while (1)
 960     {
 961       if (scm_is_null (rest))
 962         return SCM_BOOL_F;
 963
 964       if (SCM_CHAR (SCM_CAAR (rest)) == c)
 965         return SCM_CDAR (rest);
 966
 967       rest = SCM_CDR (rest);
 968     }
 969 }
 970
 971 void
 972 scm_init_read ()
 973 {
 974   scm_read_hash_procedures =
 975     SCM_VARIABLE_LOC (scm_c_define ("read-hash-procedures", SCM_EOL));
 976
 977   scm_init_opts (scm_read_options, scm_read_opts, SCM_N_READ_OPTIONS);
 978 #include "libguile/read.x"
 979 }
 980
 981 /*
 982   Local Variables:
 983   c-file-style: "gnu"
 984   End:
 985 */