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 #if SCM_HAVE_ARRAYS
 486         case '*':
 487           j = scm_read_token (c, tok_buf, port, 0);
 488           p = scm_istr2bve (scm_c_substring_shared (*tok_buf, 1, j));
 489           if (scm_is_true (p))
 490             return p;
 491           else
 492             goto unkshrp;
 493 #endif
 494
 495         case '{':
 496           j = scm_read_token (c, tok_buf, port, 1);
 497           return scm_string_to_symbol (scm_c_substring_copy (*tok_buf, 0, j));
 498
 499         case '\\':
 500           c = scm_getc (port);
 501           j = scm_read_token (c, tok_buf, port, 0);
 502           if (j == 1)
 503             return SCM_MAKE_CHAR (c);
 504           if (c >= '0' && c < '8')
 505             {
 506               /* Dirk:FIXME::  This type of character syntax is not R5RS
 507                * compliant.  Further, it should be verified that the constant
 508                * does only consist of octal digits.  Finally, it should be
 509                * checked whether the resulting fixnum is in the range of
 510                * characters.  */
 511               p = scm_i_mem2number (scm_i_string_chars (*tok_buf), j, 8);
 512               if (SCM_I_INUMP (p))
 513                 return SCM_MAKE_CHAR (SCM_I_INUM (p));
 514             }
 515           for (c = 0; c < scm_n_charnames; c++)
 516             if (scm_charnames[c]
 517                 && (scm_i_casei_streq (scm_charnames[c],
 518                                        scm_i_string_chars (*tok_buf), j)))
 519               return SCM_MAKE_CHAR (scm_charnums[c]);
 520           scm_i_input_error (FUNC_NAME, port, "unknown character name ~a",
 521                              scm_list_1 (scm_c_substring (*tok_buf, 0, j)));
 522
 523           /* #:SYMBOL is a syntax for keywords supported in all contexts.  */
 524         case ':':
 525           return scm_symbol_to_keyword (scm_read (port));
 526
 527         default:
 528         callshrp:
 529           {
 530             SCM sharp = scm_get_hash_procedure (c);
 531
 532             if (scm_is_true (sharp))
 533               {
 534                 int line = SCM_LINUM (port);
 535                 int column = SCM_COL (port) - 2;
 536                 SCM got;
 537
 538                 got = scm_call_2 (sharp, SCM_MAKE_CHAR (c), port);
 539                 if (scm_is_eq (got, SCM_UNSPECIFIED))
 540                   goto unkshrp;
 541                 if (SCM_RECORD_POSITIONS_P)
 542                   return *copy = recsexpr (got, line, column,
 543                                            SCM_FILENAME (port));
 544                 else
 545                   return got;
 546               }
 547           }
 548         unkshrp:
 549         scm_i_input_error (FUNC_NAME, port, "Unknown # object: ~S",
 550                            scm_list_1 (SCM_MAKE_CHAR (c)));
 551         }
 552
 553     case '"':
 554       j = 0;
 555       while ('"' != (c = scm_getc (port)))
 556         {
 557           if (c == EOF)
 558             str_eof: scm_i_input_error (FUNC_NAME, port,
 559                                         "end of file in string constant",
 560                                         SCM_EOL);
 561
 562           while (j + 2 >= scm_i_string_length (*tok_buf))
 563             scm_grow_tok_buf (tok_buf);
 564
 565           if (c == '\\')
 566             switch (c = scm_getc (port))
 567               {
 568               case EOF:
 569                 goto str_eof;
 570               case '"':
 571               case '\\':
 572                 break;
 573 #if SCM_ENABLE_ELISP
 574               case '(':
 575               case ')':
 576                 if (SCM_ESCAPED_PARENS_P)
 577                   break;
 578                 goto bad_escaped;
 579 #endif
 580               case '\n':
 581                 continue;
 582               case '0':
 583                 c = '\0';
 584                 break;
 585               case 'f':
 586                 c = '\f';
 587                 break;
 588               case 'n':
 589                 c = '\n';
 590                 break;
 591               case 'r':
 592                 c = '\r';
 593                 break;
 594               case 't':
 595                 c = '\t';
 596                 break;
 597               case 'a':
 598                 c = '\007';
 599                 break;
 600               case 'v':
 601                 c = '\v';
 602                 break;
 603               case 'x':
 604                 {
 605                   int a, b;
 606                   a = scm_getc (port);
 607                   if (a == EOF) goto str_eof;
 608                   b = scm_getc (port);
 609                   if (b == EOF) goto str_eof;
 610                   if      ('0' <= a && a <= '9') a -= '0';
 611                   else if ('A' <= a && a <= 'F') a = a - 'A' + 10;
 612                   else if ('a' <= a && a <= 'f') a = a - 'a' + 10;
 613                   else goto bad_escaped;
 614                   if      ('0' <= b && b <= '9') b -= '0';
 615                   else if ('A' <= b && b <= 'F') b = b - 'A' + 10;
 616                   else if ('a' <= b && b <= 'f') b = b - 'a' + 10;
 617                   else goto bad_escaped;
 618                   c = a * 16 + b;
 619                   break;
 620                 }
 621               default:
 622               bad_escaped:
 623                 scm_i_input_error(FUNC_NAME, port,
 624                                   "illegal character in escape sequence: ~S",
 625                                   scm_list_1 (SCM_MAKE_CHAR (c)));
 626               }
 627           scm_c_string_set_x (*tok_buf, j, SCM_MAKE_CHAR (c));
 628           ++j;
 629         }
 630       if (j == 0)
 631         return scm_nullstr;
 632
 633       /* Change this to scm_c_substring_read_only when
 634          SCM_STRING_CHARS has been removed.
 635       */
 636       return scm_c_substring_copy (*tok_buf, 0, j);
 637
 638     case '0': case '1': case '2': case '3': case '4':
 639     case '5': case '6': case '7': case '8': case '9':
 640     case '.':
 641     case '-':
 642     case '+':
 643     num:
 644       j = scm_read_token (c, tok_buf, port, 0);
 645       if (j == 1 && (c == '+' || c == '-'))
 646         /* Shortcut:  Detected symbol '+ or '- */
 647         goto tok;
 648
 649       p = scm_i_mem2number (scm_i_string_chars (*tok_buf), j, 10);
 650       if (scm_is_true (p))
 651         return p;
 652       if (c == '#')
 653         {
 654           if ((j == 2) && (scm_getc (port) == '('))
 655             {
 656               scm_ungetc ('(', port);
 657               c = scm_i_string_chars (*tok_buf)[1];
 658               goto callshrp;
 659             }
 660           scm_i_input_error (FUNC_NAME, port, "unknown # object", SCM_EOL);
 661         }
 662       goto tok;
 663
 664     case ':':
 665       if (scm_is_eq (SCM_PACK (SCM_KEYWORD_STYLE), scm_keyword_prefix))
 666         return scm_symbol_to_keyword (scm_read (port));
 667
 668       /* fallthrough */
 669     default:
 670 #if SCM_ENABLE_ELISP
 671     read_token:
 672 #endif
 673       j = scm_read_token (c, tok_buf, port, 0);
 674       /* fallthrough */
 675
 676     tok:
 677       return scm_string_to_symbol (scm_c_substring (*tok_buf, 0, j));
 678     }
 679 }
 680 #undef FUNC_NAME
 681
 682
 683 #ifdef _UNICOS
 684 _Pragma ("noopt");              /* # pragma _CRI noopt */
 685 #endif
 686
 687 size_t
 688 scm_read_token (int ic, SCM *tok_buf, SCM port, int weird)
 689 {
 690   size_t j;
 691   int c;
 692
 693   c = (SCM_CASE_INSENSITIVE_P ? scm_c_downcase(ic) : ic);
 694
 695   if (weird)
 696     j = 0;
 697   else
 698     {
 699       j = 0;
 700       while (j + 2 >= scm_i_string_length (*tok_buf))
 701         scm_grow_tok_buf (tok_buf);
 702       scm_c_string_set_x (*tok_buf, j, SCM_MAKE_CHAR (c));
 703       ++j;
 704     }
 705
 706   while (1)
 707     {
 708       while (j + 2 >= scm_i_string_length (*tok_buf))
 709         scm_grow_tok_buf (tok_buf);
 710       c = scm_getc (port);
 711       switch (c)
 712         {
 713         case '(':
 714         case ')':
 715 #if SCM_ENABLE_ELISP
 716         case '[':
 717         case ']':
 718 #endif
 719         case '"':
 720         case ';':
 721         case SCM_WHITE_SPACES:
 722         case SCM_LINE_INCREMENTORS:
 723           if (weird
 724 #if SCM_ENABLE_ELISP
 725               || ((!SCM_ELISP_VECTORS_P) && ((c == '[') || (c == ']')))
 726 #endif
 727               )
 728             goto default_case;
 729
 730           scm_ungetc (c, port);
 731         case EOF:
 732         eof_case:
 733           return j;
 734         case '\\':
 735           if (!weird)
 736             goto default_case;
 737           else
 738             {
 739               c = scm_getc (port);
 740               if (c == EOF)
 741                 goto eof_case;
 742               else
 743                 goto default_case;
 744             }
 745         case '}':
 746           if (!weird)
 747             goto default_case;
 748
 749           c = scm_getc (port);
 750           if (c == '#')
 751             {
 752               return j;
 753             }
 754           else
 755             {
 756               scm_ungetc (c, port);
 757               c = '}';
 758               goto default_case;
 759             }
 760
 761         default:
 762         default_case:
 763           {
 764             c = (SCM_CASE_INSENSITIVE_P ? scm_c_downcase(c) : c);
 765             scm_c_string_set_x (*tok_buf, j, SCM_MAKE_CHAR (c));
 766             ++j;
 767           }
 768
 769         }
 770     }
 771 }
 772
 773 #ifdef _UNICOS
 774 _Pragma ("opt");                /* # pragma _CRI opt */
 775 #endif
 776
 777 static SCM
 778 scm_i_lreadparen (SCM *tok_buf, SCM port, char *name, SCM *copy, char term_char)
 779 #define FUNC_NAME "scm_i_lreadparen"
 780 {
 781   SCM tmp;
 782   SCM tl;
 783   SCM ans;
 784   int c;
 785
 786   c = scm_flush_ws (port, name);
 787   if (term_char == c)
 788     return SCM_EOL;
 789   scm_ungetc (c, port);
 790   if (scm_is_eq (scm_sym_dot, (tmp = scm_lreadr (tok_buf, port, copy))))
 791     {
 792       ans = scm_lreadr (tok_buf, port, copy);
 793     closeit:
 794       if (term_char != (c = scm_flush_ws (port, name)))
 795         scm_i_input_error (FUNC_NAME, port, "missing close paren", SCM_EOL);
 796       return ans;
 797     }
 798   ans = tl = scm_cons (tmp, SCM_EOL);
 799   while (term_char != (c = scm_flush_ws (port, name)))
 800     {
 801       scm_ungetc (c, port);
 802       if (scm_is_eq (scm_sym_dot, (tmp = scm_lreadr (tok_buf, port, copy))))
 803         {
 804           SCM_SETCDR (tl, scm_lreadr (tok_buf, port, copy));
 805           goto closeit;
 806         }
 807       SCM_SETCDR (tl, scm_cons (tmp, SCM_EOL));
 808       tl = SCM_CDR (tl);
 809     }
 810   return ans;
 811 }
 812 #undef FUNC_NAME
 813
 814
 815 SCM
 816 scm_lreadrecparen (SCM *tok_buf, SCM port, char *name, SCM *copy)
 817 #define FUNC_NAME "scm_lreadrecparen"
 818 {
 819   register int c;
 820   register SCM tmp;
 821   register SCM tl, tl2 = SCM_EOL;
 822   SCM ans, ans2 = SCM_EOL;
 823   /* Need to capture line and column numbers here. */
 824   int line = SCM_LINUM (port);
 825   int column = SCM_COL (port) - 1;
 826
 827   c = scm_flush_ws (port, name);
 828   if (')' == c)
 829     return SCM_EOL;
 830   scm_ungetc (c, port);
 831   if (scm_is_eq (scm_sym_dot, (tmp = scm_lreadr (tok_buf, port, copy))))
 832     {
 833       ans = scm_lreadr (tok_buf, port, copy);
 834       if (')' != (c = scm_flush_ws (port, name)))
 835         scm_i_input_error (FUNC_NAME, port, "missing close paren", SCM_EOL);
 836       return ans;
 837     }
 838   /* Build the head of the list structure. */
 839   ans = tl = scm_cons (tmp, SCM_EOL);
 840   if (SCM_COPY_SOURCE_P)
 841     ans2 = tl2 = scm_cons (scm_is_pair (tmp)
 842                            ? *copy
 843                            : tmp,
 844                            SCM_EOL);
 845   while (')' != (c = scm_flush_ws (port, name)))
 846     {
 847       SCM new_tail;
 848
 849       scm_ungetc (c, port);
 850       if (scm_is_eq (scm_sym_dot, (tmp = scm_lreadr (tok_buf, port, copy))))
 851         {
 852           SCM_SETCDR (tl, tmp = scm_lreadr (tok_buf, port, copy));
 853           if (SCM_COPY_SOURCE_P)
 854             SCM_SETCDR (tl2, scm_cons (scm_is_pair (tmp)
 855                                        ? *copy
 856                                        : tmp,
 857                                        SCM_EOL));
 858           if (')' != (c = scm_flush_ws (port, name)))
 859             scm_i_input_error (FUNC_NAME, port,
 860                                "missing close paren", SCM_EOL);
 861           goto exit;
 862         }
 863
 864       new_tail = scm_cons (tmp, SCM_EOL);
 865       SCM_SETCDR (tl, new_tail);
 866       tl = new_tail;
 867
 868       if (SCM_COPY_SOURCE_P)
 869         {
 870           SCM new_tail2 = scm_cons (scm_is_pair (tmp) ? *copy : tmp, SCM_EOL);
 871           SCM_SETCDR (tl2, new_tail2);
 872           tl2 = new_tail2;
 873         }
 874     }
 875 exit:
 876   scm_whash_insert (scm_source_whash,
 877                     ans,
 878                     scm_make_srcprops (line,
 879                                        column,
 880                                        SCM_FILENAME (port),
 881                                        SCM_COPY_SOURCE_P
 882                                        ? *copy = ans2
 883                                        : SCM_UNDEFINED,
 884                                        SCM_EOL));
 885   return ans;
 886 }
 887 #undef FUNC_NAME
 888
 889
 890 \f
 891
 892 /* Manipulate the read-hash-procedures alist.  This could be written in
 893    Scheme, but maybe it will also be used by C code during initialisation.  */
 894 SCM_DEFINE (scm_read_hash_extend, "read-hash-extend", 2, 0, 0,
 895             (SCM chr, SCM proc),
 896             "Install the procedure @var{proc} for reading expressions\n"
 897             "starting with the character sequence @code{#} and @var{chr}.\n"
 898             "@var{proc} will be called with two arguments:  the character\n"
 899             "@var{chr} and the port to read further data from. The object\n"
 900             "returned will be the return value of @code{read}.")
 901 #define FUNC_NAME s_scm_read_hash_extend
 902 {
 903   SCM this;
 904   SCM prev;
 905
 906   SCM_VALIDATE_CHAR (1, chr);
 907   SCM_ASSERT (scm_is_false (proc)
 908               || scm_is_eq (scm_procedure_p (proc), SCM_BOOL_T),
 909               proc, SCM_ARG2, FUNC_NAME);
 910
 911   /* Check if chr is already in the alist.  */
 912   this = *scm_read_hash_procedures;
 913   prev = SCM_BOOL_F;
 914   while (1)
 915     {
 916       if (scm_is_null (this))
 917         {
 918           /* not found, so add it to the beginning.  */
 919           if (scm_is_true (proc))
 920             {
 921               *scm_read_hash_procedures =
 922                 scm_cons (scm_cons (chr, proc), *scm_read_hash_procedures);
 923             }
 924           break;
 925         }
 926       if (scm_is_eq (chr, SCM_CAAR (this)))
 927         {
 928           /* already in the alist.  */
 929           if (scm_is_false (proc))
 930             {
 931               /* remove it.  */
 932               if (scm_is_false (prev))
 933                 {
 934                   *scm_read_hash_procedures =
 935                     SCM_CDR (*scm_read_hash_procedures);
 936                 }
 937               else
 938                 scm_set_cdr_x (prev, SCM_CDR (this));
 939             }
 940           else
 941             {
 942               /* replace it.  */
 943               scm_set_cdr_x (SCM_CAR (this), proc);
 944             }
 945           break;
 946         }
 947       prev = this;
 948       this = SCM_CDR (this);
 949     }
 950
 951   return SCM_UNSPECIFIED;
 952 }
 953 #undef FUNC_NAME
 954
 955 /* Recover the read-hash procedure corresponding to char c.  */
 956 static SCM
 957 scm_get_hash_procedure (int c)
 958 {
 959   SCM rest = *scm_read_hash_procedures;
 960
 961   while (1)
 962     {
 963       if (scm_is_null (rest))
 964         return SCM_BOOL_F;
 965
 966       if (SCM_CHAR (SCM_CAAR (rest)) == c)
 967         return SCM_CDAR (rest);
 968
 969       rest = SCM_CDR (rest);
 970     }
 971 }
 972
 973 void
 974 scm_init_read ()
 975 {
 976   scm_read_hash_procedures =
 977     SCM_VARIABLE_LOC (scm_c_define ("read-hash-procedures", SCM_EOL));
 978
 979   scm_init_opts (scm_read_options, scm_read_opts, SCM_N_READ_OPTIONS);
 980 #include "libguile/read.x"
 981 }
 982
 983 /*
 984   Local Variables:
 985   c-file-style: "gnu"
 986   End:
 987 */