/* Copyright (C) 1995, 1996, 1997, 1999, 2000, 2001, 2003, 2004, 2006, * 2007, 2008, 2009, 2010, 2011, 2012, 2014 Free Software Foundation, Inc. * * This library is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public License * as published by the Free Software Foundation; either version 3 of * the License, or (at your option) any later version. * * This library is distributed in the hope that it will be useful, but * WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with this library; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA * 02110-1301 USA */ #ifdef HAVE_CONFIG_H # include #endif #include #include #include #include #include #include #include #include #include "libguile/_scm.h" #include "libguile/bytevectors.h" #include "libguile/chars.h" #include "libguile/eval.h" #include "libguile/arrays.h" #include "libguile/bitvectors.h" #include "libguile/keywords.h" #include "libguile/alist.h" #include "libguile/srcprop.h" #include "libguile/hashtab.h" #include "libguile/hash.h" #include "libguile/ports.h" #include "libguile/fports.h" #include "libguile/root.h" #include "libguile/strings.h" #include "libguile/strports.h" #include "libguile/vectors.h" #include "libguile/validate.h" #include "libguile/srfi-4.h" #include "libguile/srfi-13.h" #include "libguile/read.h" #include "libguile/private-options.h" SCM_GLOBAL_SYMBOL (scm_sym_dot, "."); SCM_SYMBOL (scm_keyword_prefix, "prefix"); SCM_SYMBOL (scm_keyword_postfix, "postfix"); SCM_SYMBOL (sym_nil, "nil"); /* SRFI-105 curly infix expression support */ SCM_SYMBOL (sym_nfx, "$nfx$"); SCM_SYMBOL (sym_bracket_list, "$bracket-list$"); SCM_SYMBOL (sym_bracket_apply, "$bracket-apply$"); scm_t_option scm_read_opts[] = { { SCM_OPTION_BOOLEAN, "copy", 0, "Copy source code expressions." }, { SCM_OPTION_BOOLEAN, "positions", 1, "Record positions of source code expressions." }, { SCM_OPTION_BOOLEAN, "case-insensitive", 0, "Convert symbols to lower case."}, { SCM_OPTION_SCM, "keywords", (scm_t_bits) SCM_BOOL_F_BITS, "Style of keyword recognition: #f, 'prefix or 'postfix."}, { SCM_OPTION_BOOLEAN, "r6rs-hex-escapes", 0, "Use R6RS variable-length character and string hex escapes."}, { SCM_OPTION_BOOLEAN, "square-brackets", 1, "Treat `[' and `]' as parentheses, for R6RS compatibility."}, { SCM_OPTION_BOOLEAN, "hungry-eol-escapes", 0, "In strings, consume leading whitespace after an escaped end-of-line."}, { SCM_OPTION_BOOLEAN, "curly-infix", 0, "Support SRFI-105 curly infix expressions."}, { SCM_OPTION_BOOLEAN, "r7rs-symbols", 0, "Support R7RS |...| symbol notation."}, { 0, }, }; /* Internal read options structure. This is initialized by 'scm_read' from the global and per-port read options, and a pointer is passed down to all helper functions. */ enum t_keyword_style { KEYWORD_STYLE_HASH_PREFIX, KEYWORD_STYLE_PREFIX, KEYWORD_STYLE_POSTFIX }; struct t_read_opts { enum t_keyword_style keyword_style; unsigned int copy_source_p : 1; unsigned int record_positions_p : 1; unsigned int case_insensitive_p : 1; unsigned int r6rs_escapes_p : 1; unsigned int square_brackets_p : 1; unsigned int hungry_eol_escapes_p : 1; unsigned int curly_infix_p : 1; unsigned int neoteric_p : 1; unsigned int r7rs_symbols_p : 1; }; typedef struct t_read_opts scm_t_read_opts; /* Give meaningful error messages for errors We use the format FILE:LINE:COL: MESSAGE This happened in .... This is not standard GNU format, but the test-suite likes the real message to be in front. */ void scm_i_input_error (char const *function, SCM port, const char *message, SCM arg) { SCM fn = (scm_is_string (SCM_FILENAME(port)) ? SCM_FILENAME(port) : scm_from_locale_string ("#")); SCM string_port = scm_open_output_string (); SCM string = SCM_EOL; scm_simple_format (string_port, scm_from_locale_string ("~A:~S:~S: ~A"), scm_list_4 (fn, scm_from_long (SCM_LINUM (port) + 1), scm_from_int (SCM_COL (port) + 1), scm_from_locale_string (message))); string = scm_get_output_string (string_port); scm_close_output_port (string_port); scm_error_scm (scm_from_latin1_symbol ("read-error"), function? scm_from_locale_string (function) : SCM_BOOL_F, string, arg, SCM_BOOL_F); } SCM_DEFINE (scm_read_options, "read-options-interface", 0, 1, 0, (SCM setting), "Option interface for the read options. Instead of using\n" "this procedure directly, use the procedures @code{read-enable},\n" "@code{read-disable}, @code{read-set!} and @code{read-options}.") #define FUNC_NAME s_scm_read_options { SCM ans = scm_options (setting, scm_read_opts, FUNC_NAME); if (SCM_COPY_SOURCE_P) SCM_RECORD_POSITIONS_P = 1; return ans; } #undef FUNC_NAME /* A fluid referring to an association list mapping extra hash characters to procedures. */ static SCM *scm_i_read_hash_procedures; static SCM scm_i_read_hash_procedures_ref (void) { return scm_fluid_ref (*scm_i_read_hash_procedures); } static void scm_i_read_hash_procedures_set_x (SCM value) { scm_fluid_set_x (*scm_i_read_hash_procedures, value); } /* Token readers. */ /* Size of the C buffer used to read symbols and numbers. */ #define READER_BUFFER_SIZE 128 /* Number of 32-bit codepoints in the buffer used to read strings. */ #define READER_STRING_BUFFER_SIZE 128 /* The maximum size of Scheme character names. */ #define READER_CHAR_NAME_MAX_SIZE 50 /* The maximum size of reader directive names. */ #define READER_DIRECTIVE_NAME_MAX_SIZE 50 /* `isblank' is only in C99. */ #define CHAR_IS_BLANK_(_chr) \ (((_chr) == ' ') || ((_chr) == '\t') || ((_chr) == '\n') \ || ((_chr) == '\f') || ((_chr) == '\r')) #ifdef MSDOS # define CHAR_IS_BLANK(_chr) \ ((CHAR_IS_BLANK_ (chr)) || ((_chr) == 26)) #else # define CHAR_IS_BLANK CHAR_IS_BLANK_ #endif /* R5RS one-character delimiters (see section 7.1.1, ``Lexical structure''). */ #define CHAR_IS_R5RS_DELIMITER(c) \ (CHAR_IS_BLANK (c) \ || (c) == ')' || (c) == '(' || (c) == ';' || (c) == '"') #define CHAR_IS_DELIMITER(c) \ (CHAR_IS_R5RS_DELIMITER (c) \ || (((c) == ']' || (c) == '[') && (opts->square_brackets_p \ || opts->curly_infix_p)) \ || (((c) == '}' || (c) == '{') && opts->curly_infix_p)) /* Exponent markers, as defined in section 7.1.1 of R5RS, ``Lexical Structure''. */ #define CHAR_IS_EXPONENT_MARKER(_chr) \ (((_chr) == 'e') || ((_chr) == 's') || ((_chr) == 'f') \ || ((_chr) == 'd') || ((_chr) == 'l')) /* Read an SCSH block comment. */ static SCM scm_read_scsh_block_comment (scm_t_wchar, SCM); static SCM scm_read_r6rs_block_comment (scm_t_wchar, SCM); static SCM scm_read_commented_expression (scm_t_wchar, SCM, scm_t_read_opts *); static SCM scm_read_shebang (scm_t_wchar, SCM, scm_t_read_opts *); static SCM scm_get_hash_procedure (int); /* Read from PORT until a delimiter (e.g., a whitespace) is read. Put the result in the pre-allocated buffer BUF. Return zero if the whole token has fewer than BUF_SIZE bytes, non-zero otherwise. READ will be set the number of bytes actually read. */ static int read_token (SCM port, scm_t_read_opts *opts, char *buf, size_t buf_size, size_t *read) { *read = 0; while (*read < buf_size) { int chr; chr = scm_get_byte_or_eof (port); if (chr == EOF) return 0; else if (CHAR_IS_DELIMITER (chr)) { scm_unget_byte (chr, port); return 0; } else { *buf = (char) chr; buf++, (*read)++; } } return 1; } /* Like `read_token', but return either BUFFER, or a GC-allocated buffer if the token doesn't fit in BUFFER_SIZE bytes. */ static char * read_complete_token (SCM port, scm_t_read_opts *opts, char *buffer, size_t buffer_size, size_t *read) { int overflow = 0; size_t bytes_read, overflow_size = 0; char *overflow_buffer = NULL; do { overflow = read_token (port, opts, buffer, buffer_size, &bytes_read); if (bytes_read == 0) break; if (overflow || overflow_size != 0) { if (overflow_size == 0) { overflow_buffer = scm_gc_malloc_pointerless (bytes_read, "read"); memcpy (overflow_buffer, buffer, bytes_read); overflow_size = bytes_read; } else { char *new_buf = scm_gc_malloc_pointerless (overflow_size + bytes_read, "read"); memcpy (new_buf, overflow_buffer, overflow_size); memcpy (new_buf + overflow_size, buffer, bytes_read); overflow_buffer = new_buf; overflow_size += bytes_read; } } } while (overflow); if (overflow_size) *read = overflow_size; else *read = bytes_read; return (overflow_size > 0 ? overflow_buffer : buffer); } /* Skip whitespace from PORT and return the first non-whitespace character read. Raise an error on end-of-file. */ static int flush_ws (SCM port, scm_t_read_opts *opts, const char *eoferr) { scm_t_wchar c; while (1) switch (c = scm_getc (port)) { case EOF: goteof: if (eoferr) { scm_i_input_error (eoferr, port, "end of file", SCM_EOL); } return c; case ';': lp: switch (c = scm_getc (port)) { case EOF: goto goteof; default: goto lp; case SCM_LINE_INCREMENTORS: break; } break; case '#': switch (c = scm_getc (port)) { case EOF: eoferr = "read_sharp"; goto goteof; case '!': scm_read_shebang (c, port, opts); break; case ';': scm_read_commented_expression (c, port, opts); break; case '|': if (scm_is_false (scm_get_hash_procedure (c))) { scm_read_r6rs_block_comment (c, port); break; } /* fall through */ default: scm_ungetc (c, port); return '#'; } break; case SCM_LINE_INCREMENTORS: case SCM_SINGLE_SPACES: case '\t': break; default: return c; } return 0; } /* Token readers. */ static SCM scm_read_expression (SCM port, scm_t_read_opts *opts); static SCM scm_read_sharp (int chr, SCM port, scm_t_read_opts *opts, long line, int column); static SCM maybe_annotate_source (SCM x, SCM port, scm_t_read_opts *opts, long line, int column) { if (opts->record_positions_p) scm_i_set_source_properties_x (x, line, column, SCM_FILENAME (port)); return x; } static SCM scm_read_sexp (scm_t_wchar chr, SCM port, scm_t_read_opts *opts) #define FUNC_NAME "scm_i_lreadparen" { int c; SCM tmp, tl, ans = SCM_EOL; const int curly_list_p = (chr == '{') && opts->curly_infix_p; const int terminating_char = ((chr == '{') ? '}' : ((chr == '[') ? ']' : ')')); /* Need to capture line and column numbers here. */ long line = SCM_LINUM (port); int column = SCM_COL (port) - 1; c = flush_ws (port, opts, FUNC_NAME); if (terminating_char == c) return SCM_EOL; scm_ungetc (c, port); tmp = scm_read_expression (port, opts); /* Note that it is possible for scm_read_expression to return scm_sym_dot, but not as part of a dotted pair: as in #{.}#. So check that it's a real dot by checking `c'. */ if (c == '.' && scm_is_eq (scm_sym_dot, tmp)) { ans = scm_read_expression (port, opts); if (terminating_char != (c = flush_ws (port, opts, FUNC_NAME))) scm_i_input_error (FUNC_NAME, port, "missing close paren", SCM_EOL); return ans; } /* Build the head of the list structure. */ ans = tl = scm_cons (tmp, SCM_EOL); while (terminating_char != (c = flush_ws (port, opts, FUNC_NAME))) { SCM new_tail; if (c == ')' || (c == ']' && opts->square_brackets_p) || ((c == '}' || c == ']') && opts->curly_infix_p)) scm_i_input_error (FUNC_NAME, port, "in pair: mismatched close paren: ~A", scm_list_1 (SCM_MAKE_CHAR (c))); scm_ungetc (c, port); tmp = scm_read_expression (port, opts); /* See above note about scm_sym_dot. */ if (c == '.' && scm_is_eq (scm_sym_dot, tmp)) { SCM_SETCDR (tl, scm_read_expression (port, opts)); c = flush_ws (port, opts, FUNC_NAME); if (terminating_char != c) scm_i_input_error (FUNC_NAME, port, "in pair: missing close paren", SCM_EOL); break; } new_tail = scm_cons (tmp, SCM_EOL); SCM_SETCDR (tl, new_tail); tl = new_tail; } if (curly_list_p) { /* In addition to finding the length, 'scm_ilength' checks for improper or circular lists, in which case it returns -1. */ int len = scm_ilength (ans); /* The (len == 0) case is handled above */ if (len == 1) /* Return directly to avoid re-annotating the element's source location with the position of the outer brace. Also, it might not be possible to annotate the element. */ return scm_car (ans); /* {e} => e */ else if (len == 2) ; /* Leave the list unchanged: {e1 e2} => (e1 e2) */ else if (len >= 3 && (len & 1)) { /* It's a proper list whose length is odd and at least 3. If the elements at odd indices (the infix operator positions) are all 'equal?', then it's a simple curly-infix list. Otherwise it's a mixed curly-infix list. */ SCM op = scm_cadr (ans); /* Check to see if the elements at odd indices are 'equal?' */ for (tl = scm_cdddr (ans); ; tl = scm_cddr (tl)) { if (scm_is_null (tl)) { /* Convert simple curly-infix list to prefix: {a b ...} => ( a b ...) */ tl = ans; while (scm_is_pair (scm_cdr (tl))) { tmp = scm_cddr (tl); SCM_SETCDR (tl, tmp); tl = tmp; } ans = scm_cons (op, ans); break; } else if (scm_is_false (scm_equal_p (op, scm_car (tl)))) { /* Mixed curly-infix list: {e ...} => ($nfx$ e ...) */ ans = scm_cons (sym_nfx, ans); break; } } } else /* Mixed curly-infix (possibly improper) list: {e . tail} => ($nfx$ e . tail) */ ans = scm_cons (sym_nfx, ans); } return maybe_annotate_source (ans, port, opts, line, column); } #undef FUNC_NAME /* Read a hexadecimal number NDIGITS in length. Put its value into the variable C. If TERMINATOR is non-null, terminate early if the TERMINATOR character is found. */ #define SCM_READ_HEX_ESCAPE(ndigits, terminator) \ do \ { \ scm_t_wchar a; \ size_t i = 0; \ c = 0; \ while (i < ndigits) \ { \ a = scm_getc (port); \ if (a == EOF) \ goto str_eof; \ if (terminator \ && (a == (scm_t_wchar) terminator) \ && (i > 0)) \ break; \ if ('0' <= a && a <= '9') \ a -= '0'; \ else if ('A' <= a && a <= 'F') \ a = a - 'A' + 10; \ else if ('a' <= a && a <= 'f') \ a = a - 'a' + 10; \ else \ { \ c = a; \ goto bad_escaped; \ } \ c = c * 16 + a; \ i ++; \ } \ } while (0) static void skip_intraline_whitespace (SCM port) { scm_t_wchar c; do { c = scm_getc (port); if (c == EOF) return; } while (c == '\t' || uc_is_general_category (c, UC_SPACE_SEPARATOR)); scm_ungetc (c, port); } /* Read either a double-quoted string or an R7RS-style symbol delimited by vertical lines, depending on the value of 'chr' ('"' or '|'). Regardless, the result is always returned as a string. */ static SCM scm_read_string_like_syntax (int chr, SCM port, scm_t_read_opts *opts) #define FUNC_NAME "scm_lreadr" { /* For strings smaller than C_STR, this function creates only one Scheme object (the string returned). */ SCM str = SCM_EOL; size_t c_str_len = 0; scm_t_wchar c, c_str[READER_STRING_BUFFER_SIZE]; /* Need to capture line and column numbers here. */ long line = SCM_LINUM (port); int column = SCM_COL (port) - 1; while (chr != (c = scm_getc (port))) { if (c == EOF) { str_eof: scm_i_input_error (FUNC_NAME, port, (chr == '|' ? "end of file in symbol" : "end of file in string constant"), SCM_EOL); } if (c_str_len + 1 >= READER_STRING_BUFFER_SIZE) { str = scm_cons (scm_from_utf32_stringn (c_str, c_str_len), str); c_str_len = 0; } if (c == '\\') { switch (c = scm_getc (port)) { case EOF: goto str_eof; case '|': case '\\': break; case '\n': if (opts->hungry_eol_escapes_p) skip_intraline_whitespace (port); continue; case '0': c = '\0'; break; case 'f': c = '\f'; break; case 'n': c = '\n'; break; case 'r': c = '\r'; break; case 't': c = '\t'; break; case 'a': c = '\007'; break; case 'v': c = '\v'; break; case 'b': c = '\010'; break; case 'x': if (opts->r6rs_escapes_p || chr == '|') SCM_READ_HEX_ESCAPE (10, ';'); else SCM_READ_HEX_ESCAPE (2, '\0'); break; case 'u': if (!opts->r6rs_escapes_p) { SCM_READ_HEX_ESCAPE (4, '\0'); break; } case 'U': if (!opts->r6rs_escapes_p) { SCM_READ_HEX_ESCAPE (6, '\0'); break; } default: if (c == chr) break; bad_escaped: scm_i_input_error (FUNC_NAME, port, "illegal character in escape sequence: ~S", scm_list_1 (SCM_MAKE_CHAR (c))); } } c_str[c_str_len++] = c; } if (scm_is_null (str)) /* Fast path: we got a string that fits in C_STR. */ str = scm_from_utf32_stringn (c_str, c_str_len); else { if (c_str_len > 0) str = scm_cons (scm_from_utf32_stringn (c_str, c_str_len), str); str = scm_string_concatenate_reverse (str, SCM_UNDEFINED, SCM_UNDEFINED); } return maybe_annotate_source (str, port, opts, line, column); } #undef FUNC_NAME static SCM scm_read_string (int chr, SCM port, scm_t_read_opts *opts) { return scm_read_string_like_syntax (chr, port, opts); } static SCM scm_read_r7rs_symbol (int chr, SCM port, scm_t_read_opts *opts) { return scm_string_to_symbol (scm_read_string_like_syntax (chr, port, opts)); } static SCM scm_read_number (scm_t_wchar chr, SCM port, scm_t_read_opts *opts) { SCM result, str = SCM_EOL; char local_buffer[READER_BUFFER_SIZE], *buffer; size_t bytes_read; scm_t_port *pt = SCM_PTAB_ENTRY (port); /* Need to capture line and column numbers here. */ long line = SCM_LINUM (port); int column = SCM_COL (port) - 1; scm_ungetc (chr, port); buffer = read_complete_token (port, opts, local_buffer, sizeof local_buffer, &bytes_read); str = scm_from_stringn (buffer, bytes_read, pt->encoding, pt->ilseq_handler); result = scm_string_to_number (str, SCM_UNDEFINED); if (scm_is_false (result)) { /* Return a symbol instead of a number */ if (opts->case_insensitive_p) str = scm_string_downcase_x (str); result = scm_string_to_symbol (str); } else if (SCM_NIMP (result)) result = maybe_annotate_source (result, port, opts, line, column); SCM_COL (port) += scm_i_string_length (str); return result; } static SCM scm_read_mixed_case_symbol (scm_t_wchar chr, SCM port, scm_t_read_opts *opts) { SCM result; int ends_with_colon = 0; size_t bytes_read; int postfix = (opts->keyword_style == KEYWORD_STYLE_POSTFIX); char local_buffer[READER_BUFFER_SIZE], *buffer; scm_t_port *pt = SCM_PTAB_ENTRY (port); SCM str; scm_ungetc (chr, port); buffer = read_complete_token (port, opts, local_buffer, sizeof local_buffer, &bytes_read); if (bytes_read > 0) ends_with_colon = buffer[bytes_read - 1] == ':'; if (postfix && ends_with_colon && (bytes_read > 1)) { str = scm_from_stringn (buffer, bytes_read - 1, pt->encoding, pt->ilseq_handler); if (opts->case_insensitive_p) str = scm_string_downcase_x (str); result = scm_symbol_to_keyword (scm_string_to_symbol (str)); } else { str = scm_from_stringn (buffer, bytes_read, pt->encoding, pt->ilseq_handler); if (opts->case_insensitive_p) str = scm_string_downcase_x (str); result = scm_string_to_symbol (str); } SCM_COL (port) += scm_i_string_length (str); return result; } static SCM scm_read_number_and_radix (scm_t_wchar chr, SCM port, scm_t_read_opts *opts) #define FUNC_NAME "scm_lreadr" { SCM result; size_t read; char local_buffer[READER_BUFFER_SIZE], *buffer; unsigned int radix; SCM str; scm_t_port *pt; switch (chr) { case 'B': case 'b': radix = 2; break; case 'o': case 'O': radix = 8; break; case 'd': case 'D': radix = 10; break; case 'x': case 'X': radix = 16; break; default: scm_ungetc (chr, port); scm_ungetc ('#', port); radix = 10; } buffer = read_complete_token (port, opts, local_buffer, sizeof local_buffer, &read); pt = SCM_PTAB_ENTRY (port); str = scm_from_stringn (buffer, read, pt->encoding, pt->ilseq_handler); result = scm_string_to_number (str, scm_from_uint (radix)); SCM_COL (port) += scm_i_string_length (str); if (scm_is_true (result)) return result; scm_i_input_error (FUNC_NAME, port, "unknown # object", SCM_EOL); return SCM_BOOL_F; } #undef FUNC_NAME static SCM scm_read_quote (int chr, SCM port, scm_t_read_opts *opts) { SCM p; long line = SCM_LINUM (port); int column = SCM_COL (port) - 1; switch (chr) { case '`': p = scm_sym_quasiquote; break; case '\'': p = scm_sym_quote; break; case ',': { scm_t_wchar c; c = scm_getc (port); if ('@' == c) p = scm_sym_uq_splicing; else { scm_ungetc (c, port); p = scm_sym_unquote; } break; } default: fprintf (stderr, "%s: unhandled quote character (%i)\n", "scm_read_quote", chr); abort (); } p = scm_cons2 (p, scm_read_expression (port, opts), SCM_EOL); return maybe_annotate_source (p, port, opts, line, column); } SCM_SYMBOL (sym_syntax, "syntax"); SCM_SYMBOL (sym_quasisyntax, "quasisyntax"); SCM_SYMBOL (sym_unsyntax, "unsyntax"); SCM_SYMBOL (sym_unsyntax_splicing, "unsyntax-splicing"); static SCM scm_read_syntax (int chr, SCM port, scm_t_read_opts *opts) { SCM p; long line = SCM_LINUM (port); int column = SCM_COL (port) - 1; switch (chr) { case '`': p = sym_quasisyntax; break; case '\'': p = sym_syntax; break; case ',': { int c; c = scm_getc (port); if ('@' == c) p = sym_unsyntax_splicing; else { scm_ungetc (c, port); p = sym_unsyntax; } break; } default: fprintf (stderr, "%s: unhandled syntax character (%i)\n", "scm_read_syntax", chr); abort (); } p = scm_cons2 (p, scm_read_expression (port, opts), SCM_EOL); return maybe_annotate_source (p, port, opts, line, column); } static SCM scm_read_nil (int chr, SCM port, scm_t_read_opts *opts) { SCM id = scm_read_mixed_case_symbol (chr, port, opts); if (!scm_is_eq (id, sym_nil)) scm_i_input_error ("scm_read_nil", port, "unexpected input while reading #nil: ~a", scm_list_1 (id)); return SCM_ELISP_NIL; } static SCM scm_read_semicolon_comment (int chr, SCM port) { int c; /* We use the get_byte here because there is no need to get the locale correct with comment input. This presumes that newline always represents itself no matter what the encoding is. */ for (c = scm_get_byte_or_eof (port); (c != EOF) && (c != '\n'); c = scm_get_byte_or_eof (port)); return SCM_UNSPECIFIED; } /* If the EXPECTED_CHARS are the next ones available from PORT, then consume them and return 1. Otherwise leave the port position where it was and return 0. EXPECTED_CHARS should be all lowercase, and will be matched case-insensitively against the characters read from PORT. */ static int try_read_ci_chars (SCM port, const char *expected_chars) { int num_chars_wanted = strlen (expected_chars); int num_chars_read = 0; char *chars_read = alloca (num_chars_wanted); int c; while (num_chars_read < num_chars_wanted) { c = scm_getc (port); if (c == EOF) break; else if (c_tolower (c) != expected_chars[num_chars_read]) { scm_ungetc (c, port); break; } else chars_read[num_chars_read++] = c; } if (num_chars_read == num_chars_wanted) return 1; else { while (num_chars_read > 0) scm_ungetc (chars_read[--num_chars_read], port); return 0; } } /* Sharp readers, i.e. readers called after a `#' sign has been read. */ static SCM scm_read_boolean (int chr, SCM port) { switch (chr) { case 't': case 'T': try_read_ci_chars (port, "rue"); return SCM_BOOL_T; case 'f': case 'F': try_read_ci_chars (port, "alse"); return SCM_BOOL_F; } return SCM_UNSPECIFIED; } static SCM scm_read_character (scm_t_wchar chr, SCM port, scm_t_read_opts *opts) #define FUNC_NAME "scm_lreadr" { char buffer[READER_CHAR_NAME_MAX_SIZE]; SCM charname; size_t charname_len, bytes_read; scm_t_wchar cp; int overflow; scm_t_port *pt; overflow = read_token (port, opts, buffer, READER_CHAR_NAME_MAX_SIZE, &bytes_read); if (overflow) scm_i_input_error (FUNC_NAME, port, "character name too long", SCM_EOL); if (bytes_read == 0) { chr = scm_getc (port); if (chr == EOF) scm_i_input_error (FUNC_NAME, port, "unexpected end of file " "while reading character", SCM_EOL); /* CHR must be a token delimiter, like a whitespace. */ return (SCM_MAKE_CHAR (chr)); } pt = SCM_PTAB_ENTRY (port); /* Simple ASCII characters can be processed immediately. Also, simple ISO-8859-1 characters can be processed immediately if the encoding for this port is ISO-8859-1. */ if (bytes_read == 1 && ((unsigned char) buffer[0] <= 127 || pt->encoding == NULL)) { SCM_COL (port) += 1; return SCM_MAKE_CHAR (buffer[0]); } /* Otherwise, convert the buffer into a proper scheme string for processing. */ charname = scm_from_stringn (buffer, bytes_read, pt->encoding, pt->ilseq_handler); charname_len = scm_i_string_length (charname); SCM_COL (port) += charname_len; cp = scm_i_string_ref (charname, 0); if (charname_len == 1) return SCM_MAKE_CHAR (cp); /* Ignore dotted circles, which may be used to keep combining characters from combining with the backslash in #\charname. */ if (cp == SCM_CODEPOINT_DOTTED_CIRCLE && charname_len == 2) return SCM_MAKE_CHAR (scm_i_string_ref (charname, 1)); if (cp >= '0' && cp < '8') { /* Dirk:FIXME:: This type of character syntax is not R5RS * compliant. Further, it should be verified that the constant * does only consist of octal digits. */ SCM p = scm_string_to_number (charname, scm_from_uint (8)); if (SCM_I_INUMP (p)) { scm_t_wchar c = scm_to_uint32 (p); if (SCM_IS_UNICODE_CHAR (c)) return SCM_MAKE_CHAR (c); else scm_i_input_error (FUNC_NAME, port, "out-of-range octal character escape: ~a", scm_list_1 (charname)); } } if (cp == 'x' && (charname_len > 1)) { SCM p; /* Convert from hex, skipping the initial 'x' character in CHARNAME */ p = scm_string_to_number (scm_c_substring (charname, 1, charname_len), scm_from_uint (16)); if (SCM_I_INUMP (p)) { scm_t_wchar c = scm_to_uint32 (p); if (SCM_IS_UNICODE_CHAR (c)) return SCM_MAKE_CHAR (c); else scm_i_input_error (FUNC_NAME, port, "out-of-range hex character escape: ~a", scm_list_1 (charname)); } } /* The names of characters should never have non-Latin1 characters. */ if (scm_i_is_narrow_string (charname) || scm_i_try_narrow_string (charname)) { SCM ch = scm_i_charname_to_char (scm_i_string_chars (charname), charname_len); if (scm_is_true (ch)) return ch; } scm_i_input_error (FUNC_NAME, port, "unknown character name ~a", scm_list_1 (charname)); return SCM_UNSPECIFIED; } #undef FUNC_NAME static SCM scm_read_keyword (int chr, SCM port, scm_t_read_opts *opts) { SCM symbol; /* Read the symbol that comprises the keyword. Doing this instead of invoking a specific symbol reader function allows `scm_read_keyword ()' to adapt to the delimiters currently valid of symbols. XXX: This implementation allows sloppy syntaxes like `#: key'. */ symbol = scm_read_expression (port, opts); if (!scm_is_symbol (symbol)) scm_i_input_error ("scm_read_keyword", port, "keyword prefix `~a' not followed by a symbol: ~s", scm_list_2 (SCM_MAKE_CHAR (chr), symbol)); return (scm_symbol_to_keyword (symbol)); } static SCM scm_read_vector (int chr, SCM port, scm_t_read_opts *opts, long line, int column) { /* Note: We call `scm_read_sexp ()' rather than READER here in order to guarantee that it's going to do what we want. After all, this is an implementation detail of `scm_read_vector ()', not a desirable property. */ return maybe_annotate_source (scm_vector (scm_read_sexp (chr, port, opts)), port, opts, line, column); } /* Helper used by scm_read_array */ static int read_decimal_integer (SCM port, int c, ssize_t *resp) { ssize_t sign = 1; ssize_t res = 0; int got_it = 0; if (c == '-') { sign = -1; c = scm_getc (port); } while ('0' <= c && c <= '9') { if (((SSIZE_MAX - (c-'0')) / 10) <= res) scm_i_input_error ("read_decimal_integer", port, "number too large", SCM_EOL); res = 10*res + c-'0'; got_it = 1; c = scm_getc (port); } if (got_it) *resp = sign * res; return c; } /* Read an array. This function can also read vectors and uniform vectors. Also, the conflict between '#f' and '#f32' and '#f64' is handled here. C is the first character read after the '#'. */ static SCM scm_read_array (int c, SCM port, scm_t_read_opts *opts, long line, int column) { ssize_t rank; scm_t_wchar tag_buf[8]; int tag_len; SCM tag, shape = SCM_BOOL_F, elements, array; /* XXX - shortcut for ordinary vectors. Shouldn't be necessary but the array code can not deal with zero-length dimensions yet, and we want to allow zero-length vectors, of course. */ if (c == '(') return scm_read_vector (c, port, opts, line, column); /* Disambiguate between '#f' and uniform floating point vectors. */ if (c == 'f') { c = scm_getc (port); if (c != '3' && c != '6') { if (c == 'a' && try_read_ci_chars (port, "lse")) return SCM_BOOL_F; else if (c != EOF) scm_ungetc (c, port); return SCM_BOOL_F; } rank = 1; tag_buf[0] = 'f'; tag_len = 1; goto continue_reading_tag; } /* Read rank. */ rank = 1; c = read_decimal_integer (port, c, &rank); if (rank < 0) scm_i_input_error (NULL, port, "array rank must be non-negative", SCM_EOL); /* Read tag. */ tag_len = 0; continue_reading_tag: while (c != EOF && c != '(' && c != '@' && c != ':' && tag_len < sizeof tag_buf / sizeof tag_buf[0]) { tag_buf[tag_len++] = c; c = scm_getc (port); } if (tag_len == 0) tag = SCM_BOOL_T; else { tag = scm_string_to_symbol (scm_from_utf32_stringn (tag_buf, tag_len)); if (tag_len == sizeof tag_buf / sizeof tag_buf[0]) scm_i_input_error (NULL, port, "invalid array tag, starting with: ~a", scm_list_1 (tag)); } /* Read shape. */ if (c == '@' || c == ':') { shape = SCM_EOL; do { ssize_t lbnd = 0, len = 0; SCM s; if (c == '@') { c = scm_getc (port); c = read_decimal_integer (port, c, &lbnd); } s = scm_from_ssize_t (lbnd); if (c == ':') { c = scm_getc (port); c = read_decimal_integer (port, c, &len); if (len < 0) scm_i_input_error (NULL, port, "array length must be non-negative", SCM_EOL); s = scm_list_2 (s, scm_from_ssize_t (lbnd+len-1)); } shape = scm_cons (s, shape); } while (c == '@' || c == ':'); shape = scm_reverse_x (shape, SCM_EOL); } /* Read nested lists of elements. */ if (c != '(') scm_i_input_error (NULL, port, "missing '(' in vector or array literal", SCM_EOL); elements = scm_read_sexp (c, port, opts); if (scm_is_false (shape)) shape = scm_from_ssize_t (rank); else if (scm_ilength (shape) != rank) scm_i_input_error (NULL, port, "the number of shape specifications must match the array rank", SCM_EOL); /* Handle special print syntax of rank zero arrays; see scm_i_print_array for a rationale. */ if (rank == 0) { if (!scm_is_pair (elements)) scm_i_input_error (NULL, port, "too few elements in array literal, need 1", SCM_EOL); if (!scm_is_null (SCM_CDR (elements))) scm_i_input_error (NULL, port, "too many elements in array literal, want 1", SCM_EOL); elements = SCM_CAR (elements); } /* Construct array, annotate with source location, and return. */ array = scm_list_to_typed_array (tag, shape, elements); return maybe_annotate_source (array, port, opts, line, column); } static SCM scm_read_srfi4_vector (int chr, SCM port, scm_t_read_opts *opts, long line, int column) { return scm_read_array (chr, port, opts, line, column); } static SCM scm_read_bytevector (scm_t_wchar chr, SCM port, scm_t_read_opts *opts, long line, int column) { chr = scm_getc (port); if (chr != 'u') goto syntax; chr = scm_getc (port); if (chr != '8') goto syntax; chr = scm_getc (port); if (chr != '(') goto syntax; return maybe_annotate_source (scm_u8_list_to_bytevector (scm_read_sexp (chr, port, opts)), port, opts, line, column); syntax: scm_i_input_error ("read_bytevector", port, "invalid bytevector prefix", SCM_MAKE_CHAR (chr)); return SCM_UNSPECIFIED; } static SCM scm_read_guile_bit_vector (scm_t_wchar chr, SCM port, scm_t_read_opts *opts, long line, int column) { /* Read the `#*10101'-style read syntax for bit vectors in Guile. This is terribly inefficient but who cares? */ SCM s_bits = SCM_EOL; for (chr = scm_getc (port); (chr != EOF) && ((chr == '0') || (chr == '1')); chr = scm_getc (port)) { s_bits = scm_cons ((chr == '0') ? SCM_BOOL_F : SCM_BOOL_T, s_bits); } if (chr != EOF) scm_ungetc (chr, port); return maybe_annotate_source (scm_bitvector (scm_reverse_x (s_bits, SCM_EOL)), port, opts, line, column); } static SCM scm_read_scsh_block_comment (scm_t_wchar chr, SCM port) { int bang_seen = 0; for (;;) { int c = scm_getc (port); if (c == EOF) scm_i_input_error ("skip_block_comment", port, "unterminated `#! ... !#' comment", SCM_EOL); if (c == '!') bang_seen = 1; else if (c == '#' && bang_seen) break; else bang_seen = 0; } return SCM_UNSPECIFIED; } static void set_port_case_insensitive_p (SCM port, scm_t_read_opts *opts, int value); static void set_port_square_brackets_p (SCM port, scm_t_read_opts *opts, int value); static void set_port_curly_infix_p (SCM port, scm_t_read_opts *opts, int value); static SCM scm_read_shebang (scm_t_wchar chr, SCM port, scm_t_read_opts *opts) { char name[READER_DIRECTIVE_NAME_MAX_SIZE + 1]; int c; int i = 0; while (i <= READER_DIRECTIVE_NAME_MAX_SIZE) { c = scm_getc (port); if (c == EOF) scm_i_input_error ("skip_block_comment", port, "unterminated `#! ... !#' comment", SCM_EOL); else if (('a' <= c && c <= 'z') || ('0' <= c && c <= '9') || c == '-') name[i++] = c; else if (CHAR_IS_DELIMITER (c)) { scm_ungetc (c, port); name[i] = '\0'; if (0 == strcmp ("r6rs", name)) ; /* Silently ignore */ else if (0 == strcmp ("fold-case", name)) set_port_case_insensitive_p (port, opts, 1); else if (0 == strcmp ("no-fold-case", name)) set_port_case_insensitive_p (port, opts, 0); else if (0 == strcmp ("curly-infix", name)) set_port_curly_infix_p (port, opts, 1); else if (0 == strcmp ("curly-infix-and-bracket-lists", name)) { set_port_curly_infix_p (port, opts, 1); set_port_square_brackets_p (port, opts, 0); } else break; return SCM_UNSPECIFIED; } else { scm_ungetc (c, port); break; } } while (i > 0) scm_ungetc (name[--i], port); return scm_read_scsh_block_comment (chr, port); } static SCM scm_read_r6rs_block_comment (scm_t_wchar chr, SCM port) { /* Unlike SCSH-style block comments, SRFI-30/R6RS block comments may be nested. So care must be taken. */ int nesting_level = 1; int a = scm_getc (port); if (a == EOF) scm_i_input_error ("scm_read_r6rs_block_comment", port, "unterminated `#| ... |#' comment", SCM_EOL); while (nesting_level > 0) { int b = scm_getc (port); if (b == EOF) scm_i_input_error ("scm_read_r6rs_block_comment", port, "unterminated `#| ... |#' comment", SCM_EOL); if (a == '|' && b == '#') { nesting_level--; b = EOF; } else if (a == '#' && b == '|') { nesting_level++; b = EOF; } a = b; } return SCM_UNSPECIFIED; } static SCM scm_read_commented_expression (scm_t_wchar chr, SCM port, scm_t_read_opts *opts) { scm_t_wchar c; c = flush_ws (port, opts, (char *) NULL); if (EOF == c) scm_i_input_error ("read_commented_expression", port, "no expression after #; comment", SCM_EOL); scm_ungetc (c, port); scm_read_expression (port, opts); return SCM_UNSPECIFIED; } static SCM scm_read_extended_symbol (scm_t_wchar chr, SCM port) { /* Guile's extended symbol read syntax looks like this: #{This is all a symbol name}# So here, CHR is expected to be `{'. */ int saw_brace = 0; size_t len = 0; SCM buf = scm_i_make_string (1024, NULL, 0); buf = scm_i_string_start_writing (buf); while ((chr = scm_getc (port)) != EOF) { if (saw_brace) { if (chr == '#') { break; } else { saw_brace = 0; scm_i_string_set_x (buf, len++, '}'); } } if (chr == '}') saw_brace = 1; else if (chr == '\\') { /* It used to be that print.c would print extended-read-syntax symbols with backslashes before "non-standard" chars, but this routine wouldn't do anything with those escapes. Bummer. What we've done is to change print.c to output R6RS hex escapes for those characters, relying on the fact that the extended read syntax would never put a `\' before an `x'. For now, we just ignore other instances of backslash in the string. */ switch ((chr = scm_getc (port))) { case EOF: goto done; case 'x': { scm_t_wchar c; SCM_READ_HEX_ESCAPE (10, ';'); scm_i_string_set_x (buf, len++, c); break; str_eof: chr = EOF; goto done; bad_escaped: scm_i_string_stop_writing (); scm_i_input_error ("scm_read_extended_symbol", port, "illegal character in escape sequence: ~S", scm_list_1 (SCM_MAKE_CHAR (c))); break; } default: scm_i_string_set_x (buf, len++, chr); break; } } else scm_i_string_set_x (buf, len++, chr); if (len >= scm_i_string_length (buf) - 2) { SCM addy; scm_i_string_stop_writing (); addy = scm_i_make_string (1024, NULL, 0); buf = scm_string_append (scm_list_2 (buf, addy)); len = 0; buf = scm_i_string_start_writing (buf); } } done: scm_i_string_stop_writing (); if (chr == EOF) scm_i_input_error ("scm_read_extended_symbol", port, "end of file while reading symbol", SCM_EOL); return (scm_string_to_symbol (scm_c_substring (buf, 0, len))); } /* Top-level token readers, i.e., dispatchers. */ static SCM scm_read_sharp_extension (int chr, SCM port, scm_t_read_opts *opts) { SCM proc; proc = scm_get_hash_procedure (chr); if (scm_is_true (scm_procedure_p (proc))) { long line = SCM_LINUM (port); int column = SCM_COL (port) - 2; SCM got; got = scm_call_2 (proc, SCM_MAKE_CHAR (chr), port); if (opts->record_positions_p && SCM_NIMP (got) && !scm_i_has_source_properties (got)) scm_i_set_source_properties_x (got, line, column, SCM_FILENAME (port)); return got; } return SCM_UNSPECIFIED; } /* The reader for the sharp `#' character. It basically dispatches reads among the above token readers. */ static SCM scm_read_sharp (scm_t_wchar chr, SCM port, scm_t_read_opts *opts, long line, int column) #define FUNC_NAME "scm_lreadr" { SCM result; chr = scm_getc (port); result = scm_read_sharp_extension (chr, port, opts); if (!scm_is_eq (result, SCM_UNSPECIFIED)) return result; switch (chr) { case '\\': return (scm_read_character (chr, port, opts)); case '(': return (scm_read_vector (chr, port, opts, line, column)); case 's': case 'u': case 'f': case 'c': /* This one may return either a boolean or an SRFI-4 vector. */ return (scm_read_srfi4_vector (chr, port, opts, line, column)); case 'v': return (scm_read_bytevector (chr, port, opts, line, column)); case '*': return (scm_read_guile_bit_vector (chr, port, opts, line, column)); case 't': case 'T': case 'F': return (scm_read_boolean (chr, port)); case ':': return (scm_read_keyword (chr, port, opts)); case '0': case '1': case '2': case '3': case '4': case '5': case '6': case '7': case '8': case '9': case '@': #if SCM_ENABLE_DEPRECATED /* See below for 'i' and 'e'. */ case 'a': case 'y': case 'h': case 'l': #endif return (scm_read_array (chr, port, opts, line, column)); case 'i': case 'e': #if SCM_ENABLE_DEPRECATED { /* When next char is '(', it really is an old-style uniform array. */ scm_t_wchar next_c = scm_getc (port); if (next_c != EOF) scm_ungetc (next_c, port); if (next_c == '(') return scm_read_array (chr, port, opts, line, column); /* Fall through. */ } #endif case 'b': case 'B': case 'o': case 'O': case 'd': case 'D': case 'x': case 'X': case 'I': case 'E': return (scm_read_number_and_radix (chr, port, opts)); case '{': return (scm_read_extended_symbol (chr, port)); case '!': return (scm_read_shebang (chr, port, opts)); case ';': return (scm_read_commented_expression (chr, port, opts)); case '`': case '\'': case ',': return (scm_read_syntax (chr, port, opts)); case 'n': return (scm_read_nil (chr, port, opts)); default: result = scm_read_sharp_extension (chr, port, opts); if (scm_is_eq (result, SCM_UNSPECIFIED)) { /* To remain compatible with 1.8 and earlier, the following characters have lower precedence than `read-hash-extend' characters. */ switch (chr) { case '|': return scm_read_r6rs_block_comment (chr, port); default: scm_i_input_error (FUNC_NAME, port, "Unknown # object: ~S", scm_list_1 (SCM_MAKE_CHAR (chr))); } } else return result; } return SCM_UNSPECIFIED; } #undef FUNC_NAME static SCM read_inner_expression (SCM port, scm_t_read_opts *opts) #define FUNC_NAME "read_inner_expression" { while (1) { scm_t_wchar chr; chr = scm_getc (port); switch (chr) { case SCM_WHITE_SPACES: case SCM_LINE_INCREMENTORS: break; case ';': (void) scm_read_semicolon_comment (chr, port); break; case '{': if (opts->curly_infix_p) { if (opts->neoteric_p) return scm_read_sexp (chr, port, opts); else { SCM expr; /* Enable neoteric expressions within curly braces */ opts->neoteric_p = 1; expr = scm_read_sexp (chr, port, opts); opts->neoteric_p = 0; return expr; } } else return scm_read_mixed_case_symbol (chr, port, opts); case '[': if (opts->square_brackets_p) return scm_read_sexp (chr, port, opts); else if (opts->curly_infix_p) { /* The syntax of neoteric expressions requires that '[' be a delimiter when curly-infix is enabled, so it cannot be part of an unescaped symbol. We might as well do something useful with it, so we adopt Kawa's convention: [...] => ($bracket-list$ ...) */ long line = SCM_LINUM (port); int column = SCM_COL (port) - 1; return maybe_annotate_source (scm_cons (sym_bracket_list, scm_read_sexp (chr, port, opts)), port, opts, line, column); } else return scm_read_mixed_case_symbol (chr, port, opts); case '(': return (scm_read_sexp (chr, port, opts)); case '"': return (scm_read_string (chr, port, opts)); case '|': if (opts->r7rs_symbols_p) return scm_read_r7rs_symbol (chr, port, opts); else return scm_read_mixed_case_symbol (chr, port, opts); case '\'': case '`': case ',': return (scm_read_quote (chr, port, opts)); case '#': { long line = SCM_LINUM (port); int column = SCM_COL (port) - 1; SCM result = scm_read_sharp (chr, port, opts, line, column); if (scm_is_eq (result, SCM_UNSPECIFIED)) /* We read a comment or some such. */ break; else return result; } case ')': scm_i_input_error (FUNC_NAME, port, "unexpected \")\"", SCM_EOL); break; case '}': if (opts->curly_infix_p) scm_i_input_error (FUNC_NAME, port, "unexpected \"}\"", SCM_EOL); else return scm_read_mixed_case_symbol (chr, port, opts); case ']': if (opts->square_brackets_p) scm_i_input_error (FUNC_NAME, port, "unexpected \"]\"", SCM_EOL); /* otherwise fall through */ case EOF: return SCM_EOF_VAL; case ':': if (opts->keyword_style == KEYWORD_STYLE_PREFIX) return scm_symbol_to_keyword (scm_read_expression (port, opts)); /* Fall through. */ default: { if (((chr >= '0') && (chr <= '9')) || (strchr ("+-.", chr))) return (scm_read_number (chr, port, opts)); else return (scm_read_mixed_case_symbol (chr, port, opts)); } } } } #undef FUNC_NAME static SCM scm_read_expression (SCM port, scm_t_read_opts *opts) #define FUNC_NAME "scm_read_expression" { if (!opts->neoteric_p) return read_inner_expression (port, opts); else { long line = 0; int column = 0; SCM expr; if (opts->record_positions_p) { /* We need to get the position of the first non-whitespace character in order to correctly annotate neoteric expressions. For example, for the expression 'f(x)', the first call to 'read_inner_expression' reads the 'f' (which cannot be annotated), and then we later read the '(x)' and use it to construct the new list (f x). */ int c = flush_ws (port, opts, (char *) NULL); if (c == EOF) return SCM_EOF_VAL; scm_ungetc (c, port); line = SCM_LINUM (port); column = SCM_COL (port); } expr = read_inner_expression (port, opts); /* 'expr' is the first component of the neoteric expression. Now we loop, and as long as the next character is '(', '[', or '{', (without any intervening whitespace), we use it to construct a new expression. For example, f{n - 1}(x) => ((f (- n 1)) x). */ for (;;) { int chr = scm_getc (port); if (chr == '(') /* e(...) => (e ...) */ expr = scm_cons (expr, scm_read_sexp (chr, port, opts)); else if (chr == '[') /* e[...] => ($bracket-apply$ e ...) */ expr = scm_cons (sym_bracket_apply, scm_cons (expr, scm_read_sexp (chr, port, opts))); else if (chr == '{') { SCM arg = scm_read_sexp (chr, port, opts); if (scm_is_null (arg)) expr = scm_list_1 (expr); /* e{} => (e) */ else expr = scm_list_2 (expr, arg); /* e{...} => (e {...}) */ } else { if (chr != EOF) scm_ungetc (chr, port); break; } maybe_annotate_source (expr, port, opts, line, column); } return expr; } } #undef FUNC_NAME /* Actual reader. */ static void init_read_options (SCM port, scm_t_read_opts *opts); SCM_DEFINE (scm_read, "read", 0, 1, 0, (SCM port), "Read an s-expression from the input port @var{port}, or from\n" "the current input port if @var{port} is not specified.\n" "Any whitespace before the next token is discarded.") #define FUNC_NAME s_scm_read { scm_t_read_opts opts; int c; if (SCM_UNBNDP (port)) port = scm_current_input_port (); SCM_VALIDATE_OPINPORT (1, port); init_read_options (port, &opts); c = flush_ws (port, &opts, (char *) NULL); if (EOF == c) return SCM_EOF_VAL; scm_ungetc (c, port); return (scm_read_expression (port, &opts)); } #undef FUNC_NAME /* Manipulate the read-hash-procedures alist. This could be written in Scheme, but maybe it will also be used by C code during initialisation. */ SCM_DEFINE (scm_read_hash_extend, "read-hash-extend", 2, 0, 0, (SCM chr, SCM proc), "Install the procedure @var{proc} for reading expressions\n" "starting with the character sequence @code{#} and @var{chr}.\n" "@var{proc} will be called with two arguments: the character\n" "@var{chr} and the port to read further data from. The object\n" "returned will be the return value of @code{read}. \n" "Passing @code{#f} for @var{proc} will remove a previous setting. \n" ) #define FUNC_NAME s_scm_read_hash_extend { SCM this; SCM prev; SCM_VALIDATE_CHAR (1, chr); SCM_ASSERT (scm_is_false (proc) || scm_is_eq (scm_procedure_p (proc), SCM_BOOL_T), proc, SCM_ARG2, FUNC_NAME); /* Check if chr is already in the alist. */ this = scm_i_read_hash_procedures_ref (); prev = SCM_BOOL_F; while (1) { if (scm_is_null (this)) { /* not found, so add it to the beginning. */ if (scm_is_true (proc)) { SCM new = scm_cons (scm_cons (chr, proc), scm_i_read_hash_procedures_ref ()); scm_i_read_hash_procedures_set_x (new); } break; } if (scm_is_eq (chr, SCM_CAAR (this))) { /* already in the alist. */ if (scm_is_false (proc)) { /* remove it. */ if (scm_is_false (prev)) { SCM rest = SCM_CDR (scm_i_read_hash_procedures_ref ()); scm_i_read_hash_procedures_set_x (rest); } else scm_set_cdr_x (prev, SCM_CDR (this)); } else { /* replace it. */ scm_set_cdr_x (SCM_CAR (this), proc); } break; } prev = this; this = SCM_CDR (this); } return SCM_UNSPECIFIED; } #undef FUNC_NAME /* Recover the read-hash procedure corresponding to char c. */ static SCM scm_get_hash_procedure (int c) { SCM rest = scm_i_read_hash_procedures_ref (); while (1) { if (scm_is_null (rest)) return SCM_BOOL_F; if (SCM_CHAR (SCM_CAAR (rest)) == c) return SCM_CDAR (rest); rest = SCM_CDR (rest); } } /* Maximum size of an encoding name. This is a bit more than the longest name listed at ("ISO-2022-JP-2", 13 characters.) */ #define ENCODING_NAME_MAX_SIZE 20 /* Number of bytes at the beginning or end of a file that are scanned for a "coding:" declaration. */ #define SCM_ENCODING_SEARCH_SIZE (500 + ENCODING_NAME_MAX_SIZE) /* Search the SCM_ENCODING_SEARCH_SIZE bytes of a file for an Emacs-like coding declaration. Returns either NULL or a string whose storage has been allocated with `scm_gc_malloc'. */ char * scm_i_scan_for_encoding (SCM port) { scm_t_port *pt; char header[SCM_ENCODING_SEARCH_SIZE+1]; size_t bytes_read, encoding_length, i; char *encoding = NULL; char *pos, *encoding_start; int in_comment; pt = SCM_PTAB_ENTRY (port); if (pt->rw_active == SCM_PORT_WRITE) scm_flush (port); if (pt->rw_random) pt->rw_active = SCM_PORT_READ; if (pt->read_pos == pt->read_end) { /* We can use the read buffer, and thus avoid a seek. */ if (scm_fill_input (port) == EOF) return NULL; bytes_read = pt->read_end - pt->read_pos; if (bytes_read > SCM_ENCODING_SEARCH_SIZE) bytes_read = SCM_ENCODING_SEARCH_SIZE; if (bytes_read <= 1) /* An unbuffered port -- don't scan. */ return NULL; memcpy (header, pt->read_pos, bytes_read); header[bytes_read] = '\0'; } else { /* Try to read some bytes and then seek back. Not all ports support seeking back; and indeed some file ports (like /dev/urandom) will succeed on an lseek (fd, 0, SEEK_CUR)---the check performed by SCM_FPORT_FDES---but fail to seek backwards. Hence this block comes second. We prefer to use the read buffer in-place. */ if (SCM_FPORTP (port) && !SCM_FDES_RANDOM_P (SCM_FPORT_FDES (port))) return NULL; bytes_read = scm_c_read (port, header, SCM_ENCODING_SEARCH_SIZE); header[bytes_read] = '\0'; scm_seek (port, scm_from_int (0), scm_from_int (SEEK_SET)); } /* search past "coding[:=]" */ pos = header; while (1) { if ((pos = strstr(pos, "coding")) == NULL) return NULL; pos += strlen ("coding"); if (pos - header >= SCM_ENCODING_SEARCH_SIZE || (*pos == ':' || *pos == '=')) { pos ++; break; } } /* skip spaces */ while (pos - header <= SCM_ENCODING_SEARCH_SIZE && (*pos == ' ' || *pos == '\t')) pos ++; if (pos - header >= SCM_ENCODING_SEARCH_SIZE - ENCODING_NAME_MAX_SIZE) /* We found the "coding:" string, but there is probably not enough room to store an encoding name in its entirety, so ignore it. This makes sure we do not end up returning a truncated encoding name. */ return NULL; /* grab the next token */ encoding_start = pos; i = 0; while (encoding_start + i - header <= SCM_ENCODING_SEARCH_SIZE && encoding_start + i - header < bytes_read && (isalnum ((int) encoding_start[i]) || strchr ("_-.:/,+=()", encoding_start[i]) != NULL)) i++; encoding_length = i; if (encoding_length == 0) return NULL; encoding = scm_gc_strndup (encoding_start, encoding_length, "encoding"); for (i = 0; i < encoding_length; i++) encoding[i] = toupper ((int) encoding[i]); /* push backwards to make sure we were in a comment */ in_comment = 0; pos = encoding_start; while (pos >= header) { if (*pos == ';') { in_comment = 1; break; } else if (*pos == '\n' || pos == header) { /* This wasn't in a semicolon comment. Check for a hash-bang comment. */ char *beg = strstr (header, "#!"); char *end = strstr (header, "!#"); if (beg < encoding_start && encoding_start + encoding_length <= end) in_comment = 1; break; } else { pos --; continue; } } if (!in_comment) /* This wasn't in a comment */ return NULL; return encoding; } SCM_DEFINE (scm_file_encoding, "file-encoding", 1, 0, 0, (SCM port), "Scans the port for an Emacs-like character coding declaration\n" "near the top of the contents of a port with random-accessible contents.\n" "The coding declaration is of the form\n" "@code{coding: XXXXX} and must appear in a scheme comment.\n" "\n" "Returns a string containing the character encoding of the file\n" "if a declaration was found, or @code{#f} otherwise.\n") #define FUNC_NAME s_scm_file_encoding { char *enc; SCM s_enc; SCM_VALIDATE_OPINPORT (SCM_ARG1, port); enc = scm_i_scan_for_encoding (port); if (enc == NULL) return SCM_BOOL_F; else { s_enc = scm_from_locale_string (enc); return s_enc; } return SCM_BOOL_F; } #undef FUNC_NAME /* Per-port read options. We store per-port read options in the 'port-read-options' port property, which is stored in the internal port structure. The value stored is a single integer that contains a two-bit field for each read option. If a bit field contains READ_OPTION_INHERIT (3), that indicates that the applicable value should be inherited from the corresponding global read option. Otherwise, the bit field contains the value of the read option. For boolean read options that have been set per-port, the possible values are 0 or 1. If the 'keyword_style' read option has been set per-port, its possible values are those in 'enum t_keyword_style'. */ /* Key to read options in port properties. */ SCM_SYMBOL (sym_port_read_options, "port-read-options"); /* Offsets of bit fields for each per-port override */ #define READ_OPTION_COPY_SOURCE_P 0 #define READ_OPTION_RECORD_POSITIONS_P 2 #define READ_OPTION_CASE_INSENSITIVE_P 4 #define READ_OPTION_KEYWORD_STYLE 6 #define READ_OPTION_R6RS_ESCAPES_P 8 #define READ_OPTION_SQUARE_BRACKETS_P 10 #define READ_OPTION_HUNGRY_EOL_ESCAPES_P 12 #define READ_OPTION_CURLY_INFIX_P 14 #define READ_OPTION_R7RS_SYMBOLS_P 16 /* The total width in bits of the per-port overrides */ #define READ_OPTIONS_NUM_BITS 18 #define READ_OPTIONS_INHERIT_ALL ((1UL << READ_OPTIONS_NUM_BITS) - 1) #define READ_OPTIONS_MAX_VALUE READ_OPTIONS_INHERIT_ALL #define READ_OPTION_MASK 3 #define READ_OPTION_INHERIT 3 static void set_port_read_option (SCM port, int option, int new_value) { SCM scm_read_options; unsigned int read_options; new_value &= READ_OPTION_MASK; scm_read_options = scm_i_port_property (port, sym_port_read_options); if (scm_is_unsigned_integer (scm_read_options, 0, READ_OPTIONS_MAX_VALUE)) read_options = scm_to_uint (scm_read_options); else read_options = READ_OPTIONS_INHERIT_ALL; read_options &= ~(READ_OPTION_MASK << option); read_options |= new_value << option; scm_read_options = scm_from_uint (read_options); scm_i_set_port_property_x (port, sym_port_read_options, scm_read_options); } /* Set OPTS and PORT's case-insensitivity according to VALUE. */ static void set_port_case_insensitive_p (SCM port, scm_t_read_opts *opts, int value) { value = !!value; opts->case_insensitive_p = value; set_port_read_option (port, READ_OPTION_CASE_INSENSITIVE_P, value); } /* Set OPTS and PORT's square_brackets_p option according to VALUE. */ static void set_port_square_brackets_p (SCM port, scm_t_read_opts *opts, int value) { value = !!value; opts->square_brackets_p = value; set_port_read_option (port, READ_OPTION_SQUARE_BRACKETS_P, value); } /* Set OPTS and PORT's curly_infix_p option according to VALUE. */ static void set_port_curly_infix_p (SCM port, scm_t_read_opts *opts, int value) { value = !!value; opts->curly_infix_p = value; set_port_read_option (port, READ_OPTION_CURLY_INFIX_P, value); } /* Initialize OPTS based on PORT's read options and the global read options. */ static void init_read_options (SCM port, scm_t_read_opts *opts) { SCM val, scm_read_options; unsigned int read_options, x; scm_read_options = scm_i_port_property (port, sym_port_read_options); if (scm_is_unsigned_integer (scm_read_options, 0, READ_OPTIONS_MAX_VALUE)) read_options = scm_to_uint (scm_read_options); else read_options = READ_OPTIONS_INHERIT_ALL; x = READ_OPTION_MASK & (read_options >> READ_OPTION_KEYWORD_STYLE); if (x == READ_OPTION_INHERIT) { val = SCM_PACK (SCM_KEYWORD_STYLE); if (scm_is_eq (val, scm_keyword_prefix)) x = KEYWORD_STYLE_PREFIX; else if (scm_is_eq (val, scm_keyword_postfix)) x = KEYWORD_STYLE_POSTFIX; else x = KEYWORD_STYLE_HASH_PREFIX; } opts->keyword_style = x; #define RESOLVE_BOOLEAN_OPTION(NAME, name) \ do \ { \ x = READ_OPTION_MASK & (read_options >> READ_OPTION_ ## NAME); \ if (x == READ_OPTION_INHERIT) \ x = !!SCM_ ## NAME; \ opts->name = x; \ } \ while (0) RESOLVE_BOOLEAN_OPTION (COPY_SOURCE_P, copy_source_p); RESOLVE_BOOLEAN_OPTION (RECORD_POSITIONS_P, record_positions_p); RESOLVE_BOOLEAN_OPTION (CASE_INSENSITIVE_P, case_insensitive_p); RESOLVE_BOOLEAN_OPTION (R6RS_ESCAPES_P, r6rs_escapes_p); RESOLVE_BOOLEAN_OPTION (SQUARE_BRACKETS_P, square_brackets_p); RESOLVE_BOOLEAN_OPTION (HUNGRY_EOL_ESCAPES_P, hungry_eol_escapes_p); RESOLVE_BOOLEAN_OPTION (CURLY_INFIX_P, curly_infix_p); RESOLVE_BOOLEAN_OPTION (R7RS_SYMBOLS_P, r7rs_symbols_p); #undef RESOLVE_BOOLEAN_OPTION opts->neoteric_p = 0; } void scm_init_read () { SCM read_hash_procs; read_hash_procs = scm_make_fluid_with_default (SCM_EOL); scm_i_read_hash_procedures = SCM_VARIABLE_LOC (scm_c_define ("%read-hash-procedures", read_hash_procs)); scm_init_opts (scm_read_options, scm_read_opts); #include "libguile/read.x" } /* Local Variables: c-file-style: "gnu" End: */