/* Copyright (C) 1995, 1996, 1997, 1998, 2000, 2001, 2003, 2004, * 2006, 2009, 2011 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 "libguile/_scm.h" #include "libguile/chars.h" #include "libguile/eval.h" #include "libguile/hash.h" #include "libguile/smob.h" #include "libguile/variable.h" #include "libguile/alist.h" #include "libguile/fluids.h" #include "libguile/strings.h" #include "libguile/vectors.h" #include "libguile/hashtab.h" #include "libguile/weaks.h" #include "libguile/modules.h" #include "libguile/read.h" #include "libguile/srfi-13.h" #include "libguile/validate.h" #include "libguile/symbols.h" #include "libguile/private-options.h" #ifdef HAVE_STRING_H #include #endif static SCM symbols; static scm_i_pthread_mutex_t symbols_lock = SCM_I_PTHREAD_MUTEX_INITIALIZER; #ifdef GUILE_DEBUG SCM_DEFINE (scm_sys_symbols, "%symbols", 0, 0, 0, (), "Return the system symbol obarray.") #define FUNC_NAME s_scm_sys_symbols { return symbols; } #undef FUNC_NAME #endif /* {Symbols} */ unsigned long scm_i_hash_symbol (SCM obj, unsigned long n, void *closure) { return scm_i_symbol_hash (obj) % n; } struct string_lookup_data { SCM string; unsigned long string_hash; }; static int string_lookup_predicate_fn (SCM sym, void *closure) { struct string_lookup_data *data = closure; if (scm_i_symbol_hash (sym) == data->string_hash && scm_i_symbol_length (sym) == scm_i_string_length (data->string)) { size_t n = scm_i_symbol_length (sym); while (n--) if (scm_i_symbol_ref (sym, n) != scm_i_string_ref (data->string, n)) return 0; return 1; } else return 0; } static SCM lookup_interned_symbol (SCM name, unsigned long raw_hash) { struct string_lookup_data data; SCM handle; data.string = name; data.string_hash = raw_hash; scm_i_pthread_mutex_lock (&symbols_lock); handle = scm_hash_fn_get_handle_by_hash (symbols, raw_hash, string_lookup_predicate_fn, &data); scm_i_pthread_mutex_unlock (&symbols_lock); if (scm_is_true (handle)) return SCM_CAR (handle); else return SCM_BOOL_F; } struct latin1_lookup_data { const char *str; size_t len; unsigned long string_hash; }; static int latin1_lookup_predicate_fn (SCM sym, void *closure) { struct latin1_lookup_data *data = closure; return scm_i_symbol_hash (sym) == data->string_hash && scm_i_is_narrow_symbol (sym) && scm_i_symbol_length (sym) == data->len && strncmp (scm_i_symbol_chars (sym), data->str, data->len) == 0; } static SCM lookup_interned_latin1_symbol (const char *str, size_t len, unsigned long raw_hash) { struct latin1_lookup_data data; SCM handle; data.str = str; data.len = len; data.string_hash = raw_hash; scm_i_pthread_mutex_lock (&symbols_lock); handle = scm_hash_fn_get_handle_by_hash (symbols, raw_hash, latin1_lookup_predicate_fn, &data); scm_i_pthread_mutex_unlock (&symbols_lock); if (scm_is_true (handle)) return SCM_CAR (handle); else return SCM_BOOL_F; } static unsigned long symbol_lookup_hash_fn (SCM obj, unsigned long max, void *closure) { return scm_i_symbol_hash (obj) % max; } static SCM symbol_lookup_assoc_fn (SCM obj, SCM alist, void *closure) { for (; !scm_is_null (alist); alist = SCM_CDR (alist)) { SCM sym = SCM_CAAR (alist); if (scm_i_symbol_hash (sym) == scm_i_symbol_hash (obj) && scm_is_true (scm_string_equal_p (scm_symbol_to_string (sym), scm_symbol_to_string (obj)))) return SCM_CAR (alist); } return SCM_BOOL_F; } /* Intern SYMBOL, an uninterned symbol. Might return a different symbol, if another one was interned at the same time. */ static SCM intern_symbol (SCM symbol) { SCM handle; scm_i_pthread_mutex_lock (&symbols_lock); handle = scm_hash_fn_create_handle_x (symbols, symbol, SCM_UNDEFINED, symbol_lookup_hash_fn, symbol_lookup_assoc_fn, NULL); scm_i_pthread_mutex_unlock (&symbols_lock); return SCM_CAR (handle); } static SCM scm_i_str2symbol (SCM str) { SCM symbol; size_t raw_hash = scm_i_string_hash (str); symbol = lookup_interned_symbol (str, raw_hash); if (scm_is_true (symbol)) return symbol; else { /* The symbol was not found, create it. */ symbol = scm_i_make_symbol (str, 0, raw_hash, scm_cons (SCM_BOOL_F, SCM_EOL)); return intern_symbol (symbol); } } static SCM scm_i_str2uninterned_symbol (SCM str) { size_t raw_hash = scm_i_string_hash (str); return scm_i_make_symbol (str, SCM_I_F_SYMBOL_UNINTERNED, raw_hash, scm_cons (SCM_BOOL_F, SCM_EOL)); } SCM_DEFINE (scm_symbol_p, "symbol?", 1, 0, 0, (SCM obj), "Return @code{#t} if @var{obj} is a symbol, otherwise return\n" "@code{#f}.") #define FUNC_NAME s_scm_symbol_p { return scm_from_bool (scm_is_symbol (obj)); } #undef FUNC_NAME SCM_DEFINE (scm_symbol_interned_p, "symbol-interned?", 1, 0, 0, (SCM symbol), "Return @code{#t} if @var{symbol} is interned, otherwise return\n" "@code{#f}.") #define FUNC_NAME s_scm_symbol_interned_p { SCM_VALIDATE_SYMBOL (1, symbol); return scm_from_bool (scm_i_symbol_is_interned (symbol)); } #undef FUNC_NAME SCM_DEFINE (scm_make_symbol, "make-symbol", 1, 0, 0, (SCM name), "Return a new uninterned symbol with the name @var{name}. " "The returned symbol is guaranteed to be unique and future " "calls to @code{string->symbol} will not return it.") #define FUNC_NAME s_scm_make_symbol { SCM_VALIDATE_STRING (1, name); return scm_i_str2uninterned_symbol (name); } #undef FUNC_NAME SCM_DEFINE (scm_symbol_to_string, "symbol->string", 1, 0, 0, (SCM s), "Return the name of @var{symbol} as a string. If the symbol was\n" "part of an object returned as the value of a literal expression\n" "(section @pxref{Literal expressions,,,r5rs, The Revised^5\n" "Report on Scheme}) or by a call to the @code{read} procedure,\n" "and its name contains alphabetic characters, then the string\n" "returned will contain characters in the implementation's\n" "preferred standard case---some implementations will prefer\n" "upper case, others lower case. If the symbol was returned by\n" "@code{string->symbol}, the case of characters in the string\n" "returned will be the same as the case in the string that was\n" "passed to @code{string->symbol}. It is an error to apply\n" "mutation procedures like @code{string-set!} to strings returned\n" "by this procedure.\n" "\n" "The following examples assume that the implementation's\n" "standard case is lower case:\n" "\n" "@lisp\n" "(symbol->string 'flying-fish) @result{} \"flying-fish\"\n" "(symbol->string 'Martin) @result{} \"martin\"\n" "(symbol->string\n" " (string->symbol \"Malvina\")) @result{} \"Malvina\"\n" "@end lisp") #define FUNC_NAME s_scm_symbol_to_string { SCM_VALIDATE_SYMBOL (1, s); return scm_i_symbol_substring (s, 0, scm_i_symbol_length (s)); } #undef FUNC_NAME SCM_DEFINE (scm_string_to_symbol, "string->symbol", 1, 0, 0, (SCM string), "Return the symbol whose name is @var{string}. This procedure\n" "can create symbols with names containing special characters or\n" "letters in the non-standard case, but it is usually a bad idea\n" "to create such symbols because in some implementations of\n" "Scheme they cannot be read as themselves. See\n" "@code{symbol->string}.\n" "\n" "The following examples assume that the implementation's\n" "standard case is lower case:\n" "\n" "@lisp\n" "(eq? 'mISSISSIppi 'mississippi) @result{} #t\n" "(string->symbol \"mISSISSIppi\") @result{} @r{the symbol with name \"mISSISSIppi\"}\n" "(eq? 'bitBlt (string->symbol \"bitBlt\")) @result{} #f\n" "(eq? 'JollyWog\n" " (string->symbol (symbol->string 'JollyWog))) @result{} #t\n" "(string=? \"K. Harper, M.D.\"\n" " (symbol->string\n" " (string->symbol \"K. Harper, M.D.\"))) @result{}#t\n" "@end lisp") #define FUNC_NAME s_scm_string_to_symbol { SCM_VALIDATE_STRING (1, string); return scm_i_str2symbol (string); } #undef FUNC_NAME SCM_DEFINE (scm_string_ci_to_symbol, "string-ci->symbol", 1, 0, 0, (SCM str), "Return the symbol whose name is @var{str}. @var{str} is\n" "converted to lowercase before the conversion is done, if Guile\n" "is currently reading symbols case-insensitively.") #define FUNC_NAME s_scm_string_ci_to_symbol { return scm_string_to_symbol (SCM_CASE_INSENSITIVE_P ? scm_string_downcase(str) : str); } #undef FUNC_NAME /* The default prefix for `gensym'd symbols. */ static SCM default_gensym_prefix; #define MAX_PREFIX_LENGTH 30 SCM_DEFINE (scm_gensym, "gensym", 0, 1, 0, (SCM prefix), "Create a new symbol with a name constructed from a prefix and\n" "a counter value. The string @var{prefix} can be specified as\n" "an optional argument. Default prefix is @code{ g}. The counter\n" "is increased by 1 at each call. There is no provision for\n" "resetting the counter.") #define FUNC_NAME s_scm_gensym { static int gensym_counter = 0; SCM suffix, name; int n, n_digits; char buf[SCM_INTBUFLEN]; if (SCM_UNBNDP (prefix)) prefix = default_gensym_prefix; /* mutex in case another thread looks and incs at the exact same moment */ scm_i_scm_pthread_mutex_lock (&scm_i_misc_mutex); n = gensym_counter++; scm_i_pthread_mutex_unlock (&scm_i_misc_mutex); n_digits = scm_iint2str (n, 10, buf); suffix = scm_from_latin1_stringn (buf, n_digits); name = scm_string_append (scm_list_2 (prefix, suffix)); return scm_string_to_symbol (name); } #undef FUNC_NAME SCM_DEFINE (scm_symbol_hash, "symbol-hash", 1, 0, 0, (SCM symbol), "Return a hash value for @var{symbol}.") #define FUNC_NAME s_scm_symbol_hash { SCM_VALIDATE_SYMBOL (1, symbol); return scm_from_ulong (scm_i_symbol_hash (symbol)); } #undef FUNC_NAME SCM_DEFINE (scm_symbol_fref, "symbol-fref", 1, 0, 0, (SCM s), "Return the contents of the symbol @var{s}'s @dfn{function slot}.") #define FUNC_NAME s_scm_symbol_fref { SCM_VALIDATE_SYMBOL (1, s); return SCM_CAR (SCM_CELL_OBJECT_3 (s)); } #undef FUNC_NAME SCM_DEFINE (scm_symbol_pref, "symbol-pref", 1, 0, 0, (SCM s), "Return the @dfn{property list} currently associated with the\n" "symbol @var{s}.") #define FUNC_NAME s_scm_symbol_pref { SCM_VALIDATE_SYMBOL (1, s); return SCM_CDR (SCM_CELL_OBJECT_3 (s)); } #undef FUNC_NAME SCM_DEFINE (scm_symbol_fset_x, "symbol-fset!", 2, 0, 0, (SCM s, SCM val), "Change the binding of the symbol @var{s}'s function slot.") #define FUNC_NAME s_scm_symbol_fset_x { SCM_VALIDATE_SYMBOL (1, s); SCM_SETCAR (SCM_CELL_OBJECT_3 (s), val); return SCM_UNSPECIFIED; } #undef FUNC_NAME SCM_DEFINE (scm_symbol_pset_x, "symbol-pset!", 2, 0, 0, (SCM s, SCM val), "Change the binding of the symbol @var{s}'s property slot.") #define FUNC_NAME s_scm_symbol_pset_x { SCM_VALIDATE_SYMBOL (1, s); SCM_SETCDR (SCM_CELL_OBJECT_3 (s), val); return SCM_UNSPECIFIED; } #undef FUNC_NAME SCM scm_from_locale_symbol (const char *sym) { return scm_from_locale_symboln (sym, -1); } SCM scm_from_locale_symboln (const char *sym, size_t len) { SCM str = scm_from_locale_stringn (sym, len); return scm_i_str2symbol (str); } SCM scm_take_locale_symboln (char *sym, size_t len) { SCM str; str = scm_take_locale_stringn (sym, len); return scm_i_str2symbol (str); } SCM scm_take_locale_symbol (char *sym) { return scm_take_locale_symboln (sym, (size_t)-1); } SCM scm_from_latin1_symbol (const char *sym) { return scm_from_latin1_symboln (sym, -1); } SCM scm_from_latin1_symboln (const char *sym, size_t len) { unsigned long hash; SCM ret; if (len == (size_t) -1) len = strlen (sym); hash = scm_i_latin1_string_hash (sym, len); ret = lookup_interned_latin1_symbol (sym, len, hash); if (scm_is_false (ret)) { SCM str = scm_from_latin1_stringn (sym, len); ret = scm_i_str2symbol (str); } return ret; } SCM scm_from_utf8_symbol (const char *sym) { return scm_from_utf8_symboln (sym, -1); } SCM scm_from_utf8_symboln (const char *sym, size_t len) { SCM str = scm_from_utf8_stringn (sym, len); return scm_i_str2symbol (str); } void scm_symbols_prehistory () { symbols = scm_make_weak_key_hash_table (scm_from_int (2139)); } void scm_init_symbols () { #include "libguile/symbols.x" default_gensym_prefix = scm_from_latin1_string (" g"); } /* Local Variables: c-file-style: "gnu" End: */