/* Copyright (C) 1995,1996,1997,1998,2000,2001 Free Software Foundation, Inc. * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2, or (at your option) * any later version. * * This program 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 General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this software; see the file COPYING. If not, write to * the Free Software Foundation, Inc., 59 Temple Place, Suite 330, * Boston, MA 02111-1307 USA * * As a special exception, the Free Software Foundation gives permission * for additional uses of the text contained in its release of GUILE. * * The exception is that, if you link the GUILE library with other files * to produce an executable, this does not by itself cause the * resulting executable to be covered by the GNU General Public License. * Your use of that executable is in no way restricted on account of * linking the GUILE library code into it. * * This exception does not however invalidate any other reasons why * the executable file might be covered by the GNU General Public License. * * This exception applies only to the code released by the * Free Software Foundation under the name GUILE. If you copy * code from other Free Software Foundation releases into a copy of * GUILE, as the General Public License permits, the exception does * not apply to the code that you add in this way. To avoid misleading * anyone as to the status of such modified files, you must delete * this exception notice from them. * * If you write modifications of your own for GUILE, it is your choice * whether to permit this exception to apply to your modifications. * If you do not wish that, delete this exception notice. */ #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/validate.h" #include "libguile/symbols.h" #ifdef HAVE_STRING_H #include #endif static SCM symbols; #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} */ SCM scm_mem2symbol (const char *name, size_t len) { size_t raw_hash = scm_string_hash ((const unsigned char *) name, len); size_t hash = raw_hash % SCM_VECTOR_LENGTH (symbols); { /* Try to find the symbol in the symbols table */ SCM l; for (l = SCM_VELTS (symbols) [hash]; !SCM_NULLP (l); l = SCM_CDR (l)) { SCM sym = SCM_CAAR (l); if (SCM_SYMBOL_HASH (sym) == raw_hash && SCM_SYMBOL_LENGTH (sym) == len) { char *chrs = SCM_SYMBOL_CHARS (sym); size_t i = len; while (i != 0) { --i; if (name[i] != chrs[i]) goto next_symbol; } return sym; } next_symbol: ; } } { /* The symbol was not found - create it. */ SCM symbol; SCM cell; SCM slot; SCM_NEWCELL2 (symbol); SCM_SET_SYMBOL_CHARS (symbol, scm_must_strndup (name, len)); SCM_SET_SYMBOL_HASH (symbol, raw_hash); SCM_SET_PROP_SLOTS (symbol, scm_cons (SCM_BOOL_F, SCM_EOL)); SCM_SET_SYMBOL_LENGTH (symbol, (long) len); slot = SCM_VELTS (symbols) [hash]; cell = scm_cons (symbol, SCM_UNDEFINED); SCM_VELTS (symbols) [hash] = scm_cons (cell, slot); return symbol; } } SCM scm_str2symbol (const char *str) { return scm_mem2symbol (str, strlen (str)); } 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_BOOL (SCM_SYMBOLP (obj)); } #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 str; SCM_VALIDATE_SYMBOL (1, s); str = scm_mem2string (SCM_SYMBOL_CHARS (s), SCM_SYMBOL_LENGTH (s)); scm_remember_upto_here_1 (s); return str; } #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_mem2symbol (SCM_STRING_CHARS (string), SCM_STRING_LENGTH (string)); } #undef FUNC_NAME #define MAX_PREFIX_LENGTH 30 static int gensym_counter; 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 { char buf[MAX_PREFIX_LENGTH + SCM_INTBUFLEN]; char *name = buf; size_t len; if (SCM_UNBNDP (prefix)) { name[0] = ' '; name[1] = 'g'; len = 2; } else { SCM_VALIDATE_STRING (1, prefix); len = SCM_STRING_LENGTH (prefix); if (len > MAX_PREFIX_LENGTH) name = SCM_MUST_MALLOC (len + SCM_INTBUFLEN); memcpy (name, SCM_STRING_CHARS (prefix), len); } { int n_digits = scm_iint2str (gensym_counter++, 10, &name[len]); SCM res = scm_mem2symbol (name, len + n_digits); if (name != buf) scm_must_free (name); return res; } } #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_MAKINUM (SCM_SYMBOL_HASH (symbol)); } #undef FUNC_NAME SCM_DEFINE (scm_symbol_fref, "symbol-fref", 1, 0, 0, (SCM s), "Return the contents of @var{symbol}'s @dfn{function slot}.") #define FUNC_NAME s_scm_symbol_fref { SCM_VALIDATE_SYMBOL (1,s); return SCM_SYMBOL_FUNC (s); } #undef FUNC_NAME SCM_DEFINE (scm_symbol_pref, "symbol-pref", 1, 0, 0, (SCM s), "Return the @dfn{property list} currently associated with @var{symbol}.") #define FUNC_NAME s_scm_symbol_pref { SCM_VALIDATE_SYMBOL (1,s); return SCM_SYMBOL_PROPS (s); } #undef FUNC_NAME SCM_DEFINE (scm_symbol_fset_x, "symbol-fset!", 2, 0, 0, (SCM s, SCM val), "Change the binding of @var{symbol}'s function slot.") #define FUNC_NAME s_scm_symbol_fset_x { SCM_VALIDATE_SYMBOL (1,s); SCM_SET_SYMBOL_FUNC (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 @var{symbol}'s property slot.") #define FUNC_NAME s_scm_symbol_pset_x { SCM_VALIDATE_SYMBOL (1,s); SCM_DEFER_INTS; SCM_SET_SYMBOL_PROPS (s, val); SCM_ALLOW_INTS; return SCM_UNSPECIFIED; } #undef FUNC_NAME void scm_symbols_prehistory () { symbols = scm_make_weak_key_hash_table (SCM_MAKINUM (1009)); scm_permanent_object (symbols); } void scm_init_symbols () { gensym_counter = 0; #include "libguile/symbols.x" #if SCM_ENABLE_VCELLS scm_init_symbols_deprecated (); #endif } /* Local Variables: c-file-style: "gnu" End: */