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-rw-r--r--libguile/symbols.c563
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diff --git a/libguile/symbols.c b/libguile/symbols.c
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+++ b/libguile/symbols.c
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+/* Copyright 1995-1998,2000-2001,2003-2004,2006,2009,2011,2013,2015,2018
+ Free Software Foundation, Inc.
+
+ This file is part of Guile.
+
+ Guile 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.
+
+ Guile 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 Guile. If not, see
+ <https://www.gnu.org/licenses/>. */
+
+
+
+#ifdef HAVE_CONFIG_H
+# include <config.h>
+#endif
+
+#include <string.h>
+#include <unistr.h>
+
+#include "alist.h"
+#include "boolean.h"
+#include "chars.h"
+#include "eval.h"
+#include "fluids.h"
+#include "gsubr.h"
+#include "hash.h"
+#include "list.h"
+#include "modules.h"
+#include "numbers.h"
+#include "pairs.h"
+#include "private-options.h"
+#include "read.h"
+#include "smob.h"
+#include "srfi-13.h"
+#include "strings.h"
+#include "strorder.h"
+#include "threads.h"
+#include "variable.h"
+#include "vectors.h"
+#include "weak-set.h"
+
+#include "symbols.h"
+
+
+
+
+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}
+ */
+
+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;
+
+ data.string = name;
+ data.string_hash = raw_hash;
+
+ return scm_c_weak_set_lookup (symbols, raw_hash,
+ string_lookup_predicate_fn,
+ &data, 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;
+
+ data.str = str;
+ data.len = len;
+ data.string_hash = raw_hash;
+
+ return scm_c_weak_set_lookup (symbols, raw_hash,
+ latin1_lookup_predicate_fn,
+ &data, SCM_BOOL_F);
+}
+
+struct utf8_lookup_data
+{
+ const char *str;
+ size_t len;
+ unsigned long string_hash;
+};
+
+static int
+utf8_string_equals_wide_string (const uint8_t *narrow, size_t nlen,
+ const scm_t_wchar *wide, size_t wlen)
+{
+ size_t byte_idx = 0, char_idx = 0;
+
+ while (byte_idx < nlen && char_idx < wlen)
+ {
+ ucs4_t c;
+ int nbytes;
+
+ nbytes = u8_mbtoucr (&c, narrow + byte_idx, nlen - byte_idx);
+ if (nbytes == 0)
+ break;
+ else if (nbytes < 0)
+ /* Bad UTF-8. */
+ return 0;
+ else if (c != wide[char_idx])
+ return 0;
+
+ byte_idx += nbytes;
+ char_idx++;
+ }
+
+ return byte_idx == nlen && char_idx == wlen;
+}
+
+static int
+utf8_lookup_predicate_fn (SCM sym, void *closure)
+{
+ struct utf8_lookup_data *data = closure;
+
+ if (scm_i_symbol_hash (sym) != data->string_hash)
+ return 0;
+
+ if (scm_i_is_narrow_symbol (sym))
+ return (scm_i_symbol_length (sym) == data->len
+ && strncmp (scm_i_symbol_chars (sym), data->str, data->len) == 0);
+ else
+ return utf8_string_equals_wide_string ((const uint8_t *) data->str,
+ data->len,
+ scm_i_symbol_wide_chars (sym),
+ scm_i_symbol_length (sym));
+}
+
+static SCM
+lookup_interned_utf8_symbol (const char *str, size_t len,
+ unsigned long raw_hash)
+{
+ struct utf8_lookup_data data;
+
+ data.str = str;
+ data.len = len;
+ data.string_hash = raw_hash;
+
+ return scm_c_weak_set_lookup (symbols, raw_hash,
+ utf8_lookup_predicate_fn,
+ &data, SCM_BOOL_F);
+}
+
+static int
+symbol_lookup_predicate_fn (SCM sym, void *closure)
+{
+ SCM other = SCM_PACK_POINTER (closure);
+
+ if (scm_i_symbol_hash (sym) == scm_i_symbol_hash (other)
+ && scm_i_symbol_length (sym) == scm_i_symbol_length (other))
+ {
+ if (scm_i_is_narrow_symbol (sym))
+ return scm_i_is_narrow_symbol (other)
+ && (strncmp (scm_i_symbol_chars (sym),
+ scm_i_symbol_chars (other),
+ scm_i_symbol_length (other)) == 0);
+ else
+ return scm_is_true
+ (scm_string_equal_p (scm_symbol_to_string (sym),
+ scm_symbol_to_string (other)));
+ }
+ return 0;
+}
+
+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));
+
+ /* Might return a different symbol, if another one was interned at
+ the same time. */
+ return scm_c_weak_set_add_x (symbols, raw_hash,
+ symbol_lookup_predicate_fn,
+ SCM_UNPACK_POINTER (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_set_car_x (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_set_cdr_x (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)
+{
+ unsigned long hash;
+ SCM ret;
+
+ if (len == (size_t) -1)
+ len = strlen (sym);
+ hash = scm_i_utf8_string_hash (sym, len);
+
+ ret = lookup_interned_utf8_symbol (sym, len, hash);
+ if (scm_is_false (ret))
+ {
+ SCM str = scm_from_utf8_stringn (sym, len);
+ ret = scm_i_str2symbol (str);
+ }
+
+ return ret;
+}
+
+void
+scm_symbols_prehistory ()
+{
+ symbols = scm_c_make_weak_set (5000);
+}
+
+
+void
+scm_init_symbols ()
+{
+#include "symbols.x"
+
+ default_gensym_prefix = scm_from_latin1_string (" g");
+}