X-Git-Url: https://git.saurik.com/bison.git/blobdiff_plain/7cff04b572e7d71c2801671e21541d321862d339..258cddbc3695f2095cbfbc9ff95309b28733f7d2:/data/lalr1.cc diff --git a/data/lalr1.cc b/data/lalr1.cc index 5e0be216..e82e654f 100644 --- a/data/lalr1.cc +++ b/data/lalr1.cc @@ -1,104 +1,68 @@ # C++ skeleton for Bison -# Copyright (C) 2002, 2003, 2004, 2005, 2006, 2007 Free Software Foundation, Inc. +# Copyright (C) 2002-2012 Free Software Foundation, Inc. -# This program is free software; you can redistribute it and/or modify +# 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 of the License, or +# the Free Software Foundation, either version 3 of the License, 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 program; if not, write to the Free Software -# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA -# 02110-1301 USA +# along with this program. If not, see . m4_include(b4_pkgdatadir/[c++.m4]) m4_define([b4_parser_class_name], [b4_percent_define_get([[parser_class_name]])]) -m4_define([b4_namespace], - [b4_percent_define_get([[namespace]])]) # The header is mandatory. b4_defines_if([], [b4_fatal([b4_skeleton[: using %%defines is mandatory]])]) -# Backward compatibility. -m4_define([b4_location_constructors]) -m4_include(b4_pkgdatadir/[location.cc]) +b4_percent_define_ifdef([[location_type]], [], + [# Backward compatibility. + m4_define([b4_location_constructors]) + m4_include(b4_pkgdatadir/[location.cc])]) +m4_include(b4_pkgdatadir/[stack.hh]) # We do want M4 expansion after # for CPP macros. m4_changecom() m4_divert_push(0)dnl b4_defines_if( -[@output(b4_spec_defines_file@) +[@output(b4_spec_defines_file@)@ b4_copyright([Skeleton interface for Bison LALR(1) parsers in C++], - [2002, 2003, 2004, 2005, 2006]) -dnl FIXME: This is wrong, we want computed header guards. + [2002-2012]) [ +/** + ** \file ]b4_spec_defines_file[ + ** Define the ]b4_namespace_ref[::parser class. + */ + /* C++ LALR(1) parser skeleton written by Akim Demaille. */ -#ifndef PARSER_HEADER_H -# define PARSER_HEADER_H +]b4_cpp_guard_open([b4_spec_defines_file])[ ]b4_percent_code_get([[requires]])[ #include #include #include "stack.hh" +]b4_percent_define_ifdef([[location_type]], [], + [[#include "location.hh"]])[ -namespace ]b4_namespace[ -{ - class position; - class location; -} - -#include "location.hh" +]b4_null_define[ /* Enabling traces. */ #ifndef YYDEBUG # define YYDEBUG ]b4_debug_flag[ #endif -/* Enabling verbose error messages. */ -#ifdef YYERROR_VERBOSE -# undef YYERROR_VERBOSE -# define YYERROR_VERBOSE 1 -#else -# define YYERROR_VERBOSE ]b4_error_verbose_flag[ -#endif - -/* Enabling the token table. */ -#ifndef YYTOKEN_TABLE -# define YYTOKEN_TABLE ]b4_token_table[ -#endif - -/* YYLLOC_DEFAULT -- Set CURRENT to span from RHS[1] to RHS[N]. - If N is 0, then set CURRENT to the empty location which ends - the previous symbol: RHS[0] (always defined). */ - -#ifndef YYLLOC_DEFAULT -# define YYLLOC_DEFAULT(Current, Rhs, N) \ -do { \ - if (N) \ - { \ - (Current).begin = (Rhs)[1].begin; \ - (Current).end = (Rhs)[N].end; \ - } \ - else \ - { \ - (Current).begin = (Current).end = (Rhs)[0].end; \ - } \ -} while (false) -#endif - -namespace ]b4_namespace[ -{ +]b4_namespace_open[ /// A Bison parser. class ]b4_parser_class_name[ @@ -118,7 +82,8 @@ b4_user_stype typedef YYSTYPE semantic_type; #endif /// Symbol locations. - typedef ]b4_percent_define_get([[location_type]])[ location_type; + typedef ]b4_percent_define_get([[location_type]], + [[location]])[ location_type; /// Tokens. struct token { @@ -135,6 +100,7 @@ b4_user_stype /// \returns 0 iff parsing succeeded. virtual int parse (); +#if YYDEBUG /// The current debugging stream. std::ostream& debug_stream () const; /// Set the current debugging stream. @@ -146,6 +112,7 @@ b4_user_stype debug_level_type debug_level () const; /// Set the current debugging level. void set_debug_level (debug_level_type l); +#endif private: /// Report a syntax error. @@ -156,8 +123,7 @@ b4_user_stype /// Generate an error message. /// \param state the state where the error occurred. /// \param tok the lookahead token. - virtual std::string yysyntax_error_ (int yystate]dnl -b4_error_verbose_if([, int tok])[); + virtual std::string yysyntax_error_ (int yystate, int tok); #if YYDEBUG /// \brief Report a symbol value on the debug stream. @@ -193,6 +159,14 @@ b4_error_verbose_if([, int tok])[); /// The location stack. location_stack_type yylocation_stack_; + /// Whether the given \c yypact_ value indicates a defaulted state. + /// \param yyvalue the value to check + static bool yy_pact_value_is_default_ (int yyvalue); + + /// Whether the given \c yytable_ value indicates a syntax error. + /// \param yyvalue the value to check + static bool yy_table_value_is_error_ (int yyvalue); + /// Internal symbol numbers. typedef ]b4_int_type_for([b4_translate])[ token_number_type; /* Tables. */ @@ -200,7 +174,7 @@ b4_error_verbose_if([, int tok])[); static const ]b4_int_type_for([b4_pact])[ yypact_[]; static const ]b4_int_type(b4_pact_ninf, b4_pact_ninf)[ yypact_ninf_; - /// For a state, default rule to reduce. + /// For a state, default reduction number. /// Unless\a yytable_ specifies something else to do. /// Zero means the default is an error. static const ]b4_int_type_for([b4_defact])[ yydefact_[]; @@ -224,19 +198,15 @@ b4_error_verbose_if([, int tok])[); /// For a rule, its LHS. static const ]b4_int_type_for([b4_r1])[ yyr1_[]; /// For a rule, its RHS length. - static const ]b4_int_type_for([b4_r2])[ yyr2_[]; - -#if YYDEBUG || YYERROR_VERBOSE || YYTOKEN_TABLE - /// For a symbol, its name in clear. - static const char* const yytname_[]; -#endif + static const ]b4_int_type_for([b4_r2])[ yyr2_[]; ]b4_error_verbose_if([ -#if YYERROR_VERBOSE /// Convert the symbol name \a n to a form suitable for a diagnostic. - virtual std::string yytnamerr_ (const char *n); -#endif + static std::string yytnamerr_ (const char *n);])[ -#if YYDEBUG +]b4_token_table_if([], [[#if YYDEBUG]])[ + /// For a symbol, its name in clear. + static const char* const yytname_[]; +]b4_token_table_if([[#if YYDEBUG]])[ /// A type to store symbol numbers and -1. typedef ]b4_int_type_for([b4_rhs])[ rhs_number_type; /// A `-1'-separated list of the rules' RHS. @@ -287,23 +257,22 @@ b4_error_verbose_if([, int tok])[); static const token_number_type yyundef_token_; ]b4_parse_param_vars[ }; -} +]b4_namespace_close[ -]m4_ifval(b4_percent_define_get([[global_tokens_and_yystype]]), +]b4_percent_define_flag_if([[global_tokens_and_yystype]], [b4_token_defines(b4_tokens) #ifndef YYSTYPE /* Redirection for backward compatibility. */ -# define YYSTYPE b4_namespace::b4_parser_class_name::semantic_type +# define YYSTYPE b4_namespace_ref::b4_parser_class_name::semantic_type #endif -]) -b4_percent_code_get([[provides]])[]dnl - -[#endif /* ! defined PARSER_HEADER_H */] +])[ +]b4_percent_code_get([[provides]])[ +]b4_cpp_guard_close([b4_spec_defines_file]) ])dnl -@output(b4_parser_file_name@) +@output(b4_parser_file_name@)@ b4_copyright([Skeleton implementation for Bison LALR(1) parsers in C++], - [2002, 2003, 2004, 2005, 2006]) + [2002-2012]) b4_percent_code_get([[top]])[]dnl m4_if(b4_prefix, [yy], [], [ @@ -321,7 +290,7 @@ b4_defines_if([[ b4_percent_code_get[]dnl [#ifndef YY_ -# if YYENABLE_NLS +# if defined YYENABLE_NLS && YYENABLE_NLS # if ENABLE_NLS # include /* FIXME: INFRINGES ON USER NAME SPACE */ # define YY_(msgid) dgettext ("bison-runtime", msgid) @@ -332,6 +301,26 @@ b4_percent_code_get[]dnl # endif #endif +/* YYLLOC_DEFAULT -- Set CURRENT to span from RHS[1] to RHS[N]. + If N is 0, then set CURRENT to the empty location which ends + the previous symbol: RHS[0] (always defined). */ + +#define YYRHSLOC(Rhs, K) ((Rhs)[K]) +#ifndef YYLLOC_DEFAULT +# define YYLLOC_DEFAULT(Current, Rhs, N) \ + do \ + if (N) \ + { \ + (Current).begin = YYRHSLOC (Rhs, 1).begin; \ + (Current).end = YYRHSLOC (Rhs, N).end; \ + } \ + else \ + { \ + (Current).begin = (Current).end = YYRHSLOC (Rhs, 0).end; \ + } \ + while (false) +#endif + /* Suppress unused-variable warnings by "using" E. */ #define YYUSE(e) ((void) (e)) @@ -372,13 +361,15 @@ do { \ #endif /* !YYDEBUG */ +#define yyerrok (yyerrstatus_ = 0) +#define yyclearin (yychar = yyempty_) + #define YYACCEPT goto yyacceptlab #define YYABORT goto yyabortlab #define YYERROR goto yyerrorlab +#define YYRECOVERING() (!!yyerrstatus_) -namespace ]b4_namespace[ -{ -#if YYERROR_VERBOSE +]b4_namespace_open[]b4_error_verbose_if([[ /* Return YYSTR after stripping away unnecessary quotes and backslashes, so that it's suitable for yyerror. The heuristic is @@ -416,8 +407,7 @@ namespace ]b4_namespace[ return yystr; } - -#endif +]])[ /// Build a parser object. ]b4_parser_class_name::b4_parser_class_name[ (]b4_parse_param_decl[)]m4_ifset([b4_parse_param], [ @@ -444,6 +434,9 @@ namespace ]b4_namespace[ { YYUSE (yylocationp); YYUSE (yyvaluep); + std::ostream& yyo = debug_stream (); + std::ostream& yyoutput = yyo; + YYUSE (yyoutput); switch (yytype) { ]m4_map([b4_symbol_actions], m4_defn([b4_symbol_printers]))dnl @@ -518,6 +511,18 @@ namespace ]b4_namespace[ } #endif + inline bool + ]b4_parser_class_name[::yy_pact_value_is_default_ (int yyvalue) + { + return yyvalue == yypact_ninf_; + } + + inline bool + ]b4_parser_class_name[::yy_table_value_is_error_ (int yyvalue) + { + return yyvalue == yytable_ninf_; + } + int ]b4_parser_class_name[::parse () { @@ -539,7 +544,7 @@ namespace ]b4_namespace[ /// Location of the lookahead. location_type yylloc; /// The locations where the error started and ended. - location yyerror_range[2]; + location_type yyerror_range[3]; /// $$. semantic_type yyval; @@ -584,7 +589,7 @@ m4_popdef([b4_at_dollar])])dnl /* Try to take a decision without lookahead. */ yyn = yypact_[yystate]; - if (yyn == yypact_ninf_) + if (yy_pact_value_is_default_ (yyn)) goto yydefault; /* Read a lookahead token. */ @@ -620,8 +625,8 @@ m4_ifdef([b4_lex_param], [, ]b4_lex_param))[; yyn = yytable_[yyn]; if (yyn <= 0) { - if (yyn == 0 || yyn == yytable_ninf_) - goto yyerrlab; + if (yy_table_value_is_error_ (yyn)) + goto yyerrlab; yyn = -yyn; goto yyreduce; } @@ -676,8 +681,20 @@ m4_ifdef([b4_lex_param], [, ]b4_lex_param))[; switch (yyn) { ]b4_user_actions[ - default: break; + default: + break; } + /* User semantic actions sometimes alter yychar, and that requires + that yytoken be updated with the new translation. We take the + approach of translating immediately before every use of yytoken. + One alternative is translating here after every semantic action, + but that translation would be missed if the semantic action + invokes YYABORT, YYACCEPT, or YYERROR immediately after altering + yychar. In the case of YYABORT or YYACCEPT, an incorrect + destructor might then be invoked immediately. In the case of + YYERROR, subsequent parser actions might lead to an incorrect + destructor call or verbose syntax error message before the + lookahead is translated. */ YY_SYMBOL_PRINT ("-> $$ =", yyr1_[yyn], &yyval, &yyloc); yypop_ (yylen); @@ -701,15 +718,20 @@ m4_ifdef([b4_lex_param], [, ]b4_lex_param))[; | yyerrlab -- here on detecting error | `------------------------------------*/ yyerrlab: + /* Make sure we have latest lookahead translation. See comments at + user semantic actions for why this is necessary. */ + yytoken = yytranslate_ (yychar); + /* If not already recovering from an error, report this error. */ if (!yyerrstatus_) { ++yynerrs_; - error (yylloc, yysyntax_error_ (yystate]dnl -b4_error_verbose_if([, yytoken])[)); + if (yychar == yyempty_) + yytoken = yyempty_; + error (yylloc, yysyntax_error_ (yystate, yytoken)); } - yyerror_range[0] = yylloc; + yyerror_range[1] = yylloc; if (yyerrstatus_ == 3) { /* If just tried and failed to reuse lookahead token after an @@ -744,7 +766,7 @@ b4_error_verbose_if([, yytoken])[)); if (false) goto yyerrorlab; - yyerror_range[0] = yylocation_stack_[yylen - 1]; + yyerror_range[1] = yylocation_stack_[yylen - 1]; /* Do not reclaim the symbols of the rule which action triggered this YYERROR. */ yypop_ (yylen); @@ -761,7 +783,7 @@ b4_error_verbose_if([, yytoken])[)); for (;;) { yyn = yypact_[yystate]; - if (yyn != yypact_ninf_) + if (!yy_pact_value_is_default_ (yyn)) { yyn += yyterror_; if (0 <= yyn && yyn <= yylast_ && yycheck_[yyn] == yyterror_) @@ -776,7 +798,7 @@ b4_error_verbose_if([, yytoken])[)); if (yystate_stack_.height () == 1) YYABORT; - yyerror_range[0] = yylocation_stack_[0]; + yyerror_range[1] = yylocation_stack_[0]; yydestruct_ ("Error: popping", yystos_[yystate], &yysemantic_stack_[0], &yylocation_stack_[0]); @@ -785,16 +807,16 @@ b4_error_verbose_if([, yytoken])[)); YY_STACK_PRINT (); } - yyerror_range[1] = yylloc; + yyerror_range[2] = yylloc; // Using YYLLOC is tempting, but would change the location of // the lookahead. YYLOC is available though. - YYLLOC_DEFAULT (yyloc, (yyerror_range - 1), 2); + YYLLOC_DEFAULT (yyloc, yyerror_range, 2); yysemantic_stack_.push (yylval); yylocation_stack_.push (yyloc); /* Shift the error token. */ YY_SYMBOL_PRINT ("Shifting", yystos_[yyn], - &yysemantic_stack_[0], &yylocation_stack_[0]); + &yysemantic_stack_[0], &yylocation_stack_[0]); yystate = yyn; goto yynewstate; @@ -811,7 +833,13 @@ b4_error_verbose_if([, yytoken])[)); yyreturn: if (yychar != yyempty_) - yydestruct_ ("Cleanup: discarding lookahead", yytoken, &yylval, &yylloc); + { + /* Make sure we have latest lookahead translation. See comments + at user semantic actions for why this is necessary. */ + yytoken = yytranslate_ (yychar); + yydestruct_ ("Cleanup: discarding lookahead", yytoken, &yylval, + &yylloc); + } /* Do not reclaim the symbols of the rule which action triggered this YYABORT or YYACCEPT. */ @@ -830,52 +858,100 @@ b4_error_verbose_if([, yytoken])[)); // Generate an error message. std::string - ]b4_parser_class_name[::yysyntax_error_ (int yystate]dnl -b4_error_verbose_if([, int tok])[) - { - std::string res; - YYUSE (yystate); -#if YYERROR_VERBOSE - int yyn = yypact_[yystate]; - if (yypact_ninf_ < yyn && yyn <= yylast_) + ]b4_parser_class_name[::yysyntax_error_ (]dnl +b4_error_verbose_if([int yystate, int yytoken], + [int, int])[) + {]b4_error_verbose_if([[ + std::string yyres; + // Number of reported tokens (one for the "unexpected", one per + // "expected"). + size_t yycount = 0; + // Its maximum. + enum { YYERROR_VERBOSE_ARGS_MAXIMUM = 5 }; + // Arguments of yyformat. + char const *yyarg[YYERROR_VERBOSE_ARGS_MAXIMUM]; + + /* There are many possibilities here to consider: + - If this state is a consistent state with a default action, then + the only way this function was invoked is if the default action + is an error action. In that case, don't check for expected + tokens because there are none. + - The only way there can be no lookahead present (in yytoken) is + if this state is a consistent state with a default action. + Thus, detecting the absence of a lookahead is sufficient to + determine that there is no unexpected or expected token to + report. In that case, just report a simple "syntax error". + - Don't assume there isn't a lookahead just because this state is + a consistent state with a default action. There might have + been a previous inconsistent state, consistent state with a + non-default action, or user semantic action that manipulated + yychar. + - Of course, the expected token list depends on states to have + correct lookahead information, and it depends on the parser not + to perform extra reductions after fetching a lookahead from the + scanner and before detecting a syntax error. Thus, state + merging (from LALR or IELR) and default reductions corrupt the + expected token list. However, the list is correct for + canonical LR with one exception: it will still contain any + token that will not be accepted due to an error action in a + later state. + */ + if (yytoken != yyempty_) { - /* Start YYX at -YYN if negative to avoid negative indexes in - YYCHECK. */ - int yyxbegin = yyn < 0 ? -yyn : 0; - - /* Stay within bounds of both yycheck and yytname. */ - int yychecklim = yylast_ - yyn + 1; - int yyxend = yychecklim < yyntokens_ ? yychecklim : yyntokens_; - int count = 0; - for (int x = yyxbegin; x < yyxend; ++x) - if (yycheck_[x + yyn] == x && x != yyterror_) - ++count; - - // FIXME: This method of building the message is not compatible - // with internationalization. It should work like yacc.c does it. - // That is, first build a string that looks like this: - // "syntax error, unexpected %s or %s or %s" - // Then, invoke YY_ on this string. - // Finally, use the string as a format to output - // yytname_[tok], etc. - // Until this gets fixed, this message appears in English only. - res = "syntax error, unexpected "; - res += yytnamerr_ (yytname_[tok]); - if (count < 5) - { - count = 0; - for (int x = yyxbegin; x < yyxend; ++x) - if (yycheck_[x + yyn] == x && x != yyterror_) - { - res += (!count++) ? ", expecting " : " or "; - res += yytnamerr_ (yytname_[x]); - } - } + yyarg[yycount++] = yytname_[yytoken]; + int yyn = yypact_[yystate]; + if (!yy_pact_value_is_default_ (yyn)) + { + /* Start YYX at -YYN if negative to avoid negative indexes in + YYCHECK. In other words, skip the first -YYN actions for + this state because they are default actions. */ + int yyxbegin = yyn < 0 ? -yyn : 0; + /* Stay within bounds of both yycheck and yytname. */ + int yychecklim = yylast_ - yyn + 1; + int yyxend = yychecklim < yyntokens_ ? yychecklim : yyntokens_; + for (int yyx = yyxbegin; yyx < yyxend; ++yyx) + if (yycheck_[yyx + yyn] == yyx && yyx != yyterror_ + && !yy_table_value_is_error_ (yytable_[yyx + yyn])) + { + if (yycount == YYERROR_VERBOSE_ARGS_MAXIMUM) + { + yycount = 1; + break; + } + else + yyarg[yycount++] = yytname_[yyx]; + } + } } - else -#endif - res = YY_("syntax error"); - return res; + + char const* yyformat = YY_NULL; + switch (yycount) + { +#define YYCASE_(N, S) \ + case N: \ + yyformat = S; \ + break + YYCASE_(0, YY_("syntax error")); + YYCASE_(1, YY_("syntax error, unexpected %s")); + YYCASE_(2, YY_("syntax error, unexpected %s, expecting %s")); + YYCASE_(3, YY_("syntax error, unexpected %s, expecting %s or %s")); + YYCASE_(4, YY_("syntax error, unexpected %s, expecting %s or %s or %s")); + YYCASE_(5, YY_("syntax error, unexpected %s, expecting %s or %s or %s or %s")); +#undef YYCASE_ + } + + // Argument number. + size_t yyi = 0; + for (char const* yyp = yyformat; *yyp; ++yyp) + if (yyp[0] == '%' && yyp[1] == 's' && yyi < yycount) + { + yyres += yytnamerr_ (yyarg[yyi++]); + ++yyp; + } + else + yyres += *yyp; + return yyres;]], [[ + return YY_("syntax error");]])[ } @@ -888,9 +964,9 @@ b4_error_verbose_if([, int tok])[) ]b4_pact[ }; - /* YYDEFACT[S] -- default rule to reduce with in state S when YYTABLE - doesn't specify something else to do. Zero means the default is an - error. */ + /* YYDEFACT[S] -- default reduction number in state S. Performed when + YYTABLE doesn't specify something else to do. Zero means the + default is an error. */ const ]b4_int_type_for([b4_defact])[ ]b4_parser_class_name[::yydefact_[] = { @@ -913,7 +989,7 @@ b4_error_verbose_if([, int tok])[) /* YYTABLE[YYPACT[STATE-NUM]]. What to do in state STATE-NUM. If positive, shift that token. If negative, reduce the rule which - number is the opposite. If zero, do what YYDEFACT says. */ + number is the opposite. If YYTABLE_NINF_, syntax error. */ const ]b4_int_type(b4_table_ninf, b4_table_ninf) b4_parser_class_name::yytable_ninf_ = b4_table_ninf[; const ]b4_int_type_for([b4_table])[ ]b4_parser_class_name[::yytable_[] = @@ -960,7 +1036,7 @@ b4_error_verbose_if([, int tok])[) ]b4_r2[ }; -#if YYDEBUG || YYERROR_VERBOSE || YYTOKEN_TABLE +]b4_token_table_if([], [[#if YYDEBUG]])[ /* YYTNAME[SYMBOL-NUM] -- String name of the symbol SYMBOL-NUM. First, the terminals, then, starting at \a yyntokens_, nonterminals. */ const char* @@ -968,9 +1044,8 @@ b4_error_verbose_if([, int tok])[) { ]b4_tname[ }; -#endif -#if YYDEBUG +]b4_token_table_if([[#if YYDEBUG]])[ /* YYRHS -- A `-1'-separated list of the rules' RHS. */ const ]b4_parser_class_name[::rhs_number_type ]b4_parser_class_name[::yyrhs_[] = @@ -1050,107 +1125,6 @@ b4_error_verbose_if([, int tok])[) const unsigned int ]b4_parser_class_name[::yyuser_token_number_max_ = ]b4_user_token_number_max[; const ]b4_parser_class_name[::token_number_type ]b4_parser_class_name[::yyundef_token_ = ]b4_undef_token_number[; -} // namespace ]b4_namespace[ - +]b4_namespace_close[ ]b4_epilogue -dnl -@output(b4_dir_prefix[]stack.hh@) -b4_copyright([Stack handling for Bison parsers in C++], - [2002, 2003, 2004, 2005, 2006])[ - -#ifndef BISON_STACK_HH -# define BISON_STACK_HH - -#include - -namespace ]b4_namespace[ -{ - template > - class stack - { - public: - - // Hide our reversed order. - typedef typename S::reverse_iterator iterator; - typedef typename S::const_reverse_iterator const_iterator; - - stack () : seq_ () - { - } - - stack (unsigned int n) : seq_ (n) - { - } - - inline - T& - operator [] (unsigned int i) - { - return seq_[i]; - } - - inline - const T& - operator [] (unsigned int i) const - { - return seq_[i]; - } - - inline - void - push (const T& t) - { - seq_.push_front (t); - } - - inline - void - pop (unsigned int n = 1) - { - for (; n; --n) - seq_.pop_front (); - } - - inline - unsigned int - height () const - { - return seq_.size (); - } - - inline const_iterator begin () const { return seq_.rbegin (); } - inline const_iterator end () const { return seq_.rend (); } - - private: - - S seq_; - }; - - /// Present a slice of the top of a stack. - template > - class slice - { - public: - - slice (const S& stack, - unsigned int range) : stack_ (stack), - range_ (range) - { - } - - inline - const T& - operator [] (unsigned int i) const - { - return stack_[range_ - i]; - } - - private: - - const S& stack_; - unsigned int range_; - }; -} - -#endif // not BISON_STACK_HH] m4_divert_pop(0)