X-Git-Url: https://git.saurik.com/bison.git/blobdiff_plain/2c086d295967986a261ef6c2729b9edb62aac451..9c6a89660e930bf68907fb6141b517378147f38e:/data/lalr1.cc diff --git a/data/lalr1.cc b/data/lalr1.cc index 2e9259c2..86e6fd08 100644 --- a/data/lalr1.cc +++ b/data/lalr1.cc @@ -19,62 +19,33 @@ m4_include(b4_pkgdatadir/[c++.m4]) -# b4_args(ARG1, ...) -# _b4_args(ARG1, ...) -# ------------------- -# Join with comma, skipping empty arguments. -# b4_args calls itself recursively until it sees the first non-empty -# argument, then calls _b4_args which prepends each non-empty argument -# with a comma. -m4_define([b4_args], -[m4_if([$#$1], - [1], [], - [m4_ifval([$1], - [$1[]_$0(m4_shift($@))], - [$0(m4_shift($@))])])]) - -# _b4_args(ARGS1, ...) -# -------------------- -m4_define([_b4_args], -[m4_if([$#$1], - [1], [], - [m4_ifval([$1], [, $1])[]$0(m4_shift($@))])]) - +# b4_integral_parser_table_declare(TABLE-NAME, CONTENT, COMMENT) +# -------------------------------------------------------------- +# Declare "parser::yy_" which contents is CONTENT. +m4_define([b4_integral_parser_table_declare], +[m4_ifval([$3], [b4_c_comment([$3], [ ]) +])dnl + static const b4_int_type_for([$2]) yy$1_[[]];dnl +]) -# b4_table_define(TABLE-NAME, CONTENT) -# ------------------------------------ +# b4_integral_parser_table_define(TABLE-NAME, CONTENT, COMMENT) +# --------------------------------------------- # Define "parser::yy_" which contents is CONTENT. -m4_define([b4_table_define], -[const b4_int_type_for([$2]) +m4_define([b4_integral_parser_table_define], +[ const b4_int_type_for([$2]) b4_parser_class_name::yy$1_[[]] = { $2 - }dnl + };dnl ]) + # b4_symbol_value_template(VAL, [TYPE]) # ------------------------------------- -# Same as b4_symbol_value, but used in a template method. +# Same as b4_symbol_value, but used in a template method. It makes +# a difference when using variants. m4_copy([b4_symbol_value], [b4_symbol_value_template]) -# How the semantic value is extracted when using variants. -b4_variant_if([ - # b4_symbol_value(VAL, [TYPE]) - # ---------------------------- - m4_define([b4_symbol_value], - [m4_ifval([$2], - [$1.as<$2>()], - [$1])]) - - # b4_symbol_value_template(VAL, [TYPE]) - # ------------------------------------- - # Same as b4_symbol_value, but used in a template method. - m4_define([b4_symbol_value_template], - [m4_ifval([$2], - [$1.template as<$2>()], - [$1])]) -]) # b4_variant_if - # b4_lex_symbol_if([IF-YYLEX-RETURNS-A-COMPLETE-SYMBOL], [IF-NOT]) # ---------------------------------------------------------------- @@ -92,14 +63,14 @@ m4_define([b4_assert_if], # -------------------- # Expansion of $$. m4_define([b4_lhs_value], -[b4_symbol_value([yylhs.value], [$1])]) + [b4_symbol_value([yylhs.value], [$1])]) # b4_lhs_location() # ----------------- # Expansion of @$. m4_define([b4_lhs_location], -[yylhs.location]) + [yylhs.location]) # b4_rhs_data(RULE-LENGTH, NUM) @@ -107,11 +78,11 @@ m4_define([b4_lhs_location], # Return the data corresponding to the symbol #NUM, where the current # rule has RULE-LENGTH symbols on RHS. m4_define([b4_rhs_data], - [yystack_@{($1) - ($2)@}]) + [yystack_@{b4_subtract($@)@}]) # b4_rhs_state(RULE-LENGTH, NUM) -# ----------------------------- +# ------------------------------ # The state corresponding to the symbol #NUM, where the current # rule has RULE-LENGTH symbols on RHS. m4_define([b4_rhs_state], @@ -134,128 +105,61 @@ m4_define([b4_rhs_location], [b4_rhs_data([$1], [$2]).location]) -# b4_symbol(NUM, FIELD) -# --------------------- -# Recover a FIELD about symbol #NUM. Thanks to m4_indir, fails if -# undefined. -m4_define([b4_symbol], -[m4_indir([b4_symbol($1, $2)])]) - - -# b4_symbol_if(NUM, FIELD, IF-TRUE, IF-FALSE) -# ------------------------------------------- -# If FIELD about symbol #NUM is 1 expand IF-TRUE, if is 0, expand IF-FALSE. -# Otherwise an error. -m4_define([b4_symbol_if], -[m4_case(b4_symbol([$1], [$2]), - [1], [$3], - [0], [$4], - [m4_fatal([$0: field $2 of $1 is not a Boolean:] b4_symbol([$1], [$2]))])]) - - -# b4_symbol_actions(FILENAME, LINENO, -# SYMBOL-TAG, SYMBOL-NUM, -# SYMBOL-ACTION, SYMBOL-TYPENAME) -# ------------------------------------------------- +# b4_symbol_action(SYMBOL-NUM, KIND) +# ---------------------------------- +# Run the action KIND (destructor or printer) for SYMBOL-NUM. # Same as in C, but using references instead of pointers. -m4_define([b4_symbol_actions], +m4_define([b4_symbol_action], +[b4_symbol_if([$1], [has_$2], [m4_pushdef([b4_dollar_dollar], - [b4_symbol_value_template([yysym.value], [$6])])dnl + [b4_symbol_value_template([yysym.value], + b4_symbol_if([$1], [has_type], + [b4_symbol([$1], [type])]))])dnl m4_pushdef([b4_at_dollar], [yysym.location])dnl - case $4: // $3 -b4_syncline([$2], [$1]) - $5; + b4_symbol_case_([$1]) +b4_syncline([b4_symbol([$1], [$2_line])], ["b4_symbol([$1], [$2_file])"]) + b4_symbol([$1], [$2]) b4_syncline([@oline@], [@ofile@]) break; + m4_popdef([b4_at_dollar])dnl m4_popdef([b4_dollar_dollar])dnl -]) - - -# b4_symbol_case_(SYMBOL-NUM) -# --------------------------- -# Issue a "case NUM" for SYMBOL-NUM. -m4_define([b4_symbol_case_], -[ case b4_symbol([$1], [number]): // b4_symbol([$1], [tag]) -]) - - -# b4_type_action_(NUMS) -# --------------------- -# Run actions for the symbol NUMS that all have the same type-name. -# Skip NUMS that have no type-name. -m4_define([b4_type_action_], -[b4_symbol_if([$1], [has_type], -[m4_map([b4_symbol_case_], [$@])[]dnl - b4_dollar_dollar([b4_symbol([$1], [number])], - [b4_symbol([$1], [tag])], - [b4_symbol([$1], [type])]); - break; - ])]) - -# b4_symbol_constructor_declaration_(SYMBOL-NUMBERS) -# ---------------------------------------------------- +# b4_symbol_constructor_declaration_(SYMBOL-NUMBER) +# ------------------------------------------------- # Declare the overloaded version of make_symbol for the (common) type of # these SYMBOL-NUMBERS. Use at class-level. m4_define([b4_symbol_constructor_declaration_], -[ template - static inline symbol_type - make_symbol (b4_args(b4_symbol_if([$1], [has_type], - [const b4_symbol([$1], [type])& v]), - b4_locations_if([const location_type& l]))); - -]) - -# b4_symbol_constructor_declarations -# ---------------------------------- -# Declare the overloaded versions of make_symbol for all the value types. -# Use at class-level. -m4_define([b4_symbol_constructor_declarations], -[b4_variant_if([ - // Declaration of make_symbol for each value type. -m4_map([b4_symbol_constructor_declaration_], m4_defn([b4_type_names]))])]) - - - -# b4_symbol_constructor_specialization_(SYMBOL-NUMBER) -# ---------------------------------------------------- -# Declare the specialization of make_symbol for this each SYMBOL-NUMBER. -# Specializations cannot be declared at class-level, this must be done -# at namespace-level. -m4_define([b4_symbol_constructor_specialization_], [b4_symbol_if([$1], [is_token], [b4_symbol_if([$1], [has_id], -[ template <> - inline - b4_parser_class_name::symbol_type - b4_parser_class_name::make_symbol (dnl +[ static inline + symbol_type + make_[]b4_symbol_([$1], [id]) (dnl b4_args(b4_symbol_if([$1], [has_type], [const b4_symbol([$1], [type])& v]), b4_locations_if([const location_type& l]))); ])])]) -# b4_symbol_constructor_specializations -# ------------------------------------- -# Declare specializations of make_symbol. -m4_define([b4_symbol_constructor_specializations], + +# b4_symbol_constructor_declarations +# ---------------------------------- +# Declare symbol constructors for all the value types. +# Use at class-level. +m4_define([b4_symbol_constructor_declarations], [b4_variant_if([ - // Specializations of make_symbol for each symbol type. -m4_map([b4_symbol_constructor_specialization_], - m4_defn([b4_symbol_numbers]))])dnl -]) + // Symbol constructors declarations. +b4_symbol_foreach([b4_symbol_constructor_declaration_])])]) # b4_symbol_constructor_definition_(SYMBOL-NUMBER) # ------------------------------------------------ -# Define make_symbol for this SYMBOL-NUMBER. +# Define symbol constructor for this SYMBOL-NUMBER. m4_define([b4_symbol_constructor_definition_], [b4_symbol_if([$1], [is_token], [b4_symbol_if([$1], [has_id], -[ template <> - b4_parser_class_name::symbol_type - b4_parser_class_name::make_symbol (dnl +[ b4_parser_class_name::symbol_type + b4_parser_class_name::make_[]b4_symbol_([$1], [id]) (dnl b4_args(b4_symbol_if([$1], [has_type], [const b4_symbol([$1], [type])& v]), b4_locations_if([const location_type& l]))) @@ -346,64 +250,25 @@ m4_define([b4_symbol_constructor_definitions], { return type; } +]b4_lex_symbol_if([[ + ]b4_parser_class_name[::token_type + ]b4_parser_class_name[::symbol_type::token () const + { + // YYTOKNUM[NUM] -- (External) token number corresponding to the + // (internal) symbol number NUM (which must be that of a token). */ + static + const ]b4_int_type_for([b4_toknum])[ + yytoken_number_[] = + { + ]b4_toknum[ + }; + return static_cast (yytoken_number_[type]); + } +]])[ ]b4_variant_if( [ // Implementation of make_symbol for each symbol type. -m4_map([b4_symbol_constructor_definition_], m4_defn([b4_symbol_numbers]))])]) - - -# b4_symbol_variant(YYTYPE, YYVAL, ACTION, [ARGS]) -# ------------------------------------------------ -# Run some ACTION ("build", or "destroy") on YYVAL of symbol type -# YYTYPE. -m4_define([b4_symbol_variant], -[m4_pushdef([b4_dollar_dollar], - [$2.$3<$][3>(m4_shift3($@))])dnl - switch ($1) - { -m4_map([b4_type_action_], m4_defn([b4_type_names]))[]dnl - default: - break; - } -m4_popdef([b4_dollar_dollar])dnl -]) - - -# _b4_char_sizeof_counter -# ----------------------- -# A counter used by _b4_char_sizeof_dummy to create fresh symbols. -m4_define([_b4_char_sizeof_counter], -[0]) - -# _b4_char_sizeof_dummy -# --------------------- -# At each call return a new C++ identifier. -m4_define([_b4_char_sizeof_dummy], -[m4_define([_b4_char_sizeof_counter], m4_incr(_b4_char_sizeof_counter))dnl -dummy[]_b4_char_sizeof_counter]) - - -# b4_char_sizeof_(SYMBOL-NUM) -# --------------------------- -# A comment describing this symbol. -m4_define([b4_char_sizeof_], -[ // b4_symbol([$1], [tag]) -]) - -# b4_char_sizeof(SYMBOL-NUMS) -# -------------------------- -# To be mapped on the list of type names to produce: -# -# char dummy1[sizeof(type_name_1)]; -# char dummy2[sizeof(type_name_2)]; -# -# for defined type names. -m4_define([b4_char_sizeof], -[b4_symbol_if([$1], [has_type], -[ -m4_map([b4_char_sizeof_], [$@])dnl - char _b4_char_sizeof_dummy@{sizeof([b4_symbol([$1], [type])])@}; -])]) +b4_symbol_foreach([b4_symbol_constructor_definition_])])]) # b4_yytranslate_definition @@ -411,7 +276,7 @@ m4_map([b4_char_sizeof_], [$@])dnl # Define yytranslate_. Sometimes we want it in the header file, # sometimes the cc file suffices. m4_define([b4_yytranslate_definition], -[[ // YYTRANSLATE(YYLEX) -- Bison symbol number corresponding to YYLEX. +[[ // Symbol number corresponding to token number t. ]b4_parser_class_name[::token_number_type ]b4_parser_class_name[::yytranslate_ (]b4_lex_symbol_if([token_type], [int])[ t) @@ -449,6 +314,8 @@ b4_locations_if( [# Backward compatibility. m4_define([b4_location_constructors]) m4_include(b4_pkgdatadir/[location.cc])]) +m4_include(b4_pkgdatadir/[stack.hh]) +b4_variant_if([m4_include(b4_pkgdatadir/[variant.hh])]) # We do want M4 expansion after # for CPP macros. m4_changecom() @@ -472,104 +339,7 @@ dnl FIXME: This is wrong, we want computed header guards. ]b4_namespace_open[ ]b4_locations_if([ class position; class location;])[ -]b4_variant_if( -[[ - /// A char[S] buffer to store and retrieve objects. - /// - /// Sort of a variant, but does not keep track of the nature - /// of the stored data, since that knowledge is available - /// via the current state. - template - struct variant - {]b4_assert_if([ - /// Whether something is contained. - bool built; -])[ - /// Empty construction. - inline - variant ()]b4_assert_if([ - : built(false)])[ - {} - - /// Instantiate a \a T in here. - template - inline T& - build() - {]b4_assert_if([ - assert(!built); - built = true;])[ - return *new (buffer) T; - } - - /// Instantiate a \a T in here from \a t. - template - inline T& - build(const T& t) - {]b4_assert_if([ - assert(!built); - built = true;])[ - return *new (buffer) T(t); - } - - /// Construct and fill. - template - inline - variant (const T& t)]b4_assert_if([ - : built(true)])[ - { - new (buffer) T(t); - } - - /// Accessor to a built \a T. - template - inline T& - as() - {]b4_assert_if([ - assert(built);])[ - return reinterpret_cast(buffer); - } - - /// Const accessor to a built \a T (for %printer). - template - inline const T& - as() const - {]b4_assert_if([ - assert(built);])[ - return reinterpret_cast(buffer); - } - - /// Swap the content with \a other. - template - inline void - swap(variant& other) - { - std::swap(as(), other.as()); - } - - /// Assign the content of \a other to this. - /// Destroys \a other. - template - inline void - build(variant& other) - { - build(); - swap(other); - other.destroy(); - } - - /// Destroy the stored \a T. - template - inline void - destroy() - { - as().~T();]b4_assert_if([ - built = false;])[ - } - - /// A buffer large enough to store any of the semantic values. - char buffer[S]; - }; -]])[ +]b4_variant_if([b4_variant_definition])[ ]b4_namespace_close[ ]b4_locations_if([#include "location.hh"])[ @@ -622,7 +392,7 @@ do { \ ]b4_variant_if( [ /// An auxiliary type to compute the largest semantic type. union union_type - {]m4_map([b4_char_sizeof], m4_defn([b4_type_names]))[}; + {]b4_type_foreach([b4_char_sizeof])[}; /// Symbol semantic values. typedef variant semantic_type;], @@ -685,36 +455,11 @@ m4_ifdef([b4_stype], /// Internal symbol numbers. typedef ]b4_int_type_for([b4_translate])[ token_number_type; - /* Tables. */ - /// For a state, the index in \a yytable_ of its portion. - 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. - /// Unless\a yytable_ specifies something else to do. - /// Zero means the default is an error. - static const ]b4_int_type_for([b4_defact])[ yydefact_[]; - - static const ]b4_int_type_for([b4_pgoto])[ yypgoto_[]; - static const ]b4_int_type_for([b4_defgoto])[ yydefgoto_[]; - - /// What to do in a state. - /// \a yytable_[yypact_[s]]: what to do in state \a s. - /// - if positive, shift that token. - /// - if negative, reduce the rule which number is the opposite. - /// - if zero, do what YYDEFACT says. - static const ]b4_int_type_for([b4_table])[ yytable_[]; static const ]b4_int_type(b4_table_ninf, b4_table_ninf)[ yytable_ninf_; - static const ]b4_int_type_for([b4_check])[ yycheck_[]; - - /// For a state, its accessing symbol. - static const ]b4_int_type_for([b4_stos])[ yystos_[]; - - /// 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_[]; + /* Tables. */ +]b4_parser_tables_declare[ #if YYDEBUG || YYERROR_VERBOSE || YYTOKEN_TABLE /// For a symbol, its name in clear. @@ -725,10 +470,8 @@ m4_ifdef([b4_stype], static std::string yytnamerr_ (const char *n);])[ #if YYDEBUG - /// For each rule, its source line number. - static const ]b4_int_type_for([b4_rline])[ yyrline_[]; - /// For each scanner token number, its symbol number. - static const ]b4_int_type_for([b4_toknum])[ yytoken_number_[]; +]b4_integral_parser_table_declare([rline], [b4_rline], + [YYRLINE[YYN] -- Source line where rule number YYN was defined.])[ /// Report on the debug stream that the rule \a r is going to be reduced. virtual void yy_reduce_print_ (int r); /// Print the state stack on the debug stream. @@ -809,6 +552,9 @@ m4_ifdef([b4_stype], /// Return the type corresponding to this state. inline int type_get_ () const; + + /// Its token. + inline token_type token () const; }; ]b4_symbol_constructor_declarations[ @@ -876,7 +622,6 @@ m4_ifdef([b4_stype], }; ]b4_lex_symbol_if([b4_yytranslate_definition])[ -]b4_symbol_constructor_specializations[ ]b4_lex_symbol_if([b4_symbol_constructor_definitions])[ ]b4_namespace_close[ @@ -1065,9 +810,9 @@ b4_percent_code_get[]dnl // User destructor. switch (yytype) { -]m4_map([b4_symbol_actions], m4_defn([b4_symbol_destructors]))[ - default: - break; +]b4_symbol_foreach([b4_symbol_destructor])dnl +[ default: + break; }]b4_variant_if([ // Type destructor. @@ -1086,8 +831,8 @@ b4_percent_code_get[]dnl << yysym.location << ": "])[; switch (yytype) { -]m4_map([b4_symbol_actions], m4_defn([b4_symbol_printers]))[ - default: +]b4_symbol_foreach([b4_symbol_printer])dnl +[ default: break; } yyo << ')'; @@ -1286,7 +1031,7 @@ m4_ifdef([b4_lex_param], [, ]b4_lex_param)));])[ /* Variants are always initialized to an empty instance of the correct type. The default $$=$1 rule is NOT applied when using variants */ - ]b4_symbol_variant([[yyr1_@{yyn@}]], [yylhs.value], [build])[],[ + ]b4_symbol_variant([[yyr1_@{yyn@}]], [yylhs.value], [build]),[ /* If YYLEN is nonzero, implement the default value of the action: `$$ = $1'. Otherwise, use the top of the stack. @@ -1324,16 +1069,18 @@ m4_ifdef([b4_lex_param], [, ]b4_lex_param)));])[ yylhs.state = yystate; YY_SYMBOL_PRINT ("-> $$ =", yylhs); ]b4_variant_if([[ - // Destroy the lhs symbols. + // Destroy the rhs symbols. for (int i = 0; i < yylen; ++i) - // Destroy a variant which value may have be swapped with - // yylhs.value. The value of yylhs.value (hence maybe one of - // these lhs symbols) depends on what does the default - // contruction for this type. In the case of pointers for - // instance, nothing is done, so the value is junk. Therefore - // do not try to report the content in the debug trace, it's - // junk. Hence yymsg = 0. Besides, that keeps exactly the same - // traces as with the other Bison skeletons. + // Destroy a variant which value may have been swapped with + // yylhs.value (for instance if the action was "std::swap($$, + // $1)"). The value of yylhs.value (hence possibly one of these + // rhs symbols) depends on the default contruction for this + // type. In the case of pointers for instance, no + // initialization is done, so the value is junk. Therefore do + // not try to report the value of symbols about to be destroyed + // in the debug trace, it's possibly junk. Hence yymsg = 0. + // Besides, that keeps exactly the same traces as with the other + // Bison skeletons. yy_destroy_ (0, yystack_[i]);]])[ yypop_ (yylen); @@ -1344,9 +1091,9 @@ m4_ifdef([b4_lex_param], [, ]b4_lex_param)));])[ yypush_ (0, yylhs); goto yynewstate; - /*------------------------------------. - | yyerrlab -- here on detecting error | - `------------------------------------*/ + /*--------------------------------------. + | yyerrlab -- here on detecting error. | + `--------------------------------------*/ yyerrlab: /* If not already recovering from an error, report this error. */ if (!yyerrstatus_) @@ -1483,7 +1230,8 @@ b4_error_verbose_if([int yystate, int yytoken], int yychecklim = yylast_ - yyn + 1; int yyxend = yychecklim < yyntokens_ ? yychecklim : yyntokens_; - // Number of "expected" tokens. + // Number of reported tokens (one for the "unexpected", one per + // "expected"). size_t yycount = 0; // Its maximum. enum { YYERROR_VERBOSE_ARGS_MAXIMUM = 5 }; @@ -1534,46 +1282,11 @@ b4_error_verbose_if([int yystate, int yytoken], } - /* YYPACT[STATE-NUM] -- Index in YYTABLE of the portion describing - STATE-NUM. */ const ]b4_int_type(b4_pact_ninf, b4_pact_ninf) b4_parser_class_name::yypact_ninf_ = b4_pact_ninf[; - ]b4_table_define([pact], [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. */ - ]b4_table_define([defact], [b4_defact])[; - - /* YYPGOTO[NTERM-NUM]. */ - ]b4_table_define([pgoto], [b4_pgoto])[; - /* YYDEFGOTO[NTERM-NUM]. */ - ]b4_table_define([defgoto], [b4_defgoto])[; - - /* 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. */ const ]b4_int_type(b4_table_ninf, b4_table_ninf) b4_parser_class_name::yytable_ninf_ = b4_table_ninf[; - ]b4_table_define([table], [b4_table])[; - - /* YYCHECK. */ - ]b4_table_define([check], [b4_check])[; - - /* STOS_[STATE-NUM] -- The (internal number of the) accessing - symbol of state STATE-NUM. */ - ]b4_table_define([stos], [b4_stos])[; - -#if YYDEBUG - /* TOKEN_NUMBER_[YYLEX-NUM] -- Internal symbol number corresponding - to YYLEX-NUM. */ - ]b4_table_define([token_number], [b4_toknum])[; -#endif - - /* YYR1[YYN] -- Symbol number of symbol that rule YYN derives. */ - ]b4_table_define([r1], [b4_r1])[; - /* YYR2[YYN] -- Number of symbols composing right hand side of rule YYN. */ - ]b4_table_define([r2], [b4_r2])[; +]b4_parser_tables_define[ #if YYDEBUG || YYERROR_VERBOSE || YYTOKEN_TABLE /* YYTNAME[SYMBOL-NUM] -- String name of the symbol SYMBOL-NUM. @@ -1586,8 +1299,7 @@ b4_error_verbose_if([int yystate, int yytoken], #endif #if YYDEBUG - /* YYRLINE[YYN] -- Source line where rule number YYN was defined. */ - ]b4_table_define([rline], [b4_rline])[; +]b4_integral_parser_table_define([rline], [b4_rline])[ // Print the state stack on the debug stream. void @@ -1620,105 +1332,6 @@ b4_error_verbose_if([int yystate, int yytoken], ]b4_lex_symbol_if([], [b4_yytranslate_definition])[ ]b4_namespace_close[ - ]b4_epilogue[]dnl -@output(b4_dir_prefix[]stack.hh@)@ -b4_copyright([Stack handling for Bison parsers in C++])[ - -#ifndef BISON_STACK_HH -# define BISON_STACK_HH - -#include - -]b4_namespace_open[ - 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 - typename S::size_type - size () const - { - return seq_.size (); - } - - inline const_iterator begin () const { return seq_.rbegin (); } - inline const_iterator end () const { return seq_.rend (); } - - private: - /// The wrapped container. - 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_; - }; -]b4_namespace_close[ - -#endif // not BISON_STACK_HH[]dnl -] m4_divert_pop(0) m4_popdef([b4_copyright_years])dnl