X-Git-Url: https://git.saurik.com/bison.git/blobdiff_plain/e4678430c2506c577c05e92437b187fe9daf0b7f..baa423bd59767a687ad742adc66a5b7428a41dee:/doc/bison.texi diff --git a/doc/bison.texi b/doc/bison.texi index cd5e440e..737a119c 100644 --- a/doc/bison.texi +++ b/doc/bison.texi @@ -1,6 +1,8 @@ \input texinfo @c -*-texinfo-*- @comment %**start of header @setfilename bison.info +@documentencoding UTF-8 +@documentlanguage en @include version.texi @settitle Bison @value{VERSION} @setchapternewpage odd @@ -33,7 +35,7 @@ This manual (@value{UPDATED}) is for GNU Bison (version @value{VERSION}), the GNU parser generator. -Copyright @copyright{} 1988-1993, 1995, 1998-2013 Free Software +Copyright @copyright{} 1988-1993, 1995, 1998-2015 Free Software Foundation, Inc. @quotation @@ -3849,7 +3851,7 @@ example: @noindent specifies the union tag @code{value}, so the corresponding C type is @code{union value}. If you do not specify a tag, it defaults to -@code{YYSTYPE}. +@code{YYSTYPE} (@pxref{%define Summary,,api.value.union.name}). As another extension to POSIX, you may specify multiple @code{%union} declarations; their contents are concatenated. However, only the first @@ -5143,7 +5145,9 @@ value by default. However, when the parser displays a @code{STRING1} or a @code{string1}, it formats it as a string in double quotes. It performs only the second @code{%printer} in this case, so it prints only once. Finally, the parser print @samp{<>} for any symbol, such as @code{TAGLESS}, -that has no semantic type tag. See also +that has no semantic type tag. @xref{Mfcalc Traces, ,Enabling Debug Traces +for @code{mfcalc}}, for a complete example. + @node Expect Decl @@ -6010,12 +6014,12 @@ Use this @var{type} as semantic value. @item Default Value: @itemize @minus @item -@code{%union} if @code{%union} is used, otherwise @dots{} +@code{union-directive} if @code{%union} is used, otherwise @dots{} @item @code{int} if type tags are used (i.e., @samp{%token <@var{type}>@dots{}} or -@samp{%token <@var{type}>@dots{}} is used), otherwise @dots{} +@samp{%type <@var{type}>@dots{}} is used), otherwise @dots{} @item -@code{""} +undefined. @end itemize @item History: @@ -6026,6 +6030,30 @@ introduced in Bison 3.0. Was introduced for Java only in 2.3b as @c api.value.type +@c ================================================== api.value.union.name +@deffn Directive {%define api.value.union.name} @var{name} +@itemize @bullet +@item Language(s): +C + +@item Purpose: +The tag of the generated @code{union} (@emph{not} the name of the +@code{typedef}). This variable is set to @code{@var{id}} when @samp{%union +@var{id}} is used. There is no clear reason to give this union a name. + +@item Accepted Values: +Any valid identifier. + +@item Default Value: +@code{YYSTYPE}. + +@item History: +Introduced in Bison 3.0.3. +@end itemize +@end deffn +@c api.value.type + + @c ================================================== location_type @deffn Directive {%define location_type} Obsoleted by @code{api.location.type} since Bison 2.7. @@ -7522,7 +7550,7 @@ in an associativity related conflict, which can be specified as follows. The unary-minus is another typical example where associativity is usually over-specified, see @ref{Infix Calc, , Infix Notation -Calculator: @code{calc}}. The @code{%left} directive is traditionally +Calculator - @code{calc}}. The @code{%left} directive is traditionally used to declare the precedence of @code{NEG}, which is more than needed since it also defines its associativity. While this is harmless in the traditional example, who knows how @code{NEG} might be used in future @@ -10354,9 +10382,23 @@ declare @code{yyerror} as follows: int yyerror (char const *); @end example -Bison ignores the @code{int} value returned by this @code{yyerror}. -If you use the Yacc library's @code{main} function, your -@code{yyparse} function should have the following type signature: +@noindent +The @code{int} value returned by this @code{yyerror} is ignored. + +The implementation of Yacc library's @code{main} function is: + +@example +int main (void) +@{ + setlocale (LC_ALL, ""); + return yyparse (); +@} +@end example + +@noindent +so if you use it, the internationalization support is enabled (e.g., error +messages are translated), and your @code{yyparse} function should have the +following type signature: @example int yyparse (void); @@ -10658,12 +10700,17 @@ The first, inclusive, position of the range, and the first beyond. Forwarded to the @code{end} position. @end deftypemethod -@deftypemethod {location} {location} operator+ (const location& @var{end}) -@deftypemethodx {location} {location} operator+ (int @var{width}) +@deftypemethod {location} {location} operator+ (int @var{width}) @deftypemethodx {location} {location} operator+= (int @var{width}) -@deftypemethodx {location} {location} operator- (int @var{width}) +@deftypemethodx {location} {location} operator- (int @var{width}) @deftypemethodx {location} {location} operator-= (int @var{width}) -Various forms of syntactic sugar. +Various forms of syntactic sugar for @code{columns}. +@end deftypemethod + +@deftypemethod {location} {location} operator+ (const location& @var{end}) +@deftypemethodx {location} {location} operator+= (const location& @var{end}) +Join two locations: starts at the position of the first one, and ends at the +position of the second. @end deftypemethod @deftypemethod {location} {void} step () @@ -10701,8 +10748,8 @@ it must be copyable; in order to compute the (default) value of @code{@@$} in a reduction, the parser basically runs @example -@@$.begin = @@$1.begin; -@@$.end = @@$@var{N}.end; // The location of last right-hand side symbol. +@@$.begin = @@1.begin; +@@$.end = @@@var{N}.end; // The location of last right-hand side symbol. @end example @noindent so there must be copyable @code{begin} and @code{end} members; @@ -10854,12 +10901,12 @@ Regular union-based code in Lex scanner typically look like: @example [0-9]+ @{ - yylval.ival = text_to_int (yytext); - return yy::parser::INTEGER; + yylval->ival = text_to_int (yytext); + return yy::parser::token::INTEGER; @} [a-z]+ @{ - yylval.sval = new std::string (yytext); - return yy::parser::IDENTIFIER; + yylval->sval = new std::string (yytext); + return yy::parser::token::IDENTIFIER; @} @end example @@ -10868,12 +10915,12 @@ initialized. So the code would look like: @example [0-9]+ @{ - yylval.build() = text_to_int (yytext); - return yy::parser::INTEGER; + yylval->build () = text_to_int (yytext); + return yy::parser::token::INTEGER; @} [a-z]+ @{ - yylval.build = yytext; - return yy::parser::IDENTIFIER; + yylval->build () = yytext; + return yy::parser::token::IDENTIFIER; @} @end example @@ -10882,12 +10929,12 @@ or @example [0-9]+ @{ - yylval.build(text_to_int (yytext)); - return yy::parser::INTEGER; + yylval->build (text_to_int (yytext)); + return yy::parser::token::INTEGER; @} [a-z]+ @{ - yylval.build(yytext); - return yy::parser::IDENTIFIER; + yylval->build (yytext); + return yy::parser::token::IDENTIFIER; @} @end example @@ -10915,8 +10962,8 @@ it is still possible to give an integer as semantic value for a string. So for each token type, Bison generates named constructors as follows. -@deftypemethod {symbol_type} {} make_@var{token} (const @var{value_type}& @var{value}, const location_type& @var{location}) -@deftypemethodx {symbol_type} {} make_@var{token} (const location_type& @var{location}) +@deftypemethod {symbol_type} {} {make_@var{token}} (const @var{value_type}& @var{value}, const location_type& @var{location}) +@deftypemethodx {symbol_type} {} {make_@var{token}} (const location_type& @var{location}) Build a complete terminal symbol for the token type @var{token} (not including the @code{api.token.prefix}) whose possible semantic value is @var{value} of adequate @var{value_type}. If location tracking is enabled, @@ -10936,20 +10983,18 @@ For instance, given the following declarations: Bison generates the following functions: @example -symbol_type make_IDENTIFIER(const std::string& v, - const location_type& l); -symbol_type make_INTEGER(const int& v, - const location_type& loc); -symbol_type make_COLON(const location_type& loc); +symbol_type make_IDENTIFIER (const std::string&, const location_type&); +symbol_type make_INTEGER (const int&, const location_type&); +symbol_type make_COLON (const location_type&); @end example @noindent which should be used in a Lex-scanner as follows. @example -[0-9]+ return yy::parser::make_INTEGER(text_to_int (yytext), loc); -[a-z]+ return yy::parser::make_IDENTIFIER(yytext, loc); -":" return yy::parser::make_COLON(loc); +[0-9]+ return yy::parser::make_INTEGER (text_to_int (yytext), loc); +[a-z]+ return yy::parser::make_IDENTIFIER (yytext, loc); +":" return yy::parser::make_COLON (loc); @end example Tokens that do not have an identifier are not accessible: you cannot simply @@ -11290,7 +11335,7 @@ regular destructors. All the values are printed using their @noindent The grammar itself is straightforward (@pxref{Location Tracking Calc, , -Location Tracking Calculator: @code{ltcalc}}). +Location Tracking Calculator - @code{ltcalc}}). @comment file: calc++-parser.yy @example @@ -11414,13 +11459,13 @@ The rules are simple. The driver is used to report errors. @comment file: calc++-scanner.ll @example -"-" return yy::calcxx_parser::make_MINUS(loc); -"+" return yy::calcxx_parser::make_PLUS(loc); -"*" return yy::calcxx_parser::make_STAR(loc); -"/" return yy::calcxx_parser::make_SLASH(loc); -"(" return yy::calcxx_parser::make_LPAREN(loc); -")" return yy::calcxx_parser::make_RPAREN(loc); -":=" return yy::calcxx_parser::make_ASSIGN(loc); +"-" return yy::calcxx_parser::make_MINUS (loc); +"+" return yy::calcxx_parser::make_PLUS (loc); +"*" return yy::calcxx_parser::make_STAR (loc); +"/" return yy::calcxx_parser::make_SLASH (loc); +"(" return yy::calcxx_parser::make_LPAREN (loc); +")" return yy::calcxx_parser::make_RPAREN (loc); +":=" return yy::calcxx_parser::make_ASSIGN (loc); @group @{int@} @{ @@ -11428,12 +11473,12 @@ The rules are simple. The driver is used to report errors. long n = strtol (yytext, NULL, 10); if (! (INT_MIN <= n && n <= INT_MAX && errno != ERANGE)) driver.error (loc, "integer is out of range"); - return yy::calcxx_parser::make_NUMBER(n, loc); + return yy::calcxx_parser::make_NUMBER (n, loc); @} @end group -@{id@} return yy::calcxx_parser::make_IDENTIFIER(yytext, loc); +@{id@} return yy::calcxx_parser::make_IDENTIFIER (yytext, loc); . driver.error (loc, "invalid character"); -<> return yy::calcxx_parser::make_END(loc); +<> return yy::calcxx_parser::make_END (loc); %% @end example