Future/bison
1
0
Fork 0
mirror of https://git.savannah.gnu.org/git/bison.git synced 2026-03-09 12:23:04 +00:00
Code Issues Packages Projects Releases Wiki Activity

Tweaked spelling and grammar.

Browse Source 
Updated ISBN.
Removed reference to price of printed copy.
Mention BISON_SIMPLE and BISON_HAIRY.
This commit is contained in:
Jesse Thilo
1999-12-13 07:38:05 +00:00
parent 5191ef2421
commit 9ecbd1257c
1 changed files with 49 additions and 23 deletions
Download Patch File Download Diff File Expand all files Collapse all files

72
doc/bison.texinfo
View File

@@ -93,8 +93,8 @@ Foundation
Published by the Free Software Foundation @* Published by the Free Software Foundation @*
59 Temple Place, Suite 330 @* 59 Temple Place, Suite 330 @*
Boston, MA 02111-1307 USA @* Boston, MA 02111-1307 USA @*
Printed copies are available for $15 each.@* Printed copies are available from the Free Software Foundation.@*
ISBN 1-882114-45-0 ISBN 1-882114-44-2
Permission is granted to make and distribute verbatim copies of Permission is granted to make and distribute verbatim copies of
this manual provided the copyright notice and this permission notice this manual provided the copyright notice and this permission notice
@@ -323,12 +323,12 @@ This edition corresponds to version @value{VERSION} of Bison.
@unnumbered Conditions for Using Bison @unnumbered Conditions for Using Bison
As of Bison version 1.24, we have changed the distribution terms for As of Bison version 1.24, we have changed the distribution terms for
@code{yyparse} to permit using Bison's output in non-free programs. @code{yyparse} to permit using Bison's output in nonfree programs.
Formerly, Bison parsers could be used only in programs that were free Formerly, Bison parsers could be used only in programs that were free
software. software.
The other GNU programming tools, such as the GNU C compiler, have never The other GNU programming tools, such as the GNU C compiler, have never
had such a requirement. They could always be used for non-free had such a requirement. They could always be used for nonfree
software. The reason Bison was different was not due to a special software. The reason Bison was different was not due to a special
policy decision; it resulted from applying the usual General Public policy decision; it resulted from applying the usual General Public
License to all of the Bison source code. License to all of the Bison source code.
@@ -1499,7 +1499,7 @@ and continue parsing if the grammar contains a suitable error rule
(@pxref{Error Recovery}). Otherwise, @code{yyparse} returns nonzero. We (@pxref{Error Recovery}). Otherwise, @code{yyparse} returns nonzero. We
have not written any error rules in this example, so any invalid input will have not written any error rules in this example, so any invalid input will
cause the calculator program to exit. This is not clean behavior for a cause the calculator program to exit. This is not clean behavior for a
real calculator, but it is adequate in the first example. real calculator, but it is adequate for the first example.
@node Rpcalc Gen, Rpcalc Compile, Rpcalc Error, RPN Calc @node Rpcalc Gen, Rpcalc Compile, Rpcalc Error, RPN Calc
@subsection Running Bison to Make the Parser @subsection Running Bison to Make the Parser
@@ -1715,7 +1715,7 @@ as @code{sin}, @code{cos}, etc.
It is easy to add new operators to the infix calculator as long as they are It is easy to add new operators to the infix calculator as long as they are
only single-character literals. The lexical analyzer @code{yylex} passes only single-character literals. The lexical analyzer @code{yylex} passes
back all non-number characters as tokens, so new grammar rules suffice for back all nonnumber characters as tokens, so new grammar rules suffice for
adding a new operator. But we want something more flexible: built-in adding a new operator. But we want something more flexible: built-in
functions whose syntax has this form: functions whose syntax has this form:
@@ -2254,7 +2254,7 @@ for @code{yylex}}).
@item @item
@cindex string token @cindex string token
@cindex literal string token @cindex literal string token
@cindex multi-character literal @cindex multicharacter literal
A @dfn{literal string token} is written like a C string constant; for A @dfn{literal string token} is written like a C string constant; for
example, @code{"<="} is a literal string token. A literal string token example, @code{"<="} is a literal string token. A literal string token
doesn't need to be declared unless you need to specify its semantic doesn't need to be declared unless you need to specify its semantic
@@ -2272,7 +2272,7 @@ retrieve the token number for the literal string token from the
By convention, a literal string token is used only to represent a token By convention, a literal string token is used only to represent a token
that consists of that particular string. Thus, you should use the token that consists of that particular string. Thus, you should use the token
type @code{"<="} to represent the string @samp{<=} as a token. Bison type @code{"<="} to represent the string @samp{<=} as a token. Bison
does not enforces this convention, but if you depart from it, people who does not enforce this convention, but if you depart from it, people who
read your program will be confused. read your program will be confused.
All the escape sequences used in string literals in C can be used in All the escape sequences used in string literals in C can be used in
@@ -2321,7 +2321,7 @@ A Bison grammar rule has the following general form:
@end example @end example
@noindent @noindent
where @var{result} is the nonterminal symbol that this rule describes where @var{result} is the nonterminal symbol that this rule describes,
and @var{components} are various terminal and nonterminal symbols that and @var{components} are various terminal and nonterminal symbols that
are put together by this rule (@pxref{Symbols}). are put together by this rule (@pxref{Symbols}).
@@ -2407,8 +2407,8 @@ with no components.
A rule is called @dfn{recursive} when its @var{result} nonterminal appears A rule is called @dfn{recursive} when its @var{result} nonterminal appears
also on its right hand side. Nearly all Bison grammars need to use also on its right hand side. Nearly all Bison grammars need to use
recursion, because that is the only way to define a sequence of any number recursion, because that is the only way to define a sequence of any number
of somethings. Consider this recursive definition of a comma-separated of a particular thing. Consider this recursive definition of a
sequence of one or more expressions: comma-separated sequence of one or more expressions:
@example @example
@group @group
@@ -2868,7 +2868,7 @@ the parser, so that the function @code{yylex} (if it is in this file)
can use the name @var{name} to stand for this token type's code. can use the name @var{name} to stand for this token type's code.
Alternatively, you can use @code{%left}, @code{%right}, or @code{%nonassoc} Alternatively, you can use @code{%left}, @code{%right}, or @code{%nonassoc}
instead of @code{%token}, if you wish to specify precedence. instead of @code{%token}, if you wish to specify associativity and precedence.
@xref{Precedence Decl, ,Operator Precedence}. @xref{Precedence Decl, ,Operator Precedence}.
You can explicitly specify the numeric code for a token type by appending You can explicitly specify the numeric code for a token type by appending
@@ -3189,7 +3189,7 @@ file in its own right.
The output file @file{@var{name}.h} normally defines the tokens with The output file @file{@var{name}.h} normally defines the tokens with
Yacc-compatible token numbers. If this option is specified, the Yacc-compatible token numbers. If this option is specified, the
internal Bison numbers are used instead. (Yacc-compatible numbers start internal Bison numbers are used instead. (Yacc-compatible numbers start
at 257 except for single character tokens; Bison assigns token numbers at 257 except for single-character tokens; Bison assigns token numbers
sequentially for all tokens starting at 3.) sequentially for all tokens starting at 3.)
@item %token_table @item %token_table
@@ -3218,7 +3218,7 @@ definitions for macros @code{YYNTOKENS}, @code{YYNNTS}, and
@item YYNTOKENS @item YYNTOKENS
The highest token number, plus one. The highest token number, plus one.
@item YYNNTS @item YYNNTS
The number of non-terminal symbols. The number of nonterminal symbols.
@item YYNRULES @item YYNRULES
The number of grammar rules, The number of grammar rules,
@item YYNSTATES @item YYNSTATES
@@ -3384,9 +3384,9 @@ all others. In this case, the use of the literal string tokens in
the grammar file has no effect on @code{yylex}. the grammar file has no effect on @code{yylex}.
@item @item
@code{yylex} can find the multi-character token in the @code{yytname} @code{yylex} can find the multicharacter token in the @code{yytname}
table. The index of the token in the table is the token type's code. table. The index of the token in the table is the token type's code.
The name of a multi-character token is recorded in @code{yytname} with a The name of a multicharacter token is recorded in @code{yytname} with a
double-quote, the token's characters, and another double-quote. The double-quote, the token's characters, and another double-quote. The
token's characters are not escaped in any way; they appear verbatim in token's characters are not escaped in any way; they appear verbatim in
the contents of the string in the table. the contents of the string in the table.
@@ -3591,7 +3591,7 @@ with no arguments, as usual.
@cindex syntax error @cindex syntax error
The Bison parser detects a @dfn{parse error} or @dfn{syntax error} The Bison parser detects a @dfn{parse error} or @dfn{syntax error}
whenever it reads a token which cannot satisfy any syntax rule. A whenever it reads a token which cannot satisfy any syntax rule. An
action in the grammar can also explicitly proclaim an error, using the action in the grammar can also explicitly proclaim an error, using the
macro @code{YYERROR} (@pxref{Action Features, ,Special Features for Use in Actions}). macro @code{YYERROR} (@pxref{Action Features, ,Special Features for Use in Actions}).
@@ -4000,7 +4000,7 @@ expr: expr '-' expr
@noindent @noindent
Suppose the parser has seen the tokens @samp{1}, @samp{-} and @samp{2}; Suppose the parser has seen the tokens @samp{1}, @samp{-} and @samp{2};
should it reduce them via the rule for the addition operator? It depends should it reduce them via the rule for the subtraction operator? It depends
on the next token. Of course, if the next token is @samp{)}, we must on the next token. Of course, if the next token is @samp{)}, we must
reduce; shifting is invalid because no single rule can reduce the token reduce; shifting is invalid because no single rule can reduce the token
sequence @w{@samp{- 2 )}} or anything starting with that. But if the next sequence @w{@samp{- 2 )}} or anything starting with that. But if the next
@@ -4011,7 +4011,7 @@ results.
To decide which one Bison should do, we must consider the To decide which one Bison should do, we must consider the
results. If the next operator token @var{op} is shifted, then it results. If the next operator token @var{op} is shifted, then it
must be reduced first in order to permit another opportunity to must be reduced first in order to permit another opportunity to
reduce the sum. The result is (in effect) @w{@samp{1 - (2 reduce the difference. The result is (in effect) @w{@samp{1 - (2
@var{op} 3)}}. On the other hand, if the subtraction is reduced @var{op} 3)}}. On the other hand, if the subtraction is reduced
before shifting @var{op}, the result is @w{@samp{(1 - 2) @var{op} before shifting @var{op}, the result is @w{@samp{(1 - 2) @var{op}
3}}. Clearly, then, the choice of shift or reduce should depend 3}}. Clearly, then, the choice of shift or reduce should depend
@@ -4617,7 +4617,7 @@ static int foo (lose); /* @r{redeclare @code{foo} as function} */
Unfortunately, the name being declared is separated from the declaration Unfortunately, the name being declared is separated from the declaration
construct itself by a complicated syntactic structure---the ``declarator''. construct itself by a complicated syntactic structure---the ``declarator''.
As a result, the part of Bison parser for C needs to be duplicated, with As a result, part of the Bison parser for C needs to be duplicated, with
all the nonterminal names changed: once for parsing a declaration in which all the nonterminal names changed: once for parsing a declaration in which
a typedef name can be redefined, and once for parsing a declaration in a typedef name can be redefined, and once for parsing a declaration in
which that can't be done. Here is a part of the duplication, with actions which that can't be done. Here is a part of the duplication, with actions
@@ -4864,11 +4864,12 @@ with @samp{.tab.c}. Thus, the @samp{bison foo.y} filename yields
@menu @menu
* Bison Options:: All the options described in detail, * Bison Options:: All the options described in detail,
in alphabetical order by short options. in alphabetical order by short options.
* Environment Variables:: Variables which affect Bison execution.
* Option Cross Key:: Alphabetical list of long options. * Option Cross Key:: Alphabetical list of long options.
* VMS Invocation:: Bison command syntax on VMS. * VMS Invocation:: Bison command syntax on VMS.
@end menu @end menu
@node Bison Options, Option Cross Key, , Invocation @node Bison Options, Environment Variables, , Invocation
@section Bison Options @section Bison Options
Bison supports both traditional single-letter options and mnemonic long Bison supports both traditional single-letter options and mnemonic long
@@ -4987,7 +4988,32 @@ bison -y $*
@end example @end example
@end table @end table
@node Option Cross Key, VMS Invocation, Bison Options, Invocation @node Environment Variables, Option Cross Key, Bison Options, Invocation
@section Environment Variables
@cindex environment variables
@cindex BISON_HAIRY
@cindex BISON_SIMPLE
Here is a list of environment variables which affect the way Bison
runs.
@table @samp
@item BISON_SIMPLE
@itemx BISON_HAIRY
Much of the parser generated by Bison is copied verbatim from a file
called @file{bison.simple}. If Bison cannot find that file, or if you
would like to direct Bison to use a different copy, setting the
environment variable @code{BISON_SIMPLE} to the path of the file will
cause Bison to use that copy instead.
When the @samp{%semantic_parser} delcaration is used, Bison copies from
a file called @file{bison.hairy} instead. The location of this file can
also be specified or overridden in a similar fashion, with the
@code{BISON_HAIRY} environment variable.
@end table
@node Option Cross Key, VMS Invocation, Environment Variables, Invocation
@section Option Cross Key @section Option Cross Key
Here is a list of options, alphabetized by long option, to help you find Here is a list of options, alphabetized by long option, to help you find
@@ -5328,7 +5354,7 @@ A flag, set by actions in the grammar rules, which alters the way
tokens are parsed. @xref{Lexical Tie-ins}. tokens are parsed. @xref{Lexical Tie-ins}.
@item Literal string token @item Literal string token
A token which constists of two or more fixed characters. A token which consists of two or more fixed characters.
@xref{Symbols}. @xref{Symbols}.
@item Look-ahead token @item Look-ahead token