-This is bison.info, produced by makeinfo version 4.0 from bison.texinfo.
+Ceci est le fichier Info bison.info, produit par Makeinfo version 4.0b
+à partir bison.texinfo.
START-INFO-DIR-ENTRY
* bison: (bison). GNU Project parser generator (yacc replacement).
This file documents the Bison parser generator.
Copyright (C) 1988, 1989, 1990, 1991, 1992, 1993, 1995, 1998, 1999,
-2000 Free Software Foundation, Inc.
+2000, 2001 Free Software Foundation, Inc.
Permission is granted to make and distribute verbatim copies of this
manual provided the copyright notice and this permission notice are
\1f
File: bison.info, Node: Top, Next: Introduction, Prev: (dir), Up: (dir)
- This manual documents version 1.28a of Bison.
+ This manual documents version 1.28c of Bison.
* Menu:
* Invocation:: How to run Bison (to produce the parser source file).
* Table of Symbols:: All the keywords of the Bison language are explained.
* Glossary:: Basic concepts are explained.
+* Copying This Manual:: License for copying this manual.
* Index:: Cross-references to the text.
--- The Detailed Node Listing ---
* Option Cross Key:: Alphabetical list of long options.
* VMS Invocation:: Bison command syntax on VMS.
+Copying This Manual
+
+* GNU Free Documentation License:: License for copying this manual.
+
\1f
File: bison.info, Node: Introduction, Next: Conditions, Prev: Top, Up: Top
it Yacc-compatible. Wilfred Hansen of Carnegie Mellon University added
multi-character string literals and other features.
- This edition corresponds to version 1.28a of Bison.
+ This edition corresponds to version 1.28c of Bison.
\1f
File: bison.info, Node: Conditions, Next: Copying, Prev: Introduction, Up: Top
Version 2, June 1991
Copyright (C) 1989, 1991 Free Software Foundation, Inc.
- 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
+ 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
Everyone is permitted to copy and distribute verbatim copies
of this license document, but changing it is not allowed.
modification follow.
TERMS AND CONDITIONS FOR COPYING, DISTRIBUTION AND MODIFICATION
-
0. This License applies to any program or other work which contains a
notice placed by the copyright holder saying it may be distributed
under the terms of this General Public License. The "Program",
END OF TERMS AND CONDITIONS
-How to Apply These Terms to Your New Programs
-=============================================
+Appendix: How to Apply These Terms to Your New Programs
+=======================================================
If you develop a new program, and you want it to be of the greatest
possible use to the public, the best way to achieve this is to make it
the "copyright" line and a pointer to where the full notice is found.
ONE LINE TO GIVE THE PROGRAM'S NAME AND A BRIEF IDEA OF WHAT IT DOES.
- Copyright (C) 19YY NAME OF AUTHOR
+ Copyright (C) YYYY NAME OF AUTHOR
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
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., 59 Temple Place - Suite 330,
- Boston, MA 02111-1307, USA.
+ Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
Also add information on how to contact you by electronic and paper
mail.
this when it starts in an interactive mode:
Gnomovision version 69, Copyright (C) 19YY NAME OF AUTHOR
- Gnomovision comes with ABSOLUTELY NO WARRANTY; for details
- type `show w'.
+ Gnomovision comes with ABSOLUTELY NO WARRANTY; for details type `show w'.
This is free software, and you are welcome to redistribute it
under certain conditions; type `show c' for details.
a semantic value (the value of an integer,
the name of an identifier, etc.).
* Semantic Actions:: Each rule can have an action containing C code.
+* Locations Overview:: Tracking Locations.
* Bison Parser:: What are Bison's input and output,
how is the output used?
* Stages:: Stages in writing and running Bison grammars.
is a tree structure describing the meaning of the expression.
\1f
-File: bison.info, Node: Semantic Actions, Next: Bison Parser, Prev: Semantic Values, Up: Concepts
+File: bison.info, Node: Semantic Actions, Next: Locations Overview, Prev: Semantic Values, Up: Concepts
Semantic Actions
================
from the values of the two subexpressions.
\1f
-File: bison.info, Node: Bison Parser, Next: Stages, Prev: Semantic Actions, Up: Concepts
+File: bison.info, Node: Locations Overview, Next: Bison Parser, Prev: Semantic Actions, Up: Concepts
+
+Locations
+=========
+
+ Many applications, like interpreters or compilers, have to produce
+verbose and useful error messages. To achieve this, one must be able to
+keep track of the "textual position", or "location", of each syntactic
+construct. Bison provides a mechanism for handling these locations.
+
+ Each token has a semantic value. In a similar fashion, each token
+has an associated location, but the type of locations is the same for
+all tokens and groupings. Moreover, the output parser is equipped with
+a default data structure for storing locations (*note Locations::, for
+more details).
+
+ Like semantic values, locations can be reached in actions using a
+dedicated set of constructs. In the example above, the location of the
+whole grouping is `@$', while the locations of the subexpressions are
+`@1' and `@3'.
+
+ When a rule is matched, a default action is used to compute the
+semantic value of its left hand side (*note Actions::). In the same
+way, another default action is used for locations. However, the action
+for locations is general enough for most cases, meaning there is
+usually no need to describe for each rule how `@$' should be formed.
+When building a new location for a given grouping, the default behavior
+of the output parser is to take the beginning of the first symbol, and
+the end of the last symbol.
+
+\1f
+File: bison.info, Node: Bison Parser, Next: Stages, Prev: Locations Overview, Up: Concepts
Bison Output: the Parser File
=============================
* Gen: Rpcalc Gen. Running Bison on the grammar file.
* Comp: Rpcalc Compile. Run the C compiler on the output code.
-\1f
-File: bison.info, Node: Rpcalc Decls, Next: Rpcalc Rules, Up: RPN Calc
-
-Declarations for `rpcalc'
--------------------------
-
- Here are the C and Bison declarations for the reverse polish notation
-calculator. As in C, comments are placed between `/*...*/'.
-
- /* Reverse polish notation calculator. */
-
- %{
- #define YYSTYPE double
- #include <math.h>
- %}
-
- %token NUM
-
- %% /* Grammar rules and actions follow */
-
- The C declarations section (*note The C Declarations Section: C
-Declarations.) contains two preprocessor directives.
-
- The `#define' directive defines the macro `YYSTYPE', thus specifying
-the C data type for semantic values of both tokens and groupings (*note
-Data Types of Semantic Values: Value Type.). The Bison parser will use
-whatever type `YYSTYPE' is defined as; if you don't define it, `int' is
-the default. Because we specify `double', each token and each
-expression has an associated value, which is a floating point number.
-
- The `#include' directive is used to declare the exponentiation
-function `pow'.
-
- The second section, Bison declarations, provides information to
-Bison about the token types (*note The Bison Declarations Section:
-Bison Declarations.). Each terminal symbol that is not a
-single-character literal must be declared here. (Single-character
-literals normally don't need to be declared.) In this example, all the
-arithmetic operators are designated by single-character literals, so the
-only terminal symbol that needs to be declared is `NUM', the token type
-for numeric constants.
-
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