* m4/strerror_r.m4: New.

[bison.git] / doc / bison.info-4

diff --git a/doc/bison.info-4 b/doc/bison.info-4
index 323fed0025aabf9341927be444799c03bf7e1527..ae2509a431ec939ec96e7acf1342b2654a12e46b 100644 (file)
--- a/doc/bison.info-4
+++ b/doc/bison.info-4
@@ -28,6 +28,51 @@ License", "Conditions for Using Bison" and this permission notice may be
 included in translations approved by the Free Software Foundation
 instead of in the original English.
 
 included in translations approved by the Free Software Foundation
 instead of in the original English.
 

+\1f
+File: bison.info,  Node: Using Precedence,  Next: Precedence Examples,  Prev: Why Precedence,  Up: Precedence
+
+Specifying Operator Precedence
+------------------------------
+
+   Bison allows you to specify these choices with the operator
+precedence declarations `%left' and `%right'.  Each such declaration
+contains a list of tokens, which are operators whose precedence and
+associativity is being declared.  The `%left' declaration makes all
+those operators left-associative and the `%right' declaration makes
+them right-associative.  A third alternative is `%nonassoc', which
+declares that it is a syntax error to find the same operator twice "in a
+row".
+
+   The relative precedence of different operators is controlled by the
+order in which they are declared.  The first `%left' or `%right'
+declaration in the file declares the operators whose precedence is
+lowest, the next such declaration declares the operators whose
+precedence is a little higher, and so on.
+
+\1f
+File: bison.info,  Node: Precedence Examples,  Next: How Precedence,  Prev: Using Precedence,  Up: Precedence
+
+Precedence Examples
+-------------------
+
+   In our example, we would want the following declarations:
+
+     %left '<'
+     %left '-'
+     %left '*'
+
+   In a more complete example, which supports other operators as well,
+we would declare them in groups of equal precedence.  For example,
+`'+'' is declared with `'-'':
+
+     %left '<' '>' '=' NE LE GE
+     %left '+' '-'
+     %left '*' '/'
+
+(Here `NE' and so on stand for the operators for "not equal" and so on.
+We assume that these tokens are more than one character long and
+therefore are represented by names, not character literals.)
+

 \1f
 File: bison.info,  Node: How Precedence,  Prev: Precedence Examples,  Up: Precedence
 
 \1f
 File: bison.info,  Node: How Precedence,  Prev: Precedence Examples,  Up: Precedence
 


@@ -803,9 +848,9 @@ Tuning the parser:
 
 `-t'
 `--debug'
 
 `-t'
 `--debug'

-     Output a definition of the macro `YYDEBUG' into the parser file,
-     so that the debugging facilities are compiled.  *Note Debugging
-     Your Parser: Debugging.
+     Output a definition of the macro `YYDEBUG' into the parser file, so
+     that the debugging facilities are compiled.  *Note Debugging Your
+     Parser: Debugging.

 
 `--locations'
      Pretend that `%locactions' was specified.  *Note Decl Summary::.
 
 `--locations'
      Pretend that `%locactions' was specified.  *Note Decl Summary::.


@@ -833,13 +878,7 @@ Tuning the parser:
 
 `-n'
 `--no-parser'
 
 `-n'
 `--no-parser'

-     Do not include any C code in the parser file; generate tables
-     only.  The parser file contains just `#define' directives and
-     static variable declarations.
-
-     This option also tells Bison to write the C code for the grammar
-     actions into a file named `FILENAME.act', in the form of a
-     brace-surrounded body fit for a `switch' statement.
+     Pretend that `%no_parser' was specified.  *Note Decl Summary::.

 
 `-r'
 `--raw'
 
 `-r'
 `--raw'


@@ -853,17 +892,10 @@ Adjust the output:
 
 `-d'
 `--defines'
 
 `-d'
 `--defines'

-     Write an extra output file containing macro definitions for the
-     token type names defined in the grammar and the semantic value type
-     `YYSTYPE', as well as a few `extern' variable declarations.
-
-     If the parser output file is named `NAME.c' then this file is
-     named `NAME.h'.
-
-     This output file is essential if you wish to put the definition of
-     `yylex' in a separate source file, because `yylex' needs to be
-     able to refer to token type codes and the variable `yylval'.
-     *Note Semantic Values of Tokens: Token Values.
+     Pretend that `%verbose' was specified, i.e., write an extra output
+     file containing macro definitions for the token type names defined
+     in the grammar and the semantic value type `YYSTYPE', as well as a
+     few `extern' variable declarations.  *Note Decl Summary::.

 
 `-b FILE-PREFIX'
 `--file-prefix=PREFIX'
 
 `-b FILE-PREFIX'
 `--file-prefix=PREFIX'


@@ -872,19 +904,9 @@ Adjust the output:
 
 `-v'
 `--verbose'
 
 `-v'
 `--verbose'

-     Write an extra output file containing verbose descriptions of the
-     parser states and what is done for each type of look-ahead token in
-     that state.
-
-     This file also describes all the conflicts, both those resolved by
-     operator precedence and the unresolved ones.
-
-     The file's name is made by removing `.tab.c' or `.c' from the
-     parser output file name, and adding `.output' instead.
-
-     Therefore, if the input file is `foo.y', then the parser file is
-     called `foo.tab.c' by default.  As a consequence, the verbose
-     output file is called `foo.output'.
+     Pretend that `%verbose' was specified, i.e, write an extra output
+     file containing verbose descriptions of the grammar and parser.
+     *Note Decl Summary::, for more.

 
 `-o OUTFILE'
 `--output-file=OUTFILE'
 
 `-o OUTFILE'
 `--output-file=OUTFILE'


@@ -1093,6 +1115,13 @@ Bison Symbols
      The parser function produced by Bison; call this function to start
      parsing.  *Note The Parser Function `yyparse': Parser Function.
 
      The parser function produced by Bison; call this function to start
      parsing.  *Note The Parser Function `yyparse': Parser Function.
 

+`%debug'
+     Equip the parser for debugging.  *Note Decl Summary::.
+
+`%defines'
+     Bison declaration to create a header file meant for the scanner.
+     *Note Decl Summary::.
+

 `%left'
      Bison declaration to assign left associativity to token(s).  *Note
      Operator Precedence: Precedence Decl.
 `%left'
      Bison declaration to assign left associativity to token(s).  *Note
      Operator Precedence: Precedence Decl.


@@ -1169,169 +1198,3 @@ Bison Symbols
      Separates alternate rules for the same result nonterminal.  *Note
      Syntax of Grammar Rules: Rules.
 
      Separates alternate rules for the same result nonterminal.  *Note
      Syntax of Grammar Rules: Rules.
 

-\1f
-File: bison.info,  Node: Glossary,  Next: Index,  Prev: Table of Symbols,  Up: Top
-
-Glossary
-********
-
-Backus-Naur Form (BNF)
-     Formal method of specifying context-free grammars.  BNF was first
-     used in the `ALGOL-60' report, 1963.  *Note Languages and
-     Context-Free Grammars: Language and Grammar.
-
-Context-free grammars
-     Grammars specified as rules that can be applied regardless of
-     context.  Thus, if there is a rule which says that an integer can
-     be used as an expression, integers are allowed _anywhere_ an
-     expression is permitted.  *Note Languages and Context-Free
-     Grammars: Language and Grammar.
-
-Dynamic allocation
-     Allocation of memory that occurs during execution, rather than at
-     compile time or on entry to a function.
-
-Empty string
-     Analogous to the empty set in set theory, the empty string is a
-     character string of length zero.
-
-Finite-state stack machine
-     A "machine" that has discrete states in which it is said to exist
-     at each instant in time.  As input to the machine is processed, the
-     machine moves from state to state as specified by the logic of the
-     machine.  In the case of the parser, the input is the language
-     being parsed, and the states correspond to various stages in the
-     grammar rules.  *Note The Bison Parser Algorithm: Algorithm.
-
-Grouping
-     A language construct that is (in general) grammatically divisible;
-     for example, `expression' or `declaration' in C.  *Note Languages
-     and Context-Free Grammars: Language and Grammar.
-
-Infix operator
-     An arithmetic operator that is placed between the operands on
-     which it performs some operation.
-
-Input stream
-     A continuous flow of data between devices or programs.
-
-Language construct
-     One of the typical usage schemas of the language.  For example,
-     one of the constructs of the C language is the `if' statement.
-     *Note Languages and Context-Free Grammars: Language and Grammar.
-
-Left associativity
-     Operators having left associativity are analyzed from left to
-     right: `a+b+c' first computes `a+b' and then combines with `c'.
-     *Note Operator Precedence: Precedence.
-
-Left recursion
-     A rule whose result symbol is also its first component symbol; for
-     example, `expseq1 : expseq1 ',' exp;'.  *Note Recursive Rules:
-     Recursion.
-
-Left-to-right parsing
-     Parsing a sentence of a language by analyzing it token by token
-     from left to right.  *Note The Bison Parser Algorithm: Algorithm.
-
-Lexical analyzer (scanner)
-     A function that reads an input stream and returns tokens one by
-     one.  *Note The Lexical Analyzer Function `yylex': Lexical.
-
-Lexical tie-in
-     A flag, set by actions in the grammar rules, which alters the way
-     tokens are parsed.  *Note Lexical Tie-ins::.
-
-Literal string token
-     A token which consists of two or more fixed characters.  *Note
-     Symbols::.
-
-Look-ahead token
-     A token already read but not yet shifted.  *Note Look-Ahead
-     Tokens: Look-Ahead.
-
-LALR(1)
-     The class of context-free grammars that Bison (like most other
-     parser generators) can handle; a subset of LR(1).  *Note
-     Mysterious Reduce/Reduce Conflicts: Mystery Conflicts.
-
-LR(1)
-     The class of context-free grammars in which at most one token of
-     look-ahead is needed to disambiguate the parsing of any piece of
-     input.
-
-Nonterminal symbol
-     A grammar symbol standing for a grammatical construct that can be
-     expressed through rules in terms of smaller constructs; in other
-     words, a construct that is not a token.  *Note Symbols::.
-
-Parse error
-     An error encountered during parsing of an input stream due to
-     invalid syntax.  *Note Error Recovery::.
-
-Parser
-     A function that recognizes valid sentences of a language by
-     analyzing the syntax structure of a set of tokens passed to it
-     from a lexical analyzer.
-
-Postfix operator
-     An arithmetic operator that is placed after the operands upon
-     which it performs some operation.
-
-Reduction
-     Replacing a string of nonterminals and/or terminals with a single
-     nonterminal, according to a grammar rule.  *Note The Bison Parser
-     Algorithm: Algorithm.
-
-Reentrant
-     A reentrant subprogram is a subprogram which can be in invoked any
-     number of times in parallel, without interference between the
-     various invocations.  *Note A Pure (Reentrant) Parser: Pure Decl.
-
-Reverse polish notation
-     A language in which all operators are postfix operators.
-
-Right recursion
-     A rule whose result symbol is also its last component symbol; for
-     example, `expseq1: exp ',' expseq1;'.  *Note Recursive Rules:
-     Recursion.
-
-Semantics
-     In computer languages, the semantics are specified by the actions
-     taken for each instance of the language, i.e., the meaning of each
-     statement.  *Note Defining Language Semantics: Semantics.
-
-Shift
-     A parser is said to shift when it makes the choice of analyzing
-     further input from the stream rather than reducing immediately some
-     already-recognized rule.  *Note The Bison Parser Algorithm:
-     Algorithm.
-
-Single-character literal
-     A single character that is recognized and interpreted as is.
-     *Note From Formal Rules to Bison Input: Grammar in Bison.
-
-Start symbol
-     The nonterminal symbol that stands for a complete valid utterance
-     in the language being parsed.  The start symbol is usually listed
-     as the first nonterminal symbol in a language specification.
-     *Note The Start-Symbol: Start Decl.
-
-Symbol table
-     A data structure where symbol names and associated data are stored
-     during parsing to allow for recognition and use of existing
-     information in repeated uses of a symbol.  *Note Multi-function
-     Calc::.
-
-Token
-     A basic, grammatically indivisible unit of a language.  The symbol
-     that describes a token in the grammar is a terminal symbol.  The
-     input of the Bison parser is a stream of tokens which comes from
-     the lexical analyzer.  *Note Symbols::.
-
-Terminal symbol
-     A grammar symbol that has no rules in the grammar and therefore is
-     grammatically indivisible.  The piece of text it represents is a
-     token.  *Note Languages and Context-Free Grammars: Language and
-     Grammar.
-