* Contextual Precedence:: When an operator's precedence depends on context.
* Parser States:: The parser is a finite-state-machine with stack.
* Reduce/Reduce:: When two rules are applicable in the same situation.
-* Mystery Conflicts:: Reduce/reduce conflicts that look unjustified.
+* Mysterious Conflicts:: Conflicts that look unjustified.
* Tuning LR:: How to tune fundamental aspects of LR-based parsing.
* Generalized LR Parsing:: Parsing arbitrary context-free grammars.
* Memory Management:: What happens when memory is exhausted. How to avoid it.
to tell how to parse any portion of an input string with just a single token
of lookahead. For historical reasons, Bison by default is limited by the
additional restrictions of LALR(1), which is hard to explain simply.
-@xref{Mystery Conflicts, ,Mysterious Reduce/Reduce Conflicts}, for more
-information on this. As an experimental feature, you can escape these
-additional restrictions by requesting IELR(1) or canonical LR(1) parser
-tables. @xref{LR Table Construction}, to learn how.
+@xref{Mysterious Conflicts}, for more information on this. As an
+experimental feature, you can escape these additional restrictions by
+requesting IELR(1) or canonical LR(1) parser tables. @xref{LR Table
+Construction}, to learn how.
@cindex GLR parsing
@cindex generalized LR (GLR) parsing
specify where default reductions should be used is experimental. More user
feedback will help to stabilize it.)
-@item Accepted Values: @code{full}, @code{consistent}, @code{accepting}
+@item Accepted Values: @code{most}, @code{consistent}, @code{accepting}
@item Default Value:
@itemize
@item @code{accepting} if @code{lr.type} is @code{canonical-lr}.
-@item @code{full} otherwise.
+@item @code{most} otherwise.
@end itemize
@end itemize
* Contextual Precedence:: When an operator's precedence depends on context.
* Parser States:: The parser is a finite-state-machine with stack.
* Reduce/Reduce:: When two rules are applicable in the same situation.
-* Mystery Conflicts:: Reduce/reduce conflicts that look unjustified.
+* Mysterious Conflicts:: Conflicts that look unjustified.
* Tuning LR:: How to tune fundamental aspects of LR-based parsing.
* Generalized LR Parsing:: Parsing arbitrary context-free grammars.
* Memory Management:: What happens when memory is exhausted. How to avoid it.
;
@end example
-@node Mystery Conflicts
-@section Mysterious Reduce/Reduce Conflicts
+@node Mysterious Conflicts
+@section Mysterious Conflicts
@cindex Mysterious Conflicts
Sometimes reduce/reduce conflicts can occur that don't look warranted.
For historical reasons, Bison constructs LALR(1) parser tables by default.
However, LALR does not possess the full language-recognition power of LR.
As a result, the behavior of parsers employing LALR parser tables is often
-mysterious. We presented a simple example of this effect in @ref{Mystery
+mysterious. We presented a simple example of this effect in @ref{Mysterious
Conflicts}.
As we also demonstrated in that example, the traditional approach to
%define lr.type ielr
@end example
-@noindent For the example in @ref{Mystery Conflicts}, the mysterious
+@noindent For the example in @ref{Mysterious Conflicts}, the mysterious
conflict is then eliminated, so there is no need to invest time in
comprehending the conflict or restructuring the grammar to fix it. If,
during future development, the grammar evolves such that all mysterious
Specify the kind of states that are permitted to contain default reductions.
The accepted values of @var{WHERE} are:
@itemize
-@item @code{full} (default for LALR and IELR)
+@item @code{most} (default for LALR and IELR)
@item @code{consistent}
@item @code{accepting} (default for canonical LR)
@end itemize
has proven insignificant for practical grammars.
@end itemize
+While the LAC algorithm shares techniques that have been recognized in the
+parser community for years, for the publication that introduces LAC,
+@pxref{Bibliography,,Denny 2010 May}.
+
@node Unreachable States
@subsection Unreachable States
@findex %define lr.keep-unreachable-states
The same is true of languages that require more than one symbol of
lookahead, since the parser lacks the information necessary to make a
decision at the point it must be made in a shift-reduce parser.
-Finally, as previously mentioned (@pxref{Mystery Conflicts}),
+Finally, as previously mentioned (@pxref{Mysterious Conflicts}),
there are languages where Bison's default choice of how to
summarize the input seen so far loses necessary information.
be false alarms in existing grammars employing the Yacc constructs
@code{$0} or @code{$-@var{n}} (where @var{n} is some positive integer).
-
@item yacc
Incompatibilities with POSIX Yacc.
+@item other
+All warnings not categorized above. These warnings are enabled by default.
+
+This category is provided merely for the sake of completeness. Future
+releases of Bison may move warnings from this category to new, more specific
+categories.
+
@item all
All the warnings.
@item none
@item LALR(1)
The class of context-free grammars that Bison (like most other parser
generators) can handle by default; a subset of LR(1).
-@xref{Mystery Conflicts, ,Mysterious Reduce/Reduce Conflicts}.
+@xref{Mysterious Conflicts}.
@item LR(1)
The class of context-free grammars in which at most one token of
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