regen

[bison.git] / doc / bison.texi

diff --git a/doc/bison.texi b/doc/bison.texi
index 848bca45bfe0180a745b340d02e3e0d519432c9e..bc7b167c220c3b4386ed8f737445081ffda9791e 100644 (file)
--- a/doc/bison.texi
+++ b/doc/bison.texi
@@ -211,6 +211,12 @@ Defining Language Semantics
                       This says when, why and how to use the exceptional
                         action in the middle of a rule.
 
                       This says when, why and how to use the exceptional
                         action in the middle of a rule.
 

+Actions in Mid-Rule
+
+* Using Mid-Rule Actions::       Putting an action in the middle of a rule.
+* Mid-Rule Action Translation::  How mid-rule actions are actually processed.
+* Mid-Rule Conflicts::           Mid-rule actions can cause conflicts.
+

 Tracking Locations
 
 * Location Type::               Specifying a data type for locations.
 Tracking Locations
 
 * Location Type::               Specifying a data type for locations.


@@ -280,6 +286,7 @@ Operator Precedence
 * Precedence Only::   How to specify precedence only.
 * Precedence Examples::  How these features are used in the previous example.
 * How Precedence::    How they work.
 * Precedence Only::   How to specify precedence only.
 * Precedence Examples::  How these features are used in the previous example.
 * How Precedence::    How they work.

+* Non Operators::     Using precedence for general conflicts.

 
 Tuning LR
 
 
 Tuning LR
 


@@ -299,6 +306,7 @@ Debugging Your Parser
 
 * Understanding::     Understanding the structure of your parser.
 * Graphviz::          Getting a visual representation of the parser.
 
 * Understanding::     Understanding the structure of your parser.
 * Graphviz::          Getting a visual representation of the parser.

+* Xml::               Getting a markup representation of the parser.

 * Tracing::           Tracing the execution of your parser.
 
 Tracing Your Parser
 * Tracing::           Tracing the execution of your parser.
 
 Tracing Your Parser


@@ -894,10 +902,7 @@ parses a vastly simplified form of Pascal type declarations.
 @end group
 
 %%
 @end group
 
 %%

-
-@group

 type_decl: TYPE ID '=' type ';' ;
 type_decl: TYPE ID '=' type ';' ;

-@end group

 
 @group
 type:
 
 @group
 type:


@@ -1867,9 +1872,7 @@ here is the definition we will use:
 
 @comment file: rpcalc.y
 @example
 
 @comment file: rpcalc.y
 @example

-@group

 #include <stdio.h>
 #include <stdio.h>

-@end group

 
 @group
 /* Called by yyparse on error.  */
 
 @group
 /* Called by yyparse on error.  */


@@ -2639,9 +2642,7 @@ operators in @code{yylex}.
 
 @comment file: mfcalc.y: 3
 @example
 
 @comment file: mfcalc.y: 3
 @example

-@group

 #include <ctype.h>
 #include <ctype.h>

-@end group

 
 @group
 int
 
 @group
 int


@@ -2796,6 +2797,9 @@ The Bison grammar file conventionally has a name ending in @samp{.y}.
 
 @node Grammar Outline
 @section Outline of a Bison Grammar
 
 @node Grammar Outline
 @section Outline of a Bison Grammar

+@cindex comment
+@findex // @dots{}
+@findex /* @dots{} */

 
 A Bison grammar file has four main sections, shown here with the
 appropriate delimiters:
 
 A Bison grammar file has four main sections, shown here with the
 appropriate delimiters:


@@ -2815,8 +2819,8 @@ appropriate delimiters:
 @end example
 
 Comments enclosed in @samp{/* @dots{} */} may appear in any of the sections.
 @end example
 
 Comments enclosed in @samp{/* @dots{} */} may appear in any of the sections.

-As a GNU extension, @samp{//} introduces a comment that
-continues until end of line.
+As a GNU extension, @samp{//} introduces a comment that continues until end
+of line.

 
 @menu
 * Prologue::              Syntax and usage of the prologue.
 
 @menu
 * Prologue::              Syntax and usage of the prologue.


@@ -3393,9 +3397,7 @@ one of your tokens with a @code{%token} declaration.
 A Bison grammar rule has the following general form:
 
 @example
 A Bison grammar rule has the following general form:
 
 @example

-@group

 @var{result}: @var{components}@dots{};
 @var{result}: @var{components}@dots{};

-@end group

 @end example
 
 @noindent
 @end example
 
 @noindent


@@ -3406,9 +3408,7 @@ are put together by this rule (@pxref{Symbols}).
 For example,
 
 @example
 For example,
 
 @example

-@group

 exp: exp '+' exp;
 exp: exp '+' exp;

-@end group

 @end example
 
 @noindent
 @end example
 
 @noindent


@@ -3712,9 +3712,7 @@ difference with tools like Flex, for which @samp{|} stands for either
 following example, the action is triggered only when @samp{b} is found:
 
 @example
 following example, the action is triggered only when @samp{b} is found:
 
 @example

-@group

 a-or-b: 'a'|'b'   @{ a_or_b_found = 1; @};
 a-or-b: 'a'|'b'   @{ a_or_b_found = 1; @};

-@end group

 @end example
 
 @cindex default action
 @end example
 
 @cindex default action


@@ -3810,6 +3808,15 @@ Occasionally it is useful to put an action in the middle of a rule.
 These actions are written just like usual end-of-rule actions, but they
 are executed before the parser even recognizes the following components.
 
 These actions are written just like usual end-of-rule actions, but they
 are executed before the parser even recognizes the following components.
 

+@menu
+* Using Mid-Rule Actions::       Putting an action in the middle of a rule.
+* Mid-Rule Action Translation::  How mid-rule actions are actually processed.
+* Mid-Rule Conflicts::           Mid-rule actions can cause conflicts.
+@end menu
+
+@node Using Mid-Rule Actions
+@subsubsection Using Mid-Rule Actions
+

 A mid-rule action may refer to the components preceding it using
 @code{$@var{n}}, but it may not refer to subsequent components because
 it is run before they are parsed.
 A mid-rule action may refer to the components preceding it using
 @code{$@var{n}}, but it may not refer to subsequent components because
 it is run before they are parsed.


@@ -3842,10 +3849,16 @@ remove it afterward.  Here is how it is done:
 @example
 @group
 stmt:
 @example
 @group
 stmt:

-  LET '(' var ')'
-    @{ $<context>$ = push_context (); declare_variable ($3); @}
+  "let" '(' var ')'
+    @{
+      $<context>$ = push_context ();
+      declare_variable ($3);
+    @}

   stmt
   stmt

-    @{ $$ = $6; pop_context ($<context>5); @}
+    @{
+      $$ = $6;
+      pop_context ($<context>5);
+    @}

 @end group
 @end example
 
 @end group
 @end example
 


@@ -3856,8 +3869,27 @@ list of accessible variables) as its semantic value, using alternative
 @code{context} in the data-type union.  Then it calls
 @code{declare_variable} to add the new variable to that list.  Once the
 first action is finished, the embedded statement @code{stmt} can be
 @code{context} in the data-type union.  Then it calls
 @code{declare_variable} to add the new variable to that list.  Once the
 first action is finished, the embedded statement @code{stmt} can be

-parsed.  Note that the mid-rule action is component number 5, so the
-@samp{stmt} is component number 6.
+parsed.
+
+Note that the mid-rule action is component number 5, so the @samp{stmt} is
+component number 6.  Named references can be used to improve the readability
+and maintainability (@pxref{Named References}):
+
+@example
+@group
+stmt:
+  "let" '(' var ')'
+    @{
+      $<context>let = push_context ();
+      declare_variable ($3);
+    @}[let]
+  stmt
+    @{
+      $$ = $6;
+      pop_context ($<context>let);
+    @}
+@end group
+@end example

 
 After the embedded statement is parsed, its semantic value becomes the
 value of the entire @code{let}-statement.  Then the semantic value from the
 
 After the embedded statement is parsed, its semantic value becomes the
 value of the entire @code{let}-statement.  Then the semantic value from the


@@ -3891,13 +3923,13 @@ stmt:
   let stmt
     @{
       $$ = $2;
   let stmt
     @{
       $$ = $2;

-      pop_context ($1);
+      pop_context ($let);

     @};
 
 let:
     @};
 
 let:

-  LET '(' var ')'
+  "let" '(' var ')'

     @{
     @{

-      $$ = push_context ();
+      $let = push_context ();

       declare_variable ($3);
     @};
 
       declare_variable ($3);
     @};
 


@@ -3909,6 +3941,76 @@ Note that the action is now at the end of its rule.
 Any mid-rule action can be converted to an end-of-rule action in this way, and
 this is what Bison actually does to implement mid-rule actions.
 
 Any mid-rule action can be converted to an end-of-rule action in this way, and
 this is what Bison actually does to implement mid-rule actions.
 

+@node Mid-Rule Action Translation
+@subsubsection Mid-Rule Action Translation
+@vindex $@@@var{n}
+@vindex @@@var{n}
+
+As hinted earlier, mid-rule actions are actually transformed into regular
+rules and actions.  The various reports generated by Bison (textual,
+graphical, etc., see @ref{Understanding, , Understanding Your Parser})
+reveal this translation, best explained by means of an example.  The
+following rule:
+
+@example
+exp: @{ a(); @} "b" @{ c(); @} @{ d(); @} "e" @{ f(); @};
+@end example
+
+@noindent
+is translated into:
+
+@example
+$@@1: /* empty */ @{ a(); @};
+$@@2: /* empty */ @{ c(); @};
+$@@3: /* empty */ @{ d(); @};
+exp: $@@1 "b" $@@2 $@@3 "e" @{ f(); @};
+@end example
+
+@noindent
+with new nonterminal symbols @code{$@@@var{n}}, where @var{n} is a number.
+
+A mid-rule action is expected to generate a value if it uses @code{$$}, or
+the (final) action uses @code{$@var{n}} where @var{n} denote the mid-rule
+action.  In that case its nonterminal is rather named @code{@@@var{n}}:
+
+@example
+exp: @{ a(); @} "b" @{ $$ = c(); @} @{ d(); @} "e" @{ f = $1; @};
+@end example
+
+@noindent
+is translated into
+
+@example
+@@1: /* empty */ @{ a(); @};
+@@2: /* empty */ @{ $$ = c(); @};
+$@@3: /* empty */ @{ d(); @};
+exp: @@1 "b" @@2 $@@3 "e" @{ f = $1; @}
+@end example
+
+There are probably two errors in the above example: the first mid-rule
+action does not generate a value (it does not use @code{$$} although the
+final action uses it), and the value of the second one is not used (the
+final action does not use @code{$3}).  Bison reports these errors when the
+@code{midrule-value} warnings are enabled (@pxref{Invocation, ,Invoking
+Bison}):
+
+@example
+$ bison -fcaret -Wmidrule-value mid.y
+@group
+mid.y:2.6-13: warning: unset value: $$
+ exp: @{ a(); @} "b" @{ $$ = c(); @} @{ d(); @} "e" @{ f = $1; @};
+      ^^^^^^^^
+@end group
+@group
+mid.y:2.19-31: warning: unused value: $3
+ exp: @{ a(); @} "b" @{ $$ = c(); @} @{ d(); @} "e" @{ f = $1; @};
+                   ^^^^^^^^^^^^^
+@end group
+@end example
+
+
+@node Mid-Rule Conflicts
+@subsubsection Conflicts due to Mid-Rule Actions

 Taking action before a rule is completely recognized often leads to
 conflicts since the parser must commit to a parse in order to execute the
 action.  For example, the following two rules, without mid-rule actions,
 Taking action before a rule is completely recognized often leads to
 conflicts since the parser must commit to a parse in order to execute the
 action.  For example, the following two rules, without mid-rule actions,


@@ -4006,6 +4108,7 @@ compound:
 Now Bison can execute the action in the rule for @code{subroutine} without
 deciding which rule for @code{compound} it will eventually use.
 
 Now Bison can execute the action in the rule for @code{subroutine} without
 deciding which rule for @code{compound} it will eventually use.
 

+

 @node Tracking Locations
 @section Tracking Locations
 @cindex location
 @node Tracking Locations
 @section Tracking Locations
 @cindex location


@@ -4965,7 +5068,7 @@ declaration @samp{%define api.pure} says that you want the parser to be
 reentrant.  It looks like this:
 
 @example
 reentrant.  It looks like this:
 
 @example

-%define api.pure
+%define api.pure full

 @end example
 
 The result is that the communication variables @code{yylval} and
 @end example
 
 The result is that the communication variables @code{yylval} and


@@ -4974,7 +5077,7 @@ calling convention is used for the lexical analyzer function
 @code{yylex}.  @xref{Pure Calling, ,Calling Conventions for Pure
 Parsers}, for the details of this.  The variable @code{yynerrs}
 becomes local in @code{yyparse} in pull mode but it becomes a member
 @code{yylex}.  @xref{Pure Calling, ,Calling Conventions for Pure
 Parsers}, for the details of this.  The variable @code{yynerrs}
 becomes local in @code{yyparse} in pull mode but it becomes a member

-of yypstate in push mode.  (@pxref{Error Reporting, ,The Error
+of @code{yypstate} in push mode.  (@pxref{Error Reporting, ,The Error

 Reporting Function @code{yyerror}}).  The convention for calling
 @code{yyparse} itself is unchanged.
 
 Reporting Function @code{yyerror}}).  The convention for calling
 @code{yyparse} itself is unchanged.
 


@@ -5015,7 +5118,7 @@ compatibility with the impure Yacc pull mode interface.  Unless you know
 what you are doing, your declarations should look like this:
 
 @example
 what you are doing, your declarations should look like this:
 
 @example

-%define api.pure
+%define api.pure full

 %define api.push-pull push
 @end example
 
 %define api.push-pull push
 @end example
 


@@ -5248,8 +5351,6 @@ Specify the programming language for the generated parser.  Currently
 supported languages include C, C++, and Java.
 @var{language} is case-insensitive.
 
 supported languages include C, C++, and Java.
 @var{language} is case-insensitive.
 

-This directive is experimental and its effect may be modified in future
-releases.

 @end deffn
 
 @deffn {Directive} %locations
 @end deffn
 
 @deffn {Directive} %locations


@@ -5519,9 +5620,41 @@ The parser namespace is @code{foo} and @code{yylex} is referenced as
 @item Purpose: Request a pure (reentrant) parser program.
 @xref{Pure Decl, ,A Pure (Reentrant) Parser}.
 
 @item Purpose: Request a pure (reentrant) parser program.
 @xref{Pure Decl, ,A Pure (Reentrant) Parser}.
 

-@item Accepted Values: Boolean
+@item Accepted Values: @code{true}, @code{false}, @code{full}
+
+The value may be omitted: this is equivalent to specifying @code{true}, as is
+the case for Boolean values.
+
+When @code{%define api.pure full} is used, the parser is made reentrant. This
+changes the signature for @code{yylex} (@pxref{Pure Calling}), and also that of
+@code{yyerror} when the tracking of locations has been activated, as shown
+below.
+
+The @code{true} value is very similar to the @code{full} value, the only
+difference is in the signature of @code{yyerror} on Yacc parsers without
+@code{%parse-param}, for historical reasons.
+
+I.e., if @samp{%locations %define api.pure} is passed then the prototypes for
+@code{yyerror} are:
+
+@example
+void yyerror (char const *msg);                 // Yacc parsers.
+void yyerror (YYLTYPE *locp, char const *msg);  // GLR parsers.
+@end example
+
+But if @samp{%locations %define api.pure %parse-param @{int *nastiness@}} is
+used, then both parsers have the same signature:
+
+@example
+void yyerror (YYLTYPE *llocp, int *nastiness, char const *msg);
+@end example
+
+(@pxref{Error Reporting, ,The Error
+Reporting Function @code{yyerror}})

 
 @item Default Value: @code{false}
 
 @item Default Value: @code{false}

+
+@item History: the @code{full} value was introduced in Bison 2.7

 @end itemize
 @c api.pure
 
 @end itemize
 @c api.pure
 


@@ -5611,6 +5744,26 @@ introduced in Bison 2.8
 @c api.token.prefix
 
 
 @c api.token.prefix
 
 

+@c ================================================== api.value.type
+@item %define api.value.type variant
+@findex %define api.value.type variant
+
+@itemize @bullet
+@item Language(s):
+C++
+
+@item Purpose:
+Request variant-based semantic values.
+@xref{C++ Variants}.
+
+@c FIXME: @item Accepted Values:
+@c FIXME: Boolean.
+
+@c @item Default Value:
+@c @code{false}
+@ @end itemize
+@c api.value.type
+

 @c ================================================== lr.default-reduction
 
 @item lr.default-reduction
 @c ================================================== lr.default-reduction
 
 @item lr.default-reduction


@@ -5648,7 +5801,7 @@ remain in the parser tables.  @xref{Unreachable States}.
 @item Default Value: @code{false}
 @end itemize
 introduced as @code{lr.keep_unreachable_states} in 2.3b, renamed as
 @item Default Value: @code{false}
 @end itemize
 introduced as @code{lr.keep_unreachable_states} in 2.3b, renamed as

-@code{lr.keep-unreachable-state} in 2.5, and as
+@code{lr.keep-unreachable-states} in 2.5, and as

 @code{lr.keep-unreachable-state} in 2.8.
 @c lr.keep-unreachable-state
 
 @code{lr.keep-unreachable-state} in 2.8.
 @c lr.keep-unreachable-state
 


@@ -5758,29 +5911,8 @@ compiled.
 @item Default Value: @code{false}
 @end itemize
 @c parse.trace
 @item Default Value: @code{false}
 @end itemize
 @c parse.trace

-
-@c ================================================== variant
-@item variant
-@findex %define variant
-
-@itemize @bullet
-@item Language(s):
-C++
-
-@item Purpose:
-Request variant-based semantic values.
-@xref{C++ Variants}.
-
-@item Accepted Values:
-Boolean.
-
-@item Default Value:
-@code{false}
-@end itemize
-@c variant

 @end table
 
 @end table
 

-

 @node %code Summary
 @subsection %code Summary
 @findex %code
 @node %code Summary
 @subsection %code Summary
 @findex %code


@@ -5960,7 +6092,7 @@ parsers.  To comply with this tradition, when @code{api.prefix} is used,
 @code{YYDEBUG} (not renamed) is used as a default value:
 
 @example
 @code{YYDEBUG} (not renamed) is used as a default value:
 
 @example

-/* Enabling traces.  */
+/* Debug traces.  */

 #ifndef CDEBUG
 # if defined YYDEBUG
 #  if YYDEBUG
 #ifndef CDEBUG
 # if defined YYDEBUG
 #  if YYDEBUG


@@ -6084,6 +6216,27 @@ In the grammar actions, use expressions like this to refer to the data:
 exp: @dots{}    @{ @dots{}; *randomness += 1; @dots{} @}
 @end example
 
 exp: @dots{}    @{ @dots{}; *randomness += 1; @dots{} @}
 @end example
 

+@noindent
+Using the following:
+@example
+%parse-param @{int *randomness@}
+@end example
+
+Results in these signatures:
+@example
+void yyerror (int *randomness, const char *msg);
+int  yyparse (int *randomness);
+@end example
+
+@noindent
+Or, if both @code{%define api.pure full} (or just @code{%define api.pure})
+and @code{%locations} are used:
+
+@example
+void yyerror (YYLTYPE *llocp, int *randomness, const char *msg);
+int  yyparse (int *randomness);
+@end example
+

 @node Push Parser Function
 @section The Push Parser Function @code{yypush_parse}
 @findex yypush_parse
 @node Push Parser Function
 @section The Push Parser Function @code{yypush_parse}
 @findex yypush_parse


@@ -6096,7 +6249,7 @@ function is available if either the @samp{%define api.push-pull push} or
 @samp{%define api.push-pull both} declaration is used.
 @xref{Push Decl, ,A Push Parser}.
 
 @samp{%define api.push-pull both} declaration is used.
 @xref{Push Decl, ,A Push Parser}.
 

-@deftypefun int yypush_parse (yypstate *yyps)
+@deftypefun int yypush_parse (yypstate *@var{yyps})

 The value returned by @code{yypush_parse} is the same as for yyparse with
 the following exception: it returns @code{YYPUSH_MORE} if more input is
 required to finish parsing the grammar.
 The value returned by @code{yypush_parse} is the same as for yyparse with
 the following exception: it returns @code{YYPUSH_MORE} if more input is
 required to finish parsing the grammar.


@@ -6114,7 +6267,7 @@ stream.  This function is available if the @samp{%define api.push-pull both}
 declaration is used.
 @xref{Push Decl, ,A Push Parser}.
 
 declaration is used.
 @xref{Push Decl, ,A Push Parser}.
 

-@deftypefun int yypull_parse (yypstate *yyps)
+@deftypefun int yypull_parse (yypstate *@var{yyps})

 The value returned by @code{yypull_parse} is the same as for @code{yyparse}.
 @end deftypefun
 
 The value returned by @code{yypull_parse} is the same as for @code{yyparse}.
 @end deftypefun
 


@@ -6149,7 +6302,7 @@ function is available if either the @samp{%define api.push-pull push} or
 @samp{%define api.push-pull both} declaration is used.
 @xref{Push Decl, ,A Push Parser}.
 
 @samp{%define api.push-pull both} declaration is used.
 @xref{Push Decl, ,A Push Parser}.
 

-@deftypefun void yypstate_delete (yypstate *yyps)
+@deftypefun void yypstate_delete (yypstate *@var{yyps})

 This function will reclaim the memory associated with a parser instance.
 After this call, you should no longer attempt to use the parser instance.
 @end deftypefun
 This function will reclaim the memory associated with a parser instance.
 After this call, you should no longer attempt to use the parser instance.
 @end deftypefun


@@ -6335,7 +6488,7 @@ The data type of @code{yylloc} has the name @code{YYLTYPE}.
 @node Pure Calling
 @subsection Calling Conventions for Pure Parsers
 
 @node Pure Calling
 @subsection Calling Conventions for Pure Parsers
 

-When you use the Bison declaration @samp{%define api.pure} to request a
+When you use the Bison declaration @code{%define api.pure full} to request a

 pure, reentrant parser, the global communication variables @code{yylval}
 and @code{yylloc} cannot be used.  (@xref{Pure Decl, ,A Pure (Reentrant)
 Parser}.)  In such parsers the two global variables are replaced by
 pure, reentrant parser, the global communication variables @code{yylval}
 and @code{yylloc} cannot be used.  (@xref{Pure Decl, ,A Pure (Reentrant)
 Parser}.)  In such parsers the two global variables are replaced by


@@ -6380,6 +6533,7 @@ Specify that @var{argument-declaration} are additional
 declarations, which is equivalent to repeating @code{%param}.
 @end deffn
 
 declarations, which is equivalent to repeating @code{%param}.
 @end deffn
 

+@noindent

 For instance:
 
 @example
 For instance:
 
 @example


@@ -6396,7 +6550,7 @@ int yylex   (scanner_mode *mode, environment_type *env);
 int yyparse (parser_mode *mode, environment_type *env);
 @end example
 
 int yyparse (parser_mode *mode, environment_type *env);
 @end example
 

-If @samp{%define api.pure} is added:
+If @samp{%define api.pure full} is added:

 
 @example
 int yylex   (YYSTYPE *lvalp, scanner_mode *mode, environment_type *env);
 
 @example
 int yylex   (YYSTYPE *lvalp, scanner_mode *mode, environment_type *env);


@@ -6404,7 +6558,8 @@ int yyparse (parser_mode *mode, environment_type *env);
 @end example
 
 @noindent
 @end example
 
 @noindent

-and finally, if both @samp{%define api.pure} and @code{%locations} are used:
+and finally, if both @samp{%define api.pure full} and @code{%locations} are
+used:

 
 @example
 int yylex   (YYSTYPE *lvalp, YYLTYPE *llocp,
 
 @example
 int yylex   (YYSTYPE *lvalp, YYLTYPE *llocp,


@@ -6469,50 +6624,16 @@ error recovery if you have written suitable error recovery grammar rules
 immediately return 1.
 
 Obviously, in location tracking pure parsers, @code{yyerror} should have
 immediately return 1.
 
 Obviously, in location tracking pure parsers, @code{yyerror} should have

-an access to the current location.
-This is indeed the case for the GLR
-parsers, but not for the Yacc parser, for historical reasons.  I.e., if
-@samp{%locations %define api.pure} is passed then the prototypes for
-@code{yyerror} are:
-
-@example
-void yyerror (char const *msg);                 /* Yacc parsers.  */
-void yyerror (YYLTYPE *locp, char const *msg);  /* GLR parsers.   */
-@end example
-
-If @samp{%parse-param @{int *nastiness@}} is used, then:
-
-@example
-void yyerror (int *nastiness, char const *msg);  /* Yacc parsers.  */
-void yyerror (int *nastiness, char const *msg);  /* GLR parsers.   */
-@end example
+an access to the current location. With @code{%define api.pure}, this is
+indeed the case for the GLR parsers, but not for the Yacc parser, for
+historical reasons, and this is the why @code{%define api.pure full} should be
+prefered over @code{%define api.pure}.

 
 

-Finally, GLR and Yacc parsers share the same @code{yyerror} calling
-convention for absolutely pure parsers, i.e., when the calling
-convention of @code{yylex} @emph{and} the calling convention of
-@samp{%define api.pure} are pure.
-I.e.:
+When @code{%locations %define api.pure full} is used, @code{yyerror} has the
+following signature:

 
 @example
 
 @example

-/* Location tracking.  */
-%locations
-/* Pure yylex.  */
-%define api.pure
-%lex-param   @{int *nastiness@}
-/* Pure yyparse.  */
-%parse-param @{int *nastiness@}
-%parse-param @{int *randomness@}
-@end example
-
-@noindent
-results in the following signatures for all the parser kinds:
-
-@example
-int yylex (YYSTYPE *lvalp, YYLTYPE *llocp, int *nastiness);
-int yyparse (int *nastiness, int *randomness);
-void yyerror (YYLTYPE *locp,
-              int *nastiness, int *randomness,
-              char const *msg);
+void yyerror (YYLTYPE *locp, char const *msg);

 @end example
 
 @noindent
 @end example
 
 @noindent


@@ -6654,7 +6775,6 @@ Actions}).
 @end deffn
 
 @deffn {Value} @@$
 @end deffn
 
 @deffn {Value} @@$

-@findex @@$

 Acts like a structure variable containing information on the textual
 location of the grouping made by the current rule.  @xref{Tracking
 Locations}.
 Acts like a structure variable containing information on the textual
 location of the grouping made by the current rule.  @xref{Tracking
 Locations}.


@@ -6713,7 +6833,7 @@ GNU Automake.
 @item
 @cindex bison-i18n.m4
 Into the directory containing the GNU Autoconf macros used
 @item
 @cindex bison-i18n.m4
 Into the directory containing the GNU Autoconf macros used

-by the package---often called @file{m4}---copy the
+by the package ---often called @file{m4}--- copy the

 @file{bison-i18n.m4} file installed by Bison under
 @samp{share/aclocal/bison-i18n.m4} in Bison's installation directory.
 For example:
 @file{bison-i18n.m4} file installed by Bison under
 @samp{share/aclocal/bison-i18n.m4} in Bison's installation directory.
 For example:


@@ -6874,7 +6994,7 @@ expr:
 term:
   '(' expr ')'
 | term '!'
 term:
   '(' expr ')'
 | term '!'

-| NUMBER
+| "number"

 ;
 @end group
 @end example
 ;
 @end group
 @end example


@@ -6913,20 +7033,20 @@ statements, with a pair of rules like this:
 @example
 @group
 if_stmt:
 @example
 @group
 if_stmt:

-  IF expr THEN stmt
-| IF expr THEN stmt ELSE stmt
+  "if" expr "then" stmt
+| "if" expr "then" stmt "else" stmt

 ;
 @end group
 @end example
 
 @noindent
 ;
 @end group
 @end example
 
 @noindent

-Here we assume that @code{IF}, @code{THEN} and @code{ELSE} are
-terminal symbols for specific keyword tokens.
+Here @code{"if"}, @code{"then"} and @code{"else"} are terminal symbols for
+specific keyword tokens.

 
 

-When the @code{ELSE} token is read and becomes the lookahead token, the
+When the @code{"else"} token is read and becomes the lookahead token, the

 contents of the stack (assuming the input is valid) are just right for
 reduction by the first rule.  But it is also legitimate to shift the
 contents of the stack (assuming the input is valid) are just right for
 reduction by the first rule.  But it is also legitimate to shift the

-@code{ELSE}, because that would lead to eventual reduction by the second
+@code{"else"}, because that would lead to eventual reduction by the second

 rule.
 
 This situation, where either a shift or a reduction would be valid, is
 rule.
 
 This situation, where either a shift or a reduction would be valid, is


@@ -6935,14 +7055,14 @@ these conflicts by choosing to shift, unless otherwise directed by
 operator precedence declarations.  To see the reason for this, let's
 contrast it with the other alternative.
 
 operator precedence declarations.  To see the reason for this, let's
 contrast it with the other alternative.
 

-Since the parser prefers to shift the @code{ELSE}, the result is to attach
+Since the parser prefers to shift the @code{"else"}, the result is to attach

 the else-clause to the innermost if-statement, making these two inputs
 equivalent:
 
 @example
 the else-clause to the innermost if-statement, making these two inputs
 equivalent:
 
 @example

-if x then if y then win (); else lose;
+if x then if y then win; else lose;

 
 

-if x then do; if y then win (); else lose; end;
+if x then do; if y then win; else lose; end;

 @end example
 
 But if the parser chose to reduce when possible rather than shift, the
 @end example
 
 But if the parser chose to reduce when possible rather than shift, the


@@ -6950,9 +7070,9 @@ result would be to attach the else-clause to the outermost if-statement,
 making these two inputs equivalent:
 
 @example
 making these two inputs equivalent:
 
 @example

-if x then if y then win (); else lose;
+if x then if y then win; else lose;

 
 

-if x then do; if y then win (); end; else lose;
+if x then do; if y then win; end; else lose;

 @end example
 
 The conflict exists because the grammar as written is ambiguous: either
 @end example
 
 The conflict exists because the grammar as written is ambiguous: either


@@ -6965,11 +7085,16 @@ This particular ambiguity was first encountered in the specifications of
 Algol 60 and is called the ``dangling @code{else}'' ambiguity.
 
 To avoid warnings from Bison about predictable, legitimate shift/reduce
 Algol 60 and is called the ``dangling @code{else}'' ambiguity.
 
 To avoid warnings from Bison about predictable, legitimate shift/reduce

-conflicts, use the @code{%expect @var{n}} declaration.
+conflicts, you can use the @code{%expect @var{n}} declaration.

 There will be no warning as long as the number of shift/reduce conflicts
 is exactly @var{n}, and Bison will report an error if there is a
 different number.
 There will be no warning as long as the number of shift/reduce conflicts
 is exactly @var{n}, and Bison will report an error if there is a
 different number.

-@xref{Expect Decl, ,Suppressing Conflict Warnings}.
+@xref{Expect Decl, ,Suppressing Conflict Warnings}.  However, we don't
+recommend the use of @code{%expect} (except @samp{%expect 0}!), as an equal
+number of conflicts does not mean that they are the @emph{same}.  When
+possible, you should rather use precedence directives to @emph{fix} the
+conflicts explicitly (@pxref{Non Operators,, Using Precedence For Non
+Operators}).

 
 The definition of @code{if_stmt} above is solely to blame for the
 conflict, but the conflict does not actually appear without additional
 
 The definition of @code{if_stmt} above is solely to blame for the
 conflict, but the conflict does not actually appear without additional


@@ -6977,10 +7102,7 @@ rules.  Here is a complete Bison grammar file that actually manifests
 the conflict:
 
 @example
 the conflict:
 
 @example

-@group
-%token IF THEN ELSE variable

 %%
 %%

-@end group

 @group
 stmt:
   expr
 @group
 stmt:
   expr


@@ -6990,13 +7112,13 @@ stmt:
 
 @group
 if_stmt:
 
 @group
 if_stmt:

-  IF expr THEN stmt
-| IF expr THEN stmt ELSE stmt
+  "if" expr "then" stmt
+| "if" expr "then" stmt "else" stmt

 ;
 @end group
 
 expr:
 ;
 @end group
 
 expr:

-  variable
+  "identifier"

 ;
 @end example
 
 ;
 @end example
 


@@ -7016,6 +7138,7 @@ shift and when to reduce.
 * Precedence Only::   How to specify precedence only.
 * Precedence Examples::  How these features are used in the previous example.
 * How Precedence::    How they work.
 * Precedence Only::   How to specify precedence only.
 * Precedence Examples::  How these features are used in the previous example.
 * How Precedence::    How they work.

+* Non Operators::     Using precedence for general conflicts.

 @end menu
 
 @node Why Precedence
 @end menu
 
 @node Why Precedence


@@ -7154,16 +7277,11 @@ would declare them in groups of equal precedence.  For example, @code{'+'} is
 declared with @code{'-'}:
 
 @example
 declared with @code{'-'}:
 
 @example

-%left '<' '>' '=' NE LE GE
+%left '<' '>' '=' "!=" "<=" ">="

 %left '+' '-'
 %left '*' '/'
 @end example
 
 %left '+' '-'
 %left '*' '/'
 @end example
 

-@noindent
-(Here @code{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.)
-

 @node How Precedence
 @subsection How Precedence Works
 
 @node How Precedence
 @subsection How Precedence Works
 


@@ -7186,6 +7304,44 @@ resolved.
 Not all rules and not all tokens have precedence.  If either the rule or
 the lookahead token has no precedence, then the default is to shift.
 
 Not all rules and not all tokens have precedence.  If either the rule or
 the lookahead token has no precedence, then the default is to shift.
 

+@node Non Operators
+@subsection Using Precedence For Non Operators
+
+Using properly precedence and associativity directives can help fixing
+shift/reduce conflicts that do not involve arithmetics-like operators.  For
+instance, the ``dangling @code{else}'' problem (@pxref{Shift/Reduce, ,
+Shift/Reduce Conflicts}) can be solved elegantly in two different ways.
+
+In the present case, the conflict is between the token @code{"else"} willing
+to be shifted, and the rule @samp{if_stmt: "if" expr "then" stmt}, asking
+for reduction.  By default, the precedence of a rule is that of its last
+token, here @code{"then"}, so the conflict will be solved appropriately
+by giving @code{"else"} a precedence higher than that of @code{"then"}, for
+instance as follows:
+
+@example
+@group
+%precedence "then"
+%precedence "else"
+@end group
+@end example
+
+Alternatively, you may give both tokens the same precedence, in which case
+associativity is used to solve the conflict.  To preserve the shift action,
+use right associativity:
+
+@example
+%right "then" "else"
+@end example
+
+Neither solution is perfect however.  Since Bison does not provide, so far,
+``scoped'' precedence, both force you to declare the precedence
+of these keywords with respect to the other operators your grammar.
+Therefore, instead of being warned about new conflicts you would be unaware
+of (e.g., a shift/reduce conflict due to @samp{if test then 1 else 2 + 3}
+being ambiguous: @samp{if test then 1 else (2 + 3)} or @samp{(if test then 1
+else 2) + 3}?), the conflict will be already ``fixed''.
+

 @node Contextual Precedence
 @section Context-Dependent Precedence
 @cindex context-dependent precedence
 @node Contextual Precedence
 @section Context-Dependent Precedence
 @cindex context-dependent precedence


@@ -7346,30 +7502,38 @@ reduce/reduce conflict must be studied and usually eliminated.  Here is the
 proper way to define @code{sequence}:
 
 @example
 proper way to define @code{sequence}:
 
 @example

+@group

 sequence:
   /* empty */    @{ printf ("empty sequence\n"); @}
 | sequence word  @{ printf ("added word %s\n", $2); @}
 ;
 sequence:
   /* empty */    @{ printf ("empty sequence\n"); @}
 | sequence word  @{ printf ("added word %s\n", $2); @}
 ;

+@end group

 @end example
 
 Here is another common error that yields a reduce/reduce conflict:
 
 @example
 @end example
 
 Here is another common error that yields a reduce/reduce conflict:
 
 @example

+@group

 sequence:
   /* empty */
 | sequence words
 | sequence redirects
 ;
 sequence:
   /* empty */
 | sequence words
 | sequence redirects
 ;

+@end group

 
 

+@group

 words:
   /* empty */
 | words word
 ;
 words:
   /* empty */
 | words word
 ;

+@end group

 
 

+@group

 redirects:
   /* empty */
 | redirects redirect
 ;
 redirects:
   /* empty */
 | redirects redirect
 ;

+@end group

 @end example
 
 @noindent
 @end example
 
 @noindent


@@ -7422,6 +7586,58 @@ redirects:
 @end group
 @end example
 
 @end group
 @end example
 

+Yet this proposal introduces another kind of ambiguity!  The input
+@samp{word word} can be parsed as a single @code{words} composed of two
+@samp{word}s, or as two one-@code{word} @code{words} (and likewise for
+@code{redirect}/@code{redirects}).  However this ambiguity is now a
+shift/reduce conflict, and therefore it can now be addressed with precedence
+directives.
+
+To simplify the matter, we will proceed with @code{word} and @code{redirect}
+being tokens: @code{"word"} and @code{"redirect"}.
+
+To prefer the longest @code{words}, the conflict between the token
+@code{"word"} and the rule @samp{sequence: sequence words} must be resolved
+as a shift.  To this end, we use the same techniques as exposed above, see
+@ref{Non Operators,, Using Precedence For Non Operators}.  One solution
+relies on precedences: use @code{%prec} to give a lower precedence to the
+rule:
+
+@example
+%precedence "word"
+%precedence "sequence"
+%%
+@group
+sequence:
+  /* empty */
+| sequence word      %prec "sequence"
+| sequence redirect  %prec "sequence"
+;
+@end group
+
+@group
+words:
+  word
+| words "word"
+;
+@end group
+@end example
+
+Another solution relies on associativity: provide both the token and the
+rule with the same precedence, but make them right-associative:
+
+@example
+%right "word" "redirect"
+%%
+@group
+sequence:
+  /* empty */
+| sequence word      %prec "word"
+| sequence redirect  %prec "redirect"
+;
+@end group
+@end example
+

 @node Mysterious Conflicts
 @section Mysterious Conflicts
 @cindex Mysterious Conflicts
 @node Mysterious Conflicts
 @section Mysterious Conflicts
 @cindex Mysterious Conflicts


@@ -7431,8 +7647,6 @@ Here is an example:
 
 @example
 @group
 
 @example
 @group

-%token ID
-

 %%
 def: param_spec return_spec ',';
 param_spec:
 %%
 def: param_spec return_spec ',';
 param_spec:


@@ -7440,17 +7654,18 @@ param_spec:
 | name_list ':' type
 ;
 @end group
 | name_list ':' type
 ;
 @end group

+

 @group
 return_spec:
   type
 | name ':' type
 ;
 @end group
 @group
 return_spec:
   type
 | name ':' type
 ;
 @end group

+
+type: "id";
+

 @group
 @group

-type: ID;
-@end group
-@group
-name: ID;
+name: "id";

 name_list:
   name
 | name ',' name_list
 name_list:
   name
 | name ',' name_list


@@ -7458,16 +7673,16 @@ name_list:
 @end group
 @end example
 
 @end group
 @end example
 

-It would seem that this grammar can be parsed with only a single token
-of lookahead: when a @code{param_spec} is being read, an @code{ID} is
-a @code{name} if a comma or colon follows, or a @code{type} if another
-@code{ID} follows.  In other words, this grammar is LR(1).
+It would seem that this grammar can be parsed with only a single token of
+lookahead: when a @code{param_spec} is being read, an @code{"id"} is a
+@code{name} if a comma or colon follows, or a @code{type} if another
+@code{"id"} follows.  In other words, this grammar is LR(1).

 
 @cindex LR
 @cindex LALR
 However, for historical reasons, Bison cannot by default handle all
 LR(1) grammars.
 
 @cindex LR
 @cindex LALR
 However, for historical reasons, Bison cannot by default handle all
 LR(1) grammars.

-In this grammar, two contexts, that after an @code{ID} at the beginning
+In this grammar, two contexts, that after an @code{"id"} at the beginning

 of a @code{param_spec} and likewise at the beginning of a
 @code{return_spec}, are similar enough that Bison assumes they are the
 same.
 of a @code{param_spec} and likewise at the beginning of a
 @code{return_spec}, are similar enough that Bison assumes they are the
 same.


@@ -7498,41 +7713,43 @@ distinct.  In the above example, adding one rule to
 
 @example
 @group
 
 @example
 @group

-%token BOGUS
-@dots{}
-%%

 @dots{}
 return_spec:
   type
 | name ':' type
 @dots{}
 return_spec:
   type
 | name ':' type

-| ID BOGUS       /* This rule is never used.  */
+| "id" "bogus"       /* This rule is never used.  */

 ;
 @end group
 @end example
 
 This corrects the problem because it introduces the possibility of an
 ;
 @end group
 @end example
 
 This corrects the problem because it introduces the possibility of an

-additional active rule in the context after the @code{ID} at the beginning of
+additional active rule in the context after the @code{"id"} at the beginning of

 @code{return_spec}.  This rule is not active in the corresponding context
 in a @code{param_spec}, so the two contexts receive distinct parser states.
 @code{return_spec}.  This rule is not active in the corresponding context
 in a @code{param_spec}, so the two contexts receive distinct parser states.

-As long as the token @code{BOGUS} is never generated by @code{yylex},
+As long as the token @code{"bogus"} is never generated by @code{yylex},

 the added rule cannot alter the way actual input is parsed.
 
 In this particular example, there is another way to solve the problem:
 the added rule cannot alter the way actual input is parsed.
 
 In this particular example, there is another way to solve the problem:

-rewrite the rule for @code{return_spec} to use @code{ID} directly
+rewrite the rule for @code{return_spec} to use @code{"id"} directly

 instead of via @code{name}.  This also causes the two confusing
 contexts to have different sets of active rules, because the one for
 @code{return_spec} activates the altered rule for @code{return_spec}
 rather than the one for @code{name}.
 
 @example
 instead of via @code{name}.  This also causes the two confusing
 contexts to have different sets of active rules, because the one for
 @code{return_spec} activates the altered rule for @code{return_spec}
 rather than the one for @code{name}.
 
 @example

+@group

 param_spec:
   type
 | name_list ':' type
 ;
 param_spec:
   type
 | name_list ':' type
 ;

+@end group
+
+@group

 return_spec:
   type
 return_spec:
   type

-| ID ':' type
+| "id" ':' type

 ;
 ;

+@end group

 @end example
 
 For a more detailed exposition of LALR(1) parsers and parser
 @end example
 
 For a more detailed exposition of LALR(1) parsers and parser


@@ -7589,9 +7806,9 @@ mysterious behavior altogether.  You simply need to activate a more powerful
 parser table construction algorithm by using the @code{%define lr.type}
 directive.
 
 parser table construction algorithm by using the @code{%define lr.type}
 directive.
 

-@deffn {Directive} {%define lr.type @var{TYPE}}
+@deffn {Directive} {%define lr.type} @var{type}

 Specify the type of parser tables within the LR(1) family.  The accepted
 Specify the type of parser tables within the LR(1) family.  The accepted

-values for @var{TYPE} are:
+values for @var{type} are:

 
 @itemize
 @item @code{lalr} (default)
 
 @itemize
 @item @code{lalr} (default)


@@ -7637,7 +7854,8 @@ There are at least two scenarios where LALR can be worthwhile:
 
 @cindex GLR with LALR
 When employing GLR parsers (@pxref{GLR Parsers}), if you do not resolve any
 
 @cindex GLR with LALR
 When employing GLR parsers (@pxref{GLR Parsers}), if you do not resolve any

-conflicts statically (for example, with @code{%left} or @code{%prec}), then
+conflicts statically (for example, with @code{%left} or @code{%precedence}),
+then

 the parser explores all potential parses of any given input.  In this case,
 the choice of parser table construction algorithm is guaranteed not to alter
 the language accepted by the parser.  LALR parser tables are the smallest
 the parser explores all potential parses of any given input.  In this case,
 the choice of parser table construction algorithm is guaranteed not to alter
 the language accepted by the parser.  LALR parser tables are the smallest


@@ -7778,9 +7996,9 @@ split the parse instead.
 To adjust which states have default reductions enabled, use the
 @code{%define lr.default-reduction} directive.
 
 To adjust which states have default reductions enabled, use the
 @code{%define lr.default-reduction} directive.
 

-@deffn {Directive} {%define lr.default-reduction @var{WHERE}}
+@deffn {Directive} {%define lr.default-reduction} @var{where}

 Specify the kind of states that are permitted to contain default reductions.
 Specify the kind of states that are permitted to contain default reductions.

-The accepted values of @var{WHERE} are:
+The accepted values of @var{where} are:

 @itemize
 @item @code{most} (default for LALR and IELR)
 @item @code{consistent}
 @itemize
 @item @code{most} (default for LALR and IELR)
 @item @code{consistent}


@@ -7818,7 +8036,7 @@ that solves these problems for canonical LR, IELR, and LALR without
 sacrificing @code{%nonassoc}, default reductions, or state merging.  You can
 enable LAC with the @code{%define parse.lac} directive.
 
 sacrificing @code{%nonassoc}, default reductions, or state merging.  You can
 enable LAC with the @code{%define parse.lac} directive.
 

-@deffn {Directive} {%define parse.lac @var{VALUE}}
+@deffn {Directive} {%define parse.lac} @var{value}

 Enable LAC to improve syntax error handling.
 @itemize
 @item @code{none} (default)
 Enable LAC to improve syntax error handling.
 @itemize
 @item @code{none} (default)


@@ -7914,9 +8132,9 @@ resolution because they are useless in the generated parser.  However,
 keeping unreachable states is sometimes useful when trying to understand the
 relationship between the parser and the grammar.
 
 keeping unreachable states is sometimes useful when trying to understand the
 relationship between the parser and the grammar.
 

-@deffn {Directive} {%define lr.keep-unreachable-state @var{VALUE}}
+@deffn {Directive} {%define lr.keep-unreachable-state} @var{value}

 Request that Bison allow unreachable states to remain in the parser tables.
 Request that Bison allow unreachable states to remain in the parser tables.

-@var{VALUE} must be a Boolean.  The default is @code{false}.
+@var{value} must be a Boolean.  The default is @code{false}.

 @end deffn
 
 There are a few caveats to consider:
 @end deffn
 
 There are a few caveats to consider:


@@ -8420,12 +8638,31 @@ clear the flag.
 
 Developing a parser can be a challenge, especially if you don't understand
 the algorithm (@pxref{Algorithm, ,The Bison Parser Algorithm}).  This
 
 Developing a parser can be a challenge, especially if you don't understand
 the algorithm (@pxref{Algorithm, ,The Bison Parser Algorithm}).  This

-chapter explains how to generate and read the detailed description of the
-automaton, and how to enable and understand the parser run-time traces.
+chapter explains how understand and debug a parser.
+
+The first sections focus on the static part of the parser: its structure.
+They explain how to generate and read the detailed description of the
+automaton.  There are several formats available:
+@itemize @minus
+@item
+as text, see @ref{Understanding, , Understanding Your Parser};
+
+@item
+as a graph, see @ref{Graphviz,, Visualizing Your Parser};
+
+@item
+or as a markup report that can be turned, for instance, into HTML, see
+@ref{Xml,, Visualizing your parser in multiple formats}.
+@end itemize
+
+The last section focuses on the dynamic part of the parser: how to enable
+and understand the parser run-time traces (@pxref{Tracing, ,Tracing Your
+Parser}).

 
 @menu
 * Understanding::     Understanding the structure of your parser.
 * Graphviz::          Getting a visual representation of the parser.
 
 @menu
 * Understanding::     Understanding the structure of your parser.
 * Graphviz::          Getting a visual representation of the parser.

+* Xml::               Getting a markup representation of the parser.

 * Tracing::           Tracing the execution of your parser.
 @end menu
 
 * Tracing::           Tracing the execution of your parser.
 @end menu
 


@@ -8435,8 +8672,7 @@ automaton, and how to enable and understand the parser run-time traces.
 As documented elsewhere (@pxref{Algorithm, ,The Bison Parser Algorithm})
 Bison parsers are @dfn{shift/reduce automata}.  In some cases (much more
 frequent than one would hope), looking at this automaton is required to
 As documented elsewhere (@pxref{Algorithm, ,The Bison Parser Algorithm})
 Bison parsers are @dfn{shift/reduce automata}.  In some cases (much more
 frequent than one would hope), looking at this automaton is required to

-tune or simply fix a parser.  Bison provides two different
-representation of it, either textually or graphically (as a DOT file).
+tune or simply fix a parser.

 
 The textual file is generated when the options @option{--report} or
 @option{--verbose} are specified, see @ref{Invocation, , Invoking
 
 The textual file is generated when the options @option{--report} or
 @option{--verbose} are specified, see @ref{Invocation, , Invoking


@@ -8450,9 +8686,12 @@ The following grammar file, @file{calc.y}, will be used in the sequel:
 
 @example
 %token NUM STR
 
 @example
 %token NUM STR

+@group

 %left '+' '-'
 %left '*'
 %left '+' '-'
 %left '*'

+@end group

 %%
 %%

+@group

 exp:
   exp '+' exp
 | exp '-' exp
 exp:
   exp '+' exp
 | exp '-' exp


@@ -8460,6 +8699,7 @@ exp:
 | exp '/' exp
 | NUM
 ;
 | exp '/' exp
 | NUM
 ;

+@end group

 useless: STR;
 %%
 @end example
 useless: STR;
 %%
 @end example


@@ -8469,8 +8709,8 @@ useless: STR;
 @example
 calc.y: warning: 1 nonterminal useless in grammar
 calc.y: warning: 1 rule useless in grammar
 @example
 calc.y: warning: 1 nonterminal useless in grammar
 calc.y: warning: 1 rule useless in grammar

-calc.y:11.1-7: warning: nonterminal useless in grammar: useless
-calc.y:11.10-12: warning: rule useless in grammar: useless: STR
+calc.y:12.1-7: warning: nonterminal useless in grammar: useless
+calc.y:12.10-12: warning: rule useless in grammar: useless: STR

 calc.y: conflicts: 7 shift/reduce
 @end example
 
 calc.y: conflicts: 7 shift/reduce
 @end example
 


@@ -8564,7 +8804,7 @@ item is a production rule together with a point (@samp{.}) marking
 the location of the input cursor.
 
 @example
 the location of the input cursor.
 
 @example

-state 0
+State 0

 
     0 $accept: . exp $end
 
 
     0 $accept: . exp $end
 


@@ -8594,7 +8834,7 @@ you want to see more detail you can invoke @command{bison} with
 @option{--report=itemset} to list the derived items as well:
 
 @example
 @option{--report=itemset} to list the derived items as well:
 
 @example

-state 0
+State 0

 
     0 $accept: . exp $end
     1 exp: . exp '+' exp
 
     0 $accept: . exp $end
     1 exp: . exp '+' exp


@@ -8612,7 +8852,7 @@ state 0
 In the state 1@dots{}
 
 @example
 In the state 1@dots{}
 
 @example

-state 1
+State 1

 
     5 exp: NUM .
 
 
     5 exp: NUM .
 


@@ -8622,11 +8862,11 @@ state 1
 @noindent
 the rule 5, @samp{exp: NUM;}, is completed.  Whatever the lookahead token
 (@samp{$default}), the parser will reduce it.  If it was coming from
 @noindent
 the rule 5, @samp{exp: NUM;}, is completed.  Whatever the lookahead token
 (@samp{$default}), the parser will reduce it.  If it was coming from

-state 0, then, after this reduction it will return to state 0, and will
+State 0, then, after this reduction it will return to state 0, and will

 jump to state 2 (@samp{exp: go to state 2}).
 
 @example
 jump to state 2 (@samp{exp: go to state 2}).
 
 @example

-state 2
+State 2

 
     0 $accept: exp . $end
     1 exp: exp . '+' exp
 
     0 $accept: exp . $end
     1 exp: exp . '+' exp


@@ -8654,7 +8894,7 @@ The state 3 is named the @dfn{final state}, or the @dfn{accepting
 state}:
 
 @example
 state}:
 
 @example

-state 3
+State 3

 
     0 $accept: exp $end .
 
 
     0 $accept: exp $end .
 


@@ -8669,7 +8909,7 @@ The interpretation of states 4 to 7 is straightforward, and is left to
 the reader.
 
 @example
 the reader.
 
 @example

-state 4
+State 4

 
     1 exp: exp '+' . exp
 
 
     1 exp: exp '+' . exp
 


@@ -8678,7 +8918,7 @@ state 4
     exp  go to state 8
 
 
     exp  go to state 8
 
 

-state 5
+State 5

 
     2 exp: exp '-' . exp
 
 
     2 exp: exp '-' . exp
 


@@ -8687,7 +8927,7 @@ state 5
     exp  go to state 9
 
 
     exp  go to state 9
 
 

-state 6
+State 6

 
     3 exp: exp '*' . exp
 
 
     3 exp: exp '*' . exp
 


@@ -8696,7 +8936,7 @@ state 6
     exp  go to state 10
 
 
     exp  go to state 10
 
 

-state 7
+State 7

 
     4 exp: exp '/' . exp
 
 
     4 exp: exp '/' . exp
 


@@ -8709,7 +8949,7 @@ As was announced in beginning of the report, @samp{State 8 conflicts:
 1 shift/reduce}:
 
 @example
 1 shift/reduce}:
 
 @example

-state 8
+State 8

 
     1 exp: exp . '+' exp
     1    | exp '+' exp .
 
     1 exp: exp . '+' exp
     1    | exp '+' exp .


@@ -8752,7 +8992,7 @@ with some set of possible lookahead tokens.  When run with
 @option{--report=lookahead}, Bison specifies these lookahead tokens:
 
 @example
 @option{--report=lookahead}, Bison specifies these lookahead tokens:
 
 @example

-state 8
+State 8

 
     1 exp: exp . '+' exp
     1    | exp '+' exp .  [$end, '+', '-', '/']
 
     1 exp: exp . '+' exp
     1    | exp '+' exp .  [$end, '+', '-', '/']


@@ -8784,7 +9024,7 @@ The remaining states are similar:
 
 @example
 @group
 
 @example
 @group

-state 9
+State 9

 
     1 exp: exp . '+' exp
     2    | exp . '-' exp
 
     1 exp: exp . '+' exp
     2    | exp . '-' exp


@@ -8800,7 +9040,7 @@ state 9
 @end group
 
 @group
 @end group
 
 @group

-state 10
+State 10

 
     1 exp: exp . '+' exp
     2    | exp . '-' exp
 
     1 exp: exp . '+' exp
     2    | exp . '-' exp


@@ -8815,7 +9055,7 @@ state 10
 @end group
 
 @group
 @end group
 
 @group

-state 11
+State 11

 
     1 exp: exp . '+' exp
     2    | exp . '-' exp
 
     1 exp: exp . '+' exp
     2    | exp . '-' exp


@@ -8838,9 +9078,11 @@ state 11
 
 @noindent
 Observe that state 11 contains conflicts not only due to the lack of
 
 @noindent
 Observe that state 11 contains conflicts not only due to the lack of

-precedence of @samp{/} with respect to @samp{+}, @samp{-}, and
-@samp{*}, but also because the
-associativity of @samp{/} is not specified.
+precedence of @samp{/} with respect to @samp{+}, @samp{-}, and @samp{*}, but
+also because the associativity of @samp{/} is not specified.
+
+Bison may also produce an HTML version of this output, via an XML file and
+XSLT processing (@pxref{Xml,,Visualizing your parser in multiple formats}).

 
 @c ================================================= Graphical Representation
 
 
 @c ================================================= Graphical Representation
 


@@ -8856,11 +9098,14 @@ a PDF or PNG file from it will take very long, and more often than not it will
 fail due to memory exhaustion). This option was rather designed for beginners,
 to help them understand LR parsers.
 
 fail due to memory exhaustion). This option was rather designed for beginners,
 to help them understand LR parsers.
 

-This file is generated when the @option{--graph} option is specified (see
-@pxref{Invocation, , Invoking Bison}).  Its name is made by removing
+This file is generated when the @option{--graph} option is specified
+(@pxref{Invocation, , Invoking Bison}).  Its name is made by removing

 @samp{.tab.c} or @samp{.c} from the parser implementation file name, and
 adding @samp{.dot} instead.  If the grammar file is @file{foo.y}, the
 @samp{.tab.c} or @samp{.c} from the parser implementation file name, and
 adding @samp{.dot} instead.  If the grammar file is @file{foo.y}, the

-Graphviz output file is called @file{foo.dot}.
+Graphviz output file is called @file{foo.dot}.  A DOT file may also be
+produced via an XML file and XSLT processing (@pxref{Xml,,Visualizing your
+parser in multiple formats}).
+

 
 The following grammar file, @file{rr.y}, will be used in the sequel:
 
 
 The following grammar file, @file{rr.y}, will be used in the sequel:
 


@@ -8873,10 +9118,20 @@ b: "0";
 @end group
 @end example
 
 @end group
 @end example
 

-The graphical output is very similar to the textual one, and as such it is
-easier understood by making direct comparisons between them. See
-@ref{Debugging, , Debugging Your Parser} for a detailled analysis of the
-textual report.
+The graphical output
+@ifnotinfo
+(see @ref{fig:graph})
+@end ifnotinfo
+is very similar to the textual one, and as such it is easier understood by
+making direct comparisons between them.  @xref{Debugging, , Debugging Your
+Parser}, for a detailled analysis of the textual report.
+
+@ifnotinfo
+@float Figure,fig:graph
+@image{figs/example, 430pt}
+@caption{A graphical rendering of the parser.}
+@end float
+@end ifnotinfo

 
 @subheading Graphical Representation of States
 
 
 @subheading Graphical Representation of States
 


@@ -8901,7 +9156,7 @@ shift. The following describes a reduction in the @file{rr.output} file:
 
 @example
 @group
 
 @example
 @group

-state 3
+State 3

 
     1 exp: a . ";"
 
 
     1 exp: a . ";"
 


@@ -8922,7 +9177,7 @@ action for the given state, there is no such label.
 
 This is how reductions are represented in the verbose file @file{rr.output}:
 @example
 
 This is how reductions are represented in the verbose file @file{rr.output}:
 @example

-state 1
+State 1

 
     3 a: "0" .  [";"]
     4 b: "0" .  ["."]
 
     3 a: "0" .  [";"]
     4 b: "0" .  ["."]


@@ -8941,14 +9196,61 @@ reduction, see @ref{Shift/Reduce, , Shift/Reduce Conflicts}.  Discarded actions
 are distinguished by a red filling color on these nodes, just like how they are
 reported between square brackets in the verbose file.
 
 are distinguished by a red filling color on these nodes, just like how they are
 reported between square brackets in the verbose file.
 

-The reduction corresponding to the rule number 0 is the acceptation state. It
-is shown as a blue diamond, labelled "Acc".
+The reduction corresponding to the rule number 0 is the acceptation
+state. It is shown as a blue diamond, labelled ``Acc''.

 
 @subheading Graphical representation of go tos
 
 The @samp{go to} jump transitions are represented as dotted lines bearing
 the name of the rule being jumped to.
 
 
 @subheading Graphical representation of go tos
 
 The @samp{go to} jump transitions are represented as dotted lines bearing
 the name of the rule being jumped to.
 

+@c ================================================= XML
+
+@node Xml
+@section Visualizing your parser in multiple formats
+@cindex xml
+
+Bison supports two major report formats: textual output
+(@pxref{Understanding, ,Understanding Your Parser}) when invoked
+with option @option{--verbose}, and DOT
+(@pxref{Graphviz,, Visualizing Your Parser}) when invoked with
+option @option{--graph}. However,
+another alternative is to output an XML file that may then be, with
+@command{xsltproc}, rendered as either a raw text format equivalent to the
+verbose file, or as an HTML version of the same file, with clickable
+transitions, or even as a DOT. The @file{.output} and DOT files obtained via
+XSLT have no difference whatsoever with those obtained by invoking
+@command{bison} with options @option{--verbose} or @option{--graph}.
+
+The XML file is generated when the options @option{-x} or
+@option{--xml[=FILE]} are specified, see @ref{Invocation,,Invoking Bison}.
+If not specified, its name is made by removing @samp{.tab.c} or @samp{.c}
+from the parser implementation file name, and adding @samp{.xml} instead.
+For instance, if the grammar file is @file{foo.y}, the default XML output
+file is @file{foo.xml}.
+
+Bison ships with a @file{data/xslt} directory, containing XSL Transformation
+files to apply to the XML file. Their names are non-ambiguous:
+
+@table @file
+@item xml2dot.xsl
+Used to output a copy of the DOT visualization of the automaton.
+@item xml2text.xsl
+Used to output a copy of the @samp{.output} file.
+@item xml2xhtml.xsl
+Used to output an xhtml enhancement of the @samp{.output} file.
+@end table
+
+Sample usage (requires @command{xsltproc}):
+@example
+$ bison -x gr.y
+@group
+$ bison --print-datadir
+/usr/local/share/bison
+@end group
+$ xsltproc /usr/local/share/bison/xslt/xml2xhtml.xsl gr.xml >gr.html
+@end example
+

 @c ================================================= Tracing
 
 @node Tracing
 @c ================================================= Tracing
 
 @node Tracing


@@ -9144,7 +9446,7 @@ Entering state 24
 
 @noindent
 The previous reduction demonstrates the @code{%printer} directive for
 
 @noindent
 The previous reduction demonstrates the @code{%printer} directive for

-@code{<val>}: both the token @code{NUM} and the resulting non-terminal
+@code{<val>}: both the token @code{NUM} and the resulting nonterminal

 @code{exp} have @samp{1} as value.
 
 @example
 @code{exp} have @samp{1} as value.
 
 @example


@@ -9448,6 +9750,56 @@ S/R conflicts as errors.
 $ bison -Werror=yacc,conflicts-sr input.y
 $ bison -Werror=yacc,error=conflicts-sr input.y
 @end example
 $ bison -Werror=yacc,conflicts-sr input.y
 $ bison -Werror=yacc,error=conflicts-sr input.y
 @end example

+
+@item -f [@var{feature}]
+@itemx --feature[=@var{feature}]
+Activate miscellaneous @var{feature}. @var{feature} can be one of:
+@table @code
+@item caret
+@itemx diagnostics-show-caret
+Show caret errors, in a manner similar to GCC's
+@option{-fdiagnostics-show-caret}, or Clang's @option{-fcaret-diagnotics}. The
+location provided with the message is used to quote the corresponding line of
+the source file, underlining the important part of it with carets (^). Here is
+an example, using the following file @file{in.y}:
+
+@example
+%type <ival> exp
+%%
+exp: exp '+' exp @{ $exp = $1 + $2; @};
+@end example
+
+When invoked with @option{-fcaret}, Bison will report:
+
+@example
+@group
+in.y:3.20-23: error: ambiguous reference: '$exp'
+ exp: exp '+' exp @{ $exp = $1 + $2; @};
+                    ^^^^
+@end group
+@group
+in.y:3.1-3:       refers to: $exp at $$
+ exp: exp '+' exp @{ $exp = $1 + $2; @};
+ ^^^
+@end group
+@group
+in.y:3.6-8:       refers to: $exp at $1
+ exp: exp '+' exp @{ $exp = $1 + $2; @};
+      ^^^
+@end group
+@group
+in.y:3.14-16:     refers to: $exp at $3
+ exp: exp '+' exp @{ $exp = $1 + $2; @};
+              ^^^
+@end group
+@group
+in.y:3.32-33: error: $2 of 'exp' has no declared type
+ exp: exp '+' exp @{ $exp = $1 + $2; @};
+                                ^^
+@end group
+@end example
+
+@end table

 @end table
 
 @noindent
 @end table
 
 @noindent


@@ -9496,9 +9848,6 @@ Specify the programming language for the generated parser, as if
 Summary}).  Currently supported languages include C, C++, and Java.
 @var{language} is case-insensitive.
 
 Summary}).  Currently supported languages include C, C++, and Java.
 @var{language} is case-insensitive.
 

-This option is experimental and its effect may be modified in future
-releases.
-

 @item --locations
 Pretend that @code{%locations} was specified.  @xref{Decl Summary}.
 
 @item --locations
 Pretend that @code{%locations} was specified.  @xref{Decl Summary}.
 


@@ -9765,10 +10114,9 @@ Symbols}.
 @node C++ Variants
 @subsubsection C++ Variants
 
 @node C++ Variants
 @subsubsection C++ Variants
 

-Starting with version 2.6, Bison provides a @emph{variant} based
-implementation of semantic values for C++.  This alleviates all the
-limitations reported in the previous section, and in particular, object
-types can be used without pointers.
+Bison provides a @emph{variant} based implementation of semantic values for
+C++.  This alleviates all the limitations reported in the previous section,
+and in particular, object types can be used without pointers.

 
 To enable variant-based semantic values, set @code{%define} variable
 @code{variant} (@pxref{%define Summary,, variant}).  Once this defined,
 
 To enable variant-based semantic values, set @code{%define} variable
 @code{variant} (@pxref{%define Summary,, variant}).  Once this defined,


@@ -10139,7 +10487,7 @@ depends whether you use unions, or variants.
 @node Split Symbols
 @subsubsection Split Symbols
 
 @node Split Symbols
 @subsubsection Split Symbols
 

-Therefore the interface is as follows.
+The interface is as follows.

 
 @deftypemethod {parser} {int} yylex (semantic_type* @var{yylval}, location_type* @var{yylloc}, @var{type1} @var{arg1}, ...)
 @deftypemethodx {parser} {int} yylex (semantic_type* @var{yylval}, @var{type1} @var{arg1}, ...)
 
 @deftypemethod {parser} {int} yylex (semantic_type* @var{yylval}, location_type* @var{yylloc}, @var{type1} @var{arg1}, ...)
 @deftypemethodx {parser} {int} yylex (semantic_type* @var{yylval}, @var{type1} @var{arg1}, ...)


@@ -10196,7 +10544,7 @@ or
 @node Complete Symbols
 @subsubsection Complete Symbols
 
 @node Complete Symbols
 @subsubsection Complete Symbols
 

-If you specified both @code{%define variant} and
+If you specified both @code{%define api.value.type variant} and

 @code{%define api.token.constructor},
 the @code{parser} class also defines the class @code{parser::symbol_type}
 which defines a @emph{complete} symbol, aggregating its type (i.e., the
 @code{%define api.token.constructor},
 the @code{parser} class also defines the class @code{parser::symbol_type}
 which defines a @emph{complete} symbol, aggregating its type (i.e., the


@@ -10460,7 +10808,7 @@ the grammar for.
 
 @noindent
 @findex %define api.token.constructor
 
 @noindent
 @findex %define api.token.constructor

-@findex %define variant
+@findex %define api.value.type variant

 This example will use genuine C++ objects as semantic values, therefore, we
 require the variant-based interface.  To make sure we properly use it, we
 enable assertions.  To fully benefit from type-safety and more natural
 This example will use genuine C++ objects as semantic values, therefore, we
 require the variant-based interface.  To make sure we properly use it, we
 enable assertions.  To fully benefit from type-safety and more natural


@@ -10469,8 +10817,8 @@ definition of ``symbol'', we enable @code{api.token.constructor}.
 @comment file: calc++-parser.yy
 @example
 %define api.token.constructor
 @comment file: calc++-parser.yy
 @example
 %define api.token.constructor

+%define api.value.type variant

 %define parse.assert
 %define parse.assert

-%define variant

 @end example
 
 @noindent
 @end example
 
 @noindent


@@ -10838,8 +11186,7 @@ You can create documentation for generated parsers using Javadoc.
 Contrary to C parsers, Java parsers do not use global variables; the
 state of the parser is always local to an instance of the parser class.
 Therefore, all Java parsers are ``pure'', and the @code{%pure-parser}
 Contrary to C parsers, Java parsers do not use global variables; the
 state of the parser is always local to an instance of the parser class.
 Therefore, all Java parsers are ``pure'', and the @code{%pure-parser}

-and @samp{%define api.pure} directives does not do anything when used in
-Java.
+and @code{%define api.pure} directives do nothing when used in Java.

 
 Push parsers are currently unsupported in Java and @code{%define
 api.push-pull} have no effect.
 
 Push parsers are currently unsupported in Java and @code{%define
 api.push-pull} have no effect.


@@ -11473,7 +11820,7 @@ or
 @quotation
 My parser includes support for an @samp{#include}-like feature, in
 which case I run @code{yyparse} from @code{yyparse}.  This fails
 @quotation
 My parser includes support for an @samp{#include}-like feature, in
 which case I run @code{yyparse} from @code{yyparse}.  This fails

-although I did specify @samp{%define api.pure}.
+although I did specify @samp{%define api.pure full}.

 @end quotation
 
 These problems typically come not from Bison itself, but from
 @end quotation
 
 These problems typically come not from Bison itself, but from


@@ -11836,18 +12183,23 @@ In an action, the location of the left-hand side of the rule.
 @end deffn
 
 @deffn {Variable} @@@var{n}
 @end deffn
 
 @deffn {Variable} @@@var{n}

+@deffnx {Symbol} @@@var{n}

 In an action, the location of the @var{n}-th symbol of the right-hand side
 of the rule.  @xref{Tracking Locations}.
 In an action, the location of the @var{n}-th symbol of the right-hand side
 of the rule.  @xref{Tracking Locations}.

+
+In a grammar, the Bison-generated nonterminal symbol for a mid-rule action
+with a semantical value.  @xref{Mid-Rule Action Translation}.

 @end deffn
 
 @deffn {Variable} @@@var{name}
 @end deffn
 
 @deffn {Variable} @@@var{name}

-In an action, the location of a symbol addressed by name.  @xref{Tracking
-Locations}.
+@deffnx {Variable} @@[@var{name}]
+In an action, the location of a symbol addressed by @var{name}.
+@xref{Tracking Locations}.

 @end deffn
 
 @end deffn
 

-@deffn {Variable} @@[@var{name}]
-In an action, the location of a symbol addressed by name.  @xref{Tracking
-Locations}.
+@deffn {Symbol} $@@@var{n}
+In a grammar, the Bison-generated nonterminal symbol for a mid-rule action
+with no semantical value.  @xref{Mid-Rule Action Translation}.

 @end deffn
 
 @deffn {Variable} $$
 @end deffn
 
 @deffn {Variable} $$


@@ -11861,12 +12213,8 @@ right-hand side of the rule.  @xref{Actions}.
 @end deffn
 
 @deffn {Variable} $@var{name}
 @end deffn
 
 @deffn {Variable} $@var{name}

-In an action, the semantic value of a symbol addressed by name.
-@xref{Actions}.
-@end deffn
-
-@deffn {Variable} $[@var{name}]
-In an action, the semantic value of a symbol addressed by name.
+@deffnx {Variable} $[@var{name}]
+In an action, the semantic value of a symbol addressed by @var{name}.

 @xref{Actions}.
 @end deffn
 
 @xref{Actions}.
 @end deffn
 


@@ -11897,8 +12245,9 @@ More user feedback will help to determine whether it should become a permanent
 feature.
 @end deffn
 
 feature.
 @end deffn
 

-@deffn {Construct} /*@dots{}*/
-Comment delimiters, as in C.
+@deffn {Construct} /* @dots{} */
+@deffnx {Construct} // @dots{}
+Comments, as in C/C++.

 @end deffn
 
 @deffn {Delimiter} :
 @end deffn
 
 @deffn {Delimiter} :


@@ -12255,13 +12604,6 @@ the next token.  @xref{Lexical, ,The Lexical Analyzer Function
 @code{yylex}}.
 @end deffn
 
 @code{yylex}}.
 @end deffn
 

-@deffn {Macro} YYLEX_PARAM
-An obsolete macro for specifying an extra argument (or list of extra
-arguments) for @code{yyparse} to pass to @code{yylex}.  The use of this
-macro is deprecated, and is supported only for Yacc like parsers.
-@xref{Pure Calling,, Calling Conventions for Pure Parsers}.
-@end deffn
-

 @deffn {Variable} yylloc
 External variable in which @code{yylex} should place the line and column
 numbers associated with a token.  (In a pure parser, it is a local
 @deffn {Variable} yylloc
 External variable in which @code{yylex} should place the line and column
 numbers associated with a token.  (In a pure parser, it is a local


@@ -12297,7 +12639,7 @@ Management}.
 @deffn {Variable} yynerrs
 Global variable which Bison increments each time it reports a syntax error.
 (In a pure parser, it is a local variable within @code{yyparse}. In a
 @deffn {Variable} yynerrs
 Global variable which Bison increments each time it reports a syntax error.
 (In a pure parser, it is a local variable within @code{yyparse}. In a

-pure push parser, it is a member of yypstate.)
+pure push parser, it is a member of @code{yypstate}.)

 @xref{Error Reporting, ,The Error Reporting Function @code{yyerror}}.
 @end deffn
 
 @xref{Error Reporting, ,The Error Reporting Function @code{yyerror}}.
 @end deffn
 


@@ -12383,7 +12725,7 @@ Data type of semantic values; @code{int} by default.
 @item Accepting state
 A state whose only action is the accept action.
 The accepting state is thus a consistent state.
 @item Accepting state
 A state whose only action is the accept action.
 The accepting state is thus a consistent state.

-@xref{Understanding,,}.
+@xref{Understanding, ,Understanding Your Parser}.

 
 @item Backus-Naur Form (BNF; also called ``Backus Normal Form'')
 Formal method of specifying context-free grammars originally proposed
 
 @item Backus-Naur Form (BNF; also called ``Backus Normal Form'')
 Formal method of specifying context-free grammars originally proposed


@@ -12693,7 +13035,10 @@ London, Department of Computer Science, TR-00-12 (December 2000).
 @c LocalWords: subdirectory Solaris nonassociativity perror schemas Malloy ints
 @c LocalWords: Scannerless ispell american ChangeLog smallexample CSTYPE CLTYPE
 @c LocalWords: clval CDEBUG cdebug deftypeopx yyterminate LocationType
 @c LocalWords: subdirectory Solaris nonassociativity perror schemas Malloy ints
 @c LocalWords: Scannerless ispell american ChangeLog smallexample CSTYPE CLTYPE
 @c LocalWords: clval CDEBUG cdebug deftypeopx yyterminate LocationType

-@c LocalWords: errorVerbose
+@c LocalWords: parsers parser's
+@c LocalWords: associativity subclasses precedences unresolvable runnable
+@c LocalWords: allocators subunit initializations unreferenced untyped
+@c LocalWords: errorVerbose subtype subtypes

 
 @c Local Variables:
 @c ispell-dictionary: "american"
 
 @c Local Variables:
 @c ispell-dictionary: "american"