@q Copyright 2012-2014, Alexander Shibakov@>
@q This file is part of SPLinT@>

@q SPLinT is free software: you can redistribute it and/or modify@>
@q it under the terms of the GNU General Public License as published by@>
@q the Free Software Foundation, either version 3 of the License, or@>
@q (at your option) any later version.@>

@q SPLinT is distributed in the hope that it will be useful,@>
@q but WITHOUT ANY WARRANTY; without even the implied warranty of@>
@q MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the@>
@q GNU General Public License for more details.@>

@q You should have received a copy of the GNU General Public License@>
@q along with SPLinT.  If not, see <http://www.gnu.org/licenses/>.@>

@*1 The name parser. What follows is an example parser for the name
processing. This approach (i.e. using a `full blown' parser/scanner
combination) is probably not the best way to implement such machinery
but its main purpose is to demonstrate a way to create a separate
parser for local purposes.
% We include the macros here since this file is intended to be
% included by the documentation `aggregator' so putting bare \TeX\
% at the beginning of the file runs the risk of producing and error
% of having \TeX\ material inside a \Cee\ section.
\let\currentparsernamespace\parsernamespace
    \let\parsernamespace\smallparsernamespace
    \let\hostparsernamespace\smallparsernamespace
    \input stokenset.sty
\let\parsernamespace\currentparsernamespace
@(small_parser.yy@>=
@G Switch to generic mode.
%{@> @<Name parser \Cee\ preamble@> @=%}
@g
@<Bison options@>@;
@G
%union {@> @<Union of parser types@> @=}
%{@> @<Name parser \Cee\ postamble@> @=%}
@g
@<Token and types ...@>@;
@G
%%
@g
@<Parser productions@>@;
@G
%%
@g

@ @<Bison options@>=
@G
%token-table
%debug
%start full_name
@g

@ @<Token and types declarations@>=
@G
%token PERCENT_IDENTIFIER
%token IDENTIFIER
%token OPTIONAL
%token NO_ATTR
%token INTEGER
%token EXTENDED
@g

@ @<Parser productions@>=
@G
full_name:
  identifier_string suffixes.opt  {@> @<Compose the full name@> @=}
;

identifier_string:
   PERCENT_IDENTIFIER             {@> @<Attach option name@> @=}  
|  IDENTIFIER                     {@> @<Start with an identifier@> @=}
|  '<' IDENTIFIER '>'             {@> @<Start with a tag@> @=}
|  qualifier                      {@> @<Turn a qualifier into an identifier@> @=}
|  identifier_string IDENTIFIER   {@> @<Attach an identifier@> @=}
|  identifier_string qualifier    {@> @<Attach qualifier to a name@> @=}
|  identifier_string INTEGER      {@> @<Attach an integer@> @=}
;

suffixes.opt:
                                  {@> TeX_( "/yy0{}" ); @=}
|  '.'                            {@> TeX_( "/yy0{/nx/dotsp/nx/sfxnone}" ); @=}
|  '.' suffixes                   {@> @<Attach suffixes@> @=}
|  '.' qualified_suffixes         {@> @<Attach qualified suffixes@> @=}
;

suffixes:
   IDENTIFIER                     {@> @<Start with a named suffix@> @=}
|  INTEGER                        {@> @<Start with a numeric suffix@> @=}
|  suffixes '.'                   {@> @<Add a dot separator@> @=}
|  suffixes IDENTIFIER            {@> @<Attach a named suffix@> @=}
|  suffixes INTEGER               {@> @<Attach integer suffix@> @=}
|  qualifier '.'                  {@> TeX_( "/yy0{/nx/sfxn/the/yy(1)/nx/dotsp}" ); @=}
|  suffixes qualifier '.'         {@> TeX_( "/yy0{/the/yy(1)/nx/sfxn/the/yy(1)/nx/dotsp}" ); @=}
;

qualified_suffixes:
  suffixes qualifier              {@> @<Attach a qualifier@> @=}
| qualifier                       {@> @<Start suffixes with a qualifier@> @=}
;

qualifier:
  OPTIONAL                        {@> TeX_( "/yy0{/the/yy(1)}" ); @=}
| NO_ATTR                         {@> TeX_( "/yy0{/the/yy(1)}" ); @=}
| EXTENDED                        {@> TeX_( "/yy0{/the/yy(1)}" ); @=}
;
@g

@ @<Compose the full name@>=
  @[TeX_( "/yy0{/the/yy(1)/the/yy(2)}/namechars/yyval" );@]@;

@ @<Attach option name@>=
  @[TeX_( "/getfirst{/yy(1)}/to/toksa" );@]@;
  @[TeX_( "/getsecond{/yy(1)}/to/toksb" );@]@;
  @[TeX_( "/yy0{/nx/optstr{/the/toksa}{/the/toksb}}" );@]@;

@ @<Start with an identifier@>=
  @[TeX_( "/getfirst{/yy(1)}/to/toksa" );@]@;
  @[TeX_( "/getsecond{/yy(1)}/to/toksb" );@]@;
  @[TeX_( "/yy0{/idstr{/the/toksa}{/the/toksb}}" );@]@;

@ @<Start with a tag@>=
  @[TeX_( "/getfirst{/yy(2)}/to/toksa" );@]@;
  @[TeX_( "/getsecond{/yy(2)}/to/toksb" );@]@;
  @[TeX_( "/yy0{/idstr{</the/toksa>}{</the/toksb>}}" );@]@;

@ @<Turn a qualifier into an identifier@>=
  @<Start with an identifier@>@;

@ @<Attach an identifier@>=
  @[TeX_( "/getsecond{/yy(1)}/to/toksa" );@]@;
  @[TeX_( "/appendr/toksa{/space}" );@]@;  
  @[TeX_( "/getfirst{/yy(2)}/to/toksb" );@]@;
  @[TeX_( "/concat/toksa/toksb" );@]@;
  @[TeX_( "/getthird{/yy(1)}/to/toksb" );@]@;
  @[TeX_( "/appendr/toksb{/space}" );@]@;  
  @[TeX_( "/getsecond{/yy(2)}/to/toksc" );@]@;
  @[TeX_( "/concat/toksb/toksc" );@]@;
  @[TeX_( "/yy0{/idstr{/the/toksa}{/the/toksb}}" );@]@;

@ @<Attach qualifier to a name@>=
  @<Attach an identifier@>

@ @<Attach an integer@>=
  @<Attach an identifier@>@;
                               
@ @<Attach suffixes@>=
  @[TeX_( "/yy0{/nx/dotsp/the/yy(2)}" );@]@;

@ @<Attach qualified suffixes@>=
  @<Attach suffixes@>@;

@ @<Start with a named suffix@>=
  @[TeX_( "/yy0{/nx/sfxn/the/yy(1)}" );@]@;

@ @<Start with a numeric suffix@>=
  @[TeX_( "/yy0{/nx/sfxi/the/yy(1)}" );@]@;

@ @<Add a dot separator@>=
  @[TeX_( "/yy0{/the/yy(1)/nx/dotsp}" );@]@;

@ @<Attach integer suffix@>=
  @[TeX_( "/yy0{/the/yy(1)/nx/sfxi/the/yy(2)}" );@]@;

@ @<Attach a named suffix@>=
  @[TeX_( "/yy0{/the/yy(1)/nx/sfxn/the/yy(2)}" );@]@;

@ @<Attach a qualifier@>=
  @[TeX_( "/yy0{/the/yy(1)/nx/qual/the/yy(2)}" );@]@;

@ @<Start suffixes with a qualifier@>=
  @[TeX_( "/yy0{/nx/qual/the/yy(1)}" );@]@;

@ \Cee\ preamble. In this case, there are no `real' actions that our
grammar performs, only \TeX\ output, so this section is empty.

@<Name parser \Cee\ preamble@>=

@ \Cee\ postamble. It is tricky to insert function definitions that use \bison's internal types,
as they have to be inserted in a place that is aware of the internal definitions but before said 
definitions are used.

@<Name parser \Cee\ postamble@>=
#define YYPRINT(file, type, value)   @[yyprint (file, type, value)@]
  static void yyprint (FILE *file, int type, YYSTYPE value){}

@ Union of types.

@<Union of parser types@>=

@*1 The name scanner.
%\checktabletrue
@(small_lexer.ll@>=

@<Lexer definitions@>@;

@G
%{@> @<Lexer \Cee\ preamble@> @=%}
@g
@<Lexer options@>@;
@G
%%
@g
@<Regular expressions@>@;
@G
%%
@g

  void define_all_states( void ) {

      @<Collect all state definitions@>@;

  }

@ @<Lexer definitions@>=
  @<Lexer states@>@;
@G
letter    [_abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ]
id        {letter}({letter}|[-0-9])*
int       [0-9]+
@g

@ @<Collect all state definitions@>=
#define _register_name( name ) @[Define_State( #name, name )@]
/* nothing for now */
#undef _register_name

@ Strings and characters in directives/rules.
@<Lexer states@>=
@G
%x SC_ESCAPED_STRING SC_ESCAPED_CHARACTER
@g

@ @<Lexer \Cee\ preamble@>=

#include <stdint.h>
#include <stdbool.h>

@ @<Lexer options@>=
@G
%option bison-bridge
%option noyywrap nounput noinput reentrant 
%option noyy_top_state
%option debug
%option stack
%option outfile="small_lexer.c"
@g

@ @<Regular expressions@>=
  @<Scan white space@>@;
  @<Scan identifiers@>@;

@ White space skipping. 
\traceparserstatestrue
\tracestackstrue
\tracerulestrue
\traceactionstrue
\tracelookaheadtrue
\traceparseresultstrue
\tracebadcharstrue
\yyflexdebugtrue
%
\traceparserstatesfalse
\tracestacksfalse
\tracerulesfalse
\traceactionsfalse
\tracelookaheadfalse
\traceparseresultsfalse
\tracebadcharsfalse
\yyflexdebugfalse
%
\yyskipparsetrue
@<Scan white space@>=
@G
[ \f\n\t\v]                        {@> @[TeX_( "/yylexnext" );@]@=}
@g

@ This collection of regular expressions might seem redundant, and in
its present state, it certainly is. However, if later on the
typesetting style for some of the keywords would need to be adjusted,
such changes would be easy to implement, since the template is already
here.
\yyskipparsefalse % this is not necessary
@<Scan identifiers@>=
@G
"%binary"                          {@> @[TeX_( "/yylexreturnval{PERCENT_IDENTIFIER}" );@]@=}
"%code"                            {@> @[TeX_( "/yylexreturnval{PERCENT_IDENTIFIER}" );@]@=}
"%debug"                           {@> @[TeX_( "/yylexreturnval{PERCENT_IDENTIFIER}" );@]@=}
"%default-prec"                    {@> @[TeX_( "/yylexreturnval{PERCENT_IDENTIFIER}" );@]@=}
"%define"                          {@> @[TeX_( "/yylexreturnval{PERCENT_IDENTIFIER}" );@]@=}
"%defines"                         {@> @[TeX_( "/yylexreturnval{PERCENT_IDENTIFIER}" );@]@=}
"%destructor"                      {@> @[TeX_( "/yylexreturnval{PERCENT_IDENTIFIER}" );@]@=}
"%dprec"                           {@> @[TeX_( "/yylexreturnval{PERCENT_IDENTIFIER}" );@]@=}
"%empty"                           {@> @[TeX_( "/yylexreturnval{PERCENT_IDENTIFIER}" );@]@=}
"%error-verbose"                   {@> @[TeX_( "/yylexreturnval{PERCENT_IDENTIFIER}" );@]@=}
"%expect"                          {@> @[TeX_( "/yylexreturnval{PERCENT_IDENTIFIER}" );@]@=}
"%expect-rr"                       {@> @[TeX_( "/yylexreturnval{PERCENT_IDENTIFIER}" );@]@=}
"%file-prefix"                     {@> @[TeX_( "/yylexreturnval{PERCENT_IDENTIFIER}" );@]@=}
"%fixed-output-files"              {@> @[TeX_( "/yylexreturnval{PERCENT_IDENTIFIER}" );@]@=}
"%initial-action"                  {@> @[TeX_( "/yylexreturnval{PERCENT_IDENTIFIER}" );@]@=}
"%glr-parser"                      {@> @[TeX_( "/yylexreturnval{PERCENT_IDENTIFIER}" );@]@=}
"%language"                        {@> @[TeX_( "/yylexreturnval{PERCENT_IDENTIFIER}" );@]@=}
"%left"                            {@> @[TeX_( "/yylexreturnval{PERCENT_IDENTIFIER}" );@]@=}
"%lex-param"                       {@> @[TeX_( "/yylexreturnval{PERCENT_IDENTIFIER}" );@]@=}
"%locations"                       {@> @[TeX_( "/yylexreturnval{PERCENT_IDENTIFIER}" );@]@=}
"%merge"                           {@> @[TeX_( "/yylexreturnval{PERCENT_IDENTIFIER}" );@]@=}
"%name-prefix"                     {@> @[TeX_( "/yylexreturnval{PERCENT_IDENTIFIER}" );@]@=}
"%no-default-prec"                 {@> @[TeX_( "/yylexreturnval{PERCENT_IDENTIFIER}" );@]@=}
"%no-lines"                        {@> @[TeX_( "/yylexreturnval{PERCENT_IDENTIFIER}" );@]@=}
"%nonassoc"                        {@> @[TeX_( "/yylexreturnval{PERCENT_IDENTIFIER}" );@]@=}
"%nondeterministic-parser"         {@> @[TeX_( "/yylexreturnval{PERCENT_IDENTIFIER}" );@]@=}
"%nterm"                           {@> @[TeX_( "/yylexreturnval{PERCENT_IDENTIFIER}" );@]@=}
"%output"                          {@> @[TeX_( "/yylexreturnval{PERCENT_IDENTIFIER}" );@]@=}
"%param"                           {@> @[TeX_( "/yylexreturnval{PERCENT_IDENTIFIER}" );@]@=}
"%parse-param"                     {@> @[TeX_( "/yylexreturnval{PERCENT_IDENTIFIER}" );@]@=}
"%prec"                            {@> @[TeX_( "/yylexreturnval{PERCENT_IDENTIFIER}" );@]@=}
"%precedence"                      {@> @[TeX_( "/yylexreturnval{PERCENT_IDENTIFIER}" );@]@=}
"%printer"                         {@> @[TeX_( "/yylexreturnval{PERCENT_IDENTIFIER}" );@]@=}
"%pure-parser"                     {@> @[TeX_( "/yylexreturnval{PERCENT_IDENTIFIER}" );@]@=}
"%require"                         {@> @[TeX_( "/yylexreturnval{PERCENT_IDENTIFIER}" );@]@=}
"%right"                           {@> @[TeX_( "/yylexreturnval{PERCENT_IDENTIFIER}" );@]@=}
"%skeleton"                        {@> @[TeX_( "/yylexreturnval{PERCENT_IDENTIFIER}" );@]@=}
"%start"                           {@> @[TeX_( "/yylexreturnval{PERCENT_IDENTIFIER}" );@]@=}
"%term"                            {@> @[TeX_( "/yylexreturnval{PERCENT_IDENTIFIER}" );@]@=}
"%token"                           {@> @[TeX_( "/yylexreturnval{PERCENT_IDENTIFIER}" );@]@=}
"%token-table"                     {@> @[TeX_( "/yylexreturnval{PERCENT_IDENTIFIER}" );@]@=}
"%type"                            {@> @[TeX_( "/yylexreturnval{PERCENT_IDENTIFIER}" );@]@=}
"%union"                           {@> @[TeX_( "/yylexreturnval{PERCENT_IDENTIFIER}" );@]@=}
"%verbose"                         {@> @[TeX_( "/yylexreturnval{PERCENT_IDENTIFIER}" );@]@=}
"%yacc"                            {@> @[TeX_( "/yylexreturnval{PERCENT_IDENTIFIER}" );@]@=}
"%default"[-_]"prec"               {@> @[TeX_( "/yylexreturnval{PERCENT_IDENTIFIER}" );@]@=}
"%error"[-_]"verbose"              {@> @[TeX_( "/yylexreturnval{PERCENT_IDENTIFIER}" );@]@=}
"%expect"[-_]"rr"                  {@> @[TeX_( "/yylexreturnval{PERCENT_IDENTIFIER}" );@]@=}
"%fixed"[-_]"output"[-_]"files"    {@> @[TeX_( "/yylexreturnval{PERCENT_IDENTIFIER}" );@]@=}
"%name"[-_]"prefix"                {@> @[TeX_( "/yylexreturnval{PERCENT_IDENTIFIER}" );@]@=}
"%no"[-_]"default"[-_]"prec"       {@> @[TeX_( "/yylexreturnval{PERCENT_IDENTIFIER}" );@]@=}
"%no"[-_]"lines"                   {@> @[TeX_( "/yylexreturnval{PERCENT_IDENTIFIER}" );@]@=}
"%pure"[-_]"parser"                {@> @[TeX_( "/yylexreturnval{PERCENT_IDENTIFIER}" );@]@=}
"%token"[-_]"table"                {@> @[TeX_( "/yylexreturnval{PERCENT_IDENTIFIER}" );@]@=}
"%"({letter}|[0-9]|[-_]|"%"|[<>])+ {@> @[TeX_( "/yylexreturnval{PERCENT_IDENTIFIER}" );@]@=}

"opt"                              {@> @[TeX_( "/yylexreturnval{OPTIONAL}" );@]@=}
"na"                               {@> @[TeX_( "/yylexreturnval{NO_ATTR}" );@]@=}
"ext"                              {@> @[TeX_( "/yylexreturnval{EXTENDED}" );@]@=}

[<>._]                             {@> @[TeX_( "/yylexreturnchar" );@]@=}

{id}                               {@> @[@<Prepare to process an identifier@>@]@=}
{int}                              {@> @[TeX_( "/yylexreturnval{INTEGER}" );@]@=}

.                                  {@> @[@<React to a bad character@>@]@=}
@g

@ @<Prepare to process an identifier@>=
 @[TeX_( "/yylexreturnval{IDENTIFIER}" );@]@;

@ @<React to a bad character@>=
 @[TeX_( "/iftracebadchars" );@]@;
 @[TeX_( "    /yycomplain{invalid character(s): /the/yytext}" );@]@;
 @[TeX_( "/fi" );@]@;
 @[TeX_( "/yylexreturn{$undefined}" );@]@;