%{
use 5.0010;
use feature 'state';
my $is_enum = 0;
sub rangeORenum {
my $self = shift;
require Range;
state $rp = Range->new( yyerror => sub {});
my $pos = pos(${$self->input});
$rp->input($self->input);
my $t = $rp->Run;
print "After nested parsing\n";
$is_enum = $rp->YYNberr;
pos(${$self->input}) = $pos;
}
%}
%conflict rangeORenum {
if ($is_enum) { $self->YYSetReduce([',', ')'], 'ID:ENUM' ); }
else { $self->YYSetReduce([',', ')'], 'ID:RANGE' ); }
}
%token ID = /([A-Za-z]\w*)/
%token NUM = /(\d+)/
%left ','
%left '-' '+'
%left '*' '/'
%expect-rr 2
%%
type_decl : 'type' ID '=' type ';'
;
type :
%name ENUM
PRErangeORenum '(' id_list ')'
| %name RANGE
PRErangeORenum expr '..' expr
;
PRErangeORenum:
/* empty */
{
goto &rangeORenum;
}
;
id_list :
%name ID:ENUM
ID %PREC rangeORenum
| id_list ',' ID
;
expr : '(' expr ')' { $_[2] } /* bypass */
| %name PLUS expr '+' expr
| %name MINUS expr '-' expr
| %name TIMES expr '*' expr
| %name DIV expr '/' expr
| %name COMMA expr ',' expr
| %name ID:RANGE
ID %PREC rangeORenum
| %name NUM NUM
;
%%
=head1 SYNOPSIS
See
=over 2
=item * File C<userange.pl>.
=item * File C<Range.eyp>.
=item * File pascalenumeratedvsrange.eyp in examples/debuggintut/
=item * The Bison manual L<http://www.gnu.org/software/bison/manual/html_mono/bison.html>
=back
Compile it with:
eyapp Range.eyp
eyapp -TC pascalnestedeyapp.eyp
Run it with this options:
$ ./pascalnestedeyapp.pm -t -i -m 1 -c 'type e = (x, y, z);'
$ perl5.10.0 ./pascalnestedeyapp.pm -t -i -m 1 -c 'type e = (x, @, z);'
Try also these inputs:
type e = (x) .. (y);
type r = (x) .. y ;
type r = (x+2)*3 .. y/2 ;
type e = (x, y, z);
type e = (x);
type e = (x, y, z) .. (u+v);
=cut