| Server IP : 85.214.239.14 / Your IP : 3.144.25.130 Web Server : Apache/2.4.62 (Debian) System : Linux h2886529.stratoserver.net 4.9.0 #1 SMP Tue Jan 9 19:45:01 MSK 2024 x86_64 User : www-data ( 33) PHP Version : 7.4.18 Disable Function : pcntl_alarm,pcntl_fork,pcntl_waitpid,pcntl_wait,pcntl_wifexited,pcntl_wifstopped,pcntl_wifsignaled,pcntl_wifcontinued,pcntl_wexitstatus,pcntl_wtermsig,pcntl_wstopsig,pcntl_signal,pcntl_signal_get_handler,pcntl_signal_dispatch,pcntl_get_last_error,pcntl_strerror,pcntl_sigprocmask,pcntl_sigwaitinfo,pcntl_sigtimedwait,pcntl_exec,pcntl_getpriority,pcntl_setpriority,pcntl_async_signals,pcntl_unshare, MySQL : OFF | cURL : OFF | WGET : ON | Perl : ON | Python : ON | Sudo : ON | Pkexec : OFF Directory : /usr/share/doc/libparse-recdescent-perl/examples/ |
Upload File : |
#!/usr/bin/perl -sw
# A SELF-MODIFYING**2 PARSER
use Parse::RecDescent;
$grammar =
q{
type_defn : 'only' <commit> "$::keyword" is type_name ';'
{ $thisparser->Replace("type_name: '$item[5]'");
print "\"$item[5]\" is now the only valid type name\n";
}
| "$::keyword" <commit> identifier(s) is type_name /('?s)?/ ';'
{ my $newnames = join " | ", map { "'$_'" } @{$item[3]};
$thisparser->Extend("type_name: $newnames");
print "added $newnames as type name(s)\n";
}
| /change\s+$::keyword\s+to/ identifier
{ $::keyword = $item[2];
print "changed $item[0] keyword to: $item[2]\n";
}
| <error>
is : /is|are/
type_name : 'int' | 'float'
identifier: ...!is ...!"$::keyword" ...!type_name /[A-Za-z]\w*/
};
use vars qw { $keyword };
$keyword = "type";
$parse = new Parse::RecDescent ($grammar);
while (<>)
{
$parse->type_defn($_) or print "huh?\n";
}