randsexp.pl

#
# SFSEXP: Small, Fast S-Expression Library version 1.0
# Written by Matthew Sottile (mjsottile@gmail.com)
# 
# Copyright (2003-2006). The Regents of the University of California. This
# material was produced under U.S. Government contract W-7405-ENG-36 for Los
# Alamos National Laboratory, which is operated by the University of
# California for the U.S. Department of Energy. The U.S. Government has rights
# to use, reproduce, and distribute this software. NEITHER THE GOVERNMENT NOR
# THE UNIVERSITY MAKES ANY WARRANTY, EXPRESS OR IMPLIED, OR ASSUMES ANY
# LIABILITY FOR THE USE OF THIS SOFTWARE. If software is modified to produce
# derivative works, such modified software should be clearly marked, so as not
# to confuse it with the version available from LANL.
# 
# Additionally, this library is free software; you can redistribute it and/or
# modify it under the terms of the GNU Lesser General Public License as
# published by the Free Software Foundation; either version 2.1 of the
# License, or (at your option) any later version.
# 
# This library is distributed in the hope that it will be useful, but WITHOUT
# ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
# FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public License
# for more details.
# 
# You should have received a copy of the GNU Lesser General Public License
# along with this library; if not, write to the Free Software Foundation,
# Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, U SA
# 
# LA-CC-04-094
# 

#
# generate random s-expressions
#

if ($#ARGV != 2) {
    print "randsexp.pl [minatoms] [maxlen] [prob]\n";
    exit;
}

# minimum number of atoms
$mincount = $ARGV[0];

# maximum length of sexpr string in chars
$maxlength = $ARGV[1];

# probability cut off
$prob = $ARGV[2];

# initialize atom count and string
$count = 0;
$s = "";

while ($count < $mincount && length($s) < $maxlength) {
$depth = 1;
$count = 0;
$s = "(";
$tabs = "";

while ($depth > 0) {
	$r = rand();
	if ($r < $prob) {
		$depth++;
		$tabs = "";
		for ($i = 1; $i < $depth; $i++) {
			$tabs .= "  ";
		}
		$s .= "\n".$tabs."(foo$count";
	} else {
		if (1-$r < $prob) {
			$depth--;
			$tabs = "";
			for ($i = 1; $i < $depth; $i++) {
				$tabs .= "  ";
			}
			$s .= " foo$count".")\n".$tabs;
		} else {
			$s .= " foo$count";
		}
	}
	$count++;
	if ($count > ($mincount * 2)) {
		$depth = 0;
		$count = -1;
	}
}
}
print $s."\n";
#print STDERR "Elements: $count\n";