Find words for phone numbers (Bike version)

phones.bk

#!
Output the combination of strings corresponding to a given phone number.
Only include those strings one of whose substrings must exist in the dictionary.
This script uses the Linux dictionary. 
!#

load 'file.bk';

var chars_for = {
	'-': ['-'],
	'0': ['0'],
	'1': ['1'],
	'2': ['A', 'B', 'C'],
	'3': ['D', 'E', 'F'],
	'4': ['G', 'H', 'I'],
	'5': ['J', 'K', 'L'],
	'6': ['M', 'N', 'O'],
	'7': ['P', 'Q', 'R', 'S'],
	'8': ['T', 'U', 'V'],
	'9': ['W', 'X', 'Y', 'Z'],
};

var dict = { member_missing: func() { false } };
Bike.FileSystem.read('/usr/share/dict/words').upper().split().each(func(word) {
	dict[word] = true;
});

var rank = func(phone) {
	var bare_phone = phone.replaces('-', ''), length = bare_phone.length(), subs = [];
	3.upto(length + 1, func ( width ) {
		0.upto(length - width + 1, func (start) {
			subs.add( bare_phone.sub( start, width ).upper() );
		});
	});
	return subs.filter(func(sub) { dict[sub] }) 
			       .map(func(sub) { var l = sub.length(); return l*l*l; })
			       .reduce(0, func(sum, val) { sum + val });
};

var phones = func(str, results, out, index) {
	out ||= ''; 
	index ||= 0;
	if (str.length() == out.length()) {
	  var value = rank(out);
	  if (value > 0) results.add([out, value]);
		return;
	}
	var chars = chars_for[str.char(index)];
	for (var char in chars) {
		out += char;
		phones(str, results, out, index + 1);
		out = out.sub(0, out.length() - 1);
	}
};

var process = func(str) {
	var results = [];
	phones(str, results);
	results = results.sort(func(a, b){ b[1].compare_to(a[1]) });
	var out = '';
	for (var result in results) {
		out += '{0} (value: {1}){2}'.with(result[0], result[1], NL);
	}
	Bike.FileSystem.write(str + '.txt', out);
};

try {
  process('6927753');
} rescue e {
  Bike.FileSystem.write('error.txt', e.toString());
}