Tuesday April 11, 2006
OziGeocacheUK
I've been tinkering around for a while wrapping the API to OziExplorer in Java, as chronicled both here and on my personal blog. I've finally knocked together an application that uses it. OziGeocacheUK integrates information from GeocacheUK.com and Geocaching.com into OziExplorer. OziExplorer is a GPS mapping application and GeocacheUK is a database of geocaches in the UK. Hopefully this post will help google steer anyone who is looking for such a thing towards it ;-)
Posted by alanbur
( Apr 11 2006, 10:46:20 PM BST )
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Wednesday April 05, 2006
A sort of perl golf challenge
I've been reviewing some perl code code that is due to go back into Solaris shortly, and one of the routines takes a sorted array of integers and returns a string with contiguous ranges of numbers collapsed and other numbers comma-separated. For example, given an array containing 1, 3, 4, 5, 8, 9, 10, 12 the routine would return the string "1, 3-5, 8-10, 12". The routine iterates over the array looking for and collapsing sequences of numbers. It's 30 lines long, but always being one for taking up a pointless challenge I wondered if I could make it any shorter. Here's what I came up with:
sub collapse
{
my $str = join(', ', @_);
while ($str =~ s{\b(\d+), ((??{ $1 + 1 }))\b}{$1-$2}g) {}
$str =~ s{-(?:\d+-)+}{-}g;
return ($str);
}
Now I know that under the proper perl golf rules I could shorten that down by removing whitespace, using implicit assignment and matches against $_ and so forth but I'm more interested in seeing if anyone can come up with a conceptually shorter solution (i.e. one that I can still read ;-). It occured to me that you might be able to do something smart with a recursive regexp, but the requirement to use $1 + 1 to spot a sequence kept stymieing me. However I'm sure some other perl saddo out there will come up with something even shorter and far smarter. Anyone? ;-)
Posted by alanbur
( Apr 05 2006, 10:20:31 PM BST )
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