Probably because the arrays will not be equal even if their contents are equal (this is true of most mutable types in Julia).
If you try representing a position as a tuple `(0,0)` instead of as an array `[0,0]`, you'll find that it works as expected. // T On Tuesday, December 15, 2015 at 8:28:36 AM UTC+1, Jan Strube wrote: > > That's not a problem at all. In fact that's the very reason why I'm using > a Set in the first place. > > My question is: Why is the number of entries in the set different when I > add Arrays vs. adding ASCIIStrings? > > > On Monday, December 14, 2015 at 10:57:57 PM UTC-8, [email protected] wrote: >> >> I think your problem is that Sets cannot contain duplicate entries, so if >> Santa ever passes the same point twice it won't be added. >> >> Cheers >> Lex >> >> On Tuesday, December 15, 2015 at 4:23:19 PM UTC+10, Jan Strube wrote: >>> >>> I'm trying to learn a bit more Julia by solving the puzzles over on >>> http://adventofcode.com >>> On day 3, the problem is to follow a number of directions and figure out >>> how many new places you end up. >>> http://adventofcode.com/day/3 >>> >>> I thought I can solve this simply by defining a set of [x y] positions, >>> each time adding a new grid position to the set, so I'd end up with a Set{ >>> Array{Int64,2}} of the right length. >>> However, this doesn't work as expected. I get the wrong number (it's too >>> low). >>> >>> Wrapping each grid position into a string() call, however, gives me the >>> right answer. >>> The explanation is a bit convoluted. To avoid spoilers I've put the code >>> up at https://gist.github.com/jstrube/3d54e15f7d051b72032b >>> >>> I don't quite understand this. Is this expected? >>> >>>
