On 3/15/09 11:19 AM, Richard Hainsworth wrote:
The following (the n:> is to mark the lines) are legal:
1:> my @x = 1,2,3,4; ([+] @x).say; # output 10
2:> my @x = 1|11,2,3,4; ([+] @a).perl.say; # output any(10,20)
3:> my @x = 1|11,2,3,4; ([+] @a).eigenstates.min.say; # output 10
However, the next line isnt
4:> my @x = 1,2,3,4; ([+] @a).eigenstates.min.say; # Method
'eigenstates' not found for invocant of class 'Integer'
[...]
I've been pondering and experimenting with this.
Now that the Object.eigenstates patch is in, all of the above cases do
it indeed work. But what if you have more than one ace in your hand?
5:> my @x = 1|11, 1|11, 10; ([+] @x).eigenstates.min.say
Junction<0x7f89311bca30>
Not so useful.
6:> my @x = 1|11, 1|11, 10; ([+] @x).perl.say
any(any(12, 22), any(22, 32))
A junction of junctions. And three aces?
7:> my @x = 1|11, 1|11, 1|11, 10; ([+] @x).perl.say
any(any(any(13, 23), any(23, 33)), any(any(23, 33), any(33, 43)))
Yikes! Is there a way of flattening such a beast into any(13, 23, 33,
43) ? Does a deeply nested Junction have any practical value that the
flattened one does not?
At any rate, it behaves much the same as a flattened version would when
matched against:
8:> my @x = 1|11, 1|11, 1|11, 10; ([+] @x) == 23 && say "Match!"
Match!
And so, the solution almost presents itself:
9:> my @x = 1|11, 1|11, 1|11, 10; say ([+] @x) ~~ 1..21 ?? "OK" !! "Bust!"
OK
10:> my @x = 1|11, 1|11, 1|11, 10, 9; say ([+] @x) ~~ 1..21 ?? "OK" !!
"Bust!"
Bust!
And of course, that would have worked before the patch.
Oh, and ++ for coming up with such a cool use for junctions in the first
place!
Bruce
