# Do junctions support determining interesections of lists

```Almost a year ago (2005-04-27), I wrote the list asking a question about
junctions.
Specifically, the ability to find the intersection, union, etc of a list.```
```
my \$matches = any( @x_chars ) eq any( @y_chars );
my \$match = \$matches.pick;

all( any() eq any() );

Patrick Michaud offered an infix myeq to let the problem be solved in user
space
as junctions at that time did not support what I wanted to do.

Today I examined the Synopses and found a couple of intriguing things:

In Synopsis 3:

"A junction is a single value that is equivalent to multiple values."

And then later on...

"Junctions are specifically unordered. So if you say

for all(@foo) {...}

it indicates to the compiler that there is no coupling between loop
iterations and they can be run in any order or even in parallel."

This implies to me that it is possible to get the values out of a junction
without calling a .values method if used in list context.

>From Synopsis 12:

"To hyperoperate over the values of a junction you have to explicitly pull
out the values:

\$junction.valuesÂ».meth(@args);"

This implies to me that you can still get at the values by explicitly using
.values.

>From Synopsis 9:

"Some contexts, such as boolean contexts, have special rules for dealing
with junctions. In any scalar context not expecting a junction of values, a
junction produces automatic parallelization of the algorithm."

Ok, so what about a context expecting a junction of values as I think all(
any() eq any() ) is expecting?

My question today is 2 fold.

1.  Where in the synopses would I find the various methods that can be
performed on a junction?
A.  .values
B.  .pick
C.  ???

2.  Do the junctions of today support finding the union, intersection, etc
without creating your own infix operator?

Cheers,
Joshua Gatcomb
a.k.a. Limbic~Region
```