From @masak

<masak> m​: say (<jet plane> (^) <network lag>) (^) <plane network>
<camelia> rakudo-moar d60a8f​: OUTPUT«set(jet, lag)␤»
<masak> m​: say <jet plane> (^) <network lag> (^) <plane network>
<camelia> rakudo-moar d60a8f​: OUTPUT«Too many positionals passed;
expected 2 arguments but got 3 [...]
<masak> surely I should be able to do the latter too?
<masak> (a) because if nothing else, infix​:<(^)> should left-associate
<masak> (b) because maybe it even chains? I dunno.
* masak submits rakudobug

It's an interesting question in itself where the error message "Too
many positionals passed; expected 2 arguments but got 3" comes from.
Does the (^) operator somehow declare itself as chaining, but then has
no capability to handle a longer chain of operands? Just guessing
here.

From @pmichaud

On Wed, Oct 01, 2014 at 09​:00​:08PM -0700, Carl Mäsak wrote​:

<masak> m​: say <jet plane> (^) <network lag> (^) <plane network>

It's an interesting question in itself where the error message "Too
many positionals passed; expected 2 arguments but got 3" comes from.
Does the (^) operator somehow declare itself as chaining, but then has
no capability to handle a longer chain of operands? Just guessing
here.

I noticed this a few weeks ago when playing with the set operators. The problem is that infix​:<(^)> is correctly declared as having list associativity (it's at "junctive_or" precedence), but is defined as a binary operator in src/core/set_operators.pm. This is the reason for the "expected 2 arguments but got 3" message.

For comparison, note that infix​:<(|)> is defined in src/core/set_operators.pm as

  sub infix​:<(|)>(**@​p)

infix​:<(^)> needs to have a similar declaration instead of the 2-argument form that is there now.

Pm

The RT System itself - Status changed from 'new' to 'open'

From @masak

<pmichaud> see my response to RT #​122882 :)
<pmichaud> mainly, infix​:<(^)> should list associate
<pmichaud> imo, <jet plane> (^) <network lag> (^) <plane network> should result in <jet lag>
<pmichaud> more to the point, <a network> (^) <b network> (^) <a network> should result in <b> and not <b network>, which is hard to do if (^) is left-assoc
<masak> pmichaud​: I agree. that rhymes with infix​:<^^> semantics, too.
<pmichaud> exactly.
<masak> pmichaud++
<pmichaud> anyway, the problem is the way infix​:<(^)> is implemented in src/core/set_operators.pm

From @masak

<lizmat> $ 6 'say <a network> (^) <b network> (^) <a network>'
<lizmat> set(b)
<lizmat> #​122882 can be marked as TEST NEEDED :-)

Marked as testneeded.

From @pmichaud

Added tests in roast/S03-operators/set.t, marking ticket resolved.

Pm

@pmichaud - Status changed from 'open' to 'resolved'