From @masak

<masak> r​: my $in_prompt; sub issue_prompt { say ENTER { $in_prompt =
True; 42 } }; issue_prompt
<p6eval> rakudo cf2761​: OUTPUT«Nil␤»
<masak> jnthn​: why is the return value of the ENTER block Nil?
<jnthn> masak​: Probably 'cus it doesn't support r-value use.
<jnthn> masak​: Feel free to research in the spec if it should. :)
<masak> hokay.
<jnthn> And if the spec thinks it should, feel free to file a ticket :)
<masak> jnthn​: I don't see anything in S04 says they're not rvalues.
<masak> jnthn​: in fact, I'd expect ENTER to work as either an rvalue
or lvalue in block form.
<masak> r​: say ENTER { 42 }
<p6eval> rakudo cf2761​: OUTPUT«Nil␤»
<jnthn> masak​: Well, clearly a bunch of phasers are useless as r-values.
<masak> jnthn​: those that haven't happened yet, yes.
<jnthn> Like LEAVE :)
<masak> of course.
<masak> I'm not arguing against that :)
<jnthn> But yeah, I think ENTER should work
<jnthn> There's probably some nice things to do with it.
<jnthn> LEAVE say "We took {now - ENTER now}s to run";
<jnthn> For example

From @usev6

Just an update​: ENTER blocks still return Nil​:

say ENTER { 42 }
Nil

S04 states ENTER can be used for its return value (http://perlcabal.org/syn/S04.html#Phasers)

@usev6 - Status changed from 'new' to 'open'

From @jnthn

On Wed Oct 08 04​:53​:49 2014, bartolin@​gmx.de wrote​:

Just an update​: ENTER blocks still return Nil​:

say ENTER { 42 }
Nil

S04 states ENTER can be used for its return value
(http://perlcabal.org/syn/S04.html#Phasers)

Implemented, and test added in S04-phasers/enter-leave.t.

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