From @moritz

Consider this code​:

#!/usr/bin/env perl6

my $source = Supply.interval(1);
$source.tap({ say 'DEBUG​: source'});
my $heartbeat = Supply.interval(0.7);
$heartbeat.tap({ say 'DEBUG​: heartbeat'});
react {
  whenever $source.zip-latest($heartbeat) {
  say 'WHENEVER';
  }
}

# Output​:
# DEBUG​: source
# DEBUG​: heartbeat
# DEBUG​: heartbeat
# DEBUG​: source
# DEBUG​: heartbeat
#
# ... and then it hangs, and produces no output anymore.

The mere fact that I combine those two supplies with zip-latest stops
the original supplies from producing values (or at least from calling
the .tap), and the whenever block isn't executed either.

So either I totally misunderstood zip-latest, or it's totally b0rked. Or
both :-)

--
Moritz Lenz
https://deploybook.com/ -- https://perlgeek.de/ -- https://perl6.org/

From @jnthn

On Thu Jul 21 14​:42​:42 2016, moritz wrote​:

Consider this code​:

#!/usr/bin/env perl6

my $source = Supply.interval(1);
$source.tap({ say 'DEBUG​: source'});
my $heartbeat = Supply.interval(0.7);
$heartbeat.tap({ say 'DEBUG​: heartbeat'});
react {
whenever $source.zip-latest($heartbeat) {
say 'WHENEVER';
}
}

# Output​:
# DEBUG​: source
# DEBUG​: heartbeat
# DEBUG​: heartbeat
# DEBUG​: source
# DEBUG​: heartbeat
#
# ... and then it hangs, and produces no output anymore.

The mere fact that I combine those two supplies with zip-latest stops
the original supplies from producing values (or at least from calling
the .tap), and the whenever block isn't executed either.

So either I totally misunderstood zip-latest, or it's totally b0rked. Or
both :-)

It should have worked. Since this RT was filed, multiple fixes have been made to supplies, and it seems one of them nailed this bug. I committed a test in S17-supply/zip-latest.t (and checked that it hung back in the June release, so it seems it covers it decently well).

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

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