# New Ticket Created by Patrick R. Michaud
# Please include the string: [perl #122948]
# in the subject line of all future correspondence about this issue.
# <URL: https://rt.perl.org/Ticket/Display.html?id=122948 >
The .infinite method on Any is designed to return one of three values:
True - known to be infinite
False - known to be finite
Nil - finite-ness not yet known or determined
The "Nil" (undefined) result is often provided for lists that are being
evaluated lazily... rather than force eager evaluation of the list, the list
can simply return an undefined value meaning "I don't know yet if I'm finite or
infinite".
With that in mind, something about splicing Captures isn't properly honoring
.infinite. Here's an illustration:
03:08 <pmichaud> r: sub g(*@v) { say @v.infinite; }; g(4..*); # correct
03:08 <camelia> rakudo-{parrot,moar} fd017a: OUTPUT«True»
03:08 <pmichaud> r: sub g(*@v) { say @v.infinite; }; g('a',4..*); #
correct
03:08 <camelia> rakudo-{parrot,moar} fd017a: OUTPUT«Nil»
03:08 <pmichaud> r: sub g(*@v) { say @v.infinite; }; g(|('a',4..*)); #
correct
03:08 <camelia> rakudo-{parrot,moar} fd017a: OUTPUT«Nil»
03:08 <pmichaud> r: sub g(*@v) { say @v.infinite; }; g(|(4..*)); #
incorrect
03:08 <camelia> rakudo-{parrot,moar} fd017a: OUTPUT«False»
The last case shows the problem -- when a Capture has a single infinite
argument, splicing it into the slurpy paramete loses its finite nature. Either
"True" or "Nil" would be acceptable for this last answer, but "False" is the
absolute wrong result.
This is ultimately the cause of the bug described in RT #118867 dealing with
the [max] reduction operator.
Pm
