Concurrency #12
Raku++ 5.0.0-g312cde8e prints exactly what Rakudo 2026.08 prints
This is valid Raku: Rakudo 2026.08, the reference compiler, runs it without complaint, and the two outputs match character for character.
The program
The first lines compute $value. The last four lines are the same in every program: they print what kind of thing $value is, how it looks as code, as a string, and as true or false.
my $promise = Promise.broken("failure");
my $error = try await $promise;
my $value = ($promise.status.Str, $error.defined);
sub safe-str($v) { my $s = try $v.Str; $s.defined ?? $s !! '<undefined>' }
say "TYPE\t" ~ $value.^name;
say "RAKU\t" ~ $value.raku;
say "STR\t" ~ safe-str($value);
say "BOOL\t" ~ $value.Bool;
Run executes the program in your browser, with the Raku++ build this site ships. Edit it and try variations.
What each compiler printed
| Rakudo 2026.08 | Raku++ 5.0.0-g312cde8e | |
|---|---|---|
| Type .^name | List | List |
| Code form .raku | $("Broken", Bool::False) | $("Broken", Bool::False) |
| String .Str | Broken False | Broken False |
| True or false .Bool | True | True |
concurrency-v1 · seed 51 · recorded 2026-09-29 with Rakudo 2026.08 and Raku++ 5.0.0-g312cde8e · Source on GitHub ↗