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Concurrency #11

✓
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 $lock = Lock.new;
my $counter = 0;
my @work = (1..4).map({ start { $lock.protect({ $counter++ }) } });
await @work;
my $value = $counter;

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 2026.08Raku++ 5.0.0-g312cde8e
Type .^nameIntInt
Code form .raku44
String .Str44
True or false .BoolTrueTrue