Solution: Dump the data structure

Here is a possible solution to the task.

Code

my @data = 'Raku', [1, 2, 3], (key => 'value');

dd @data;
say "Structure: { @data.raku }";

🦋 You can find the source code in the file dump-the-structure.raku.

["Raku", [1, 2, 3], :key("value")]
Structure: ["Raku", [1, 2, 3], :key("value")]

dd @data prints a code-like representation of the contents of the array. It goes to the standard error stream.
The .raku method returns the same representation as a string, which is then embedded into a normal message using code interpolation and printed with say to the standard output.
The two lines look the same here, but they travel through different output streams: the first comes from dd (standard error), the second from say (standard output). Compare the following:

$ raku t.raku > /dev/null
["Raku", [1, 2, 3], :key("value")]

$ raku t.raku 2&> /dev/null
Structure: ["Raku", [1, 2, 3], :key("value")]