Rules / Types, classes & roles / exception

X::Placeholder::Mainline Reference

Compilation error due to a placeholder in the mainline

What it is #

Examples, run three ways #

Every example below comes from the official documentation, together with the output that documentation asserts. Each was then executed by Rakudo and by Raku++ when this page was built. Where the three agree, one result is shown; where they do not, all three are — because which of them is wrong is exactly the information worth having.

4 no-output

class X::Placeholder::Mainline is X::Placeholder::Block { }

Not executed: the documentation states no expected output for this example.

$^x;

Not executed: the documentation states no expected output for this example.

Cannot use placeholder parameter $^x outside of a sub or block

Not executed: the documentation states no expected output for this example.

my %h;
say %h{ $^x };
#     ^^^^^^^  not a block, so $^x is part of the mainline

Not executed: the documentation states no expected output for this example.