Course of Raku / Objects, I/O, and exceptions / Exceptions / Exception objects / Exercises / Match the type

Solution: Match the type

Here is a possible solution to the task.

Code

{
    my $x = 1 / 0;
    say $x;

    CATCH {
        when X::Numeric::DivideByZero {
            say 'cannot divide by zero';
        }
    }
}

🦋 You can find the source code in the file match-the-type.raku.

Output

cannot divide by zero

Comments

1. In Raku, 1 / 0 does not blow up immediately; it produces a lazy Failure. The exception is thrown only when we use the value, here by trying to say it.

2. The thrown exception is of the built-in type X::Numeric::DivideByZero, and when X::Numeric::DivideByZero matches it precisely. Matching on a specific type, rather than catching everything with default, lets you handle different errors in different ways.

Course navigation

← Match the type   |   Prefix the message →