NAME

Failable - Failure sum type

SYNOPSIS

use Failable;

sub cat(*@params --> Str:D) {
    my Proc:D $proc = run "cat", |@params, :out, :err;
    my Str:D  $out  = $proc.out.slurp(:close);
    my Str:D  $err  = $proc.err.slurp(:close);
    fail $err if $err;
    $out
}

my Failable[Str:D] $output = cat "/etc/hosts";
say $output.WHAT; # OUTPUT: (Str)

my Failable[Str:D] $error = cat '.';
say $error.WHAT; # OUTPUT: (Failure)

DESCRIPTION

Failable is a class for creating Failure sum types. Parameterizing Failable creates a new subset of Failure and the parameter passed. This allows you to type variables that are declared using the return values of routines that can fail.

AUTHOR

Ben Davies (Kaiepi)

COPYRIGHT AND LICENSE

This library is free software; you can redistribute it and/or modify it under the Artistic License 2.0.