CODEWITHSUNDEEP
perlraku
user266003
user266003

Reputation:

Enum or symbols in Perl 6

I want to pass a parameter to a method which may only have a predefined value. 

   method send-http($url, $http_method) { .... }

Should I create an enum to pass $http_method? If so then how?

Or does Perl 6 have something like symbols in Ruby?

Upvotes: 4

Views: 637

Answers (1)

donaldh
donaldh

Reputation: 833

As @Christoph mentioned, you can use enums:

enum Method <GET PUT POST>;
sub http-send(str $url, Method $m) { * }

http-send("http://url/", GET);

You can also use type constraints:

sub http-send(str $url, str $m where { $m ∈ <GET HEAD POST> }) { * }

http-send("http://url/", 'GET');

http-send("http://url/", 'PUT');
Constraint type check failed for parameter '$m'

I guess you could also use multi dispatch:

multi sub http-send('GET') { * }
multi sub http-send('PUT') { * }
multi sub http-send($m) { die "Method {$m} not supported." }

http-send('GET');

http-send('POST');
Method POST not supported.

Upvotes: 3

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