Monads/Maybe monad: Difference between revisions
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Thundergnat (talk | contribs) (Rename Perl 6 -> Raku, alphabetize, minor clean-up) |
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{{works with|Rakudo|2019.11}} |
{{works with|Rakudo|2019.11}} |
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It is exceptionally difficult to come up with a compelling valuable use for |
It is exceptionally difficult to come up with a compelling valuable use for |
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a Maybe monad in |
a Maybe monad in Raku. Monads are most useful in languages that don't have |
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exceptions and/or only allow a single point of entry/exit from a subroutine. |
exceptions and/or only allow a single point of entry/exit from a subroutine. |
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The task description asks for two functions that take an Int and return a Maybe |
The task description asks for two functions that take an Int and return a Maybe |
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Int or Maybe Str, but those distinctions are nearly meaningless in |
Int or Maybe Str, but those distinctions are nearly meaningless in Raku. See |
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below. |
below. |
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$monad is both an Int '''and''' a Str. It exists in a sort-of quantum state |
$monad is both an Int '''and''' a Str. It exists in a sort-of quantum state |
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where what-it-is depends on how-it-is-used. Bolting on some 'Monad' type to do |
where what-it-is depends on how-it-is-used. Bolting on some 'Monad' type to do |
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this will only ''remove'' functionality that |
this will only ''remove'' functionality that Raku already has. |
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Ok, say you have a situation where you absolutely do not want an incalculable |
Ok, say you have a situation where you absolutely do not want an incalculable |
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