[Haskell-beginners] pure instead of return?
Silent Leaf
silent.leaf0 at gmail.com
Sat Jul 1 19:54:17 UTC 2017
yeah i know, so why did you say "so if you can you might want to use that"?
2017-07-01 21:46 GMT+02:00 Stefan Risberg <steffenomak at gmail.com>:
> Every monad is applicative, but every instance of applicative does not
> have a monad one
>
> On 1 Jul. 2017 20:19, "Silent Leaf" <silent.leaf0 at gmail.com> wrote:
>
>> but i can use pure every time return is usable, can i not? every
>> applicatives are monads right? i don't get the "if you can" part. why could
>> i not?
>>
>> 2017-07-01 20:03 GMT+02:00 Francesco Ariis <fa-ml at ariis.it>:
>>
>>> On Sat, Jul 01, 2017 at 07:47:57PM +0200, Silent Leaf wrote:
>>> > [..] or is it a way to say "simplest way to wrap
>>> > the value, purest (least "modified") equivalent of the value as wrapped
>>> > value"?
>>>
>>> ^-- this one.
>>>
>>> `pure` and `return` are synonyms. There are two words for the same
>>> concept
>>> for historical reasons. Using pure does not incurs in monad constraints,
>>> so if you can you might want to use that.
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>>
>>
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