How do I declare the type of a variable inside a function in Haskell? -


this reframe of question asked @ defining variables inside function haskell

i have function beginning of looks this:

recursivels :: filepath -> io [filepath] recursivels dir =           folderexists <- doesdirectoryexist dir        if folderexists           ...

the question is, how can explicitly declare type of folderexists before assign in action?

well, let's try want in ghci:

> (a :: integer) <- return 10  <interactive>:2:7:     illegal type signature: `integer'       perhaps intended use -xscopedtypevariables     in pattern type-signature

so, should enable pragma.

> :set -xscopedtypevariables

and try again

> (a :: integer) <- return 10 :: integer

now have a equal 10, integer:

> 10 :: integer

also, believe you've forgot = in recursivels function, there should recursivels dir = ...


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