Re: [Haskell-beginners] How to use Text.Printf w/ custom types

24 Nov 2017

      I talked about PrintfType and its method `hspr`.

With PrintfArgs the same problem:

  instance PrintfArg JobEvent where
    toUPrintf _ = UString "aaa"

      ^^^ toUPrintf is not visible ERROR here...

Header of this file looks like:

  module Text.Printf(
     printf, hPrintf,
     PrintfType, HPrintfType, PrintfArg, IsChar
  ) where

so methods are not exported? And I don't see any Internal subpackage...
OK, no problem, I switched already to very cool `formatting` library :)

Thanks a lot!
...
It appears PrintfArg and its methods are fully exported.
On Fri, Nov 24, 2017 at 8:19 AM, Baa  wrote:
...
But how to do it if "methods" are not exporting?
...
According to
https://hackage.haskell.org/package/base-4.10.0.0/docs/  
Text-Printf.html#g:2,  
you only need to implement `PrintfArg`. There is also an example
for `()`.
Baa  schrieb am Fr., 24. Nov. 2017 um 13:33
Uhr:
...
Hello All!
As I understand to use Text.Printf.printf with custom types or
to return result as Text instead of String I must implement some
class instances: PrintfType, PrintfArg. But how to do this if
they are exported from module as type-names only - without its
methods (i.e. not "Printf (..)", but "Printf") ?
I tried to import Text.Printf.Internal but seems that no such
submodule...
Any ideas?
===
Best regards, Paul
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