[Haskell-beginners] Printf and bool

[Aditya Mahajan]

Hi,

I like the printf function from Text.Printf to display results on the
terminal. I noticed that there is no format specifier for Bool. Can
someone suggest how to create an instance of PrintfArg for Bool?

Aditya

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[Brent Yorgey]

On Mon, Jan 19, 2009 at 10:04:21AM -0500, Aditya Mahajan wrote:
> Hi,
>
> I like the printf function from Text.Printf to display results on the
> terminal. I noticed that there is no format specifier for Bool. Can someone
> suggest how to create an instance of PrintfArg for Bool?

Why not just use something like

printf "%s" (show b)

where b :: Bool ?

-Brent

[Aditya Mahajan]

On Mon, 19 Jan 2009, Brent Yorgey wrote:

> On Mon, Jan 19, 2009 at 10:04:21AM -0500, Aditya Mahajan wrote:
>> Hi,
>>
>> I like the printf function from Text.Printf to display results on the
>> terminal. I noticed that there is no format specifier for Bool. Can someone
>> suggest how to create an instance of PrintfArg for Bool?
>
> Why not just use something like
>
> printf "%s" (show b)
>
> where b :: Bool ?

Because it breaks type safety.

Aditya