Re: [Haskell-beginners] Overloading resolution with numbers

On Thu, Apr 5, 2012 at 8:29 PM, damodar kulkarni wrote:

See this: Prelude> :t 2.3 2.3 :: Fractional a => a

Hope this helps.

On Thu, Apr 5, 2012 at 7:24 PM, wrote:

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writes:

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Why does (read "2" + 1) works, but (read "2.3" + 1) fail at runtime?

Try this:

read "2.3" + 1 :: Float

Or this:

read "2.3" + 1.0

The reason that your version didn't work is because GHCi is guessing

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want the read operation to parse an Integer, since you're adding it to

On Thu, Apr 05, 2012 at 01:18:39PM +0000, Amy de Buitléir wrote: that you 1.

This is explanation does not seem to be enough once we consider the type of the literal 1:

Prelude> :t 1 1 :: Num a => a

That is, the literal 1 is overloaded to any numeric type. It is not necessarily an Integer.

Romildo

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-- Thanks and regards, -Damodar Kulkarni

-- Thanks and regards, -Damodar Kulkarni