Show Fractional without exponent part in Haskell

Question

How to make Haskell show Fractional values without exponent part preserving leading zeros?

For example, command show 0.0025 outputs "2.5e-3". Is there a way to redefine this behavior?

You might want to try function `printf` from module [Text.Printf](https://hackage.haskell.org/package/base-4.14.0.0/docs/Text-Printf.html) ; expression `printf "%f\n" 0.0025` seems to return what you want. Of course it helps to be familiar with the printf() function in C. — jpmarinier, Sep 12 '20 at 15:03

score 4 · Answer 1 · edited Sep 12 '20 at 15:34

4

I tested first answer in this question , and it works

import Numeric
main = do
    putStrLn (showFFloat (Just 4)  0.0025 "")

edited Sep 12 '20 at 15:34

Daniel Wagner

answered Sep 12 '20 at 15:16

Howard_Roark

score 3 · Answer 2 · answered Sep 12 '20 at 15:03

3

You can try Text.Printf.printf. The %f format should be what you want.

> import Text.Printf
> printf "%f" 0.0025  :: String
"0.0025"

answered Sep 12 '20 at 15:03

chi

2 Answers2