formatn

A library for support of:

• significant figure rounding of numbers, and
• common number formatting patterns.

Usage

:reload
:set prompt "> "

:set -Wno-type-defaults
:set -XOverloadedStrings
import Data.FormatN

xs = [(-1),0,0.1,1,1.01,1.02,1.1,1.2]

fixed (Just 2) <$> xs
decimal (Just 2) <$> xs
formats False False (const DecimalStyle) (Just 2) xs
formats False True (const DecimalStyle) (Just 2) xs
distinguish 4 False True (const DecimalStyle) (Just 2) xs

Ok, 14 modules loaded.
> >
>
> ["-1.00","0.00","0.10","1.00","1.01","1.02","1.10","1.20"]
["-1.0","0.0","0.10","1.0","1.0","1.0","1.1","1.2"]
["-1.00","0.00","0.10","1.00","1.00","1.00","1.10","1.20"]
["-1.0","0.0","0.1","1.0","1.0","1.0","1.1","1.2"]
["-1.00","0.00","0.10","1.00","1.01","1.02","1.10","1.20"]

getting 0 right

fixed

fixed (Just 3) <$> [0, 0.5, 1.5, 2.0]

["0.000","0.500","1.500","2.000"]

fixed defaults to representing Doubles in the same manner as Haskell does ie with a trailing ’.0’

fixed Nothing <$> [0, 0.5, 1.5, 2]

["0.0","0.5","1.5","2.0"]

expt

expt Nothing 0

0e0

expt (Just 2) 1
expt (Just 2) 0

1.0e0
0.0e0

decimal

decimal Nothing 0
decimal (Just 1) 0
decimal (Just 3) 0

0
0
0.00

percent

percent is a little weird any way you cut it.

percent decimalSF (Just 4) 0
percent decimalSF (Just 4) 1

0.0%
100.0%

inclusion in lists

formats True False commaPrecStyle Nothing [0, 0.5, 1.5, 2]
formats True False commaPrecStyle (Just 1) [0, 1, 10]
formats True False commaPrecStyle (Just 1) [0, 0.5, 1.5, 2]
formats True False commaPrecStyle (Just 2) [0, 0.5, 1.5, 2]
formats True True commaPrecStyle (Just 6) [0, 0.5, 1.5, 2]

["0.0","0.5","1.5","2.0"]
[" 0"," 1","10"]
["0.0","0.5","2.0","2.0"]
["0.00","0.50","1.50","2.00"]
["0.0","0.5","1.5","2.0"]