Copyright	Soostone Inc
License	BSD3
Maintainer	libs@soostone.com
Stability	experimental
Safe Haskell	None
Language	Haskell2010

Formattable.NumFormat

Contents

Main number formatting functions and data types
Common formats
Lenses
Other formatting functions

Description

Formatting for numeric values.

Synopsis

Main number formatting functions and data types

formatNum :: Real a => NumFormat -> a -> Text Source

Primary function for formatting floating point numbers.

formatIntegral :: Integral a => NumFormat -> a -> Text Source

Primary function for formatting integrals. This was originally created to avoid depending on the double-conversion package which uses a C library and is therefore less portable. We're keeping this as a separate function because it should have the potential to be more efficient than the floating point version.

formatPct :: Real a => Int -> a -> Text Source

Convenience wrapper for percentages that lets you easily control the number of decimal places.

data NumFormat Source

The main data structure with all the necessary information for formatting numbers.

Constructors

NumFormat

Fields

_nfUnits :: Double: Units of measure to use in formatting the number. This is useful for things like percentages where you would use (units of 0.01) or financial statements (units of 1000 for example).
_nfPrefix :: Text: A prefix to add to the number, commonly used for currency designation.
_nfSuffix :: Text: A suffix for the number. Percent, for example.
_nfThouSep :: Text: The character to use as thousands separator if applicable.
_nfDecSep :: Text: Character to use for the decimal separator.
_nfStyle :: NumStyle: The formatting style
_nfPrec :: Maybe (Int, PrecisionType): Amount of precision to display
_nfNegStyle :: NegativeStyle: Styles for negative numbers

Instances

Eq NumFormat
Show NumFormat
Default NumFormat
Typeable * NumFormat

data NumStyle Source

Data structure describing available styles of number formatting.

Constructors

Exponent	Format with scientific notation
Fixed	Format with standard decimal notation
SmartExponent Int Int	The aruments a and b define bounds. If the absolute value of the number is in the interval [10 ^ a, 10 ^ b], then it uses the Fixed style. If the number is outside this interval, then use the Exponent style.
SIStyle	Adds the symbol for the closest smaller SI prefix as the suffix to the formatted number. This suffix appears before any other suffix you designate.
SmartSI Double Double	Like SIStyle but only applies the SI prefix if the number to be formatted falls within the range [a,b] given by the SmartSI arguments.

Instances

Eq NumStyle
Show NumStyle

autoStyle :: NumStyle Source

A reasonable default value for NumStyle.

data PrecisionType Source

Data structure for different methods of specifying precision.

Constructors

SigFigs	Specifies precision as a fixed number of significant digits
Decimals	Specifies precision with a fixed number of digits after the decimal place.

Instances

Eq PrecisionType
Show PrecisionType

data NegativeStyle Source

Different styles for representing negative numbers.

Constructors

NegMinusSign	Shows negative numbers as -123.000
NegParens	Shows negative numbers as (123.000)

Instances

Eq NegativeStyle
Show NegativeStyle

Common formats

rawIntFmt :: NumFormat Source

Int format with no thousands separator.

intFmt :: NumFormat Source

Int format with comma as the thousands separator.

percentFmt :: NumFormat Source

Common format for percentages. Example: 75.000%

numFmt :: NumFormat Source

Common format for generic numeric quantities of the form 123,456.99.

usdFmt :: NumFormat Source

Common format for US dollar quantities of the form $123,456.99.

Lenses

nfUnits :: Lens NumFormat NumFormat Double Double Source

nfPrefix :: Lens NumFormat NumFormat Text Text Source

nfSuffix :: Lens NumFormat NumFormat Text Text Source

nfThouSep :: Lens NumFormat NumFormat Text Text Source

nfDecSep :: Lens NumFormat NumFormat Text Text Source

nfStyle :: Lens NumFormat NumFormat NumStyle NumStyle Source

nfPrec :: Lens NumFormat NumFormat (Maybe (Int, PrecisionType)) (Maybe (Int, PrecisionType)) Source

nfNegStyle :: Lens NumFormat NumFormat NegativeStyle NegativeStyle Source

Other formatting functions

formatNumGeneric Source

Arguments

:: Real a
=> (Maybe Int -> Double -> Text)	Exponential formatter
-> (Maybe Int -> Double -> Text)	Fixed formatter
-> NumFormat	Format specification
-> a	The number to format
-> Text

Generic floating point formatting function that allows you to specify your own underlying functions for formatting exponential and fixed formats. This can allow you to use more efficient versions if available. We also use it the test suite to check behavior against the old double-conversion implementation.