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Package number

import "golang.org/x/text/number"
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Overview ▾

Package number formats numbers according to the customs of different locales.

The number formats of this package allow for greater formatting flexibility than passing values to message.Printf calls as is. It currently supports the builtin Go types and anything that implements the Convert interface (currently internal). 

p := message.NewPrinter(language.English)

p.Printf("%v bottles of beer on the wall.", number.Decimal(1234))
// Prints: 1,234 bottles of beer on the wall.

p.Printf("%v of gophers lose too much fur", number.Percent(0.12))
// Prints: 12% of gophers lose too much fur.

p := message.NewPrinter(language.Dutch)

p.Printf("There are %v bikes per household.", number.Decimal(1.2))
// Prints: Er zijn 1,2 fietsen per huishouden.

The width and scale specified in the formatting directives override the configuration of the formatter.

type FormatFunc

A FormatFunc formats a number. 

type FormatFunc func(x interface{}, opts ...Option) Formatter

func NewFormat 

func NewFormat(format FormatFunc, opts ...Option) FormatFunc

NewFormat creates a FormatFunc based on another FormatFunc and new options. Use NewFormat to cash the creation of formatters.

type Formatter 

type Formatter struct {
    // contains filtered or unexported fields
}

func Decimal 

func Decimal(x interface{}, opts ...Option) Formatter

Decimal formats a number as a floating point decimal.

func Engineering 

func Engineering(x interface{}, opts ...Option) Formatter

Engineering formats a number using engineering notation, which is like scientific notation, but with the exponent normalized to multiples of 3.

func PerMille 

func PerMille(x interface{}, opts ...Option) Formatter

PerMille formats a number as a per mille indication. A value of 1.0 means 1000‰.

func Percent 

func Percent(x interface{}, opts ...Option) Formatter

Percent formats a number as a percentage. A value of 1.0 means 100%.

func Scientific 

func Scientific(x interface{}, opts ...Option) Formatter

Scientific formats a number in scientific format.

func (Formatter) Digits 

func (f Formatter) Digits(buf []byte, tag language.Tag, scale int) number.Digits

Digits returns information about which logical digits will be presented to the user. This information is relevant, for instance, to determine plural forms.

func (Formatter) Format 

func (f Formatter) Format(state format.State, verb rune)

Format implements format.Formatter. It is for internal use only for now.

type Option

An Option configures a Formatter. 

type Option option

func FormatWidth 

func FormatWidth(n int) Option

FormatWidth sets the total format width.

func IncrementString 

func IncrementString(decimal string) Option

IncrementString sets the incremental value to which numbers should be rounded. For instance: Increment("0.05") will cause 1.44 to round to 1.45. IncrementString also sets scale to the scale of the increment.

▾ Example

Code:

p := message.NewPrinter(language.English)

p.Println(number.Decimal(1.33, number.IncrementString("0.50")))

Output:

1.50

func MaxFractionDigits 

func MaxFractionDigits(max int) Option

MaxFractionDigits specifies the maximum number of fractional digits.

func MaxIntegerDigits 

func MaxIntegerDigits(max int) Option

MaxIntegerDigits limits the number of integer digits, eliminating the most significant digits.

▾ Example

Code:

const year = 1999
p := message.NewPrinter(language.English)
p.Println("Year:", number.Decimal(year, number.MaxIntegerDigits(2)))

Output:

Year: 99

func MinFractionDigits 

func MinFractionDigits(min int) Option

MinFractionDigits specifies the minimum number of fractional digits.

func MinIntegerDigits 

func MinIntegerDigits(min int) Option

MinIntegerDigits specifies the minimum number of integer digits, adding leading zeros when needed.

func NoSeparator 

func NoSeparator() Option

NoSeparator causes a number to be displayed without grouping separators.

func Pad 

func Pad(r rune) Option

Pad sets the rune to be used for filling up to the format width.

func PatternOverrides 

func PatternOverrides(patterns map[string]string) Option

PatternOverrides allows users to specify alternative patterns for specific languages. The Pattern will be overridden for all languages in a subgroup as well. The function will panic for invalid input. It is best to create this option at startup time. PatternOverrides must be the first Option passed to a formatter.

func Precision 

func Precision(prec int) Option

Precision sets the maximum number of significant digits. A negative value means exact.

func Scale 

func Scale(decimals int) Option

Scale simultaneously sets MinFractionDigits and MaxFractionDigits to the given value.