currency - ActiveState ActiveGo 1.8

Package currency

import ""

Overview ▾

Package currency contains currency-related functionality.

NOTE: the formatting functionality is currently under development and may change without notice.


CLDRVersion is the CLDR version from which the tables in this package are derived.

const CLDRVersion = "30"

type Amount

Amount is an amount-currency unit pair.

type Amount struct {
    // contains filtered or unexported fields

func (Amount) Currency

func (a Amount) Currency() Unit

Currency reports the currency unit of this amount.

func (Amount) Format

func (a Amount) Format(s fmt.State, verb rune)

Format implements fmt.Formatter. It accepts format.State for language-specific rendering.

type Formatter

Formatter decorates a given number, Unit or Amount with formatting options.

type Formatter func(amount interface{}) formattedValue
var (
    // Uses Narrow symbols. Overrides Symbol, if present.
    NarrowSymbol Formatter = Formatter(formNarrow)

    // Use Symbols instead of ISO codes, when available.
    Symbol Formatter = Formatter(formSymbol)

    // Use ISO code as symbol.
    ISO Formatter = Formatter(formISO)

func (Formatter) Default

func (f Formatter) Default(currency Unit) Formatter

Default creates a new Formatter that defaults to currency unit c if a numeric value is passed that is not associated with a currency.

func (Formatter) Kind

func (f Formatter) Kind(k Kind) Formatter

Kind sets the kind of the underlying currency unit.

type Kind

Kind determines the rounding and rendering properties of a currency value.

type Kind struct {
    // contains filtered or unexported fields
var (
    // Standard defines standard rounding and formatting for currencies.
    Standard Kind = Kind{rounding: standard}

    // Cash defines rounding and formatting standards for cash transactions.
    Cash Kind = Kind{rounding: cash}

    // Accounting defines rounding and formatting standards for accounting.
    Accounting Kind = Kind{rounding: standard}

func (Kind) Rounding

func (k Kind) Rounding(cur Unit) (scale, increment int)

Rounding reports the rounding characteristics for the given currency, where scale is the number of fractional decimals and increment is the number of units in terms of 10^(-scale) to which to round to.

type QueryIter

QueryIter represents a set of Units. The default set includes all Units that are currently in use as legal tender in any Region.

type QueryIter interface {
    // Next returns true if there is a next element available.
    // It must be called before any of the other methods are called.
    Next() bool

    // Unit returns the unit of the current iteration.
    Unit() Unit

    // Region returns the Region for the current iteration.
    Region() language.Region

    // From returns the date from which the unit was used in the region.
    // It returns false if this date is unknown.
    From() (time.Time, bool)

    // To returns the date up till which the unit was used in the region.
    // It returns false if this date is unknown or if the unit is still in use.
    To() (time.Time, bool)

    // IsTender reports whether the unit is a legal tender in the region during
    // the specified date range.
    IsTender() bool

func Query

func Query(options ...QueryOption) QueryIter

Query represents a set of Units. The default set includes all Units that are currently in use as legal tender in any Region.



t1799, _ := time.Parse("2006-01-02", "1799-01-01")
for it := currency.Query(currency.Date(t1799)); it.Next(); {
    from := ""
    if t, ok := it.From(); ok {
        from = t.Format("2006-01-01")
    fmt.Printf("%v is used in %v since: %v\n", it.Unit(), it.Region(), from)


GBP is used in GB since: 1694-07-07
GIP is used in GI since: 1713-01-01
USD is used in US since: 1792-01-01

type QueryOption

A QueryOption can be used to change the set of unit information returned by a query.

type QueryOption func(*iter)

Historical selects the units for all dates.

var Historical QueryOption = historical

NonTender returns a new query that also includes matching Units that are not legal tender.

var NonTender QueryOption = nonTender

func Date

func Date(t time.Time) QueryOption

Date queries the units that were in use at the given point in history.

func Region

func Region(r language.Region) QueryOption

Region limits the query to only return entries for the given region.

type Unit

Unit is an ISO 4217 currency designator.

type Unit struct {
    // contains filtered or unexported fields
var (
    // Undefined and testing.
    XXX Unit = Unit{}
    XTS Unit = Unit{xts}

    // G10 currencies
    USD Unit = Unit{usd}
    EUR Unit = Unit{eur}
    JPY Unit = Unit{jpy}
    GBP Unit = Unit{gbp}
    CHF Unit = Unit{chf}
    AUD Unit = Unit{aud}
    NZD Unit = Unit{nzd}
    CAD Unit = Unit{cad}
    SEK Unit = Unit{sek}
    NOK Unit = Unit{nok}

    // Additional common currencies as defined by CLDR.
    BRL Unit = Unit{brl}
    CNY Unit = Unit{cny}
    DKK Unit = Unit{dkk}
    INR Unit = Unit{inr}
    RUB Unit = Unit{rub}
    HKD Unit = Unit{hkd}
    IDR Unit = Unit{idr}
    KRW Unit = Unit{krw}
    MXN Unit = Unit{mxn}
    PLN Unit = Unit{pln}
    SAR Unit = Unit{sar}
    THB Unit = Unit{thb}
    TRY Unit = Unit{try}
    TWD Unit = Unit{twd}
    ZAR Unit = Unit{zar}

    // Precious metals.
    XAG Unit = Unit{xag}
    XAU Unit = Unit{xau}
    XPT Unit = Unit{xpt}
    XPD Unit = Unit{xpd}

func FromRegion

func FromRegion(r language.Region) (currency Unit, ok bool)

FromRegion reports the currency unit that is currently legal tender in the given region according to CLDR. It will return false if region currently does not have a legal tender.

func FromTag

func FromTag(t language.Tag) (Unit, language.Confidence)

FromTag reports the most likely currency for the given tag. It considers the currency defined in the -u extension and infers the region if necessary.

func MustParseISO

func MustParseISO(s string) Unit

MustParseISO is like ParseISO, but panics if the given currency unit cannot be parsed. It simplifies safe initialization of Unit values.

func ParseISO

func ParseISO(s string) (Unit, error)

ParseISO parses a 3-letter ISO 4217 currency code. It returns an error if s is not well-formed or not a recognized currency code.

func (Unit) Amount

func (u Unit) Amount(amount interface{}) Amount

Amount creates an Amount for the given currency unit and amount.

func (Unit) String

func (u Unit) String() string

String returns the ISO code of u.