x/text/currency: rouble symbol is only printed with language.Russian

[ainar-g]

What version of Go are you using (go version)?

$ go version
go version go1.11 linux/amd64

Does this issue reproduce with the latest release?

Yes.

What operating system and processor architecture are you using (go env)?

go env Output

$ go env
GOARCH="amd64"
GOBIN=""
GOCACHE="/home/ainar/.cache/go-build"
GOEXE=""
GOFLAGS=""
GOHOSTARCH="amd64"
GOHOSTOS="linux"
GOOS="linux"
GOPATH="/home/ainar/go"
GOPROXY=""
GORACE=""
GOROOT="/home/ainar/go/go1.11"
GOTMPDIR=""
GOTOOLDIR="/home/ainar/go/go1.11/pkg/tool/linux_amd64"
GCCGO="/usr/bin/gccgo"
CC="gcc"
CXX="g++"
CGO_ENABLED="1"
GOMOD=""
CGO_CFLAGS="-g -O2"
CGO_CPPFLAGS=""
CGO_CXXFLAGS="-g -O2"
CGO_FFLAGS="-g -O2"
CGO_LDFLAGS="-g -O2"
PKG_CONFIG="pkg-config"
GOGCCFLAGS="-fPIC -m64 -pthread -fmessage-length=0 -fdebug-prefix-map=/tmp/go-build112907181=/tmp/go-build -gno-record-gcc-switches"

What did you do?

https://play.golang.org/p/umgrxwND7k4

(Using floats because #15274.)

What did you expect to see?

₽ 100.00 = € 1.33
100.00 ₽ = 1.33 €
100.00 ₽ = 1.33 €

What did you see instead?

RUB 100.00 = € 1.33
RUB 100.00 = € 1.33
₽ 100.00 = € 1.33

There is #14308 about the symbol position, but I don't understand why the rouble symbol is only used when I use language.Russian, while the euro symbol is used in all cases.

[jarifibrahim]

I would like to work on this issue. Can someone help me get started? I am not sure where I should be looking.

[AlexanderYastrebov]

https://cldr.unicode.org/translation/currency-names-and-symbols

If a symbol is not widely recognized around the world (eg shekel ₪)
Where the currency is official in a country, use that symbol in locales with that country (eg IL)
Where the currency would be widely recognized by users of a language, use it in the base language locale (eg he/iw).
Otherwise, use the international currency symbol (eg ILS). This can be done just by omitting the translation.

I would guess CLDR data marks ₽ as not widely recognized around the world and therefore uses symbol only in Russian locale.
It is possible to ask for NarrowSymbol to output ₽ unconditionally https://play.golang.org/p/wyIRn49F496

Besides symbol position decimal format is also not locale specific which I address in #47623