Checking in vendor folder for ease of using go get.

vendor/golang.org/x/text/currency/query.go

@@ -0,0 +1,152 @@
+// Copyright 2016 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package currency
+
+import (
+	"sort"
+	"time"
+
+	"golang.org/x/text/language"
+)
+
+// 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
+}
+
+// Query represents a set of Units. The default set includes all Units that are
+// currently in use as legal tender in any Region.
+func Query(options ...QueryOption) QueryIter {
+	it := &iter{
+		end:  len(regionData),
+		date: 0xFFFFFFFF,
+	}
+	for _, fn := range options {
+		fn(it)
+	}
+	return it
+}
+
+// NonTender returns a new query that also includes matching Units that are not
+// legal tender.
+var NonTender QueryOption = nonTender
+
+func nonTender(i *iter) {
+	i.nonTender = true
+}
+
+// Historical selects the units for all dates.
+var Historical QueryOption = historical
+
+func historical(i *iter) {
+	i.date = hist
+}
+
+// A QueryOption can be used to change the set of unit information returned by
+// a query.
+type QueryOption func(*iter)
+
+// Date queries the units that were in use at the given point in history.
+func Date(t time.Time) QueryOption {
+	d := toDate(t)
+	return func(i *iter) {
+		i.date = d
+	}
+}
+
+// Region limits the query to only return entries for the given region.
+func Region(r language.Region) QueryOption {
+	p, end := len(regionData), len(regionData)
+	x := regionToCode(r)
+	i := sort.Search(len(regionData), func(i int) bool {
+		return regionData[i].region >= x
+	})
+	if i < len(regionData) && regionData[i].region == x {
+		p = i
+		for i++; i < len(regionData) && regionData[i].region == x; i++ {
+		}
+		end = i
+	}
+	return func(i *iter) {
+		i.p, i.end = p, end
+	}
+}
+
+const (
+	hist = 0x00
+	now  = 0xFFFFFFFF
+)
+
+type iter struct {
+	*regionInfo
+	p, end    int
+	date      uint32
+	nonTender bool
+}
+
+func (i *iter) Next() bool {
+	for ; i.p < i.end; i.p++ {
+		i.regionInfo = &regionData[i.p]
+		if !i.nonTender && !i.IsTender() {
+			continue
+		}
+		if i.date == hist || (i.from <= i.date && (i.to == 0 || i.date <= i.to)) {
+			i.p++
+			return true
+		}
+	}
+	return false
+}
+
+func (r *regionInfo) Region() language.Region {
+	// TODO: this could be much faster.
+	var buf [2]byte
+	buf[0] = uint8(r.region >> 8)
+	buf[1] = uint8(r.region)
+	return language.MustParseRegion(string(buf[:]))
+}
+
+func (r *regionInfo) Unit() Unit {
+	return Unit{r.code &^ nonTenderBit}
+}
+
+func (r *regionInfo) IsTender() bool {
+	return r.code&nonTenderBit == 0
+}
+
+func (r *regionInfo) From() (time.Time, bool) {
+	if r.from == 0 {
+		return time.Time{}, false
+	}
+	return fromDate(r.from), true
+}
+
+func (r *regionInfo) To() (time.Time, bool) {
+	if r.to == 0 {
+		return time.Time{}, false
+	}
+	return fromDate(r.to), true
+}