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path: root/vendor/golang.org/x/text/currency/query.go
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-rw-r--r--vendor/golang.org/x/text/currency/query.go152
1 files changed, 152 insertions, 0 deletions
diff --git a/vendor/golang.org/x/text/currency/query.go b/vendor/golang.org/x/text/currency/query.go
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+++ b/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
+}