First commit

vendor/golang.org/x/text/message/catalog.go

@@ -0,0 +1,28 @@
+// Copyright 2015 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 message
+
+// TODO: some types in this file will need to be made public at some time.
+// Documentation and method names will reflect this by using the exported name.
+
+import (
+	"golang.org/x/text/language"
+	"golang.org/x/text/message/catalog"
+)
+
+// DefaultCatalog is used by SetString.
+var DefaultCatalog *catalog.Catalog = defaultCatalog
+
+var defaultCatalog = catalog.New()
+
+// SetString calls SetString on the initial default Catalog.
+func SetString(tag language.Tag, key string, msg string) error {
+	return defaultCatalog.SetString(tag, key, msg)
+}
+
+// Set calls Set on the initial default Catalog.
+func Set(tag language.Tag, key string, msg ...catalog.Message) error {
+	return defaultCatalog.Set(tag, key, msg...)
+}

vendor/golang.org/x/text/message/catalog/catalog.go

@@ -0,0 +1,292 @@
+// Copyright 2017 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 catalog defines collections of translated format strings.
+//
+// This package mostly defines types for populating catalogs with messages. The
+// catmsg package contains further definitions for creating custom message and
+// dictionary types as well as packages that use Catalogs.
+//
+// Package catalog defines various interfaces: Dictionary, Loader, and Message.
+// A Dictionary maintains a set of translations of format strings for a single
+// language. The Loader interface defines a source of dictionaries. A
+// translation of a format string is represented by a Message.
+//
+//
+// Catalogs
+//
+// A Catalog defines a programmatic interface for setting message translations.
+// It maintains a set of per-language dictionaries with translations for a set
+// of keys. For message translation to function properly, a translation should
+// be defined for each key for each supported language. A dictionary may be
+// underspecified, though, if there is a parent language that already defines
+// the key. For example, a Dictionary for "en-GB" could leave out entries that
+// are identical to those in a dictionary for "en".
+//
+//
+// Messages
+//
+// A Message is a format string which varies on the value of substitution
+// variables. For instance, to indicate the number of results one could want "no
+// results" if there are none, "1 result" if there is 1, and "%d results" for
+// any other number. Catalog is agnostic to the kind of format strings that are
+// used: for instance, messages can follow either the printf-style substitution
+// from package fmt or use templates.
+//
+// A Message does not substitute arguments in the format string. This job is
+// reserved for packages that render strings, such as message, that use Catalogs
+// to selected string. This separation of concerns allows Catalog to be used to
+// store any kind of formatting strings.
+//
+//
+// Selecting messages based on linguistic features of substitution arguments
+//
+// Messages may vary based on any linguistic features of the argument values.
+// The most common one is plural form, but others exist.
+//
+// Selection messages are provided in packages that provide support for a
+// specific linguistic feature. The following snippet uses plural.Select:
+//
+//   catalog.Set(language.English, "You are %d minute(s) late.",
+//       plural.Select(1,
+//           "one", "You are 1 minute late.",
+//           "other", "You are %d minutes late."))
+//
+// In this example, a message is stored in the Catalog where one of two messages
+// is selected based on the first argument, a number. The first message is
+// selected if the argument is singular (identified by the selector "one") and
+// the second message is selected in all other cases. The selectors are defined
+// by the plural rules defined in CLDR. The selector "other" is special and will
+// always match. Each language always defines one of the linguistic categories
+// to be "other." For English, singular is "one" and plural is "other".
+//
+// Selects can be nested. This allows selecting sentences based on features of
+// multiple arguments or multiple linguistic properties of a single argument.
+//
+//
+// String interpolation
+//
+// There is often a lot of commonality between the possible variants of a
+// message. For instance, in the example above the word "minute" varies based on
+// the plural catogory of the argument, but the rest of the sentence is
+// identical. Using interpolation the above message can be rewritten as:
+//
+//   catalog.Set(language.English, "You are %d minute(s) late.",
+//       catalog.Var("minutes",
+//           plural.Select(1, "one", "minute", "other", "minutes")),
+//       catalog.String("You are %[1]d ${minutes} late."))
+//
+// Var is defined to return the variable name if the message does not yield a
+// match. This allows us to further simplify this snippet to
+//
+//   catalog.Set(language.English, "You are %d minute(s) late.",
+//       catalog.Var("minutes", plural.Select(1, "one", "minute")),
+//       catalog.String("You are %d ${minutes} late."))
+//
+// Overall this is still only a minor improvement, but things can get a lot more
+// unwieldy if more than one linguistic feature is used to determine a message
+// variant. Consider the following example:
+//
+//   // argument 1: list of hosts, argument 2: list of guests
+//   catalog.Set(language.English, "%[1]v invite(s) %[2]v to their party.",
+//     catalog.Var("their",
+//         plural.Select(1,
+//             "one", gender.Select(1, "female", "her", "other", "his"))),
+//     catalog.Var("invites", plural.Select(1, "one", "invite"))
+//     catalog.String("%[1]v ${invites} %[2]v to ${their} party.")),
+//
+// Without variable substitution, this would have to be written as
+//
+//   // argument 1: list of hosts, argument 2: list of guests
+//   catalog.Set(language.English, "%[1]v invite(s) %[2]v to their party.",
+//     plural.Select(1,
+//         "one", gender.Select(1,
+//             "female", "%[1]v invites %[2]v to her party."
+//             "other", "%[1]v invites %[2]v to his party."),
+//         "other", "%[1]v invites %[2]v to their party.")
+//
+// Not necessarily shorter, but using variables there is less duplication and
+// the messages are more maintenance friendly. Moreover, languages may have up
+// to six plural forms. This makes the use of variables more welcome.
+//
+// Different messages using the same inflections can reuse variables by moving
+// them to macros. Using macros we can rewrite the message as:
+//
+//   // argument 1: list of hosts, argument 2: list of guests
+//   catalog.SetString(language.English, "%[1]v invite(s) %[2]v to their party.",
+//       "%[1]v ${invites(1)} %[2]v to ${their(1)} party.")
+//
+// Where the following macros were defined separately.
+//
+//   catalog.SetMacro(language.English, "invites", plural.Select(1, "one", "invite"))
+//   catalog.SetMacro(language.English, "their", plural.Select(1,
+//      "one", gender.Select(1, "female", "her", "other", "his"))),
+//
+// Placeholders use parentheses and the arguments to invoke a macro.
+//
+//
+// Looking up messages
+//
+// Message lookup using Catalogs is typically only done by specialized packages
+// and is not something the user should be concerned with. For instance, to
+// express the tardiness of a user using the related message we defined earlier,
+// the user may use the package message like so:
+//
+//   p := message.NewPrinter(language.English)
+//   p.Printf("You are %d minute(s) late.", 5)
+//
+// Which would print:
+//   You are 5 minutes late.
+//
+//
+// This package is UNDER CONSTRUCTION and its API may change.
+package catalog // import "golang.org/x/text/message/catalog"
+
+// TODO:
+// Some way to freeze a catalog.
+// - Locking on each lockup turns out to be about 50% of the total running time
+//   for some of the benchmarks in the message package.
+// Consider these:
+// - Sequence type to support sequences in user-defined messages.
+// - Garbage collection: Remove dictionaries that can no longer be reached
+//   as other dictionaries have been added that cover all possible keys.
+
+import (
+	"errors"
+	"fmt"
+
+	"golang.org/x/text/internal/catmsg"
+	"golang.org/x/text/language"
+)
+
+// A Catalog holds translations for messages for supported languages.
+type Catalog struct {
+	options
+
+	index  store
+	macros store
+}
+
+type options struct{}
+
+// An Option configures Catalog behavior.
+type Option func(*options)
+
+// TODO:
+// // Catalogs specifies one or more sources for a Catalog.
+// // Lookups are in order.
+// // This can be changed inserting a Catalog used for setting, which implements
+// // Loader, used for setting in the chain.
+// func Catalogs(d ...Loader) Option {
+// 	return nil
+// }
+//
+// func Delims(start, end string) Option {}
+//
+// func Dict(tag language.Tag, d ...Dictionary) Option
+
+// New returns a new Catalog.
+func New(opts ...Option) *Catalog {
+	c := &Catalog{}
+	for _, o := range opts {
+		o(&c.options)
+	}
+	return c
+}
+
+// Languages returns all languages for which the Catalog contains variants.
+func (c *Catalog) Languages() []language.Tag {
+	return c.index.languages()
+}
+
+// SetString is shorthand for Set(tag, key, String(msg)).
+func (c *Catalog) SetString(tag language.Tag, key string, msg string) error {
+	return c.set(tag, key, &c.index, String(msg))
+}
+
+// Set sets the translation for the given language and key.
+//
+// When evaluation this message, the first Message in the sequence to msgs to
+// evaluate to a string will be the message returned.
+func (c *Catalog) Set(tag language.Tag, key string, msg ...Message) error {
+	return c.set(tag, key, &c.index, msg...)
+}
+
+// SetMacro defines a Message that may be substituted in another message.
+// The arguments to a macro Message are passed as arguments in the
+// placeholder the form "${foo(arg1, arg2)}".
+func (c *Catalog) SetMacro(tag language.Tag, name string, msg ...Message) error {
+	return c.set(tag, name, &c.macros, msg...)
+}
+
+// ErrNotFound indicates there was no message for the given key.
+var ErrNotFound = errors.New("catalog: message not found")
+
+// A Message holds a collection of translations for the same phrase that may
+// vary based on the values of substitution arguments.
+type Message interface {
+	catmsg.Message
+}
+
+// String specifies a plain message string. It can be used as fallback if no
+// other strings match or as a simple standalone message.
+//
+// It is an error to pass more than one String in a message sequence.
+func String(name string) Message {
+	return catmsg.String(name)
+}
+
+// Var sets a variable that may be substituted in formatting patterns using
+// named substitution of the form "${name}". The name argument is used as a
+// fallback if the statements do not produce a match. The statement sequence may
+// not contain any Var calls.
+//
+// The name passed to a Var must be unique within message sequence.
+func Var(name string, msg ...Message) Message {
+	return &catmsg.Var{Name: name, Message: firstInSequence(msg)}
+}
+
+// firstInSequence is a message type that prints the first message in the
+// sequence that resolves to a match for the given substitution arguments.
+type firstInSequence []Message
+
+func (s firstInSequence) Compile(e *catmsg.Encoder) error {
+	e.EncodeMessageType(catmsg.First)
+	err := catmsg.ErrIncomplete
+	for i, m := range s {
+		if err == nil {
+			return fmt.Errorf("catalog: message argument %d is complete and blocks subsequent messages", i-1)
+		}
+		err = e.EncodeMessage(m)
+	}
+	return err
+}
+
+// Context returns a Context for formatting messages.
+// Only one Message may be formatted per context at any given time.
+func (c *Catalog) Context(tag language.Tag, r catmsg.Renderer) *Context {
+	return &Context{
+		cat: c,
+		tag: tag,
+		dec: catmsg.NewDecoder(tag, r, &dict{&c.macros, tag}),
+	}
+}
+
+// A Context is used for evaluating Messages.
+// Only one Message may be formatted per context at any given time.
+type Context struct {
+	cat *Catalog
+	tag language.Tag
+	dec *catmsg.Decoder
+}
+
+// Execute looks up and executes the message with the given key.
+// It returns ErrNotFound if no message could be found in the index.
+func (c *Context) Execute(key string) error {
+	data, ok := c.cat.index.lookup(c.tag, key)
+	if !ok {
+		return ErrNotFound
+	}
+	return c.dec.Execute(data)
+}

vendor/golang.org/x/text/message/catalog/catalog_test.go

@@ -0,0 +1,194 @@
+// Copyright 2017 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 catalog
+
+import (
+	"bytes"
+	"fmt"
+	"reflect"
+	"testing"
+
+	"golang.org/x/text/internal"
+	"golang.org/x/text/internal/catmsg"
+	"golang.org/x/text/language"
+)
+
+type entry struct {
+	tag, key string
+	msg      interface{}
+}
+
+var testCases = []struct {
+	desc   string
+	cat    []entry
+	lookup []entry
+}{{
+	desc: "empty catalog",
+	lookup: []entry{
+		{"en", "key", ""},
+		{"en", "", ""},
+		{"nl", "", ""},
+	},
+}, {
+	desc: "one entry",
+	cat: []entry{
+		{"en", "hello", "Hello!"},
+	},
+	lookup: []entry{
+		{"und", "hello", ""},
+		{"nl", "hello", ""},
+		{"en", "hello", "Hello!"},
+		{"en-US", "hello", "Hello!"},
+		{"en-GB", "hello", "Hello!"},
+		{"en-oxendict", "hello", "Hello!"},
+		{"en-oxendict-u-ms-metric", "hello", "Hello!"},
+	},
+}, {
+	desc: "hierarchical languages",
+	cat: []entry{
+		{"en", "hello", "Hello!"},
+		{"en-GB", "hello", "Hellø!"},
+		{"en-US", "hello", "Howdy!"},
+		{"en", "greetings", "Greetings!"},
+	},
+	lookup: []entry{
+		{"und", "hello", ""},
+		{"nl", "hello", ""},
+		{"en", "hello", "Hello!"},
+		{"en-US", "hello", "Howdy!"},
+		{"en-GB", "hello", "Hellø!"},
+		{"en-oxendict", "hello", "Hello!"},
+		{"en-US-oxendict-u-ms-metric", "hello", "Howdy!"},
+
+		{"und", "greetings", ""},
+		{"nl", "greetings", ""},
+		{"en", "greetings", "Greetings!"},
+		{"en-US", "greetings", "Greetings!"},
+		{"en-GB", "greetings", "Greetings!"},
+		{"en-oxendict", "greetings", "Greetings!"},
+		{"en-US-oxendict-u-ms-metric", "greetings", "Greetings!"},
+	},
+}, {
+	desc: "variables",
+	cat: []entry{
+		{"en", "hello %s", []Message{
+			Var("person", String("Jane")),
+			String("Hello ${person}!"),
+		}},
+		{"en", "hello error", []Message{
+			Var("person", String("Jane")),
+			noMatchMessage{}, // trigger sequence path.
+			String("Hello ${person."),
+		}},
+		{"en", "fallback to var value", []Message{
+			Var("you", noMatchMessage{}, noMatchMessage{}),
+			String("Hello ${you}."),
+		}},
+		{"en", "scopes", []Message{
+			Var("person1", String("Mark")),
+			Var("person2", String("Jane")),
+			Var("couple",
+				Var("person1", String("Joe")),
+				String("${person1} and ${person2}")),
+			String("Hello ${couple}."),
+		}},
+		{"en", "missing var", String("Hello ${missing}.")},
+	},
+	lookup: []entry{
+		{"en", "hello %s", "Hello Jane!"},
+		{"en", "hello error", "Hello $!(MISSINGBRACE)"},
+		{"en", "fallback to var value", "Hello you."},
+		{"en", "scopes", "Hello Joe and Jane."},
+		{"en", "missing var", "Hello missing."},
+	},
+}, {
+	desc: "macros",
+	cat: []entry{
+		{"en", "macro1", String("Hello ${macro1(1)}.")},
+		{"en", "macro2", String("Hello ${ macro1(2) }!")},
+		{"en", "macroWS", String("Hello ${ macro1( 2 ) }!")},
+		{"en", "missing", String("Hello ${ missing(1 }.")},
+		{"en", "badnum", String("Hello ${ badnum(1b) }.")},
+		{"en", "undefined", String("Hello ${ undefined(1) }.")},
+		{"en", "macroU", String("Hello ${ macroU(2) }!")},
+	},
+	lookup: []entry{
+		{"en", "macro1", "Hello Joe."},
+		{"en", "macro2", "Hello Joe!"},
+		{"en-US", "macroWS", "Hello Joe!"},
+		{"en-NL", "missing", "Hello $!(MISSINGPAREN)."},
+		{"en", "badnum", "Hello $!(BADNUM)."},
+		{"en", "undefined", "Hello undefined."},
+		{"en", "macroU", "Hello macroU!"},
+	}}}
+
+func initCat(entries []entry) (*Catalog, []language.Tag) {
+	tags := []language.Tag{}
+	cat := New()
+	for _, e := range entries {
+		tag := language.MustParse(e.tag)
+		tags = append(tags, tag)
+		switch msg := e.msg.(type) {
+		case string:
+			cat.SetString(tag, e.key, msg)
+		case Message:
+			cat.Set(tag, e.key, msg)
+		case []Message:
+			cat.Set(tag, e.key, msg...)
+		}
+	}
+	return cat, internal.UniqueTags(tags)
+}
+
+func TestCatalog(t *testing.T) {
+	for _, tc := range testCases {
+		t.Run(fmt.Sprintf("%s", tc.desc), func(t *testing.T) {
+			cat, wantTags := initCat(tc.cat)
+			cat.SetMacro(language.English, "macro1", String("Joe"))
+			cat.SetMacro(language.Und, "macro2", String("${macro1(1)}"))
+			cat.SetMacro(language.English, "macroU", noMatchMessage{})
+
+			if got := cat.Languages(); !reflect.DeepEqual(got, wantTags) {
+				t.Errorf("%s:Languages: got %v; want %v", tc.desc, got, wantTags)
+			}
+
+			for _, e := range tc.lookup {
+				t.Run(fmt.Sprintf("%s/%s", e.tag, e.key), func(t *testing.T) {
+					tag := language.MustParse(e.tag)
+					buf := testRenderer{}
+					ctx := cat.Context(tag, &buf)
+					want := e.msg.(string)
+					err := ctx.Execute(e.key)
+					gotFound := err != ErrNotFound
+					wantFound := want != ""
+					if gotFound != wantFound {
+						t.Fatalf("err: got %v (%v); want %v", gotFound, err, wantFound)
+					}
+					if got := buf.buf.String(); got != want {
+						t.Errorf("Lookup:\ngot  %q\nwant %q", got, want)
+					}
+				})
+			}
+		})
+	}
+}
+
+type testRenderer struct {
+	buf bytes.Buffer
+}
+
+func (f *testRenderer) Arg(i int) interface{} { return nil }
+func (f *testRenderer) Render(s string)       { f.buf.WriteString(s) }
+
+var msgNoMatch = catmsg.Register("no match", func(d *catmsg.Decoder) bool {
+	return false // no match
+})
+
+type noMatchMessage struct{}
+
+func (noMatchMessage) Compile(e *catmsg.Encoder) error {
+	e.EncodeMessageType(msgNoMatch)
+	return catmsg.ErrIncomplete
+}

vendor/golang.org/x/text/message/catalog/dict.go

@@ -0,0 +1,90 @@
+// Copyright 2017 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 catalog
+
+import (
+	"sync"
+
+	"golang.org/x/text/internal"
+	"golang.org/x/text/internal/catmsg"
+	"golang.org/x/text/language"
+)
+
+// TODO:
+// Dictionary returns a Dictionary that returns the first Message, using the
+// given language tag, that matches:
+//   1. the last one registered by one of the Set methods
+//   2. returned by one of the Loaders
+//   3. repeat from 1. using the parent language
+// This approach allows messages to be underspecified.
+// func (c *Catalog) Dictionary(tag language.Tag) (Dictionary, error) {
+// 	// TODO: verify dictionary exists.
+// 	return &dict{&c.index, tag}, nil
+// }
+
+type dict struct {
+	s   *store
+	tag language.Tag // TODO: make compact tag.
+}
+
+func (d *dict) Lookup(key string) (data string, ok bool) {
+	return d.s.lookup(d.tag, key)
+}
+
+func (c *Catalog) set(tag language.Tag, key string, s *store, msg ...Message) error {
+	data, err := catmsg.Compile(tag, &dict{&c.macros, tag}, firstInSequence(msg))
+
+	s.mutex.Lock()
+	defer s.mutex.Unlock()
+
+	m := s.index[tag]
+	if m == nil {
+		m = msgMap{}
+		if s.index == nil {
+			s.index = map[language.Tag]msgMap{}
+		}
+		s.index[tag] = m
+	}
+
+	m[key] = data
+	return err
+}
+
+type store struct {
+	mutex sync.RWMutex
+	index map[language.Tag]msgMap
+}
+
+type msgMap map[string]string
+
+func (s *store) lookup(tag language.Tag, key string) (data string, ok bool) {
+	s.mutex.RLock()
+	defer s.mutex.RUnlock()
+
+	for ; ; tag = tag.Parent() {
+		if msgs, ok := s.index[tag]; ok {
+			if msg, ok := msgs[key]; ok {
+				return msg, true
+			}
+		}
+		if tag == language.Und {
+			break
+		}
+	}
+	return "", false
+}
+
+// Languages returns all languages for which the store contains variants.
+func (s *store) languages() []language.Tag {
+	s.mutex.RLock()
+	defer s.mutex.RUnlock()
+
+	tags := make([]language.Tag, 0, len(s.index))
+	for t := range s.index {
+		tags = append(tags, t)
+	}
+	internal.SortTags(tags)
+	return tags
+}

vendor/golang.org/x/text/message/doc.go

@@ -0,0 +1,100 @@
+// Copyright 2017 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 message implements formatted I/O for localized strings with functions
+// analogous to the fmt's print functions. It is a drop-in replacement for fmt.
+//
+//
+// Localized Formatting
+//
+// A format string can be localized by replacing any of the print functions of
+// fmt with an equivalent call to a Printer.
+//
+//    p := message.NewPrinter(language.English)
+//    p.Println(123456.78) // Prints 123,456.78
+//
+//    p.Printf("%d ducks in a row", 4331) // Prints 4,331 ducks in a row
+//
+//    p := message.NewPrinter(language.Dutch)
+//    p.Println("Hoogte: %f meter", 1244.9) // Prints Hoogte: 1.244,9 meter
+//
+//    p := message.NewPrinter(language.Bengali)
+//    p.Println(123456.78) // Prints ১,২৩,৪৫৬.৭৮
+//
+// Printer currently supports numbers and specialized types for which packages
+// exist in x/text. Other builtin types such as time.Time and slices are
+// planned.
+//
+// Format strings largely have the same meaning as with fmt with the following
+// notable exceptions:
+//   - flag # always resorts to fmt for printing
+//   - verb 'f', 'e', 'g', 'd' use localized formatting unless the '#' flag is
+//     specified.
+//
+// See package fmt for more options.
+//
+//
+// Translation
+//
+// The format strings that are passed to Printf, Sprintf, Fprintf, or Errorf
+// are used as keys to look up translations for the specified languages.
+// More on how these need to be specified below.
+//
+// One can use arbitrary keys to distinguish between otherwise ambiguous
+// strings:
+//    p := message.NewPrinter(language.English)
+//    p.Printf("archive(noun)")  // Prints "archive"
+//    p.Printf("archive(verb)")  // Prints "archive"
+//
+//    p := message.NewPrinter(language.German)
+//    p.Printf("archive(noun)")  // Prints "Archiv"
+//    p.Printf("archive(verb)")  // Prints "archivieren"
+//
+// To retain the fallback functionality, use Key:
+//    p.Printf(message.Key("archive(noun)", "archive"))
+//    p.Printf(message.Key("archive(verb)", "archive"))
+//
+//
+// Translation Pipeline
+//
+// Format strings that contain text need to be translated to support different
+// locales. The first step is to extract strings that need to be translated.
+//
+// 1. Install gotext
+//    go get -u golang.org/x/text/cmd/gotext
+//    gotext -help
+//
+// 2. Mark strings in your source to be translated by using message.Printer,
+// instead of the functions of the fmt package.
+//
+// 3. Extract the strings from your source
+//
+//    gotext extract
+//
+// The output will be written to the textdata directory.
+//
+// 4. Send the files for translation
+//
+// It is planned to support multiple formats, but for now one will have to
+// rewrite the JSON output to the desired format.
+//
+// 5. Inject translations into program
+//
+// 6. Repeat from 2
+//
+// Right now this has to be done programmatically with calls to Set or
+// SetString. These functions as well as the methods defined in
+// see also package golang.org/x/text/message/catalog can be used to implement
+// either dynamic or static loading of messages.
+//
+//
+// Plural and Gender Forms
+//
+// Translated messages can vary based on the plural and gender forms of
+// substitution values. In general, it is up to the translators to provide
+// alternative translations for such forms. See the packages in
+// golang.org/x/text/feature and golang.org/x/text/message/catalog for more
+// information.
+//
+package message

vendor/golang.org/x/text/message/examples_test.go

@@ -0,0 +1,42 @@
+// Copyright 2017 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 message_test
+
+import (
+	"net/http"
+
+	"golang.org/x/text/language"
+	"golang.org/x/text/message"
+)
+
+func Example_http() {
+	// languages supported by this service:
+	matcher := language.NewMatcher(message.DefaultCatalog.Languages())
+
+	http.HandleFunc("/", func(w http.ResponseWriter, r *http.Request) {
+		lang, _ := r.Cookie("lang")
+		accept := r.Header.Get("Accept-Language")
+		fallback := "en"
+		tag, _ := language.MatchStrings(matcher, lang.String(), accept, fallback)
+
+		p := message.NewPrinter(tag)
+
+		p.Fprintln(w, "User language is", tag)
+	})
+}
+
+func ExamplePrinter_numbers() {
+	for _, lang := range []string{"en", "de", "de-CH", "fr", "bn"} {
+		p := message.NewPrinter(language.Make(lang))
+		p.Printf("%-6s %g\n", lang, 123456.78)
+	}
+
+	// Output:
+	// en     123,456.78
+	// de     123.456,78
+	// de-CH  123’456.78
+	// fr     123 456,78
+	// bn     ১,২৩,৪৫৬.৭৮
+}

vendor/golang.org/x/text/message/format.go

@@ -0,0 +1,532 @@
+// Copyright 2017 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 message
+
+import (
+	"bytes"
+	"strconv"
+	"unicode/utf8"
+)
+
+const (
+	ldigits = "0123456789abcdefx"
+	udigits = "0123456789ABCDEFX"
+)
+
+const (
+	signed   = true
+	unsigned = false
+)
+
+// flags placed in a separate struct for easy clearing.
+type fmtFlags struct {
+	widPresent  bool
+	precPresent bool
+	minus       bool
+	plus        bool
+	sharp       bool
+	space       bool
+	zero        bool
+
+	// For the formats %+v %#v, we set the plusV/sharpV flags
+	// and clear the plus/sharp flags since %+v and %#v are in effect
+	// different, flagless formats set at the top level.
+	plusV  bool
+	sharpV bool
+}
+
+// A formatInfo is the raw formatter used by Printf etc.
+// It prints into a buffer that must be set up separately.
+type formatInfo struct {
+	buf *bytes.Buffer
+
+	fmtFlags
+
+	wid  int // width
+	prec int // precision
+
+	// intbuf is large enough to store %b of an int64 with a sign and
+	// avoids padding at the end of the struct on 32 bit architectures.
+	intbuf [68]byte
+}
+
+func (f *formatInfo) clearflags() {
+	f.fmtFlags = fmtFlags{}
+}
+
+func (f *formatInfo) init(buf *bytes.Buffer) {
+	f.buf = buf
+	f.clearflags()
+}
+
+// writePadding generates n bytes of padding.
+func (f *formatInfo) writePadding(n int) {
+	if n <= 0 { // No padding bytes needed.
+		return
+	}
+	f.buf.Grow(n)
+	// Decide which byte the padding should be filled with.
+	padByte := byte(' ')
+	if f.zero {
+		padByte = byte('0')
+	}
+	// Fill padding with padByte.
+	for i := 0; i < n; i++ {
+		f.buf.WriteByte(padByte) // TODO: make more efficient.
+	}
+}
+
+// pad appends b to f.buf, padded on left (!f.minus) or right (f.minus).
+func (f *formatInfo) pad(b []byte) {
+	if !f.widPresent || f.wid == 0 {
+		f.buf.Write(b)
+		return
+	}
+	width := f.wid - utf8.RuneCount(b)
+	if !f.minus {
+		// left padding
+		f.writePadding(width)
+		f.buf.Write(b)
+	} else {
+		// right padding
+		f.buf.Write(b)
+		f.writePadding(width)
+	}
+}
+
+// padString appends s to f.buf, padded on left (!f.minus) or right (f.minus).
+func (f *formatInfo) padString(s string) {
+	if !f.widPresent || f.wid == 0 {
+		f.buf.WriteString(s)
+		return
+	}
+	width := f.wid - utf8.RuneCountInString(s)
+	if !f.minus {
+		// left padding
+		f.writePadding(width)
+		f.buf.WriteString(s)
+	} else {
+		// right padding
+		f.buf.WriteString(s)
+		f.writePadding(width)
+	}
+}
+
+// fmt_boolean formats a boolean.
+func (f *formatInfo) fmt_boolean(v bool) {
+	if v {
+		f.padString("true")
+	} else {
+		f.padString("false")
+	}
+}
+
+// fmt_unicode formats a uint64 as "U+0078" or with f.sharp set as "U+0078 'x'".
+func (f *formatInfo) fmt_unicode(u uint64) {
+	buf := f.intbuf[0:]
+
+	// With default precision set the maximum needed buf length is 18
+	// for formatting -1 with %#U ("U+FFFFFFFFFFFFFFFF") which fits
+	// into the already allocated intbuf with a capacity of 68 bytes.
+	prec := 4
+	if f.precPresent && f.prec > 4 {
+		prec = f.prec
+		// Compute space needed for "U+" , number, " '", character, "'".
+		width := 2 + prec + 2 + utf8.UTFMax + 1
+		if width > len(buf) {
+			buf = make([]byte, width)
+		}
+	}
+
+	// Format into buf, ending at buf[i]. Formatting numbers is easier right-to-left.
+	i := len(buf)
+
+	// For %#U we want to add a space and a quoted character at the end of the buffer.
+	if f.sharp && u <= utf8.MaxRune && strconv.IsPrint(rune(u)) {
+		i--
+		buf[i] = '\''
+		i -= utf8.RuneLen(rune(u))
+		utf8.EncodeRune(buf[i:], rune(u))
+		i--
+		buf[i] = '\''
+		i--
+		buf[i] = ' '
+	}
+	// Format the Unicode code point u as a hexadecimal number.
+	for u >= 16 {
+		i--
+		buf[i] = udigits[u&0xF]
+		prec--
+		u >>= 4
+	}
+	i--
+	buf[i] = udigits[u]
+	prec--
+	// Add zeros in front of the number until requested precision is reached.
+	for prec > 0 {
+		i--
+		buf[i] = '0'
+		prec--
+	}
+	// Add a leading "U+".
+	i--
+	buf[i] = '+'
+	i--
+	buf[i] = 'U'
+
+	oldZero := f.zero
+	f.zero = false
+	f.pad(buf[i:])
+	f.zero = oldZero
+}
+
+// fmt_integer formats signed and unsigned integers.
+func (f *formatInfo) fmt_integer(u uint64, base int, isSigned bool, digits string) {
+	negative := isSigned && int64(u) < 0
+	if negative {
+		u = -u
+	}
+
+	buf := f.intbuf[0:]
+	// The already allocated f.intbuf with a capacity of 68 bytes
+	// is large enough for integer formatting when no precision or width is set.
+	if f.widPresent || f.precPresent {
+		// Account 3 extra bytes for possible addition of a sign and "0x".
+		width := 3 + f.wid + f.prec // wid and prec are always positive.
+		if width > len(buf) {
+			// We're going to need a bigger boat.
+			buf = make([]byte, width)
+		}
+	}
+
+	// Two ways to ask for extra leading zero digits: %.3d or %03d.
+	// If both are specified the f.zero flag is ignored and
+	// padding with spaces is used instead.
+	prec := 0
+	if f.precPresent {
+		prec = f.prec
+		// Precision of 0 and value of 0 means "print nothing" but padding.
+		if prec == 0 && u == 0 {
+			oldZero := f.zero
+			f.zero = false
+			f.writePadding(f.wid)
+			f.zero = oldZero
+			return
+		}
+	} else if f.zero && f.widPresent {
+		prec = f.wid
+		if negative || f.plus || f.space {
+			prec-- // leave room for sign
+		}
+	}
+
+	// Because printing is easier right-to-left: format u into buf, ending at buf[i].
+	// We could make things marginally faster by splitting the 32-bit case out
+	// into a separate block but it's not worth the duplication, so u has 64 bits.
+	i := len(buf)
+	// Use constants for the division and modulo for more efficient code.
+	// Switch cases ordered by popularity.
+	switch base {
+	case 10:
+		for u >= 10 {
+			i--
+			next := u / 10
+			buf[i] = byte('0' + u - next*10)
+			u = next
+		}
+	case 16:
+		for u >= 16 {
+			i--
+			buf[i] = digits[u&0xF]
+			u >>= 4
+		}
+	case 8:
+		for u >= 8 {
+			i--
+			buf[i] = byte('0' + u&7)
+			u >>= 3
+		}
+	case 2:
+		for u >= 2 {
+			i--
+			buf[i] = byte('0' + u&1)
+			u >>= 1
+		}
+	default:
+		panic("fmt: unknown base; can't happen")
+	}
+	i--
+	buf[i] = digits[u]
+	for i > 0 && prec > len(buf)-i {
+		i--
+		buf[i] = '0'
+	}
+
+	// Various prefixes: 0x, -, etc.
+	if f.sharp {
+		switch base {
+		case 8:
+			if buf[i] != '0' {
+				i--
+				buf[i] = '0'
+			}
+		case 16:
+			// Add a leading 0x or 0X.
+			i--
+			buf[i] = digits[16]
+			i--
+			buf[i] = '0'
+		}
+	}
+
+	if negative {
+		i--
+		buf[i] = '-'
+	} else if f.plus {
+		i--
+		buf[i] = '+'
+	} else if f.space {
+		i--
+		buf[i] = ' '
+	}
+
+	// Left padding with zeros has already been handled like precision earlier
+	// or the f.zero flag is ignored due to an explicitly set precision.
+	oldZero := f.zero
+	f.zero = false
+	f.pad(buf[i:])
+	f.zero = oldZero
+}
+
+// truncate truncates the string to the specified precision, if present.
+func (f *formatInfo) truncate(s string) string {
+	if f.precPresent {
+		n := f.prec
+		for i := range s {
+			n--
+			if n < 0 {
+				return s[:i]
+			}
+		}
+	}
+	return s
+}
+
+// fmt_s formats a string.
+func (f *formatInfo) fmt_s(s string) {
+	s = f.truncate(s)
+	f.padString(s)
+}
+
+// fmt_sbx formats a string or byte slice as a hexadecimal encoding of its bytes.
+func (f *formatInfo) fmt_sbx(s string, b []byte, digits string) {
+	length := len(b)
+	if b == nil {
+		// No byte slice present. Assume string s should be encoded.
+		length = len(s)
+	}
+	// Set length to not process more bytes than the precision demands.
+	if f.precPresent && f.prec < length {
+		length = f.prec
+	}
+	// Compute width of the encoding taking into account the f.sharp and f.space flag.
+	width := 2 * length
+	if width > 0 {
+		if f.space {
+			// Each element encoded by two hexadecimals will get a leading 0x or 0X.
+			if f.sharp {
+				width *= 2
+			}
+			// Elements will be separated by a space.
+			width += length - 1
+		} else if f.sharp {
+			// Only a leading 0x or 0X will be added for the whole string.
+			width += 2
+		}
+	} else { // The byte slice or string that should be encoded is empty.
+		if f.widPresent {
+			f.writePadding(f.wid)
+		}
+		return
+	}
+	// Handle padding to the left.
+	if f.widPresent && f.wid > width && !f.minus {
+		f.writePadding(f.wid - width)
+	}
+	// Write the encoding directly into the output buffer.
+	buf := f.buf
+	if f.sharp {
+		// Add leading 0x or 0X.
+		buf.WriteByte('0')
+		buf.WriteByte(digits[16])
+	}
+	var c byte
+	for i := 0; i < length; i++ {
+		if f.space && i > 0 {
+			// Separate elements with a space.
+			buf.WriteByte(' ')
+			if f.sharp {
+				// Add leading 0x or 0X for each element.
+				buf.WriteByte('0')
+				buf.WriteByte(digits[16])
+			}
+		}
+		if b != nil {
+			c = b[i] // Take a byte from the input byte slice.
+		} else {
+			c = s[i] // Take a byte from the input string.
+		}
+		// Encode each byte as two hexadecimal digits.
+		buf.WriteByte(digits[c>>4])
+		buf.WriteByte(digits[c&0xF])
+	}
+	// Handle padding to the right.
+	if f.widPresent && f.wid > width && f.minus {
+		f.writePadding(f.wid - width)
+	}
+}
+
+// fmt_sx formats a string as a hexadecimal encoding of its bytes.
+func (f *formatInfo) fmt_sx(s, digits string) {
+	f.fmt_sbx(s, nil, digits)
+}
+
+// fmt_bx formats a byte slice as a hexadecimal encoding of its bytes.
+func (f *formatInfo) fmt_bx(b []byte, digits string) {
+	f.fmt_sbx("", b, digits)
+}
+
+// fmt_q formats a string as a double-quoted, escaped Go string constant.
+// If f.sharp is set a raw (backquoted) string may be returned instead
+// if the string does not contain any control characters other than tab.
+func (f *formatInfo) fmt_q(s string) {
+	s = f.truncate(s)
+	if f.sharp && strconv.CanBackquote(s) {
+		f.padString("`" + s + "`")
+		return
+	}
+	buf := f.intbuf[:0]
+	if f.plus {
+		f.pad(strconv.AppendQuoteToASCII(buf, s))
+	} else {
+		f.pad(strconv.AppendQuote(buf, s))
+	}
+}
+
+// fmt_c formats an integer as a Unicode character.
+// If the character is not valid Unicode, it will print '\ufffd'.
+func (f *formatInfo) fmt_c(c uint64) {
+	r := rune(c)
+	if c > utf8.MaxRune {
+		r = utf8.RuneError
+	}
+	buf := f.intbuf[:0]
+	w := utf8.EncodeRune(buf[:utf8.UTFMax], r)
+	f.pad(buf[:w])
+}
+
+// fmt_qc formats an integer as a single-quoted, escaped Go character constant.
+// If the character is not valid Unicode, it will print '\ufffd'.
+func (f *formatInfo) fmt_qc(c uint64) {
+	r := rune(c)
+	if c > utf8.MaxRune {
+		r = utf8.RuneError
+	}
+	buf := f.intbuf[:0]
+	if f.plus {
+		f.pad(strconv.AppendQuoteRuneToASCII(buf, r))
+	} else {
+		f.pad(strconv.AppendQuoteRune(buf, r))
+	}
+}
+
+// fmt_float formats a float64. It assumes that verb is a valid format specifier
+// for strconv.AppendFloat and therefore fits into a byte.
+func (f *formatInfo) fmt_float(v float64, size int, verb rune, prec int) {
+	// Explicit precision in format specifier overrules default precision.
+	if f.precPresent {
+		prec = f.prec
+	}
+	// Format number, reserving space for leading + sign if needed.
+	num := strconv.AppendFloat(f.intbuf[:1], v, byte(verb), prec, size)
+	if num[1] == '-' || num[1] == '+' {
+		num = num[1:]
+	} else {
+		num[0] = '+'
+	}
+	// f.space means to add a leading space instead of a "+" sign unless
+	// the sign is explicitly asked for by f.plus.
+	if f.space && num[0] == '+' && !f.plus {
+		num[0] = ' '
+	}
+	// Special handling for infinities and NaN,
+	// which don't look like a number so shouldn't be padded with zeros.
+	if num[1] == 'I' || num[1] == 'N' {
+		oldZero := f.zero
+		f.zero = false
+		// Remove sign before NaN if not asked for.
+		if num[1] == 'N' && !f.space && !f.plus {
+			num = num[1:]
+		}
+		f.pad(num)
+		f.zero = oldZero
+		return
+	}
+	// The sharp flag forces printing a decimal point for non-binary formats
+	// and retains trailing zeros, which we may need to restore.
+	if f.sharp && verb != 'b' {
+		digits := 0
+		switch verb {
+		case 'v', 'g', 'G':
+			digits = prec
+			// If no precision is set explicitly use a precision of 6.
+			if digits == -1 {
+				digits = 6
+			}
+		}
+
+		// Buffer pre-allocated with enough room for
+		// exponent notations of the form "e+123".
+		var tailBuf [5]byte
+		tail := tailBuf[:0]
+
+		hasDecimalPoint := false
+		// Starting from i = 1 to skip sign at num[0].
+		for i := 1; i < len(num); i++ {
+			switch num[i] {
+			case '.':
+				hasDecimalPoint = true
+			case 'e', 'E':
+				tail = append(tail, num[i:]...)
+				num = num[:i]
+			default:
+				digits--
+			}
+		}
+		if !hasDecimalPoint {
+			num = append(num, '.')
+		}
+		for digits > 0 {
+			num = append(num, '0')
+			digits--
+		}
+		num = append(num, tail...)
+	}
+	// We want a sign if asked for and if the sign is not positive.
+	if f.plus || num[0] != '+' {
+		// If we're zero padding to the left we want the sign before the leading zeros.
+		// Achieve this by writing the sign out and then padding the unsigned number.
+		if f.zero && f.widPresent && f.wid > len(num) {
+			f.buf.WriteByte(num[0])
+			f.writePadding(f.wid - len(num))
+			f.buf.Write(num[1:])
+			return
+		}
+		f.pad(num)
+		return
+	}
+	// No sign to show and the number is positive; just print the unsigned number.
+	f.pad(num[1:])
+}

vendor/golang.org/x/text/message/message.go

@@ -0,0 +1,169 @@
+// Copyright 2015 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 message // import "golang.org/x/text/message"
+
+import (
+	"io"
+	"os"
+
+	"golang.org/x/text/language"
+	"golang.org/x/text/message/catalog"
+)
+
+// TODO: allow more than one goroutine per printer. This will allow porting from
+// fmt much less error prone.
+
+// A Printer implements language-specific formatted I/O analogous to the fmt
+// package. Only one goroutine may use a Printer at the same time.
+type Printer struct {
+	// Wrap the fields in a hidden type to hide some of the implemented methods.
+	printer printer
+
+	// NOTE: limiting one goroutine per Printer allows for many optimizations
+	// and simplifications. We can consider removing this restriction down the
+	// road if it the benefits do not seem to outweigh the disadvantages.
+}
+
+type options struct {
+	cat *catalog.Catalog
+	// TODO:
+	// - allow %s to print integers in written form (tables are likely too large
+	//   to enable this by default).
+	// - list behavior
+	//
+}
+
+// An Option defines an option of a Printer.
+type Option func(o *options)
+
+// Catalog defines the catalog to be used.
+func Catalog(c *catalog.Catalog) Option {
+	return func(o *options) { o.cat = c }
+}
+
+// NewPrinter returns a Printer that formats messages tailored to language t.
+func NewPrinter(t language.Tag, opts ...Option) *Printer {
+	options := &options{
+		cat: defaultCatalog,
+	}
+	for _, o := range opts {
+		o(options)
+	}
+	p := &Printer{printer{
+		tag: t,
+	}}
+	p.printer.toDecimal.InitDecimal(t)
+	p.printer.toScientific.InitScientific(t)
+	p.printer.catContext = options.cat.Context(t, &p.printer)
+	return p
+}
+
+// Sprint is like fmt.Sprint, but using language-specific formatting.
+func (p *Printer) Sprint(a ...interface{}) string {
+	p.printer.reset()
+	p.printer.doPrint(a)
+	return p.printer.String()
+}
+
+// Fprint is like fmt.Fprint, but using language-specific formatting.
+func (p *Printer) Fprint(w io.Writer, a ...interface{}) (n int, err error) {
+	p.printer.reset()
+	p.printer.doPrint(a)
+	n64, err := io.Copy(w, &p.printer.Buffer)
+	return int(n64), err
+}
+
+// Print is like fmt.Print, but using language-specific formatting.
+func (p *Printer) Print(a ...interface{}) (n int, err error) {
+	return p.Fprint(os.Stdout, a...)
+}
+
+// Sprintln is like fmt.Sprintln, but using language-specific formatting.
+func (p *Printer) Sprintln(a ...interface{}) string {
+	p.printer.reset()
+	p.printer.doPrintln(a)
+	return p.printer.String()
+}
+
+// Fprintln is like fmt.Fprintln, but using language-specific formatting.
+func (p *Printer) Fprintln(w io.Writer, a ...interface{}) (n int, err error) {
+	p.printer.reset()
+	p.printer.doPrintln(a)
+	n64, err := io.Copy(w, &p.printer.Buffer)
+	return int(n64), err
+}
+
+// Println is like fmt.Println, but using language-specific formatting.
+func (p *Printer) Println(a ...interface{}) (n int, err error) {
+	return p.Fprintln(os.Stdout, a...)
+}
+
+// Sprintf is like fmt.Sprintf, but using language-specific formatting.
+func (p *Printer) Sprintf(key Reference, a ...interface{}) string {
+	lookupAndFormat(p, key, a)
+	return p.printer.String()
+}
+
+// Fprintf is like fmt.Fprintf, but using language-specific formatting.
+func (p *Printer) Fprintf(w io.Writer, key Reference, a ...interface{}) (n int, err error) {
+	lookupAndFormat(p, key, a)
+	return w.Write(p.printer.Bytes())
+}
+
+// Printf is like fmt.Printf, but using language-specific formatting.
+func (p *Printer) Printf(key Reference, a ...interface{}) (n int, err error) {
+	lookupAndFormat(p, key, a)
+	return os.Stdout.Write(p.printer.Bytes())
+}
+
+func lookupAndFormat(p *Printer, r Reference, a []interface{}) {
+	p.printer.reset()
+	p.printer.args = a
+	var id, msg string
+	switch v := r.(type) {
+	case string:
+		id, msg = v, v
+	case key:
+		id, msg = v.id, v.fallback
+	default:
+		panic("key argument is not a Reference")
+	}
+
+	if p.printer.catContext.Execute(id) == catalog.ErrNotFound {
+		if p.printer.catContext.Execute(msg) == catalog.ErrNotFound {
+			p.printer.Render(msg)
+			return
+		}
+	}
+}
+
+// Arg implements catmsg.Renderer.
+func (p *printer) Arg(i int) interface{} { // TODO, also return "ok" bool
+	i--
+	if uint(i) < uint(len(p.args)) {
+		return p.args[i]
+	}
+	return nil
+}
+
+// Render implements catmsg.Renderer.
+func (p *printer) Render(msg string) {
+	p.doPrintf(msg)
+}
+
+// A Reference is a string or a message reference.
+type Reference interface {
+	// TODO: also allow []string
+}
+
+// Key creates a message Reference for a message where the given id is used for
+// message lookup and the fallback is returned when no matches are found.
+func Key(id string, fallback string) Reference {
+	return key{id, fallback}
+}
+
+type key struct {
+	id, fallback string
+}

vendor/golang.org/x/text/message/message_test.go

@@ -0,0 +1,181 @@
+// Copyright 2015 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 message
+
+import (
+	"bytes"
+	"fmt"
+	"io"
+	"testing"
+
+	"golang.org/x/text/internal"
+	"golang.org/x/text/internal/format"
+	"golang.org/x/text/language"
+	"golang.org/x/text/message/catalog"
+)
+
+type formatFunc func(s fmt.State, v rune)
+
+func (f formatFunc) Format(s fmt.State, v rune) { f(s, v) }
+
+func TestBinding(t *testing.T) {
+	testCases := []struct {
+		tag   string
+		value interface{}
+		want  string
+	}{
+		{"en", 1, "1"},
+		{"en", "2", "2"},
+		{ // Language is passed.
+			"en",
+			formatFunc(func(fs fmt.State, v rune) {
+				s := fs.(format.State)
+				io.WriteString(s, s.Language().String())
+			}),
+			"en",
+		},
+	}
+	for i, tc := range testCases {
+		p := NewPrinter(language.MustParse(tc.tag))
+		if got := p.Sprint(tc.value); got != tc.want {
+			t.Errorf("%d:%s:Sprint(%v) = %q; want %q", i, tc.tag, tc.value, got, tc.want)
+		}
+		var buf bytes.Buffer
+		p.Fprint(&buf, tc.value)
+		if got := buf.String(); got != tc.want {
+			t.Errorf("%d:%s:Fprint(%v) = %q; want %q", i, tc.tag, tc.value, got, tc.want)
+		}
+	}
+}
+
+func TestLocalization(t *testing.T) {
+	type test struct {
+		tag  string
+		key  Reference
+		args []interface{}
+		want string
+	}
+	args := func(x ...interface{}) []interface{} { return x }
+	empty := []interface{}{}
+	joe := []interface{}{"Joe"}
+	joeAndMary := []interface{}{"Joe", "Mary"}
+
+	testCases := []struct {
+		desc string
+		cat  []entry
+		test []test
+	}{{
+		desc: "empty",
+		test: []test{
+			{"en", "key", empty, "key"},
+			{"en", "", empty, ""},
+			{"nl", "", empty, ""},
+		},
+	}, {
+		desc: "hierarchical languages",
+		cat: []entry{
+			{"en", "hello %s", "Hello %s!"},
+			{"en-GB", "hello %s", "Hellø %s!"},
+			{"en-US", "hello %s", "Howdy %s!"},
+			{"en", "greetings %s and %s", "Greetings %s and %s!"},
+		},
+		test: []test{
+			{"und", "hello %s", joe, "hello Joe"},
+			{"nl", "hello %s", joe, "hello Joe"},
+			{"en", "hello %s", joe, "Hello Joe!"},
+			{"en-US", "hello %s", joe, "Howdy Joe!"},
+			{"en-GB", "hello %s", joe, "Hellø Joe!"},
+			{"en-oxendict", "hello %s", joe, "Hello Joe!"},
+			{"en-US-oxendict-u-ms-metric", "hello %s", joe, "Howdy Joe!"},
+
+			{"und", "greetings %s and %s", joeAndMary, "greetings Joe and Mary"},
+			{"nl", "greetings %s and %s", joeAndMary, "greetings Joe and Mary"},
+			{"en", "greetings %s and %s", joeAndMary, "Greetings Joe and Mary!"},
+			{"en-US", "greetings %s and %s", joeAndMary, "Greetings Joe and Mary!"},
+			{"en-GB", "greetings %s and %s", joeAndMary, "Greetings Joe and Mary!"},
+			{"en-oxendict", "greetings %s and %s", joeAndMary, "Greetings Joe and Mary!"},
+			{"en-US-oxendict-u-ms-metric", "greetings %s and %s", joeAndMary, "Greetings Joe and Mary!"},
+		},
+	}, {
+		desc: "references",
+		cat: []entry{
+			{"en", "hello", "Hello!"},
+		},
+		test: []test{
+			{"en", "hello", empty, "Hello!"},
+			{"en", Key("hello", "fallback"), empty, "Hello!"},
+			{"en", Key("xxx", "fallback"), empty, "fallback"},
+			{"und", Key("hello", "fallback"), empty, "fallback"},
+		},
+	}, {
+		desc: "zero substitution", // work around limitation of fmt
+		cat: []entry{
+			{"en", "hello %s", "Hello!"},
+			{"en", "hi %s and %s", "Hello %[2]s!"},
+		},
+		test: []test{
+			{"en", "hello %s", joe, "Hello!"},
+			{"en", "hello %s", joeAndMary, "Hello!"},
+			{"en", "hi %s and %s", joeAndMary, "Hello Mary!"},
+			// The following tests resolve to the fallback string.
+			{"und", "hello", joeAndMary, "hello"},
+			{"und", "hello %%%%", joeAndMary, "hello %%"},
+			{"und", "hello %#%%4.2%  ", joeAndMary, "hello %%  "},
+			{"und", "hello %s", joeAndMary, "hello Joe%!(EXTRA string=Mary)"},
+			{"und", "hello %+%%s", joeAndMary, "hello %Joe%!(EXTRA string=Mary)"},
+			{"und", "hello %-42%%s ", joeAndMary, "hello %Joe %!(EXTRA string=Mary)"},
+		},
+	}, {
+		desc: "number formatting", // work around limitation of fmt
+		cat: []entry{
+			{"und", "files", "%d files left"},
+			{"und", "meters", "%.2f meters"},
+			{"de", "files", "%d Dateien übrig"},
+		},
+		test: []test{
+			{"en", "meters", args(3000.2), "3,000.20 meters"},
+			{"en-u-nu-gujr", "files", args(123456), "૧૨૩,૪૫૬ files left"},
+			{"de", "files", args(1234), "1.234 Dateien übrig"},
+			{"de-CH", "files", args(1234), "1’234 Dateien übrig"},
+			{"de-CH-u-nu-mong", "files", args(1234), "᠑’᠒᠓᠔ Dateien übrig"},
+		},
+	}}
+
+	for _, tc := range testCases {
+		cat, _ := initCat(tc.cat)
+
+		for i, pt := range tc.test {
+			t.Run(fmt.Sprintf("%s:%d", tc.desc, i), func(t *testing.T) {
+				p := NewPrinter(language.MustParse(pt.tag), Catalog(cat))
+
+				if got := p.Sprintf(pt.key, pt.args...); got != pt.want {
+					t.Errorf("Sprintf(%q, %v) = %s; want %s",
+						pt.key, pt.args, got, pt.want)
+					return // Next error will likely be the same.
+				}
+
+				w := &bytes.Buffer{}
+				p.Fprintf(w, pt.key, pt.args...)
+				if got := w.String(); got != pt.want {
+					t.Errorf("Fprintf(%q, %v) = %s; want %s",
+						pt.key, pt.args, got, pt.want)
+				}
+			})
+		}
+	}
+}
+
+type entry struct{ tag, key, msg string }
+
+func initCat(entries []entry) (*catalog.Catalog, []language.Tag) {
+	tags := []language.Tag{}
+	cat := catalog.New()
+	for _, e := range entries {
+		tag := language.MustParse(e.tag)
+		tags = append(tags, tag)
+		cat.SetString(tag, e.key, e.msg)
+	}
+	return cat, internal.UniqueTags(tags)
+}