From 621e49bb465f500cc46d47e39e828cf76d6381d7 Mon Sep 17 00:00:00 2001 From: Dimitri Sokolyuk Date: Tue, 24 Jul 2018 14:35:44 +0200 Subject: update vendor --- vendor/golang.org/x/text/internal/catmsg/catmsg.go | 376 +++++++++++++++++++++ 1 file changed, 376 insertions(+) create mode 100644 vendor/golang.org/x/text/internal/catmsg/catmsg.go (limited to 'vendor/golang.org/x/text/internal/catmsg/catmsg.go') diff --git a/vendor/golang.org/x/text/internal/catmsg/catmsg.go b/vendor/golang.org/x/text/internal/catmsg/catmsg.go new file mode 100644 index 0000000..32d6c20 --- /dev/null +++ b/vendor/golang.org/x/text/internal/catmsg/catmsg.go @@ -0,0 +1,376 @@ +// 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 catmsg contains support types for package x/text/message/catalog. +// +// This package contains the low-level implementations of Message used by the +// catalog package and provides primitives for other packages to implement their +// own. For instance, the plural package provides functionality for selecting +// translation strings based on the plural category of substitution arguments. +// +// +// Encoding and Decoding +// +// Catalogs store Messages encoded as a single string. Compiling a message into +// a string both results in compacter representation and speeds up evaluation. +// +// A Message must implement a Compile method to convert its arbitrary +// representation to a string. The Compile method takes an Encoder which +// facilitates serializing the message. Encoders also provide more context of +// the messages's creation (such as for which language the message is intended), +// which may not be known at the time of the creation of the message. +// +// Each message type must also have an accompanying decoder registered to decode +// the message. This decoder takes a Decoder argument which provides the +// counterparts for the decoding. +// +// +// Renderers +// +// A Decoder must be initialized with a Renderer implementation. These +// implementations must be provided by packages that use Catalogs, typically +// formatting packages such as x/text/message. A typical user will not need to +// worry about this type; it is only relevant to packages that do string +// formatting and want to use the catalog package to handle localized strings. +// +// A package that uses catalogs for selecting strings receives selection results +// as sequence of substrings passed to the Renderer. The following snippet shows +// how to express the above example using the message package. +// +// message.Set(language.English, "You are %d minute(s) late.", +// catalog.Var("minutes", plural.Select(1, "one", "minute")), +// catalog.String("You are %[1]d ${minutes} late.")) +// +// p := message.NewPrinter(language.English) +// p.Printf("You are %d minute(s) late.", 5) // always 5 minutes late. +// +// To evaluate the Printf, package message wraps the arguments in a Renderer +// that is passed to the catalog for message decoding. The call sequence that +// results from evaluating the above message, assuming the person is rather +// tardy, is: +// +// Render("You are %[1]d ") +// Arg(1) +// Render("minutes") +// Render(" late.") +// +// The calls to Arg is caused by the plural.Select execution, which evaluates +// the argument to determine whether the singular or plural message form should +// be selected. The calls to Render reports the partial results to the message +// package for further evaluation. +package catmsg + +import ( + "errors" + "fmt" + "strconv" + "strings" + "sync" + + "golang.org/x/text/language" +) + +// A Handle refers to a registered message type. +type Handle int + +// A Handler decodes and evaluates data compiled by a Message and sends the +// result to the Decoder. The output may depend on the value of the substitution +// arguments, accessible by the Decoder's Arg method. The Handler returns false +// if there is no translation for the given substitution arguments. +type Handler func(d *Decoder) bool + +// Register records the existence of a message type and returns a Handle that +// can be used in the Encoder's EncodeMessageType method to create such +// messages. The prefix of the name should be the package path followed by +// an optional disambiguating string. +// Register will panic if a handle for the same name was already registered. +func Register(name string, handler Handler) Handle { + mutex.Lock() + defer mutex.Unlock() + + if _, ok := names[name]; ok { + panic(fmt.Errorf("catmsg: handler for %q already exists", name)) + } + h := Handle(len(handlers)) + names[name] = h + handlers = append(handlers, handler) + return h +} + +// These handlers require fixed positions in the handlers slice. +const ( + msgVars Handle = iota + msgFirst + msgRaw + msgString + numFixed +) + +const prefix = "golang.org/x/text/internal/catmsg." + +var ( + mutex sync.Mutex + names = map[string]Handle{ + prefix + "Vars": msgVars, + prefix + "First": msgFirst, + prefix + "Raw": msgRaw, + prefix + "String": msgString, + } + handlers = make([]Handler, numFixed) +) + +func init() { + // This handler is a message type wrapper that initializes a decoder + // with a variable block. This message type, if present, is always at the + // start of an encoded message. + handlers[msgVars] = func(d *Decoder) bool { + blockSize := int(d.DecodeUint()) + d.vars = d.data[:blockSize] + d.data = d.data[blockSize:] + return d.executeMessage() + } + + // First takes the first message in a sequence that results in a match for + // the given substitution arguments. + handlers[msgFirst] = func(d *Decoder) bool { + for !d.Done() { + if d.ExecuteMessage() { + return true + } + } + return false + } + + handlers[msgRaw] = func(d *Decoder) bool { + d.Render(d.data) + return true + } + + // A String message alternates between a string constant and a variable + // substitution. + handlers[msgString] = func(d *Decoder) bool { + for !d.Done() { + if str := d.DecodeString(); str != "" { + d.Render(str) + } + if d.Done() { + break + } + d.ExecuteSubstitution() + } + return true + } +} + +var ( + // ErrIncomplete indicates a compiled message does not define translations + // for all possible argument values. If this message is returned, evaluating + // a message may result in the ErrNoMatch error. + ErrIncomplete = errors.New("catmsg: incomplete message; may not give result for all inputs") + + // ErrNoMatch indicates no translation message matched the given input + // parameters when evaluating a message. + ErrNoMatch = errors.New("catmsg: no translation for inputs") +) + +// A Message holds a collection of translations for the same phrase that may +// vary based on the values of substitution arguments. +type Message interface { + // Compile encodes the format string(s) of the message as a string for later + // evaluation. + // + // The first call Compile makes on the encoder must be EncodeMessageType. + // The handle passed to this call may either be a handle returned by + // Register to encode a single custom message, or HandleFirst followed by + // a sequence of calls to EncodeMessage. + // + // Compile must return ErrIncomplete if it is possible for evaluation to + // not match any translation for a given set of formatting parameters. + // For example, selecting a translation based on plural form may not yield + // a match if the form "Other" is not one of the selectors. + // + // Compile may return any other application-specific error. For backwards + // compatibility with package like fmt, which often do not do sanity + // checking of format strings ahead of time, Compile should still make an + // effort to have some sensible fallback in case of an error. + Compile(e *Encoder) error +} + +// Compile converts a Message to a data string that can be stored in a Catalog. +// The resulting string can subsequently be decoded by passing to the Execute +// method of a Decoder. +func Compile(tag language.Tag, macros Dictionary, m Message) (data string, err error) { + // TODO: pass macros so they can be used for validation. + v := &Encoder{inBody: true} // encoder for variables + v.root = v + e := &Encoder{root: v, parent: v, tag: tag} // encoder for messages + err = m.Compile(e) + // This package serves te message package, which in turn is meant to be a + // drop-in replacement for fmt. With the fmt package, format strings are + // evaluated lazily and errors are handled by substituting strings in the + // result, rather then returning an error. Dealing with multiple languages + // makes it more important to check errors ahead of time. We chose to be + // consistent and compatible and allow graceful degradation in case of + // errors. + buf := e.buf[stripPrefix(e.buf):] + if len(v.buf) > 0 { + // Prepend variable block. + b := make([]byte, 1+maxVarintBytes+len(v.buf)+len(buf)) + b[0] = byte(msgVars) + b = b[:1+encodeUint(b[1:], uint64(len(v.buf)))] + b = append(b, v.buf...) + b = append(b, buf...) + buf = b + } + if err == nil { + err = v.err + } + return string(buf), err +} + +// FirstOf is a message type that prints the first message in the sequence that +// resolves to a match for the given substitution arguments. +type FirstOf []Message + +// Compile implements Message. +func (s FirstOf) Compile(e *Encoder) error { + e.EncodeMessageType(msgFirst) + err := 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 +} + +// Var defines a message that can be substituted for a placeholder of the same +// name. If an expression does not result in a string after evaluation, Name is +// used as the substitution. For example: +// Var{ +// Name: "minutes", +// Message: plural.Select(1, "one", "minute"), +// } +// will resolve to minute for singular and minutes for plural forms. +type Var struct { + Name string + Message Message +} + +var errIsVar = errors.New("catmsg: variable used as message") + +// Compile implements Message. +// +// Note that this method merely registers a variable; it does not create an +// encoded message. +func (v *Var) Compile(e *Encoder) error { + if err := e.addVar(v.Name, v.Message); err != nil { + return err + } + // Using a Var by itself is an error. If it is in a sequence followed by + // other messages referring to it, this error will be ignored. + return errIsVar +} + +// Raw is a message consisting of a single format string that is passed as is +// to the Renderer. +// +// Note that a Renderer may still do its own variable substitution. +type Raw string + +// Compile implements Message. +func (r Raw) Compile(e *Encoder) (err error) { + e.EncodeMessageType(msgRaw) + // Special case: raw strings don't have a size encoding and so don't use + // EncodeString. + e.buf = append(e.buf, r...) + return nil +} + +// String is a message consisting of a single format string which contains +// placeholders that may be substituted with variables. +// +// Variable substitutions are marked with placeholders and a variable name of +// the form ${name}. Any other substitutions such as Go templates or +// printf-style substitutions are left to be done by the Renderer. +// +// When evaluation a string interpolation, a Renderer will receive separate +// calls for each placeholder and interstitial string. For example, for the +// message: "%[1]v ${invites} %[2]v to ${their} party." The sequence of calls +// is: +// d.Render("%[1]v ") +// d.Arg(1) +// d.Render(resultOfInvites) +// d.Render(" %[2]v to ") +// d.Arg(2) +// d.Render(resultOfTheir) +// d.Render(" party.") +// where the messages for "invites" and "their" both use a plural.Select +// referring to the first argument. +// +// Strings may also invoke macros. Macros are essentially variables that can be +// reused. Macros may, for instance, be used to make selections between +// different conjugations of a verb. See the catalog package description for an +// overview of macros. +type String string + +// Compile implements Message. It parses the placeholder formats and returns +// any error. +func (s String) Compile(e *Encoder) (err error) { + msg := string(s) + const subStart = "${" + hasHeader := false + p := 0 + b := []byte{} + for { + i := strings.Index(msg[p:], subStart) + if i == -1 { + break + } + b = append(b, msg[p:p+i]...) + p += i + len(subStart) + if i = strings.IndexByte(msg[p:], '}'); i == -1 { + b = append(b, "$!(MISSINGBRACE)"...) + err = fmt.Errorf("catmsg: missing '}'") + p = len(msg) + break + } + name := strings.TrimSpace(msg[p : p+i]) + if q := strings.IndexByte(name, '('); q == -1 { + if !hasHeader { + hasHeader = true + e.EncodeMessageType(msgString) + } + e.EncodeString(string(b)) + e.EncodeSubstitution(name) + b = b[:0] + } else if j := strings.IndexByte(name[q:], ')'); j == -1 { + // TODO: what should the error be? + b = append(b, "$!(MISSINGPAREN)"...) + err = fmt.Errorf("catmsg: missing ')'") + } else if x, sErr := strconv.ParseUint(strings.TrimSpace(name[q+1:q+j]), 10, 32); sErr != nil { + // TODO: handle more than one argument + b = append(b, "$!(BADNUM)"...) + err = fmt.Errorf("catmsg: invalid number %q", strings.TrimSpace(name[q+1:q+j])) + } else { + if !hasHeader { + hasHeader = true + e.EncodeMessageType(msgString) + } + e.EncodeString(string(b)) + e.EncodeSubstitution(name[:q], int(x)) + b = b[:0] + } + p += i + 1 + } + b = append(b, msg[p:]...) + if !hasHeader { + // Simplify string to a raw string. + Raw(string(b)).Compile(e) + } else if len(b) > 0 { + e.EncodeString(string(b)) + } + return err +} -- cgit v1.2.3