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Diffstat (limited to 'vendor/google.golang.org/protobuf/internal/encoding/text/decode_token.go')
-rw-r--r--vendor/google.golang.org/protobuf/internal/encoding/text/decode_token.go373
1 files changed, 373 insertions, 0 deletions
diff --git a/vendor/google.golang.org/protobuf/internal/encoding/text/decode_token.go b/vendor/google.golang.org/protobuf/internal/encoding/text/decode_token.go
new file mode 100644
index 000000000..83d2b0d5a
--- /dev/null
+++ b/vendor/google.golang.org/protobuf/internal/encoding/text/decode_token.go
@@ -0,0 +1,373 @@
+// Copyright 2018 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 text
+
+import (
+ "bytes"
+ "fmt"
+ "math"
+ "strconv"
+ "strings"
+
+ "google.golang.org/protobuf/internal/flags"
+)
+
+// Kind represents a token kind expressible in the textproto format.
+type Kind uint8
+
+// Kind values.
+const (
+ Invalid Kind = iota
+ EOF
+ Name // Name indicates the field name.
+ Scalar // Scalar are scalar values, e.g. "string", 47, ENUM_LITERAL, true.
+ MessageOpen
+ MessageClose
+ ListOpen
+ ListClose
+
+ // comma and semi-colon are only for parsing in between values and should not be exposed.
+ comma
+ semicolon
+
+ // bof indicates beginning of file, which is the default token
+ // kind at the beginning of parsing.
+ bof = Invalid
+)
+
+func (t Kind) String() string {
+ switch t {
+ case Invalid:
+ return "<invalid>"
+ case EOF:
+ return "eof"
+ case Scalar:
+ return "scalar"
+ case Name:
+ return "name"
+ case MessageOpen:
+ return "{"
+ case MessageClose:
+ return "}"
+ case ListOpen:
+ return "["
+ case ListClose:
+ return "]"
+ case comma:
+ return ","
+ case semicolon:
+ return ";"
+ default:
+ return fmt.Sprintf("<invalid:%v>", uint8(t))
+ }
+}
+
+// NameKind represents different types of field names.
+type NameKind uint8
+
+// NameKind values.
+const (
+ IdentName NameKind = iota + 1
+ TypeName
+ FieldNumber
+)
+
+func (t NameKind) String() string {
+ switch t {
+ case IdentName:
+ return "IdentName"
+ case TypeName:
+ return "TypeName"
+ case FieldNumber:
+ return "FieldNumber"
+ default:
+ return fmt.Sprintf("<invalid:%v>", uint8(t))
+ }
+}
+
+// Bit mask in Token.attrs to indicate if a Name token is followed by the
+// separator char ':'. The field name separator char is optional for message
+// field or repeated message field, but required for all other types. Decoder
+// simply indicates whether a Name token is followed by separator or not. It is
+// up to the prototext package to validate.
+const hasSeparator = 1 << 7
+
+// Scalar value types.
+const (
+ numberValue = iota + 1
+ stringValue
+ literalValue
+)
+
+// Bit mask in Token.numAttrs to indicate that the number is a negative.
+const isNegative = 1 << 7
+
+// Token provides a parsed token kind and value. Values are provided by the
+// different accessor methods.
+type Token struct {
+ // Kind of the Token object.
+ kind Kind
+ // attrs contains metadata for the following Kinds:
+ // Name: hasSeparator bit and one of NameKind.
+ // Scalar: one of numberValue, stringValue, literalValue.
+ attrs uint8
+ // numAttrs contains metadata for numberValue:
+ // - highest bit is whether negative or positive.
+ // - lower bits indicate one of numDec, numHex, numOct, numFloat.
+ numAttrs uint8
+ // pos provides the position of the token in the original input.
+ pos int
+ // raw bytes of the serialized token.
+ // This is a subslice into the original input.
+ raw []byte
+ // str contains parsed string for the following:
+ // - stringValue of Scalar kind
+ // - numberValue of Scalar kind
+ // - TypeName of Name kind
+ str string
+}
+
+// Kind returns the token kind.
+func (t Token) Kind() Kind {
+ return t.kind
+}
+
+// RawString returns the read value in string.
+func (t Token) RawString() string {
+ return string(t.raw)
+}
+
+// Pos returns the token position from the input.
+func (t Token) Pos() int {
+ return t.pos
+}
+
+// NameKind returns IdentName, TypeName or FieldNumber.
+// It panics if type is not Name.
+func (t Token) NameKind() NameKind {
+ if t.kind == Name {
+ return NameKind(t.attrs &^ hasSeparator)
+ }
+ panic(fmt.Sprintf("Token is not a Name type: %s", t.kind))
+}
+
+// HasSeparator returns true if the field name is followed by the separator char
+// ':', else false. It panics if type is not Name.
+func (t Token) HasSeparator() bool {
+ if t.kind == Name {
+ return t.attrs&hasSeparator != 0
+ }
+ panic(fmt.Sprintf("Token is not a Name type: %s", t.kind))
+}
+
+// IdentName returns the value for IdentName type.
+func (t Token) IdentName() string {
+ if t.kind == Name && t.attrs&uint8(IdentName) != 0 {
+ return string(t.raw)
+ }
+ panic(fmt.Sprintf("Token is not an IdentName: %s:%s", t.kind, NameKind(t.attrs&^hasSeparator)))
+}
+
+// TypeName returns the value for TypeName type.
+func (t Token) TypeName() string {
+ if t.kind == Name && t.attrs&uint8(TypeName) != 0 {
+ return t.str
+ }
+ panic(fmt.Sprintf("Token is not a TypeName: %s:%s", t.kind, NameKind(t.attrs&^hasSeparator)))
+}
+
+// FieldNumber returns the value for FieldNumber type. It returns a
+// non-negative int32 value. Caller will still need to validate for the correct
+// field number range.
+func (t Token) FieldNumber() int32 {
+ if t.kind != Name || t.attrs&uint8(FieldNumber) == 0 {
+ panic(fmt.Sprintf("Token is not a FieldNumber: %s:%s", t.kind, NameKind(t.attrs&^hasSeparator)))
+ }
+ // Following should not return an error as it had already been called right
+ // before this Token was constructed.
+ num, _ := strconv.ParseInt(string(t.raw), 10, 32)
+ return int32(num)
+}
+
+// String returns the string value for a Scalar type.
+func (t Token) String() (string, bool) {
+ if t.kind != Scalar || t.attrs != stringValue {
+ return "", false
+ }
+ return t.str, true
+}
+
+// Enum returns the literal value for a Scalar type for use as enum literals.
+func (t Token) Enum() (string, bool) {
+ if t.kind != Scalar || t.attrs != literalValue || (len(t.raw) > 0 && t.raw[0] == '-') {
+ return "", false
+ }
+ return string(t.raw), true
+}
+
+// Bool returns the bool value for a Scalar type.
+func (t Token) Bool() (bool, bool) {
+ if t.kind != Scalar {
+ return false, false
+ }
+ switch t.attrs {
+ case literalValue:
+ if b, ok := boolLits[string(t.raw)]; ok {
+ return b, true
+ }
+ case numberValue:
+ // Unsigned integer representation of 0 or 1 is permitted: 00, 0x0, 01,
+ // 0x1, etc.
+ n, err := strconv.ParseUint(t.str, 0, 64)
+ if err == nil {
+ switch n {
+ case 0:
+ return false, true
+ case 1:
+ return true, true
+ }
+ }
+ }
+ return false, false
+}
+
+// These exact boolean literals are the ones supported in C++.
+var boolLits = map[string]bool{
+ "t": true,
+ "true": true,
+ "True": true,
+ "f": false,
+ "false": false,
+ "False": false,
+}
+
+// Uint64 returns the uint64 value for a Scalar type.
+func (t Token) Uint64() (uint64, bool) {
+ if t.kind != Scalar || t.attrs != numberValue ||
+ t.numAttrs&isNegative > 0 || t.numAttrs&numFloat > 0 {
+ return 0, false
+ }
+ n, err := strconv.ParseUint(t.str, 0, 64)
+ if err != nil {
+ return 0, false
+ }
+ return n, true
+}
+
+// Uint32 returns the uint32 value for a Scalar type.
+func (t Token) Uint32() (uint32, bool) {
+ if t.kind != Scalar || t.attrs != numberValue ||
+ t.numAttrs&isNegative > 0 || t.numAttrs&numFloat > 0 {
+ return 0, false
+ }
+ n, err := strconv.ParseUint(t.str, 0, 32)
+ if err != nil {
+ return 0, false
+ }
+ return uint32(n), true
+}
+
+// Int64 returns the int64 value for a Scalar type.
+func (t Token) Int64() (int64, bool) {
+ if t.kind != Scalar || t.attrs != numberValue || t.numAttrs&numFloat > 0 {
+ return 0, false
+ }
+ if n, err := strconv.ParseInt(t.str, 0, 64); err == nil {
+ return n, true
+ }
+ // C++ accepts large positive hex numbers as negative values.
+ // This feature is here for proto1 backwards compatibility purposes.
+ if flags.ProtoLegacy && (t.numAttrs == numHex) {
+ if n, err := strconv.ParseUint(t.str, 0, 64); err == nil {
+ return int64(n), true
+ }
+ }
+ return 0, false
+}
+
+// Int32 returns the int32 value for a Scalar type.
+func (t Token) Int32() (int32, bool) {
+ if t.kind != Scalar || t.attrs != numberValue || t.numAttrs&numFloat > 0 {
+ return 0, false
+ }
+ if n, err := strconv.ParseInt(t.str, 0, 32); err == nil {
+ return int32(n), true
+ }
+ // C++ accepts large positive hex numbers as negative values.
+ // This feature is here for proto1 backwards compatibility purposes.
+ if flags.ProtoLegacy && (t.numAttrs == numHex) {
+ if n, err := strconv.ParseUint(t.str, 0, 32); err == nil {
+ return int32(n), true
+ }
+ }
+ return 0, false
+}
+
+// Float64 returns the float64 value for a Scalar type.
+func (t Token) Float64() (float64, bool) {
+ if t.kind != Scalar {
+ return 0, false
+ }
+ switch t.attrs {
+ case literalValue:
+ if f, ok := floatLits[strings.ToLower(string(t.raw))]; ok {
+ return f, true
+ }
+ case numberValue:
+ n, err := strconv.ParseFloat(t.str, 64)
+ if err == nil {
+ return n, true
+ }
+ nerr := err.(*strconv.NumError)
+ if nerr.Err == strconv.ErrRange {
+ return n, true
+ }
+ }
+ return 0, false
+}
+
+// Float32 returns the float32 value for a Scalar type.
+func (t Token) Float32() (float32, bool) {
+ if t.kind != Scalar {
+ return 0, false
+ }
+ switch t.attrs {
+ case literalValue:
+ if f, ok := floatLits[strings.ToLower(string(t.raw))]; ok {
+ return float32(f), true
+ }
+ case numberValue:
+ n, err := strconv.ParseFloat(t.str, 64)
+ if err == nil {
+ // Overflows are treated as (-)infinity.
+ return float32(n), true
+ }
+ nerr := err.(*strconv.NumError)
+ if nerr.Err == strconv.ErrRange {
+ return float32(n), true
+ }
+ }
+ return 0, false
+}
+
+// These are the supported float literals which C++ permits case-insensitive
+// variants of these.
+var floatLits = map[string]float64{
+ "nan": math.NaN(),
+ "inf": math.Inf(1),
+ "infinity": math.Inf(1),
+ "-inf": math.Inf(-1),
+ "-infinity": math.Inf(-1),
+}
+
+// TokenEquals returns true if given Tokens are equal, else false.
+func TokenEquals(x, y Token) bool {
+ return x.kind == y.kind &&
+ x.attrs == y.attrs &&
+ x.numAttrs == y.numAttrs &&
+ x.pos == y.pos &&
+ bytes.Equal(x.raw, y.raw) &&
+ x.str == y.str
+}