Source: decode_token.go in package google.golang.org/protobuf/internal/encoding/json


package json

import (
	"bytes"
	"fmt"
	"strconv"
)

Kind represents a token kind expressible in the JSON format.

type Kind uint16

const (
	Invalid Kind = (1 << iota) / 2
	EOF
	Null
	Bool
	Number
	String
	Name
	ObjectOpen
	ObjectClose
	ArrayOpen
	ArrayClose

comma is only for parsing in between tokens and does not need to be exported.

	comma
)

func (k Kind) String() string {
	switch k {
	case EOF:
		return "eof"
	case Null:
		return "null"
	case Bool:
		return "bool"
	case Number:
		return "number"
	case String:
		return "string"
	case ObjectOpen:
		return "{"
	case ObjectClose:
		return "}"
	case Name:
		return "name"
	case ArrayOpen:
		return "["
	case ArrayClose:
		return "]"
	case comma:
		return ","
	}
	return "<invalid>"
}

Token provides a parsed token kind and value. Values are provided by the difference accessor methods. The accessor methods Name, Bool, and ParsedString will panic if called on the wrong kind. There are different accessor methods for the Number kind for converting to the appropriate Go numeric type and those methods have the ok return value.

Token kind.

pos provides the position of the token in the original input.

raw bytes of the serialized token. This is a subslice into the original input.

boo is parsed boolean value.

str is parsed string value.

	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
}

Name returns the object name if token is Name, else it will return an error.

func (t Token) Name() string {
	if t.kind == Name {
		return t.str
	}
	panic(fmt.Sprintf("Token is not a Name: %v", t.RawString()))
}

Bool returns the bool value if token kind is Bool, else it panics.

func (t Token) Bool() bool {
	if t.kind == Bool {
		return t.boo
	}
	panic(fmt.Sprintf("Token is not a Bool: %v", t.RawString()))
}

ParsedString returns the string value for a JSON string token or the read value in string if token is not a string.

func (t Token) ParsedString() string {
	if t.kind == String {
		return t.str
	}
	panic(fmt.Sprintf("Token is not a String: %v", t.RawString()))
}

Float returns the floating-point number if token kind is Number. The floating-point precision is specified by the bitSize parameter: 32 for float32 or 64 for float64. If bitSize=32, the result still has type float64, but it will be convertible to float32 without changing its value. It will return false if the number exceeds the floating point limits for given bitSize.

func (t Token) Float(bitSize int) (float64, bool) {
	if t.kind != Number {
		return 0, false
	}
	f, err := strconv.ParseFloat(t.RawString(), bitSize)
	if err != nil {
		return 0, false
	}
	return f, true
}

Int returns the signed integer number if token is Number. The given bitSize specifies the integer type that the result must fit into. It returns false if the number is not an integer value or if the result exceeds the limits for given bitSize.

func (t Token) Int(bitSize int) (int64, bool) {
	s, ok := t.getIntStr()
	if !ok {
		return 0, false
	}
	n, err := strconv.ParseInt(s, 10, bitSize)
	if err != nil {
		return 0, false
	}
	return n, true
}

Uint returns the signed integer number if token is Number, else it will return an error. The given bitSize specifies the unsigned integer type that the result must fit into. It returns false if the number is not an unsigned integer value or if the result exceeds the limits for given bitSize.

func (t Token) Uint(bitSize int) (uint64, bool) {
	s, ok := t.getIntStr()
	if !ok {
		return 0, false
	}
	n, err := strconv.ParseUint(s, 10, bitSize)
	if err != nil {
		return 0, false
	}
	return n, true
}

func (t Token) getIntStr() (string, bool) {
	if t.kind != Number {
		return "", false
	}
	parts, ok := parseNumberParts(t.raw)
	if !ok {
		return "", false
	}
	return normalizeToIntString(parts)
}

TokenEquals returns true if given Tokens are equal, else false.

func TokenEquals(x, y Token) bool {
	return x.kind == y.kind &&
		x.pos == y.pos &&
		bytes.Equal(x.raw, y.raw) &&
		x.boo == y.boo &&
		x.str == y.str