gtsocial-umbx

json.go (15278B)

---

 package json
 
 import (
 	"bytes"
 	"context"
 	"encoding/json"
 
 	"github.com/goccy/go-json/internal/encoder"
 )
 
 // Marshaler is the interface implemented by types that
 // can marshal themselves into valid JSON.
 type Marshaler interface {
 	MarshalJSON() ([]byte, error)
 }
 
 // MarshalerContext is the interface implemented by types that
 // can marshal themselves into valid JSON with context.Context.
 type MarshalerContext interface {
 	MarshalJSON(context.Context) ([]byte, error)
 }
 
 // Unmarshaler is the interface implemented by types
 // that can unmarshal a JSON description of themselves.
 // The input can be assumed to be a valid encoding of
 // a JSON value. UnmarshalJSON must copy the JSON data
 // if it wishes to retain the data after returning.
 //
 // By convention, to approximate the behavior of Unmarshal itself,
 // Unmarshalers implement UnmarshalJSON([]byte("null")) as a no-op.
 type Unmarshaler interface {
 	UnmarshalJSON([]byte) error
 }
 
 // UnmarshalerContext is the interface implemented by types
 // that can unmarshal with context.Context a JSON description of themselves.
 type UnmarshalerContext interface {
 	UnmarshalJSON(context.Context, []byte) error
 }
 
 // Marshal returns the JSON encoding of v.
 //
 // Marshal traverses the value v recursively.
 // If an encountered value implements the Marshaler interface
 // and is not a nil pointer, Marshal calls its MarshalJSON method
 // to produce JSON. If no MarshalJSON method is present but the
 // value implements encoding.TextMarshaler instead, Marshal calls
 // its MarshalText method and encodes the result as a JSON string.
 // The nil pointer exception is not strictly necessary
 // but mimics a similar, necessary exception in the behavior of
 // UnmarshalJSON.
 //
 // Otherwise, Marshal uses the following type-dependent default encodings:
 //
 // Boolean values encode as JSON booleans.
 //
 // Floating point, integer, and Number values encode as JSON numbers.
 //
 // String values encode as JSON strings coerced to valid UTF-8,
 // replacing invalid bytes with the Unicode replacement rune.
 // The angle brackets "<" and ">" are escaped to "\u003c" and "\u003e"
 // to keep some browsers from misinterpreting JSON output as HTML.
 // Ampersand "&" is also escaped to "\u0026" for the same reason.
 // This escaping can be disabled using an Encoder that had SetEscapeHTML(false)
 // called on it.
 //
 // Array and slice values encode as JSON arrays, except that
 // []byte encodes as a base64-encoded string, and a nil slice
 // encodes as the null JSON value.
 //
 // Struct values encode as JSON objects.
 // Each exported struct field becomes a member of the object, using the
 // field name as the object key, unless the field is omitted for one of the
 // reasons given below.
 //
 // The encoding of each struct field can be customized by the format string
 // stored under the "json" key in the struct field's tag.
 // The format string gives the name of the field, possibly followed by a
 // comma-separated list of options. The name may be empty in order to
 // specify options without overriding the default field name.
 //
 // The "omitempty" option specifies that the field should be omitted
 // from the encoding if the field has an empty value, defined as
 // false, 0, a nil pointer, a nil interface value, and any empty array,
 // slice, map, or string.
 //
 // As a special case, if the field tag is "-", the field is always omitted.
 // Note that a field with name "-" can still be generated using the tag "-,".
 //
 // Examples of struct field tags and their meanings:
 //
 //   // Field appears in JSON as key "myName".
 //   Field int `json:"myName"`
 //
 //   // Field appears in JSON as key "myName" and
 //   // the field is omitted from the object if its value is empty,
 //   // as defined above.
 //   Field int `json:"myName,omitempty"`
 //
 //   // Field appears in JSON as key "Field" (the default), but
 //   // the field is skipped if empty.
 //   // Note the leading comma.
 //   Field int `json:",omitempty"`
 //
 //   // Field is ignored by this package.
 //   Field int `json:"-"`
 //
 //   // Field appears in JSON as key "-".
 //   Field int `json:"-,"`
 //
 // The "string" option signals that a field is stored as JSON inside a
 // JSON-encoded string. It applies only to fields of string, floating point,
 // integer, or boolean types. This extra level of encoding is sometimes used
 // when communicating with JavaScript programs:
 //
 //    Int64String int64 `json:",string"`
 //
 // The key name will be used if it's a non-empty string consisting of
 // only Unicode letters, digits, and ASCII punctuation except quotation
 // marks, backslash, and comma.
 //
 // Anonymous struct fields are usually marshaled as if their inner exported fields
 // were fields in the outer struct, subject to the usual Go visibility rules amended
 // as described in the next paragraph.
 // An anonymous struct field with a name given in its JSON tag is treated as
 // having that name, rather than being anonymous.
 // An anonymous struct field of interface type is treated the same as having
 // that type as its name, rather than being anonymous.
 //
 // The Go visibility rules for struct fields are amended for JSON when
 // deciding which field to marshal or unmarshal. If there are
 // multiple fields at the same level, and that level is the least
 // nested (and would therefore be the nesting level selected by the
 // usual Go rules), the following extra rules apply:
 //
 // 1) Of those fields, if any are JSON-tagged, only tagged fields are considered,
 // even if there are multiple untagged fields that would otherwise conflict.
 //
 // 2) If there is exactly one field (tagged or not according to the first rule), that is selected.
 //
 // 3) Otherwise there are multiple fields, and all are ignored; no error occurs.
 //
 // Handling of anonymous struct fields is new in Go 1.1.
 // Prior to Go 1.1, anonymous struct fields were ignored. To force ignoring of
 // an anonymous struct field in both current and earlier versions, give the field
 // a JSON tag of "-".
 //
 // Map values encode as JSON objects. The map's key type must either be a
 // string, an integer type, or implement encoding.TextMarshaler. The map keys
 // are sorted and used as JSON object keys by applying the following rules,
 // subject to the UTF-8 coercion described for string values above:
 //   - string keys are used directly
 //   - encoding.TextMarshalers are marshaled
 //   - integer keys are converted to strings
 //
 // Pointer values encode as the value pointed to.
 // A nil pointer encodes as the null JSON value.
 //
 // Interface values encode as the value contained in the interface.
 // A nil interface value encodes as the null JSON value.
 //
 // Channel, complex, and function values cannot be encoded in JSON.
 // Attempting to encode such a value causes Marshal to return
 // an UnsupportedTypeError.
 //
 // JSON cannot represent cyclic data structures and Marshal does not
 // handle them. Passing cyclic structures to Marshal will result in
 // an infinite recursion.
 //
 func Marshal(v interface{}) ([]byte, error) {
 	return MarshalWithOption(v)
 }
 
 // MarshalNoEscape returns the JSON encoding of v and doesn't escape v.
 func MarshalNoEscape(v interface{}) ([]byte, error) {
 	return marshalNoEscape(v)
 }
 
 // MarshalContext returns the JSON encoding of v with context.Context and EncodeOption.
 func MarshalContext(ctx context.Context, v interface{}, optFuncs ...EncodeOptionFunc) ([]byte, error) {
 	return marshalContext(ctx, v, optFuncs...)
 }
 
 // MarshalWithOption returns the JSON encoding of v with EncodeOption.
 func MarshalWithOption(v interface{}, optFuncs ...EncodeOptionFunc) ([]byte, error) {
 	return marshal(v, optFuncs...)
 }
 
 // MarshalIndent is like Marshal but applies Indent to format the output.
 // Each JSON element in the output will begin on a new line beginning with prefix
 // followed by one or more copies of indent according to the indentation nesting.
 func MarshalIndent(v interface{}, prefix, indent string) ([]byte, error) {
 	return MarshalIndentWithOption(v, prefix, indent)
 }
 
 // MarshalIndentWithOption is like Marshal but applies Indent to format the output with EncodeOption.
 func MarshalIndentWithOption(v interface{}, prefix, indent string, optFuncs ...EncodeOptionFunc) ([]byte, error) {
 	return marshalIndent(v, prefix, indent, optFuncs...)
 }
 
 // Unmarshal parses the JSON-encoded data and stores the result
 // in the value pointed to by v. If v is nil or not a pointer,
 // Unmarshal returns an InvalidUnmarshalError.
 //
 // Unmarshal uses the inverse of the encodings that
 // Marshal uses, allocating maps, slices, and pointers as necessary,
 // with the following additional rules:
 //
 // To unmarshal JSON into a pointer, Unmarshal first handles the case of
 // the JSON being the JSON literal null. In that case, Unmarshal sets
 // the pointer to nil. Otherwise, Unmarshal unmarshals the JSON into
 // the value pointed at by the pointer. If the pointer is nil, Unmarshal
 // allocates a new value for it to point to.
 //
 // To unmarshal JSON into a value implementing the Unmarshaler interface,
 // Unmarshal calls that value's UnmarshalJSON method, including
 // when the input is a JSON null.
 // Otherwise, if the value implements encoding.TextUnmarshaler
 // and the input is a JSON quoted string, Unmarshal calls that value's
 // UnmarshalText method with the unquoted form of the string.
 //
 // To unmarshal JSON into a struct, Unmarshal matches incoming object
 // keys to the keys used by Marshal (either the struct field name or its tag),
 // preferring an exact match but also accepting a case-insensitive match. By
 // default, object keys which don't have a corresponding struct field are
 // ignored (see Decoder.DisallowUnknownFields for an alternative).
 //
 // To unmarshal JSON into an interface value,
 // Unmarshal stores one of these in the interface value:
 //
 //	bool, for JSON booleans
 //	float64, for JSON numbers
 //	string, for JSON strings
 //	[]interface{}, for JSON arrays
 //	map[string]interface{}, for JSON objects
 //	nil for JSON null
 //
 // To unmarshal a JSON array into a slice, Unmarshal resets the slice length
 // to zero and then appends each element to the slice.
 // As a special case, to unmarshal an empty JSON array into a slice,
 // Unmarshal replaces the slice with a new empty slice.
 //
 // To unmarshal a JSON array into a Go array, Unmarshal decodes
 // JSON array elements into corresponding Go array elements.
 // If the Go array is smaller than the JSON array,
 // the additional JSON array elements are discarded.
 // If the JSON array is smaller than the Go array,
 // the additional Go array elements are set to zero values.
 //
 // To unmarshal a JSON object into a map, Unmarshal first establishes a map to
 // use. If the map is nil, Unmarshal allocates a new map. Otherwise Unmarshal
 // reuses the existing map, keeping existing entries. Unmarshal then stores
 // key-value pairs from the JSON object into the map. The map's key type must
 // either be any string type, an integer, implement json.Unmarshaler, or
 // implement encoding.TextUnmarshaler.
 //
 // If a JSON value is not appropriate for a given target type,
 // or if a JSON number overflows the target type, Unmarshal
 // skips that field and completes the unmarshaling as best it can.
 // If no more serious errors are encountered, Unmarshal returns
 // an UnmarshalTypeError describing the earliest such error. In any
 // case, it's not guaranteed that all the remaining fields following
 // the problematic one will be unmarshaled into the target object.
 //
 // The JSON null value unmarshals into an interface, map, pointer, or slice
 // by setting that Go value to nil. Because null is often used in JSON to mean
 // ``not present,'' unmarshaling a JSON null into any other Go type has no effect
 // on the value and produces no error.
 //
 // When unmarshaling quoted strings, invalid UTF-8 or
 // invalid UTF-16 surrogate pairs are not treated as an error.
 // Instead, they are replaced by the Unicode replacement
 // character U+FFFD.
 //
 func Unmarshal(data []byte, v interface{}) error {
 	return unmarshal(data, v)
 }
 
 // UnmarshalContext parses the JSON-encoded data and stores the result
 // in the value pointed to by v. If you implement the UnmarshalerContext interface,
 // call it with ctx as an argument.
 func UnmarshalContext(ctx context.Context, data []byte, v interface{}, optFuncs ...DecodeOptionFunc) error {
 	return unmarshalContext(ctx, data, v)
 }
 
 func UnmarshalWithOption(data []byte, v interface{}, optFuncs ...DecodeOptionFunc) error {
 	return unmarshal(data, v, optFuncs...)
 }
 
 func UnmarshalNoEscape(data []byte, v interface{}, optFuncs ...DecodeOptionFunc) error {
 	return unmarshalNoEscape(data, v, optFuncs...)
 }
 
 // A Token holds a value of one of these types:
 //
 //	Delim, for the four JSON delimiters [ ] { }
 //	bool, for JSON booleans
 //	float64, for JSON numbers
 //	Number, for JSON numbers
 //	string, for JSON string literals
 //	nil, for JSON null
 //
 type Token = json.Token
 
 // A Number represents a JSON number literal.
 type Number = json.Number
 
 // RawMessage is a raw encoded JSON value.
 // It implements Marshaler and Unmarshaler and can
 // be used to delay JSON decoding or precompute a JSON encoding.
 type RawMessage = json.RawMessage
 
 // A Delim is a JSON array or object delimiter, one of [ ] { or }.
 type Delim = json.Delim
 
 // Compact appends to dst the JSON-encoded src with
 // insignificant space characters elided.
 func Compact(dst *bytes.Buffer, src []byte) error {
 	return encoder.Compact(dst, src, false)
 }
 
 // Indent appends to dst an indented form of the JSON-encoded src.
 // Each element in a JSON object or array begins on a new,
 // indented line beginning with prefix followed by one or more
 // copies of indent according to the indentation nesting.
 // The data appended to dst does not begin with the prefix nor
 // any indentation, to make it easier to embed inside other formatted JSON data.
 // Although leading space characters (space, tab, carriage return, newline)
 // at the beginning of src are dropped, trailing space characters
 // at the end of src are preserved and copied to dst.
 // For example, if src has no trailing spaces, neither will dst;
 // if src ends in a trailing newline, so will dst.
 func Indent(dst *bytes.Buffer, src []byte, prefix, indent string) error {
 	return encoder.Indent(dst, src, prefix, indent)
 }
 
 // HTMLEscape appends to dst the JSON-encoded src with <, >, &, U+2028 and U+2029
 // characters inside string literals changed to \u003c, \u003e, \u0026, \u2028, \u2029
 // so that the JSON will be safe to embed inside HTML <script> tags.
 // For historical reasons, web browsers don't honor standard HTML
 // escaping within <script> tags, so an alternative JSON encoding must
 // be used.
 func HTMLEscape(dst *bytes.Buffer, src []byte) {
 	var v interface{}
 	dec := NewDecoder(bytes.NewBuffer(src))
 	dec.UseNumber()
 	if err := dec.Decode(&v); err != nil {
 		return
 	}
 	buf, _ := marshal(v)
 	dst.Write(buf)
 }
 
 // Valid reports whether data is a valid JSON encoding.
 func Valid(data []byte) bool {
 	var v interface{}
 	decoder := NewDecoder(bytes.NewReader(data))
 	err := decoder.Decode(&v)
 	if err != nil {
 		return false
 	}
 	if !decoder.More() {
 		return true
 	}
 	return decoder.InputOffset() >= int64(len(data))
 }
 
 func init() {
 	encoder.Marshal = Marshal
 	encoder.Unmarshal = Unmarshal
 }