go1.20.5
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json.Marshaler

// Marshaler is the interface implemented by types that // can marshal themselves into valid JSON. type Marshaler interface { MarshalJSON() ([]byte, error) }

json.Unmarshaler

// 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 }

json.Compact

// Compact appends to dst the JSON-encoded src with // insignificant space characters elided. func Compact(dst *bytes.Buffer, src []byte) error

json.Fuzz

func Fuzz(data []byte) (score int)

json.HTMLEscape

// 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)

json.Indent

// 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 string, indent string) error

json.Marshal

// 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. // So that the JSON will be safe to embed inside HTML <script> tags, // the string is encoded using HTMLEscape, // which replaces "<", ">", "&", U+2028, and U+2029 are escaped // to "\u003c","\u003e", "\u0026", "\u2028", and "\u2029". // This replacement can be disabled when using an Encoder, // by calling SetEscapeHTML(false). // // 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: // - keys of any string type 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 error. func Marshal(v any) ([]byte, error)

json.MarshalIndent

// 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 any, prefix string, indent string) ([]byte, error)

json.NewDecoder

// NewDecoder returns a new decoder that reads from r. // // The decoder introduces its own buffering and may // read data from r beyond the JSON values requested. func NewDecoder(r io.Reader) *Decoder

json.NewEncoder

// NewEncoder returns a new encoder that writes to w. func NewEncoder(w io.Writer) *Encoder

json.Unmarshal

// 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 the JSON-encoded data contain a syntax error, Unmarshal returns a SyntaxError. // // 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 any) error

json.Valid

// Valid reports whether data is a valid JSON encoding. func Valid(data []byte) bool