Source file src/encoding/json/v2_options.go
1 // Copyright 2023 The Go Authors. All rights reserved. 2 // Use of this source code is governed by a BSD-style 3 // license that can be found in the LICENSE file. 4 5 //go:build goexperiment.jsonv2 6 7 // Migrating to v2 8 // 9 // This package (i.e., [encoding/json]) is now formally known as the v1 package 10 // since a v2 package now exists at [encoding/json/v2]. 11 // All the behavior of the v1 package is implemented in terms of 12 // the v2 package with the appropriate set of options specified that 13 // preserve the historical behavior of v1. 14 // 15 // The [jsonv2.Marshal] function is the newer equivalent of v1 [Marshal]. 16 // The [jsonv2.Unmarshal] function is the newer equivalent of v1 [Unmarshal]. 17 // The v2 functions have the same calling signature as the v1 equivalent 18 // except that they take in variadic [Options] arguments that can be specified 19 // to alter the behavior of marshal or unmarshal. Both v1 and v2 generally 20 // behave in similar ways, but there are some notable differences. 21 // 22 // The following is a list of differences between v1 and v2: 23 // 24 // - In v1, JSON object members are unmarshaled into a Go struct using a 25 // case-insensitive name match with the JSON name of the fields. 26 // In contrast, v2 matches fields using an exact, case-sensitive match. 27 // The [jsonv2.MatchCaseInsensitiveNames] and [MatchCaseSensitiveDelimiter] 28 // options control this behavior difference. To explicitly specify a Go struct 29 // field to use a particular name matching scheme, either the `case:ignore` 30 // or the `case:strict` field option can be specified. 31 // Field-specified options take precedence over caller-specified options. 32 // 33 // - In v1, when marshaling a Go struct, a field marked as `omitempty` 34 // is omitted if the field value is an "empty" Go value, which is defined as 35 // false, 0, a nil pointer, a nil interface value, and 36 // any empty array, slice, map, or string. In contrast, v2 redefines 37 // `omitempty` to omit a field if it encodes as an "empty" JSON value, 38 // which is defined as a JSON null, or an empty JSON string, object, or array. 39 // The [OmitEmptyWithLegacySemantics] option controls this behavior difference. 40 // Note that `omitempty` behaves identically in both v1 and v2 for a 41 // Go array, slice, map, or string (assuming no user-defined MarshalJSON method 42 // overrides the default representation). Existing usages of `omitempty` on a 43 // Go bool, number, pointer, or interface value should migrate to specifying 44 // `omitzero` instead (which is identically supported in both v1 and v2). 45 // 46 // - In v1, a Go struct field marked as `string` can be used to quote a 47 // Go string, bool, or number as a JSON string. It does not recursively 48 // take effect on composite Go types. In contrast, v2 restricts 49 // the `string` option to only quote a Go number as a JSON string. 50 // It does recursively take effect on Go numbers within a composite Go type. 51 // The [StringifyWithLegacySemantics] option controls this behavior difference. 52 // 53 // - In v1, a nil Go slice or Go map is marshaled as a JSON null. 54 // In contrast, v2 marshals a nil Go slice or Go map as 55 // an empty JSON array or JSON object, respectively. 56 // The [jsonv2.FormatNilSliceAsNull] and [jsonv2.FormatNilMapAsNull] options 57 // control this behavior difference. To explicitly specify a Go struct field 58 // to use a particular representation for nil, either the `format:emitempty` 59 // or `format:emitnull` field option can be specified. 60 // Field-specified options take precedence over caller-specified options. 61 // 62 // - In v1, a Go array may be unmarshaled from a JSON array of any length. 63 // In contrast, in v2 a Go array must be unmarshaled from a JSON array 64 // of the same length, otherwise it results in an error. 65 // The [UnmarshalArrayFromAnyLength] option controls this behavior difference. 66 // 67 // - In v1, a Go byte array is represented as a JSON array of JSON numbers. 68 // In contrast, in v2 a Go byte array is represented as a Base64-encoded JSON string. 69 // The [FormatByteArrayAsArray] option controls this behavior difference. 70 // To explicitly specify a Go struct field to use a particular representation, 71 // either the `format:array` or `format:base64` field option can be specified. 72 // Field-specified options take precedence over caller-specified options. 73 // 74 // - In v1, MarshalJSON methods declared on a pointer receiver are only called 75 // if the Go value is addressable. In contrast, in v2 a MarshalJSON method 76 // is always callable regardless of addressability. 77 // The [CallMethodsWithLegacySemantics] option controls this behavior difference. 78 // 79 // - In v1, MarshalJSON and UnmarshalJSON methods are never called for Go map keys. 80 // In contrast, in v2 a MarshalJSON or UnmarshalJSON method is eligible for 81 // being called for Go map keys. 82 // The [CallMethodsWithLegacySemantics] option controls this behavior difference. 83 // 84 // - In v1, a Go map is marshaled in a deterministic order. 85 // In contrast, in v2 a Go map is marshaled in a non-deterministic order. 86 // The [jsonv2.Deterministic] option controls this behavior difference. 87 // 88 // - In v1, JSON strings are encoded with HTML-specific or JavaScript-specific 89 // characters being escaped. In contrast, in v2 JSON strings use the minimal 90 // encoding and only escape if required by the JSON grammar. 91 // The [jsontext.EscapeForHTML] and [jsontext.EscapeForJS] options 92 // control this behavior difference. 93 // 94 // - In v1, bytes of invalid UTF-8 within a string are silently replaced with 95 // the Unicode replacement character. In contrast, in v2 the presence of 96 // invalid UTF-8 results in an error. The [jsontext.AllowInvalidUTF8] option 97 // controls this behavior difference. 98 // 99 // - In v1, a JSON object with duplicate names is permitted. 100 // In contrast, in v2 a JSON object with duplicate names results in an error. 101 // The [jsontext.AllowDuplicateNames] option controls this behavior difference. 102 // 103 // - In v1, when unmarshaling a JSON null into a non-empty Go value it will 104 // inconsistently either zero out the value or do nothing. 105 // In contrast, in v2 unmarshaling a JSON null will consistently and always 106 // zero out the underlying Go value. The [MergeWithLegacySemantics] option 107 // controls this behavior difference. 108 // 109 // - In v1, when unmarshaling a JSON value into a non-zero Go value, 110 // it merges into the original Go value for array elements, slice elements, 111 // struct fields (but not map values), 112 // pointer values, and interface values (only if a non-nil pointer). 113 // In contrast, in v2 unmarshal merges into the Go value 114 // for struct fields, map values, pointer values, and interface values. 115 // In general, the v2 semantic merges when unmarshaling a JSON object, 116 // otherwise it replaces the value. The [MergeWithLegacySemantics] option 117 // controls this behavior difference. 118 // 119 // - In v1, a [time.Duration] is represented as a JSON number containing 120 // the decimal number of nanoseconds. In contrast, in v2 a [time.Duration] 121 // has no default representation and results in a runtime error. 122 // The [FormatDurationAsNano] option controls this behavior difference. 123 // To explicitly specify a Go struct field to use a particular representation, 124 // either the `format:nano` or `format:units` field option can be specified. 125 // Field-specified options take precedence over caller-specified options. 126 // 127 // - In v1, errors are never reported at runtime for Go struct types 128 // that have some form of structural error (e.g., a malformed tag option). 129 // In contrast, v2 reports a runtime error for Go types that are invalid 130 // as they relate to JSON serialization. For example, a Go struct 131 // with only unexported fields cannot be serialized. 132 // The [ReportErrorsWithLegacySemantics] option controls this behavior difference. 133 // 134 // As mentioned, the entirety of v1 is implemented in terms of v2, 135 // where options are implicitly specified to opt into legacy behavior. 136 // For example, [Marshal] directly calls [jsonv2.Marshal] with [DefaultOptionsV1]. 137 // Similarly, [Unmarshal] directly calls [jsonv2.Unmarshal] with [DefaultOptionsV1]. 138 // The [DefaultOptionsV1] option represents the set of all options that specify 139 // default v1 behavior. 140 // 141 // For many of the behavior differences, there are Go struct field options 142 // that the author of a Go type can specify to control the behavior such that 143 // the type is represented identically in JSON under either v1 or v2 semantics. 144 // 145 // The availability of [DefaultOptionsV1] and [jsonv2.DefaultOptionsV2], 146 // where later options take precedence over former options allows for 147 // a gradual migration from v1 to v2. For example: 148 // 149 // - jsonv1.Marshal(v) 150 // uses default v1 semantics. 151 // 152 // - jsonv2.Marshal(v, jsonv1.DefaultOptionsV1()) 153 // is semantically equivalent to jsonv1.Marshal 154 // and thus uses default v1 semantics. 155 // 156 // - jsonv2.Marshal(v, jsonv1.DefaultOptionsV1(), jsontext.AllowDuplicateNames(false)) 157 // uses mostly v1 semantics, but opts into one particular v2-specific behavior. 158 // 159 // - jsonv2.Marshal(v, jsonv1.CallMethodsWithLegacySemantics(true)) 160 // uses mostly v2 semantics, but opts into one particular v1-specific behavior. 161 // 162 // - jsonv2.Marshal(v, ..., jsonv2.DefaultOptionsV2()) 163 // is semantically equivalent to jsonv2.Marshal since 164 // jsonv2.DefaultOptionsV2 overrides any options specified earlier 165 // and thus uses default v2 semantics. 166 // 167 // - jsonv2.Marshal(v) 168 // uses default v2 semantics. 169 // 170 // All new usages of "json" in Go should use the v2 package, 171 // but the v1 package will forever remain supported. 172 package json 173 174 // TODO(https://go.dev/issue/71631): Update the "Migrating to v2" documentation 175 // with default v2 behavior for [time.Duration]. 176 177 import ( 178 "encoding" 179 180 "encoding/json/internal/jsonflags" 181 "encoding/json/internal/jsonopts" 182 "encoding/json/jsontext" 183 jsonv2 "encoding/json/v2" 184 ) 185 186 // Reference encoding, jsonv2, and jsontext packages to assist pkgsite 187 // in being able to hotlink references to those packages. 188 var ( 189 _ encoding.TextMarshaler 190 _ encoding.TextUnmarshaler 191 _ jsonv2.Options 192 _ jsontext.Options 193 ) 194 195 // Options are a set of options to configure the v2 "json" package 196 // to operate with v1 semantics for particular features. 197 // Values of this type can be passed to v2 functions like 198 // [jsonv2.Marshal] or [jsonv2.Unmarshal]. 199 // Instead of referencing this type, use [jsonv2.Options]. 200 // 201 // See the "Migrating to v2" section for guidance on how to migrate usage 202 // of "json" from using v1 to using v2 instead. 203 type Options = jsonopts.Options 204 205 // DefaultOptionsV1 is the full set of all options that define v1 semantics. 206 // It is equivalent to the following boolean options being set to true: 207 // 208 // - [CallMethodsWithLegacySemantics] 209 // - [FormatByteArrayAsArray] 210 // - [FormatBytesWithLegacySemantics] 211 // - [FormatDurationAsNano] 212 // - [MatchCaseSensitiveDelimiter] 213 // - [MergeWithLegacySemantics] 214 // - [OmitEmptyWithLegacySemantics] 215 // - [ParseBytesWithLooseRFC4648] 216 // - [ParseTimeWithLooseRFC3339] 217 // - [ReportErrorsWithLegacySemantics] 218 // - [StringifyWithLegacySemantics] 219 // - [UnmarshalArrayFromAnyLength] 220 // - [jsonv2.Deterministic] 221 // - [jsonv2.FormatNilMapAsNull] 222 // - [jsonv2.FormatNilSliceAsNull] 223 // - [jsonv2.MatchCaseInsensitiveNames] 224 // - [jsontext.AllowDuplicateNames] 225 // - [jsontext.AllowInvalidUTF8] 226 // - [jsontext.EscapeForHTML] 227 // - [jsontext.EscapeForJS] 228 // - [jsontext.PreserveRawStrings] 229 // 230 // All other boolean options are set to false. 231 // All non-boolean options are set to the zero value, 232 // except for [jsontext.WithIndent], which defaults to "\t". 233 // 234 // The [Marshal] and [Unmarshal] functions in this package are 235 // semantically identical to calling the v2 equivalents with this option: 236 // 237 // jsonv2.Marshal(v, jsonv1.DefaultOptionsV1()) 238 // jsonv2.Unmarshal(b, v, jsonv1.DefaultOptionsV1()) 239 func DefaultOptionsV1() Options { 240 return &jsonopts.DefaultOptionsV1 241 } 242 243 // CallMethodsWithLegacySemantics specifies that calling of type-provided 244 // marshal and unmarshal methods follow legacy semantics: 245 // 246 // - When marshaling, a marshal method declared on a pointer receiver 247 // is only called if the Go value is addressable. 248 // Values obtained from an interface or map element are not addressable. 249 // Values obtained from a pointer or slice element are addressable. 250 // Values obtained from an array element or struct field inherit 251 // the addressability of the parent. In contrast, the v2 semantic 252 // is to always call marshal methods regardless of addressability. 253 // 254 // - When marshaling or unmarshaling, the [Marshaler] or [Unmarshaler] 255 // methods are ignored for map keys. However, [encoding.TextMarshaler] 256 // or [encoding.TextUnmarshaler] are still callable. 257 // In contrast, the v2 semantic is to serialize map keys 258 // like any other value (with regard to calling methods), 259 // which may include calling [Marshaler] or [Unmarshaler] methods, 260 // where it is the implementation's responsibility to represent the 261 // Go value as a JSON string (as required for JSON object names). 262 // 263 // - When marshaling, if a map key value implements a marshal method 264 // and is a nil pointer, then it is serialized as an empty JSON string. 265 // In contrast, the v2 semantic is to report an error. 266 // 267 // - When marshaling, if an interface type implements a marshal method 268 // and the interface value is a nil pointer to a concrete type, 269 // then the marshal method is always called. 270 // In contrast, the v2 semantic is to never directly call methods 271 // on interface values and to instead defer evaluation based upon 272 // the underlying concrete value. Similar to non-interface values, 273 // marshal methods are not called on nil pointers and 274 // are instead serialized as a JSON null. 275 // 276 // This affects either marshaling or unmarshaling. 277 // The v1 default is true. 278 func CallMethodsWithLegacySemantics(v bool) Options { 279 if v { 280 return jsonflags.CallMethodsWithLegacySemantics | 1 281 } else { 282 return jsonflags.CallMethodsWithLegacySemantics | 0 283 } 284 } 285 286 // FormatByteArrayAsArray specifies that a Go [N]byte is 287 // formatted as as a normal Go array in contrast to the v2 default of 288 // formatting [N]byte as using binary data encoding (RFC 4648). 289 // If a struct field has a `format` tag option, 290 // then the specified formatting takes precedence. 291 // 292 // This affects either marshaling or unmarshaling. 293 // The v1 default is true. 294 func FormatByteArrayAsArray(v bool) Options { 295 if v { 296 return jsonflags.FormatByteArrayAsArray | 1 297 } else { 298 return jsonflags.FormatByteArrayAsArray | 0 299 } 300 } 301 302 // FormatBytesWithLegacySemantics specifies that handling of 303 // []~byte and [N]~byte types follow legacy semantics: 304 // 305 // - A Go []~byte is to be treated as using some form of 306 // binary data encoding (RFC 4648) in contrast to the v2 default 307 // of only treating []byte as such. In particular, v2 does not 308 // treat slices of named byte types as representing binary data. 309 // 310 // - When marshaling, if a named byte implements a marshal method, 311 // then the slice is serialized as a JSON array of elements, 312 // each of which call the marshal method. 313 // 314 // - When unmarshaling, if the input is a JSON array, 315 // then unmarshal into the []~byte as if it were a normal Go slice. 316 // In contrast, the v2 default is to report an error unmarshaling 317 // a JSON array when expecting some form of binary data encoding. 318 // 319 // This affects either marshaling or unmarshaling. 320 // The v1 default is true. 321 func FormatBytesWithLegacySemantics(v bool) Options { 322 if v { 323 return jsonflags.FormatBytesWithLegacySemantics | 1 324 } else { 325 return jsonflags.FormatBytesWithLegacySemantics | 0 326 } 327 } 328 329 // FormatDurationAsNano specifies that a [time.Duration] is 330 // formatted as a JSON number representing the number of nanoseconds 331 // in contrast to the v2 default of reporting an error. 332 // If a duration field has a `format` tag option, 333 // then the specified formatting takes precedence. 334 // 335 // This affects either marshaling or unmarshaling. 336 // The v1 default is true. 337 func FormatDurationAsNano(v bool) Options { 338 // TODO(https://go.dev/issue/71631): Update documentation with v2 behavior. 339 if v { 340 return jsonflags.FormatDurationAsNano | 1 341 } else { 342 return jsonflags.FormatDurationAsNano | 0 343 } 344 } 345 346 // MatchCaseSensitiveDelimiter specifies that underscores and dashes are 347 // not to be ignored when performing case-insensitive name matching which 348 // occurs under [jsonv2.MatchCaseInsensitiveNames] or the `case:ignore` tag option. 349 // Thus, case-insensitive name matching is identical to [strings.EqualFold]. 350 // Use of this option diminishes the ability of case-insensitive matching 351 // to be able to match common case variants (e.g, "foo_bar" with "fooBar"). 352 // 353 // This affects either marshaling or unmarshaling. 354 // The v1 default is true. 355 func MatchCaseSensitiveDelimiter(v bool) Options { 356 if v { 357 return jsonflags.MatchCaseSensitiveDelimiter | 1 358 } else { 359 return jsonflags.MatchCaseSensitiveDelimiter | 0 360 } 361 } 362 363 // MergeWithLegacySemantics specifies that unmarshaling into a non-zero 364 // Go value follows legacy semantics: 365 // 366 // - When unmarshaling a JSON null, this preserves the original Go value 367 // if the kind is a bool, int, uint, float, string, array, or struct. 368 // Otherwise, it zeros the Go value. 369 // In contrast, the default v2 behavior is to consistently and always 370 // zero the Go value when unmarshaling a JSON null into it. 371 // 372 // - When unmarshaling a JSON value other than null, this merges into 373 // the original Go value for array elements, slice elements, 374 // struct fields (but not map values), 375 // pointer values, and interface values (only if a non-nil pointer). 376 // In contrast, the default v2 behavior is to merge into the Go value 377 // for struct fields, map values, pointer values, and interface values. 378 // In general, the v2 semantic merges when unmarshaling a JSON object, 379 // otherwise it replaces the original value. 380 // 381 // This only affects unmarshaling and is ignored when marshaling. 382 // The v1 default is true. 383 func MergeWithLegacySemantics(v bool) Options { 384 if v { 385 return jsonflags.MergeWithLegacySemantics | 1 386 } else { 387 return jsonflags.MergeWithLegacySemantics | 0 388 } 389 } 390 391 // OmitEmptyWithLegacySemantics specifies that the `omitempty` tag option 392 // follows a definition of empty where a field is omitted if the Go value is 393 // false, 0, a nil pointer, a nil interface value, 394 // or any empty array, slice, map, or string. 395 // This overrides the v2 semantic where a field is empty if the value 396 // marshals as a JSON null or an empty JSON string, object, or array. 397 // 398 // The v1 and v2 definitions of `omitempty` are practically the same for 399 // Go strings, slices, arrays, and maps. Usages of `omitempty` on 400 // Go bools, ints, uints floats, pointers, and interfaces should migrate to use 401 // the `omitzero` tag option, which omits a field if it is the zero Go value. 402 // 403 // This only affects marshaling and is ignored when unmarshaling. 404 // The v1 default is true. 405 func OmitEmptyWithLegacySemantics(v bool) Options { 406 if v { 407 return jsonflags.OmitEmptyWithLegacySemantics | 1 408 } else { 409 return jsonflags.OmitEmptyWithLegacySemantics | 0 410 } 411 } 412 413 // ParseBytesWithLooseRFC4648 specifies that when parsing 414 // binary data encoded as "base32" or "base64", 415 // to ignore the presence of '\r' and '\n' characters. 416 // In contrast, the v2 default is to report an error in order to be 417 // strictly compliant with RFC 4648, section 3.3, 418 // which specifies that non-alphabet characters must be rejected. 419 // 420 // This only affects unmarshaling and is ignored when marshaling. 421 // The v1 default is true. 422 func ParseBytesWithLooseRFC4648(v bool) Options { 423 if v { 424 return jsonflags.ParseBytesWithLooseRFC4648 | 1 425 } else { 426 return jsonflags.ParseBytesWithLooseRFC4648 | 0 427 } 428 } 429 430 // ParseTimeWithLooseRFC3339 specifies that a [time.Time] 431 // parses according to loose adherence to RFC 3339. 432 // In particular, it permits historically incorrect representations, 433 // allowing for deviations in hour format, sub-second separator, 434 // and timezone representation. In contrast, the default v2 behavior 435 // is to strictly comply with the grammar specified in RFC 3339. 436 // 437 // This only affects unmarshaling and is ignored when marshaling. 438 // The v1 default is true. 439 func ParseTimeWithLooseRFC3339(v bool) Options { 440 if v { 441 return jsonflags.ParseTimeWithLooseRFC3339 | 1 442 } else { 443 return jsonflags.ParseTimeWithLooseRFC3339 | 0 444 } 445 } 446 447 // ReportErrorsWithLegacySemantics specifies that Marshal and Unmarshal 448 // should report errors with legacy semantics: 449 // 450 // - When marshaling or unmarshaling, the returned error values are 451 // usually of types such as [SyntaxError], [MarshalerError], 452 // [UnsupportedTypeError], [UnsupportedValueError], 453 // [InvalidUnmarshalError], or [UnmarshalTypeError]. 454 // In contrast, the v2 semantic is to always return errors as either 455 // [jsonv2.SemanticError] or [jsontext.SyntacticError]. 456 // 457 // - When marshaling, if a user-defined marshal method reports an error, 458 // it is always wrapped in a [MarshalerError], even if the error itself 459 // is already a [MarshalerError], which may lead to multiple redundant 460 // layers of wrapping. In contrast, the v2 semantic is to 461 // always wrap an error within [jsonv2.SemanticError] 462 // unless it is already a semantic error. 463 // 464 // - When unmarshaling, if a user-defined unmarshal method reports an error, 465 // it is never wrapped and reported verbatim. In contrast, the v2 semantic 466 // is to always wrap an error within [jsonv2.SemanticError] 467 // unless it is already a semantic error. 468 // 469 // - When marshaling or unmarshaling, if a Go struct contains type errors 470 // (e.g., conflicting names or malformed field tags), then such errors 471 // are ignored and the Go struct uses a best-effort representation. 472 // In contrast, the v2 semantic is to report a runtime error. 473 // 474 // - When unmarshaling, the syntactic structure of the JSON input 475 // is fully validated before performing the semantic unmarshaling 476 // of the JSON data into the Go value. Practically speaking, 477 // this means that JSON input with syntactic errors do not result 478 // in any mutations of the target Go value. In contrast, the v2 semantic 479 // is to perform a streaming decode and gradually unmarshal the JSON input 480 // into the target Go value, which means that the Go value may be 481 // partially mutated when a syntactic error is encountered. 482 // 483 // - When unmarshaling, a semantic error does not immediately terminate the 484 // unmarshal procedure, but rather evaluation continues. 485 // When unmarshal returns, only the first semantic error is reported. 486 // In contrast, the v2 semantic is to terminate unmarshal the moment 487 // an error is encountered. 488 // 489 // This affects either marshaling or unmarshaling. 490 // The v1 default is true. 491 func ReportErrorsWithLegacySemantics(v bool) Options { 492 if v { 493 return jsonflags.ReportErrorsWithLegacySemantics | 1 494 } else { 495 return jsonflags.ReportErrorsWithLegacySemantics | 0 496 } 497 } 498 499 // StringifyWithLegacySemantics specifies that the `string` tag option 500 // may stringify bools and string values. It only takes effect on fields 501 // where the top-level type is a bool, string, numeric kind, or a pointer to 502 // such a kind. Specifically, `string` will not stringify bool, string, 503 // or numeric kinds within a composite data type 504 // (e.g., array, slice, struct, map, or interface). 505 // 506 // When marshaling, such Go values are serialized as their usual 507 // JSON representation, but quoted within a JSON string. 508 // When unmarshaling, such Go values must be deserialized from 509 // a JSON string containing their usual JSON representation. 510 // A JSON null quoted in a JSON string is a valid substitute for JSON null 511 // while unmarshaling into a Go value that `string` takes effect on. 512 // 513 // This affects either marshaling or unmarshaling. 514 // The v1 default is true. 515 func StringifyWithLegacySemantics(v bool) Options { 516 if v { 517 return jsonflags.StringifyWithLegacySemantics | 1 518 } else { 519 return jsonflags.StringifyWithLegacySemantics | 0 520 } 521 } 522 523 // UnmarshalArrayFromAnyLength specifies that Go arrays can be unmarshaled 524 // from input JSON arrays of any length. If the JSON array is too short, 525 // then the remaining Go array elements are zeroed. If the JSON array 526 // is too long, then the excess JSON array elements are skipped over. 527 // 528 // This only affects unmarshaling and is ignored when marshaling. 529 // The v1 default is true. 530 func UnmarshalArrayFromAnyLength(v bool) Options { 531 if v { 532 return jsonflags.UnmarshalArrayFromAnyLength | 1 533 } else { 534 return jsonflags.UnmarshalArrayFromAnyLength | 0 535 } 536 } 537 538 // unmarshalAnyWithRawNumber specifies that unmarshaling a JSON number into 539 // an empty Go interface should use the Number type instead of a float64. 540 func unmarshalAnyWithRawNumber(v bool) Options { 541 if v { 542 return jsonflags.UnmarshalAnyWithRawNumber | 1 543 } else { 544 return jsonflags.UnmarshalAnyWithRawNumber | 0 545 } 546 } 547