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, number, or pointer to such as a JSON string. 48 // In contrast, v2 restricts the `string` option to only quote a value 49 // that would normally be represented as a JSON number, 50 // but also expands support for it to operate with any Go type 51 // that would normally be represented as a JSON number. 52 // The [StringifyWithLegacySemantics] option controls this behavior difference. 53 // 54 // - In v1, a nil Go slice or Go map is marshaled as a JSON null. 55 // In contrast, v2 marshals a nil Go slice or Go map as 56 // an empty JSON array or JSON object, respectively. 57 // The [jsonv2.FormatNilSliceAsNull] and [jsonv2.FormatNilMapAsNull] options 58 // control this behavior difference. To explicitly specify a Go struct field 59 // to use a particular representation for nil, either the `format:emitempty` 60 // or `format:emitnull` field option can be specified. 61 // Field-specified options take precedence over caller-specified options. 62 // 63 // - In v1, a Go array may be unmarshaled from a JSON array of any length. 64 // In contrast, in v2 a Go array must be unmarshaled from a JSON array 65 // of the same length, otherwise it results in an error. 66 // The [UnmarshalArrayFromAnyLength] option controls this behavior difference. 67 // 68 // - In v1, a Go byte array is represented as a JSON array of JSON numbers. 69 // In contrast, in v2 a Go byte array is represented as a Base64-encoded JSON string. 70 // The [FormatByteArrayAsArray] option controls this behavior difference. 71 // To explicitly specify a Go struct field to use a particular representation, 72 // either the `format:array` or `format:base64` field option can be specified. 73 // Field-specified options take precedence over caller-specified options. 74 // 75 // - In v1, MarshalJSON methods declared on a pointer receiver are only called 76 // if the Go value is addressable. In contrast, in v2 a MarshalJSON method 77 // is always callable regardless of addressability. 78 // The [CallMethodsWithLegacySemantics] option controls this behavior difference. 79 // 80 // - In v1, MarshalJSON and UnmarshalJSON methods are never called for Go map keys. 81 // In contrast, in v2 a MarshalJSON or UnmarshalJSON method is eligible for 82 // being called for Go map keys. 83 // The [CallMethodsWithLegacySemantics] option controls this behavior difference. 84 // 85 // - In v1, a Go map is marshaled in a deterministic order. 86 // In contrast, in v2 a Go map is marshaled in a non-deterministic order. 87 // The [jsonv2.Deterministic] option controls this behavior difference. 88 // 89 // - In v1, JSON strings are encoded with HTML-specific or JavaScript-specific 90 // characters being escaped. In contrast, in v2 JSON strings use the minimal 91 // encoding and only escape if required by the JSON grammar. 92 // The [jsontext.EscapeForHTML] and [jsontext.EscapeForJS] options 93 // control this behavior difference. 94 // 95 // - In v1, bytes of invalid UTF-8 within a string are silently replaced with 96 // the Unicode replacement character. In contrast, in v2 the presence of 97 // invalid UTF-8 results in an error. The [jsontext.AllowInvalidUTF8] option 98 // controls this behavior difference. 99 // 100 // - In v1, a JSON object with duplicate names is permitted. 101 // In contrast, in v2 a JSON object with duplicate names results in an error. 102 // The [jsontext.AllowDuplicateNames] option controls this behavior difference. 103 // 104 // - In v1, when unmarshaling a JSON null into a non-empty Go value it will 105 // inconsistently either zero out the value or do nothing. 106 // In contrast, in v2 unmarshaling a JSON null will consistently and always 107 // zero out the underlying Go value. The [MergeWithLegacySemantics] option 108 // controls this behavior difference. 109 // 110 // - In v1, when unmarshaling a JSON value into a non-zero Go value, 111 // it merges into the original Go value for array elements, slice elements, 112 // struct fields (but not map values), 113 // pointer values, and interface values (only if a non-nil pointer). 114 // In contrast, in v2 unmarshal merges into the Go value 115 // for struct fields, map values, pointer values, and interface values. 116 // In general, the v2 semantic merges when unmarshaling a JSON object, 117 // otherwise it replaces the value. The [MergeWithLegacySemantics] option 118 // controls this behavior difference. 119 // 120 // - In v1, a [time.Duration] is represented as a JSON number containing 121 // the decimal number of nanoseconds. In contrast, in v2 a [time.Duration] 122 // has no default representation and results in a runtime error. 123 // The [FormatDurationAsNano] option controls this behavior difference. 124 // To explicitly specify a Go struct field to use a particular representation, 125 // either the `format:nano` or `format:units` field option can be specified. 126 // Field-specified options take precedence over caller-specified options. 127 // 128 // - In v1, errors are never reported at runtime for Go struct types 129 // that have some form of structural error (e.g., a malformed tag option). 130 // In contrast, v2 reports a runtime error for Go types that are invalid 131 // as they relate to JSON serialization. For example, a Go struct 132 // with only unexported fields cannot be serialized. 133 // The [ReportErrorsWithLegacySemantics] option controls this behavior difference. 134 // 135 // As mentioned, the entirety of v1 is implemented in terms of v2, 136 // where options are implicitly specified to opt into legacy behavior. 137 // For example, [Marshal] directly calls [jsonv2.Marshal] with [DefaultOptionsV1]. 138 // Similarly, [Unmarshal] directly calls [jsonv2.Unmarshal] with [DefaultOptionsV1]. 139 // The [DefaultOptionsV1] option represents the set of all options that specify 140 // default v1 behavior. 141 // 142 // For many of the behavior differences, there are Go struct field options 143 // that the author of a Go type can specify to control the behavior such that 144 // the type is represented identically in JSON under either v1 or v2 semantics. 145 // 146 // The availability of [DefaultOptionsV1] and [jsonv2.DefaultOptionsV2], 147 // where later options take precedence over former options allows for 148 // a gradual migration from v1 to v2. For example: 149 // 150 // - jsonv1.Marshal(v) 151 // uses default v1 semantics. 152 // 153 // - jsonv2.Marshal(v, jsonv1.DefaultOptionsV1()) 154 // is semantically equivalent to jsonv1.Marshal 155 // and thus uses default v1 semantics. 156 // 157 // - jsonv2.Marshal(v, jsonv1.DefaultOptionsV1(), jsontext.AllowDuplicateNames(false)) 158 // uses mostly v1 semantics, but opts into one particular v2-specific behavior. 159 // 160 // - jsonv2.Marshal(v, jsonv1.CallMethodsWithLegacySemantics(true)) 161 // uses mostly v2 semantics, but opts into one particular v1-specific behavior. 162 // 163 // - jsonv2.Marshal(v, ..., jsonv2.DefaultOptionsV2()) 164 // is semantically equivalent to jsonv2.Marshal since 165 // jsonv2.DefaultOptionsV2 overrides any options specified earlier 166 // and thus uses default v2 semantics. 167 // 168 // - jsonv2.Marshal(v) 169 // uses default v2 semantics. 170 // 171 // All new usages of "json" in Go should use the v2 package, 172 // but the v1 package will forever remain supported. 173 package json 174 175 // TODO(https://go.dev/issue/71631): Update the "Migrating to v2" documentation 176 // with default v2 behavior for [time.Duration]. 177 178 import ( 179 "encoding" 180 181 "encoding/json/internal/jsonflags" 182 "encoding/json/internal/jsonopts" 183 "encoding/json/jsontext" 184 jsonv2 "encoding/json/v2" 185 ) 186 187 // Reference encoding, jsonv2, and jsontext packages to assist pkgsite 188 // in being able to hotlink references to those packages. 189 var ( 190 _ encoding.TextMarshaler 191 _ encoding.TextUnmarshaler 192 _ jsonv2.Options 193 _ jsontext.Options 194 ) 195 196 // Options are a set of options to configure the v2 "json" package 197 // to operate with v1 semantics for particular features. 198 // Values of this type can be passed to v2 functions like 199 // [jsonv2.Marshal] or [jsonv2.Unmarshal]. 200 // Instead of referencing this type, use [jsonv2.Options]. 201 // 202 // See the "Migrating to v2" section for guidance on how to migrate usage 203 // of "json" from using v1 to using v2 instead. 204 type Options = jsonopts.Options 205 206 // DefaultOptionsV1 is the full set of all options that define v1 semantics. 207 // It is equivalent to the following boolean options being set to true: 208 // 209 // - [CallMethodsWithLegacySemantics] 210 // - [FormatByteArrayAsArray] 211 // - [FormatBytesWithLegacySemantics] 212 // - [FormatDurationAsNano] 213 // - [MatchCaseSensitiveDelimiter] 214 // - [MergeWithLegacySemantics] 215 // - [OmitEmptyWithLegacySemantics] 216 // - [ParseBytesWithLooseRFC4648] 217 // - [ParseTimeWithLooseRFC3339] 218 // - [ReportErrorsWithLegacySemantics] 219 // - [StringifyWithLegacySemantics] 220 // - [UnmarshalArrayFromAnyLength] 221 // - [jsonv2.Deterministic] 222 // - [jsonv2.FormatNilMapAsNull] 223 // - [jsonv2.FormatNilSliceAsNull] 224 // - [jsonv2.MatchCaseInsensitiveNames] 225 // - [jsontext.AllowDuplicateNames] 226 // - [jsontext.AllowInvalidUTF8] 227 // - [jsontext.EscapeForHTML] 228 // - [jsontext.EscapeForJS] 229 // - [jsontext.PreserveRawStrings] 230 // 231 // All other options are not present. 232 // 233 // The [Marshal] and [Unmarshal] functions in this package are 234 // semantically identical to calling the v2 equivalents with this option: 235 // 236 // jsonv2.Marshal(v, jsonv1.DefaultOptionsV1()) 237 // jsonv2.Unmarshal(b, v, jsonv1.DefaultOptionsV1()) 238 func DefaultOptionsV1() Options { 239 return &jsonopts.DefaultOptionsV1 240 } 241 242 // CallMethodsWithLegacySemantics specifies that calling of type-provided 243 // marshal and unmarshal methods follow legacy semantics: 244 // 245 // - When marshaling, a marshal method declared on a pointer receiver 246 // is only called if the Go value is addressable. 247 // Values obtained from an interface or map element are not addressable. 248 // Values obtained from a pointer or slice element are addressable. 249 // Values obtained from an array element or struct field inherit 250 // the addressability of the parent. In contrast, the v2 semantic 251 // is to always call marshal methods regardless of addressability. 252 // 253 // - When marshaling or unmarshaling, the [Marshaler] or [Unmarshaler] 254 // methods are ignored for map keys. However, [encoding.TextMarshaler] 255 // or [encoding.TextUnmarshaler] are still callable. 256 // In contrast, the v2 semantic is to serialize map keys 257 // like any other value (with regard to calling methods), 258 // which may include calling [Marshaler] or [Unmarshaler] methods, 259 // where it is the implementation's responsibility to represent the 260 // Go value as a JSON string (as required for JSON object names). 261 // 262 // - When marshaling, if a map key value implements a marshal method 263 // and is a nil pointer, then it is serialized as an empty JSON string. 264 // In contrast, the v2 semantic is to report an error. 265 // 266 // - When marshaling, if an interface type implements a marshal method 267 // and the interface value is a nil pointer to a concrete type, 268 // then the marshal method is always called. 269 // In contrast, the v2 semantic is to never directly call methods 270 // on interface values and to instead defer evaluation based upon 271 // the underlying concrete value. Similar to non-interface values, 272 // marshal methods are not called on nil pointers and 273 // are instead serialized as a JSON null. 274 // 275 // This affects either marshaling or unmarshaling. 276 // The v1 default is true. 277 func CallMethodsWithLegacySemantics(v bool) Options { 278 if v { 279 return jsonflags.CallMethodsWithLegacySemantics | 1 280 } else { 281 return jsonflags.CallMethodsWithLegacySemantics | 0 282 } 283 } 284 285 // FormatByteArrayAsArray specifies that a Go [N]byte is 286 // formatted as a normal Go array in contrast to the v2 default of 287 // formatting [N]byte as using binary data encoding (RFC 4648). 288 // If a struct field has a `format` tag option, 289 // then the specified formatting takes precedence. 290 // 291 // This affects either marshaling or unmarshaling. 292 // The v1 default is true. 293 func FormatByteArrayAsArray(v bool) Options { 294 if v { 295 return jsonflags.FormatByteArrayAsArray | 1 296 } else { 297 return jsonflags.FormatByteArrayAsArray | 0 298 } 299 } 300 301 // FormatBytesWithLegacySemantics specifies that handling of 302 // []~byte and [N]~byte types follow legacy semantics: 303 // 304 // - A Go []~byte is to be treated as using some form of 305 // binary data encoding (RFC 4648) in contrast to the v2 default 306 // of only treating []byte as such. In particular, v2 does not 307 // treat slices of named byte types as representing binary data. 308 // 309 // - When marshaling, if a named byte implements a marshal method, 310 // then the slice is serialized as a JSON array of elements, 311 // each of which call the marshal method. 312 // 313 // - When unmarshaling, if the input is a JSON array, 314 // then unmarshal into the []~byte as if it were a normal Go slice. 315 // In contrast, the v2 default is to report an error unmarshaling 316 // a JSON array when expecting some form of binary data encoding. 317 // 318 // This affects either marshaling or unmarshaling. 319 // The v1 default is true. 320 func FormatBytesWithLegacySemantics(v bool) Options { 321 if v { 322 return jsonflags.FormatBytesWithLegacySemantics | 1 323 } else { 324 return jsonflags.FormatBytesWithLegacySemantics | 0 325 } 326 } 327 328 // FormatDurationAsNano specifies that a [time.Duration] is 329 // formatted as a JSON number representing the number of nanoseconds 330 // in contrast to the v2 default of reporting an error. 331 // If a duration field has a `format` tag option, 332 // then the specified formatting takes precedence. 333 // 334 // This affects either marshaling or unmarshaling. 335 // The v1 default is true. 336 func FormatDurationAsNano(v bool) Options { 337 // TODO(https://go.dev/issue/71631): Update documentation with v2 behavior. 338 if v { 339 return jsonflags.FormatDurationAsNano | 1 340 } else { 341 return jsonflags.FormatDurationAsNano | 0 342 } 343 } 344 345 // MatchCaseSensitiveDelimiter specifies that underscores and dashes are 346 // not to be ignored when performing case-insensitive name matching which 347 // occurs under [jsonv2.MatchCaseInsensitiveNames] or the `case:ignore` tag option. 348 // Thus, case-insensitive name matching is identical to [strings.EqualFold]. 349 // Use of this option diminishes the ability of case-insensitive matching 350 // to be able to match common case variants (e.g., "foo_bar" with "fooBar"). 351 // 352 // This affects either marshaling or unmarshaling. 353 // The v1 default is true. 354 func MatchCaseSensitiveDelimiter(v bool) Options { 355 if v { 356 return jsonflags.MatchCaseSensitiveDelimiter | 1 357 } else { 358 return jsonflags.MatchCaseSensitiveDelimiter | 0 359 } 360 } 361 362 // MergeWithLegacySemantics specifies that unmarshaling into a non-zero 363 // Go value follows legacy semantics: 364 // 365 // - When unmarshaling a JSON null, this preserves the original Go value 366 // if the kind is a bool, int, uint, float, string, array, or struct. 367 // Otherwise, it zeros the Go value. 368 // In contrast, the default v2 behavior is to consistently and always 369 // zero the Go value when unmarshaling a JSON null into it. 370 // 371 // - When unmarshaling a JSON value other than null, this merges into 372 // the original Go value for array elements, slice elements, 373 // struct fields (but not map values), 374 // pointer values, and interface values (only if a non-nil pointer). 375 // For slices, it will merge into the pre-existing value of slice elements 376 // even for those past the slice length. If the original slice length 377 // was longer than the JSON array, then it is truncated to match. 378 // In contrast, the default v2 behavior is to merge into the Go value 379 // for struct fields, map values, pointer values, and interface values. 380 // In general, the v2 semantic merges when unmarshaling a JSON object, 381 // otherwise it replaces the original value. 382 // 383 // This only affects unmarshaling and is ignored when marshaling. 384 // The v1 default is true. 385 func MergeWithLegacySemantics(v bool) Options { 386 if v { 387 return jsonflags.MergeWithLegacySemantics | 1 388 } else { 389 return jsonflags.MergeWithLegacySemantics | 0 390 } 391 } 392 393 // OmitEmptyWithLegacySemantics specifies that the `omitempty` tag option 394 // follows a definition of empty where a field is omitted if the Go value is 395 // false, 0, a nil pointer, a nil interface value, 396 // or any empty array, slice, map, or string. 397 // This overrides the v2 semantic where a field is empty if the value 398 // marshals as a JSON null or an empty JSON string, object, or array. 399 // 400 // The v1 and v2 definitions of `omitempty` are practically the same for 401 // Go strings, slices, arrays, and maps. Usages of `omitempty` on 402 // Go bools, ints, uints, floats, pointers, and interfaces should migrate to use 403 // the `omitzero` tag option, which omits a field if it is the zero Go value. 404 // 405 // This only affects marshaling and is ignored when unmarshaling. 406 // The v1 default is true. 407 func OmitEmptyWithLegacySemantics(v bool) Options { 408 if v { 409 return jsonflags.OmitEmptyWithLegacySemantics | 1 410 } else { 411 return jsonflags.OmitEmptyWithLegacySemantics | 0 412 } 413 } 414 415 // ParseBytesWithLooseRFC4648 specifies that when parsing 416 // binary data encoded as "base32" or "base64", 417 // to ignore the presence of '\r' and '\n' characters. 418 // In contrast, the v2 default is to report an error in order to be 419 // strictly compliant with RFC 4648, section 3.3, 420 // which specifies that non-alphabet characters must be rejected. 421 // 422 // This only affects unmarshaling and is ignored when marshaling. 423 // The v1 default is true. 424 func ParseBytesWithLooseRFC4648(v bool) Options { 425 if v { 426 return jsonflags.ParseBytesWithLooseRFC4648 | 1 427 } else { 428 return jsonflags.ParseBytesWithLooseRFC4648 | 0 429 } 430 } 431 432 // ParseTimeWithLooseRFC3339 specifies that a [time.Time] 433 // parses according to loose adherence to RFC 3339. 434 // In particular, it permits historically incorrect representations, 435 // allowing for deviations in hour format, sub-second separator, 436 // and timezone representation. In contrast, the default v2 behavior 437 // is to strictly comply with the grammar specified in RFC 3339. 438 // 439 // This only affects unmarshaling and is ignored when marshaling. 440 // The v1 default is true. 441 func ParseTimeWithLooseRFC3339(v bool) Options { 442 if v { 443 return jsonflags.ParseTimeWithLooseRFC3339 | 1 444 } else { 445 return jsonflags.ParseTimeWithLooseRFC3339 | 0 446 } 447 } 448 449 // ReportErrorsWithLegacySemantics specifies that Marshal and Unmarshal 450 // should report errors with legacy semantics: 451 // 452 // - When marshaling or unmarshaling, the returned error values are 453 // usually of types such as [SyntaxError], [MarshalerError], 454 // [UnsupportedTypeError], [UnsupportedValueError], 455 // [InvalidUnmarshalError], or [UnmarshalTypeError]. 456 // In contrast, the v2 semantic is to always return errors as either 457 // [jsonv2.SemanticError] or [jsontext.SyntacticError]. 458 // 459 // - When marshaling, if a user-defined marshal method reports an error, 460 // it is always wrapped in a [MarshalerError], even if the error itself 461 // is already a [MarshalerError], which may lead to multiple redundant 462 // layers of wrapping. In contrast, the v2 semantic is to 463 // always wrap an error within [jsonv2.SemanticError] 464 // unless it is already a semantic error. 465 // 466 // - When unmarshaling, if a user-defined unmarshal method reports an error, 467 // it is never wrapped and reported verbatim. In contrast, the v2 semantic 468 // is to always wrap an error within [jsonv2.SemanticError] 469 // unless it is already a semantic error. 470 // 471 // - When marshaling or unmarshaling, if a Go struct contains type errors 472 // (e.g., conflicting names or malformed field tags), then such errors 473 // are ignored and the Go struct uses a best-effort representation. 474 // In contrast, the v2 semantic is to report a runtime error. 475 // 476 // - When unmarshaling, the syntactic structure of the JSON input 477 // is fully validated before performing the semantic unmarshaling 478 // of the JSON data into the Go value. Practically speaking, 479 // this means that JSON input with syntactic errors do not result 480 // in any mutations of the target Go value. In contrast, the v2 semantic 481 // is to perform a streaming decode and gradually unmarshal the JSON input 482 // into the target Go value, which means that the Go value may be 483 // partially mutated when a syntactic error is encountered. 484 // 485 // - When unmarshaling, a semantic error does not immediately terminate the 486 // unmarshal procedure, but rather evaluation continues. 487 // When unmarshal returns, only the first semantic error is reported. 488 // In contrast, the v2 semantic is to terminate unmarshal the moment 489 // an error is encountered. 490 // 491 // This affects either marshaling or unmarshaling. 492 // The v1 default is true. 493 func ReportErrorsWithLegacySemantics(v bool) Options { 494 if v { 495 return jsonflags.ReportErrorsWithLegacySemantics | 1 496 } else { 497 return jsonflags.ReportErrorsWithLegacySemantics | 0 498 } 499 } 500 501 // StringifyWithLegacySemantics specifies that the `string` tag option 502 // may stringify bools and string values. It only takes effect on fields 503 // where the top-level type is a bool, string, numeric kind, or a pointer to 504 // such a kind. 505 // 506 // When marshaling, such Go values are serialized as their usual JSON 507 // representation, but quoted within a JSON string. 508 // When unmarshaling, such Go values must be deserialized from a JSON string 509 // containing their usual JSON representation or Go number representation for 510 // that numeric kind. 511 // Note that the Go number grammar is a superset of the JSON number grammar. 512 // A JSON null quoted in a JSON string is a valid substitute for JSON null 513 // while unmarshaling into a Go value that `string` takes effect on. 514 // 515 // This affects either marshaling or unmarshaling. 516 // The v1 default is true. 517 func StringifyWithLegacySemantics(v bool) Options { 518 if v { 519 return jsonflags.StringifyWithLegacySemantics | 1 520 } else { 521 return jsonflags.StringifyWithLegacySemantics | 0 522 } 523 } 524 525 // UnmarshalArrayFromAnyLength specifies that Go arrays can be unmarshaled 526 // from input JSON arrays of any length. If the JSON array is too short, 527 // then the remaining Go array elements are zeroed. If the JSON array 528 // is too long, then the excess JSON array elements are skipped over. 529 // 530 // This only affects unmarshaling and is ignored when marshaling. 531 // The v1 default is true. 532 func UnmarshalArrayFromAnyLength(v bool) Options { 533 if v { 534 return jsonflags.UnmarshalArrayFromAnyLength | 1 535 } else { 536 return jsonflags.UnmarshalArrayFromAnyLength | 0 537 } 538 } 539 540 // unmarshalAnyWithRawNumber specifies that unmarshaling a JSON number into 541 // an empty Go interface should use the Number type instead of a float64. 542 func unmarshalAnyWithRawNumber(v bool) Options { 543 if v { 544 return jsonflags.UnmarshalAnyWithRawNumber | 1 545 } else { 546 return jsonflags.UnmarshalAnyWithRawNumber | 0 547 } 548 } 549