1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
//! # Serde JSON
//!
//! JSON is a ubiquitous open-standard format that uses human-readable text to
//! transmit data objects consisting of key-value pairs.
//!
//! ```json
//! {
//!     "name": "John Doe",
//!     "age": 43,
//!     "address": {
//!         "street": "10 Downing Street",
//!         "city": "London"
//!     },
//!     "phones": [
//!         "+44 1234567",
//!         "+44 2345678"
//!     ]
//! }
//! ```
//!
//! There are three common ways that you might find yourself needing to work
//! with JSON data in Rust.
//!
//!  - **As text data.** An unprocessed string of JSON data that you receive on
//!    an HTTP endpoint, read from a file, or prepare to send to a remote
//!    server.
//!  - **As an untyped or loosely typed representation.** Maybe you want to
//!    check that some JSON data is valid before passing it on, but without
//!    knowing the structure of what it contains. Or you want to do very basic
//!    manipulations like insert a key in a particular spot.
//!  - **As a strongly typed Rust data structure.** When you expect all or most
//!    of your data to conform to a particular structure and want to get real
//!    work done without JSON's loosey-goosey nature tripping you up.
//!
//! Serde JSON provides efficient, flexible, safe ways of converting data
//! between each of these representations.
//!
//! # Operating on untyped JSON values
//!
//! Any valid JSON data can be manipulated in the following recursive enum
//! representation. This data structure is [`serde_json::Value`][value].
//!
//! ```
//! # use serde_json::{Number, Map};
//! #
//! # #[allow(dead_code)]
//! enum Value {
//!     Null,
//!     Bool(bool),
//!     Number(Number),
//!     String(String),
//!     Array(Vec<Value>),
//!     Object(Map<String, Value>),
//! }
//! ```
//!
//! A string of JSON data can be parsed into a `serde_json::Value` by the
//! [`serde_json::from_str`][from_str] function. There is also
//! [`from_slice`][from_slice] for parsing from a byte slice &[u8] and
//! [`from_reader`][from_reader] for parsing from any `io::Read` like a File or
//! a TCP stream.
//!
//! ```
//! use serde_json::{Result, Value};
//!
//! fn untyped_example() -> Result<()> {
//!     // Some JSON input data as a &str. Maybe this comes from the user.
//!     let data = r#"
//!         {
//!             "name": "John Doe",
//!             "age": 43,
//!             "phones": [
//!                 "+44 1234567",
//!                 "+44 2345678"
//!             ]
//!         }"#;
//!
//!     // Parse the string of data into serde_json::Value.
//!     let v: Value = serde_json::from_str(data)?;
//!
//!     // Access parts of the data by indexing with square brackets.
//!     println!("Please call {} at the number {}", v["name"], v["phones"][0]);
//!
//!     Ok(())
//! }
//! #
//! # fn main() {
//! #     untyped_example().unwrap();
//! # }
//! ```
//!
//! The result of square bracket indexing like `v["name"]` is a borrow of the
//! data at that index, so the type is `&Value`. A JSON map can be indexed with
//! string keys, while a JSON array can be indexed with integer keys. If the
//! type of the data is not right for the type with which it is being indexed,
//! or if a map does not contain the key being indexed, or if the index into a
//! vector is out of bounds, the returned element is `Value::Null`.
//!
//! When a `Value` is printed, it is printed as a JSON string. So in the code
//! above, the output looks like `Please call "John Doe" at the number "+44
//! 1234567"`. The quotation marks appear because `v["name"]` is a `&Value`
//! containing a JSON string and its JSON representation is `"John Doe"`.
//! Printing as a plain string without quotation marks involves converting from
//! a JSON string to a Rust string with [`as_str()`] or avoiding the use of
//! `Value` as described in the following section.
//!
//! [`as_str()`]: https://docs.serde.rs/serde_json/enum.Value.html#method.as_str
//!
//! The `Value` representation is sufficient for very basic tasks but can be
//! tedious to work with for anything more significant. Error handling is
//! verbose to implement correctly, for example imagine trying to detect the
//! presence of unrecognized fields in the input data. The compiler is powerless
//! to help you when you make a mistake, for example imagine typoing `v["name"]`
//! as `v["nmae"]` in one of the dozens of places it is used in your code.
//!
//! # Parsing JSON as strongly typed data structures
//!
//! Serde provides a powerful way of mapping JSON data into Rust data structures
//! largely automatically.
//!
//! ```
//! use serde::{Deserialize, Serialize};
//! use serde_json::Result;
//!
//! #[derive(Serialize, Deserialize)]
//! struct Person {
//!     name: String,
//!     age: u8,
//!     phones: Vec<String>,
//! }
//!
//! fn typed_example() -> Result<()> {
//!     // Some JSON input data as a &str. Maybe this comes from the user.
//!     let data = r#"
//!         {
//!             "name": "John Doe",
//!             "age": 43,
//!             "phones": [
//!                 "+44 1234567",
//!                 "+44 2345678"
//!             ]
//!         }"#;
//!
//!     // Parse the string of data into a Person object. This is exactly the
//!     // same function as the one that produced serde_json::Value above, but
//!     // now we are asking it for a Person as output.
//!     let p: Person = serde_json::from_str(data)?;
//!
//!     // Do things just like with any other Rust data structure.
//!     println!("Please call {} at the number {}", p.name, p.phones[0]);
//!
//!     Ok(())
//! }
//! #
//! # fn main() {
//! #     typed_example().unwrap();
//! # }
//! ```
//!
//! This is the same `serde_json::from_str` function as before, but this time we
//! assign the return value to a variable of type `Person` so Serde will
//! automatically interpret the input data as a `Person` and produce informative
//! error messages if the layout does not conform to what a `Person` is expected
//! to look like.
//!
//! Any type that implements Serde's `Deserialize` trait can be deserialized
//! this way. This includes built-in Rust standard library types like `Vec<T>`
//! and `HashMap<K, V>`, as well as any structs or enums annotated with
//! `#[derive(Deserialize)]`.
//!
//! Once we have `p` of type `Person`, our IDE and the Rust compiler can help us
//! use it correctly like they do for any other Rust code. The IDE can
//! autocomplete field names to prevent typos, which was impossible in the
//! `serde_json::Value` representation. And the Rust compiler can check that
//! when we write `p.phones[0]`, then `p.phones` is guaranteed to be a
//! `Vec<String>` so indexing into it makes sense and produces a `String`.
//!
//! # Constructing JSON values
//!
//! Serde JSON provides a [`json!` macro][macro] to build `serde_json::Value`
//! objects with very natural JSON syntax.
//!
//! ```
//! use serde_json::json;
//!
//! fn main() {
//!     // The type of `john` is `serde_json::Value`
//!     let john = json!({
//!         "name": "John Doe",
//!         "age": 43,
//!         "phones": [
//!             "+44 1234567",
//!             "+44 2345678"
//!         ]
//!     });
//!
//!     println!("first phone number: {}", john["phones"][0]);
//!
//!     // Convert to a string of JSON and print it out
//!     println!("{}", john.to_string());
//! }
//! ```
//!
//! The `Value::to_string()` function converts a `serde_json::Value` into a
//! `String` of JSON text.
//!
//! One neat thing about the `json!` macro is that variables and expressions can
//! be interpolated directly into the JSON value as you are building it. Serde
//! will check at compile time that the value you are interpolating is able to
//! be represented as JSON.
//!
//! ```
//! # use serde_json::json;
//! #
//! # fn random_phone() -> u16 { 0 }
//! #
//! let full_name = "John Doe";
//! let age_last_year = 42;
//!
//! // The type of `john` is `serde_json::Value`
//! let john = json!({
//!     "name": full_name,
//!     "age": age_last_year + 1,
//!     "phones": [
//!         format!("+44 {}", random_phone())
//!     ]
//! });
//! ```
//!
//! This is amazingly convenient but we have the problem we had before with
//! `Value` which is that the IDE and Rust compiler cannot help us if we get it
//! wrong. Serde JSON provides a better way of serializing strongly-typed data
//! structures into JSON text.
//!
//! # Creating JSON by serializing data structures
//!
//! A data structure can be converted to a JSON string by
//! [`serde_json::to_string`][to_string]. There is also
//! [`serde_json::to_vec`][to_vec] which serializes to a `Vec<u8>` and
//! [`serde_json::to_writer`][to_writer] which serializes to any `io::Write`
//! such as a File or a TCP stream.
//!
//! ```
//! use serde::{Deserialize, Serialize};
//! use serde_json::Result;
//!
//! #[derive(Serialize, Deserialize)]
//! struct Address {
//!     street: String,
//!     city: String,
//! }
//!
//! fn print_an_address() -> Result<()> {
//!     // Some data structure.
//!     let address = Address {
//!         street: "10 Downing Street".to_owned(),
//!         city: "London".to_owned(),
//!     };
//!
//!     // Serialize it to a JSON string.
//!     let j = serde_json::to_string(&address)?;
//!
//!     // Print, write to a file, or send to an HTTP server.
//!     println!("{}", j);
//!
//!     Ok(())
//! }
//! #
//! # fn main() {
//! #     print_an_address().unwrap();
//! # }
//! ```
//!
//! Any type that implements Serde's `Serialize` trait can be serialized this
//! way. This includes built-in Rust standard library types like `Vec<T>` and
//! `HashMap<K, V>`, as well as any structs or enums annotated with
//! `#[derive(Serialize)]`.
//!
//! # No-std support
//!
//! As long as there is a memory allocator, it is possible to use serde_json
//! without the rest of the Rust standard library. This is supported on Rust
//! 1.36+. Disable the default "std" feature and enable the "alloc" feature:
//!
//! ```toml
//! [dependencies]
//! serde_json = { version = "1.0", default-features = false, features = ["alloc"] }
//! ```
//!
//! For JSON support in Serde without a memory allocator, please see the
//! [`serde-json-core`] crate.
//!
//! [value]: https://docs.serde.rs/serde_json/value/enum.Value.html
//! [from_str]: https://docs.serde.rs/serde_json/de/fn.from_str.html
//! [from_slice]: https://docs.serde.rs/serde_json/de/fn.from_slice.html
//! [from_reader]: https://docs.serde.rs/serde_json/de/fn.from_reader.html
//! [to_string]: https://docs.serde.rs/serde_json/ser/fn.to_string.html
//! [to_vec]: https://docs.serde.rs/serde_json/ser/fn.to_vec.html
//! [to_writer]: https://docs.serde.rs/serde_json/ser/fn.to_writer.html
//! [macro]: https://docs.serde.rs/serde_json/macro.json.html
//! [`serde-json-core`]: https://japaric.github.io/serde-json-core/serde_json_core/

#![doc(html_root_url = "https://docs.rs/serde_json/1.0.60")]
#![deny(clippy::all, clippy::pedantic)]
// Ignored clippy lints
#![allow(
    clippy::comparison_chain,
    clippy::deprecated_cfg_attr,
    clippy::doc_markdown,
    clippy::excessive_precision,
    clippy::float_cmp,
    clippy::manual_range_contains,
    clippy::match_like_matches_macro,
    clippy::match_single_binding,
    clippy::needless_doctest_main,
    clippy::transmute_ptr_to_ptr,
    clippy::unnecessary_wraps,
    // clippy bug: https://github.com/rust-lang/rust-clippy/issues/5704
    clippy::unnested_or_patterns,
)]
// Ignored clippy_pedantic lints
#![allow(
    // Deserializer::from_str, into_iter
    clippy::should_implement_trait,
    // integer and float ser/de requires these sorts of casts
    clippy::cast_possible_truncation,
    clippy::cast_possible_wrap,
    clippy::cast_precision_loss,
    clippy::cast_sign_loss,
    // correctly used
    clippy::enum_glob_use,
    clippy::if_not_else,
    clippy::integer_division,
    clippy::map_err_ignore,
    clippy::match_same_arms,
    clippy::similar_names,
    clippy::unused_self,
    clippy::wildcard_imports,
    // things are often more readable this way
    clippy::cast_lossless,
    clippy::module_name_repetitions,
    clippy::shadow_unrelated,
    clippy::single_match_else,
    clippy::too_many_lines,
    clippy::unreadable_literal,
    clippy::unseparated_literal_suffix,
    clippy::use_self,
    clippy::zero_prefixed_literal,
    // we support older compilers
    clippy::checked_conversions,
    clippy::mem_replace_with_default,
    // noisy
    clippy::missing_errors_doc,
    clippy::must_use_candidate,
)]
#![allow(non_upper_case_globals)]
#![deny(missing_docs)]
#![cfg_attr(not(feature = "std"), no_std)]

#![cfg_attr(all(feature = "mesalock_sgx", not(target_env = "sgx")), no_std)]
#![cfg_attr(all(target_env = "sgx", target_vendor = "mesalock"), feature(rustc_private))]

#[cfg(all(feature = "mesalock_sgx", not(target_env = "sgx")))]
#[macro_use]
extern crate sgx_tstd as std;

////////////////////////////////////////////////////////////////////////////////

#[cfg(not(feature = "std"))]
extern crate alloc;

/// A facade around all the types we need from the `std`, `core`, and `alloc`
/// crates. This avoids elaborate import wrangling having to happen in every
/// module.
mod lib {
    mod core {
        #[cfg(not(feature = "std"))]
        pub use core::*;
        #[cfg(feature = "std")]
        pub use std::*;
    }

    pub use self::core::cell::{Cell, RefCell};
    pub use self::core::clone::{self, Clone};
    pub use self::core::convert::{self, From, Into};
    pub use self::core::default::{self, Default};
    pub use self::core::fmt::{self, Debug, Display};
    pub use self::core::hash::{self, Hash};
    pub use self::core::iter::FusedIterator;
    pub use self::core::marker::{self, PhantomData};
    pub use self::core::ops::{Bound, RangeBounds};
    pub use self::core::result::{self, Result};
    pub use self::core::{borrow, char, cmp, iter, mem, num, ops, slice, str};

    #[cfg(not(feature = "std"))]
    pub use alloc::borrow::{Cow, ToOwned};
    #[cfg(feature = "std")]
    pub use std::borrow::{Cow, ToOwned};

    #[cfg(not(feature = "std"))]
    pub use alloc::string::{String, ToString};
    #[cfg(feature = "std")]
    pub use std::string::{String, ToString};

    #[cfg(not(feature = "std"))]
    pub use alloc::vec::{self, Vec};
    #[cfg(feature = "std")]
    pub use std::vec::{self, Vec};

    #[cfg(not(feature = "std"))]
    pub use alloc::boxed::Box;
    #[cfg(feature = "std")]
    pub use std::boxed::Box;

    #[cfg(not(feature = "std"))]
    pub use alloc::collections::{btree_map, BTreeMap};
    #[cfg(feature = "std")]
    pub use std::collections::{btree_map, BTreeMap};

    #[cfg(feature = "std")]
    pub use std::error;
}

////////////////////////////////////////////////////////////////////////////////

#[cfg(feature = "std")]
#[doc(inline)]
pub use crate::de::from_reader;
#[doc(inline)]
pub use crate::de::{from_slice, from_str, Deserializer, StreamDeserializer};
#[doc(inline)]
pub use crate::error::{Error, Result};
#[doc(inline)]
pub use crate::ser::{to_string, to_string_pretty, to_vec, to_vec_pretty};
#[cfg(feature = "std")]
#[doc(inline)]
pub use crate::ser::{to_writer, to_writer_pretty, Serializer};
#[doc(inline)]
pub use crate::value::{from_value, to_value, Map, Number, Value};

// We only use our own error type; no need for From conversions provided by the
// standard library's try! macro. This reduces lines of LLVM IR by 4%.
macro_rules! tri {
    ($e:expr) => {
        match $e {
            crate::lib::Result::Ok(val) => val,
            crate::lib::Result::Err(err) => return crate::lib::Result::Err(err),
        }
    };
    ($e:expr,) => {
        tri!($e)
    };
}

#[macro_use]
mod macros;

pub mod de;
pub mod error;
pub mod map;
#[cfg(feature = "std")]
pub mod ser;
#[cfg(not(feature = "std"))]
mod ser;
pub mod value;

mod features_check;

mod io;
#[cfg(feature = "std")]
mod iter;
#[cfg(feature = "float_roundtrip")]
mod lexical;
mod number;
mod read;

#[cfg(feature = "raw_value")]
mod raw;