1 | //! Building blocks for deserializing basic values using the `IntoDeserializer` |
2 | //! trait. |
3 | //! |
4 | //! ```edition2021 |
5 | //! use serde::de::{value, Deserialize, IntoDeserializer}; |
6 | //! use serde_derive::Deserialize; |
7 | //! use std::str::FromStr; |
8 | //! |
9 | //! #[derive(Deserialize)] |
10 | //! enum Setting { |
11 | //! On, |
12 | //! Off, |
13 | //! } |
14 | //! |
15 | //! impl FromStr for Setting { |
16 | //! type Err = value::Error; |
17 | //! |
18 | //! fn from_str(s: &str) -> Result<Self, Self::Err> { |
19 | //! Self::deserialize(s.into_deserializer()) |
20 | //! } |
21 | //! } |
22 | //! ``` |
23 | |
24 | use crate::lib::*; |
25 | |
26 | use self::private::{First, Second}; |
27 | use crate::de::{self, size_hint, Deserializer, Expected, IntoDeserializer, SeqAccess, Visitor}; |
28 | use crate::ser; |
29 | |
30 | //////////////////////////////////////////////////////////////////////////////// |
31 | |
32 | // For structs that contain a PhantomData. We do not want the trait |
33 | // bound `E: Clone` inferred by derive(Clone). |
34 | macro_rules! impl_copy_clone { |
35 | ($ty:ident $(<$lifetime:tt>)*) => { |
36 | impl<$($lifetime,)* E> Copy for $ty<$($lifetime,)* E> {} |
37 | |
38 | impl<$($lifetime,)* E> Clone for $ty<$($lifetime,)* E> { |
39 | fn clone(&self) -> Self { |
40 | *self |
41 | } |
42 | } |
43 | }; |
44 | } |
45 | |
46 | //////////////////////////////////////////////////////////////////////////////// |
47 | |
48 | /// A minimal representation of all possible errors that can occur using the |
49 | /// `IntoDeserializer` trait. |
50 | #[derive(Clone, PartialEq)] |
51 | pub struct Error { |
52 | err: ErrorImpl, |
53 | } |
54 | |
55 | #[cfg (any(feature = "std" , feature = "alloc" ))] |
56 | type ErrorImpl = Box<str>; |
57 | #[cfg (not(any(feature = "std" , feature = "alloc" )))] |
58 | type ErrorImpl = (); |
59 | |
60 | impl de::Error for Error { |
61 | #[cfg (any(feature = "std" , feature = "alloc" ))] |
62 | #[cold ] |
63 | fn custom<T>(msg: T) -> Self |
64 | where |
65 | T: Display, |
66 | { |
67 | Error { |
68 | err: msg.to_string().into_boxed_str(), |
69 | } |
70 | } |
71 | |
72 | #[cfg (not(any(feature = "std" , feature = "alloc" )))] |
73 | #[cold ] |
74 | fn custom<T>(msg: T) -> Self |
75 | where |
76 | T: Display, |
77 | { |
78 | let _ = msg; |
79 | Error { err: () } |
80 | } |
81 | } |
82 | |
83 | impl ser::Error for Error { |
84 | #[cold ] |
85 | fn custom<T>(msg: T) -> Self |
86 | where |
87 | T: Display, |
88 | { |
89 | de::Error::custom(msg) |
90 | } |
91 | } |
92 | |
93 | impl Display for Error { |
94 | #[cfg (any(feature = "std" , feature = "alloc" ))] |
95 | fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result { |
96 | formatter.write_str(&self.err) |
97 | } |
98 | |
99 | #[cfg (not(any(feature = "std" , feature = "alloc" )))] |
100 | fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result { |
101 | formatter.write_str("Serde deserialization error" ) |
102 | } |
103 | } |
104 | |
105 | impl Debug for Error { |
106 | fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result { |
107 | let mut debug = formatter.debug_tuple("Error" ); |
108 | #[cfg (any(feature = "std" , feature = "alloc" ))] |
109 | debug.field(&self.err); |
110 | debug.finish() |
111 | } |
112 | } |
113 | |
114 | #[cfg (feature = "std" )] |
115 | #[cfg_attr (doc_cfg, doc(cfg(feature = "std" )))] |
116 | impl error::Error for Error { |
117 | fn description(&self) -> &str { |
118 | &self.err |
119 | } |
120 | } |
121 | |
122 | //////////////////////////////////////////////////////////////////////////////// |
123 | |
124 | impl<'de, E> IntoDeserializer<'de, E> for () |
125 | where |
126 | E: de::Error, |
127 | { |
128 | type Deserializer = UnitDeserializer<E>; |
129 | |
130 | fn into_deserializer(self) -> UnitDeserializer<E> { |
131 | UnitDeserializer::new() |
132 | } |
133 | } |
134 | |
135 | /// A deserializer holding a `()`. |
136 | pub struct UnitDeserializer<E> { |
137 | marker: PhantomData<E>, |
138 | } |
139 | |
140 | impl_copy_clone!(UnitDeserializer); |
141 | |
142 | impl<E> UnitDeserializer<E> { |
143 | #[allow (missing_docs)] |
144 | pub fn new() -> Self { |
145 | UnitDeserializer { |
146 | marker: PhantomData, |
147 | } |
148 | } |
149 | } |
150 | |
151 | impl<'de, E> de::Deserializer<'de> for UnitDeserializer<E> |
152 | where |
153 | E: de::Error, |
154 | { |
155 | type Error = E; |
156 | |
157 | forward_to_deserialize_any! { |
158 | bool i8 i16 i32 i64 i128 u8 u16 u32 u64 u128 f32 f64 char str string |
159 | bytes byte_buf unit unit_struct newtype_struct seq tuple tuple_struct |
160 | map struct enum identifier ignored_any |
161 | } |
162 | |
163 | fn deserialize_any<V>(self, visitor: V) -> Result<V::Value, Self::Error> |
164 | where |
165 | V: de::Visitor<'de>, |
166 | { |
167 | visitor.visit_unit() |
168 | } |
169 | |
170 | fn deserialize_option<V>(self, visitor: V) -> Result<V::Value, Self::Error> |
171 | where |
172 | V: de::Visitor<'de>, |
173 | { |
174 | visitor.visit_none() |
175 | } |
176 | } |
177 | |
178 | impl<E> Debug for UnitDeserializer<E> { |
179 | fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result { |
180 | formatter.debug_struct("UnitDeserializer" ).finish() |
181 | } |
182 | } |
183 | |
184 | //////////////////////////////////////////////////////////////////////////////// |
185 | |
186 | /// A deserializer that cannot be instantiated. |
187 | #[cfg (feature = "unstable" )] |
188 | #[cfg_attr (doc_cfg, doc(cfg(feature = "unstable" )))] |
189 | pub struct NeverDeserializer<E> { |
190 | never: !, |
191 | marker: PhantomData<E>, |
192 | } |
193 | |
194 | #[cfg (feature = "unstable" )] |
195 | #[cfg_attr (doc_cfg, doc(cfg(feature = "unstable" )))] |
196 | impl<'de, E> IntoDeserializer<'de, E> for ! |
197 | where |
198 | E: de::Error, |
199 | { |
200 | type Deserializer = NeverDeserializer<E>; |
201 | |
202 | fn into_deserializer(self) -> Self::Deserializer { |
203 | self |
204 | } |
205 | } |
206 | |
207 | #[cfg (feature = "unstable" )] |
208 | impl<'de, E> de::Deserializer<'de> for NeverDeserializer<E> |
209 | where |
210 | E: de::Error, |
211 | { |
212 | type Error = E; |
213 | |
214 | fn deserialize_any<V>(self, _visitor: V) -> Result<V::Value, Self::Error> |
215 | where |
216 | V: de::Visitor<'de>, |
217 | { |
218 | self.never |
219 | } |
220 | |
221 | forward_to_deserialize_any! { |
222 | bool i8 i16 i32 i64 i128 u8 u16 u32 u64 u128 f32 f64 char str string |
223 | bytes byte_buf option unit unit_struct newtype_struct seq tuple |
224 | tuple_struct map struct enum identifier ignored_any |
225 | } |
226 | } |
227 | |
228 | //////////////////////////////////////////////////////////////////////////////// |
229 | |
230 | macro_rules! primitive_deserializer { |
231 | ($ty:ty, $doc:tt, $name:ident, $method:ident $($cast:tt)*) => { |
232 | #[doc = "A deserializer holding" ] |
233 | #[doc = $doc] |
234 | pub struct $name<E> { |
235 | value: $ty, |
236 | marker: PhantomData<E> |
237 | } |
238 | |
239 | impl_copy_clone!($name); |
240 | |
241 | impl<'de, E> IntoDeserializer<'de, E> for $ty |
242 | where |
243 | E: de::Error, |
244 | { |
245 | type Deserializer = $name<E>; |
246 | |
247 | fn into_deserializer(self) -> $name<E> { |
248 | $name::new(self) |
249 | } |
250 | } |
251 | |
252 | impl<E> $name<E> { |
253 | #[allow(missing_docs)] |
254 | pub fn new(value: $ty) -> Self { |
255 | $name { |
256 | value, |
257 | marker: PhantomData, |
258 | } |
259 | } |
260 | } |
261 | |
262 | impl<'de, E> de::Deserializer<'de> for $name<E> |
263 | where |
264 | E: de::Error, |
265 | { |
266 | type Error = E; |
267 | |
268 | forward_to_deserialize_any! { |
269 | bool i8 i16 i32 i64 i128 u8 u16 u32 u64 u128 f32 f64 char str |
270 | string bytes byte_buf option unit unit_struct newtype_struct seq |
271 | tuple tuple_struct map struct enum identifier ignored_any |
272 | } |
273 | |
274 | fn deserialize_any<V>(self, visitor: V) -> Result<V::Value, Self::Error> |
275 | where |
276 | V: de::Visitor<'de>, |
277 | { |
278 | visitor.$method(self.value $($cast)*) |
279 | } |
280 | } |
281 | |
282 | impl<E> Debug for $name<E> { |
283 | fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result { |
284 | formatter |
285 | .debug_struct(stringify!($name)) |
286 | .field("value" , &self.value) |
287 | .finish() |
288 | } |
289 | } |
290 | } |
291 | } |
292 | |
293 | primitive_deserializer!(bool, "a `bool`." , BoolDeserializer, visit_bool); |
294 | primitive_deserializer!(i8, "an `i8`." , I8Deserializer, visit_i8); |
295 | primitive_deserializer!(i16, "an `i16`." , I16Deserializer, visit_i16); |
296 | primitive_deserializer!(i32, "an `i32`." , I32Deserializer, visit_i32); |
297 | primitive_deserializer!(i64, "an `i64`." , I64Deserializer, visit_i64); |
298 | primitive_deserializer!(i128, "an `i128`." , I128Deserializer, visit_i128); |
299 | primitive_deserializer!(isize, "an `isize`." , IsizeDeserializer, visit_i64 as i64); |
300 | primitive_deserializer!(u8, "a `u8`." , U8Deserializer, visit_u8); |
301 | primitive_deserializer!(u16, "a `u16`." , U16Deserializer, visit_u16); |
302 | primitive_deserializer!(u64, "a `u64`." , U64Deserializer, visit_u64); |
303 | primitive_deserializer!(u128, "a `u128`." , U128Deserializer, visit_u128); |
304 | primitive_deserializer!(usize, "a `usize`." , UsizeDeserializer, visit_u64 as u64); |
305 | primitive_deserializer!(f32, "an `f32`." , F32Deserializer, visit_f32); |
306 | primitive_deserializer!(f64, "an `f64`." , F64Deserializer, visit_f64); |
307 | primitive_deserializer!(char, "a `char`." , CharDeserializer, visit_char); |
308 | |
309 | /// A deserializer holding a `u32`. |
310 | pub struct U32Deserializer<E> { |
311 | value: u32, |
312 | marker: PhantomData<E>, |
313 | } |
314 | |
315 | impl_copy_clone!(U32Deserializer); |
316 | |
317 | impl<'de, E> IntoDeserializer<'de, E> for u32 |
318 | where |
319 | E: de::Error, |
320 | { |
321 | type Deserializer = U32Deserializer<E>; |
322 | |
323 | fn into_deserializer(self) -> U32Deserializer<E> { |
324 | U32Deserializer::new(self) |
325 | } |
326 | } |
327 | |
328 | impl<E> U32Deserializer<E> { |
329 | #[allow (missing_docs)] |
330 | pub fn new(value: u32) -> Self { |
331 | U32Deserializer { |
332 | value, |
333 | marker: PhantomData, |
334 | } |
335 | } |
336 | } |
337 | |
338 | impl<'de, E> de::Deserializer<'de> for U32Deserializer<E> |
339 | where |
340 | E: de::Error, |
341 | { |
342 | type Error = E; |
343 | |
344 | forward_to_deserialize_any! { |
345 | bool i8 i16 i32 i64 i128 u8 u16 u32 u64 u128 f32 f64 char str string |
346 | bytes byte_buf option unit unit_struct newtype_struct seq tuple |
347 | tuple_struct map struct identifier ignored_any |
348 | } |
349 | |
350 | fn deserialize_any<V>(self, visitor: V) -> Result<V::Value, Self::Error> |
351 | where |
352 | V: de::Visitor<'de>, |
353 | { |
354 | visitor.visit_u32(self.value) |
355 | } |
356 | |
357 | fn deserialize_enum<V>( |
358 | self, |
359 | name: &str, |
360 | variants: &'static [&'static str], |
361 | visitor: V, |
362 | ) -> Result<V::Value, Self::Error> |
363 | where |
364 | V: de::Visitor<'de>, |
365 | { |
366 | let _ = name; |
367 | let _ = variants; |
368 | visitor.visit_enum(self) |
369 | } |
370 | } |
371 | |
372 | impl<'de, E> de::EnumAccess<'de> for U32Deserializer<E> |
373 | where |
374 | E: de::Error, |
375 | { |
376 | type Error = E; |
377 | type Variant = private::UnitOnly<E>; |
378 | |
379 | fn variant_seed<T>(self, seed: T) -> Result<(T::Value, Self::Variant), Self::Error> |
380 | where |
381 | T: de::DeserializeSeed<'de>, |
382 | { |
383 | seed.deserialize(self).map(private::unit_only) |
384 | } |
385 | } |
386 | |
387 | impl<E> Debug for U32Deserializer<E> { |
388 | fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result { |
389 | formatter |
390 | .debug_struct("U32Deserializer" ) |
391 | .field("value" , &self.value) |
392 | .finish() |
393 | } |
394 | } |
395 | |
396 | //////////////////////////////////////////////////////////////////////////////// |
397 | |
398 | /// A deserializer holding a `&str`. |
399 | pub struct StrDeserializer<'a, E> { |
400 | value: &'a str, |
401 | marker: PhantomData<E>, |
402 | } |
403 | |
404 | impl_copy_clone!(StrDeserializer<'de>); |
405 | |
406 | impl<'de, 'a, E> IntoDeserializer<'de, E> for &'a str |
407 | where |
408 | E: de::Error, |
409 | { |
410 | type Deserializer = StrDeserializer<'a, E>; |
411 | |
412 | fn into_deserializer(self) -> StrDeserializer<'a, E> { |
413 | StrDeserializer::new(self) |
414 | } |
415 | } |
416 | |
417 | impl<'a, E> StrDeserializer<'a, E> { |
418 | #[allow (missing_docs)] |
419 | pub fn new(value: &'a str) -> Self { |
420 | StrDeserializer { |
421 | value, |
422 | marker: PhantomData, |
423 | } |
424 | } |
425 | } |
426 | |
427 | impl<'de, 'a, E> de::Deserializer<'de> for StrDeserializer<'a, E> |
428 | where |
429 | E: de::Error, |
430 | { |
431 | type Error = E; |
432 | |
433 | fn deserialize_any<V>(self, visitor: V) -> Result<V::Value, Self::Error> |
434 | where |
435 | V: de::Visitor<'de>, |
436 | { |
437 | visitor.visit_str(self.value) |
438 | } |
439 | |
440 | fn deserialize_enum<V>( |
441 | self, |
442 | name: &str, |
443 | variants: &'static [&'static str], |
444 | visitor: V, |
445 | ) -> Result<V::Value, Self::Error> |
446 | where |
447 | V: de::Visitor<'de>, |
448 | { |
449 | let _ = name; |
450 | let _ = variants; |
451 | visitor.visit_enum(self) |
452 | } |
453 | |
454 | forward_to_deserialize_any! { |
455 | bool i8 i16 i32 i64 i128 u8 u16 u32 u64 u128 f32 f64 char str string |
456 | bytes byte_buf option unit unit_struct newtype_struct seq tuple |
457 | tuple_struct map struct identifier ignored_any |
458 | } |
459 | } |
460 | |
461 | impl<'de, 'a, E> de::EnumAccess<'de> for StrDeserializer<'a, E> |
462 | where |
463 | E: de::Error, |
464 | { |
465 | type Error = E; |
466 | type Variant = private::UnitOnly<E>; |
467 | |
468 | fn variant_seed<T>(self, seed: T) -> Result<(T::Value, Self::Variant), Self::Error> |
469 | where |
470 | T: de::DeserializeSeed<'de>, |
471 | { |
472 | seed.deserialize(self).map(private::unit_only) |
473 | } |
474 | } |
475 | |
476 | impl<'a, E> Debug for StrDeserializer<'a, E> { |
477 | fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result { |
478 | formatter |
479 | .debug_struct("StrDeserializer" ) |
480 | .field("value" , &self.value) |
481 | .finish() |
482 | } |
483 | } |
484 | |
485 | //////////////////////////////////////////////////////////////////////////////// |
486 | |
487 | /// A deserializer holding a `&str` with a lifetime tied to another |
488 | /// deserializer. |
489 | pub struct BorrowedStrDeserializer<'de, E> { |
490 | value: &'de str, |
491 | marker: PhantomData<E>, |
492 | } |
493 | |
494 | impl_copy_clone!(BorrowedStrDeserializer<'de>); |
495 | |
496 | impl<'de, E> BorrowedStrDeserializer<'de, E> { |
497 | /// Create a new borrowed deserializer from the given string. |
498 | pub fn new(value: &'de str) -> BorrowedStrDeserializer<'de, E> { |
499 | BorrowedStrDeserializer { |
500 | value, |
501 | marker: PhantomData, |
502 | } |
503 | } |
504 | } |
505 | |
506 | impl<'de, E> de::Deserializer<'de> for BorrowedStrDeserializer<'de, E> |
507 | where |
508 | E: de::Error, |
509 | { |
510 | type Error = E; |
511 | |
512 | fn deserialize_any<V>(self, visitor: V) -> Result<V::Value, Self::Error> |
513 | where |
514 | V: de::Visitor<'de>, |
515 | { |
516 | visitor.visit_borrowed_str(self.value) |
517 | } |
518 | |
519 | fn deserialize_enum<V>( |
520 | self, |
521 | name: &str, |
522 | variants: &'static [&'static str], |
523 | visitor: V, |
524 | ) -> Result<V::Value, Self::Error> |
525 | where |
526 | V: de::Visitor<'de>, |
527 | { |
528 | let _ = name; |
529 | let _ = variants; |
530 | visitor.visit_enum(self) |
531 | } |
532 | |
533 | forward_to_deserialize_any! { |
534 | bool i8 i16 i32 i64 i128 u8 u16 u32 u64 u128 f32 f64 char str string |
535 | bytes byte_buf option unit unit_struct newtype_struct seq tuple |
536 | tuple_struct map struct identifier ignored_any |
537 | } |
538 | } |
539 | |
540 | impl<'de, E> de::EnumAccess<'de> for BorrowedStrDeserializer<'de, E> |
541 | where |
542 | E: de::Error, |
543 | { |
544 | type Error = E; |
545 | type Variant = private::UnitOnly<E>; |
546 | |
547 | fn variant_seed<T>(self, seed: T) -> Result<(T::Value, Self::Variant), Self::Error> |
548 | where |
549 | T: de::DeserializeSeed<'de>, |
550 | { |
551 | seed.deserialize(self).map(private::unit_only) |
552 | } |
553 | } |
554 | |
555 | impl<'de, E> Debug for BorrowedStrDeserializer<'de, E> { |
556 | fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result { |
557 | formatter |
558 | .debug_struct("BorrowedStrDeserializer" ) |
559 | .field("value" , &self.value) |
560 | .finish() |
561 | } |
562 | } |
563 | |
564 | //////////////////////////////////////////////////////////////////////////////// |
565 | |
566 | /// A deserializer holding a `String`. |
567 | #[cfg (any(feature = "std" , feature = "alloc" ))] |
568 | #[cfg_attr (doc_cfg, doc(cfg(any(feature = "std" , feature = "alloc" ))))] |
569 | pub struct StringDeserializer<E> { |
570 | value: String, |
571 | marker: PhantomData<E>, |
572 | } |
573 | |
574 | #[cfg (any(feature = "std" , feature = "alloc" ))] |
575 | impl<E> Clone for StringDeserializer<E> { |
576 | fn clone(&self) -> Self { |
577 | StringDeserializer { |
578 | value: self.value.clone(), |
579 | marker: PhantomData, |
580 | } |
581 | } |
582 | } |
583 | |
584 | #[cfg (any(feature = "std" , feature = "alloc" ))] |
585 | #[cfg_attr (doc_cfg, doc(cfg(any(feature = "std" , feature = "alloc" ))))] |
586 | impl<'de, E> IntoDeserializer<'de, E> for String |
587 | where |
588 | E: de::Error, |
589 | { |
590 | type Deserializer = StringDeserializer<E>; |
591 | |
592 | fn into_deserializer(self) -> StringDeserializer<E> { |
593 | StringDeserializer::new(self) |
594 | } |
595 | } |
596 | |
597 | #[cfg (any(feature = "std" , feature = "alloc" ))] |
598 | impl<E> StringDeserializer<E> { |
599 | #[allow (missing_docs)] |
600 | pub fn new(value: String) -> Self { |
601 | StringDeserializer { |
602 | value, |
603 | marker: PhantomData, |
604 | } |
605 | } |
606 | } |
607 | |
608 | #[cfg (any(feature = "std" , feature = "alloc" ))] |
609 | impl<'de, E> de::Deserializer<'de> for StringDeserializer<E> |
610 | where |
611 | E: de::Error, |
612 | { |
613 | type Error = E; |
614 | |
615 | fn deserialize_any<V>(self, visitor: V) -> Result<V::Value, Self::Error> |
616 | where |
617 | V: de::Visitor<'de>, |
618 | { |
619 | visitor.visit_string(self.value) |
620 | } |
621 | |
622 | fn deserialize_enum<V>( |
623 | self, |
624 | name: &str, |
625 | variants: &'static [&'static str], |
626 | visitor: V, |
627 | ) -> Result<V::Value, Self::Error> |
628 | where |
629 | V: de::Visitor<'de>, |
630 | { |
631 | let _ = name; |
632 | let _ = variants; |
633 | visitor.visit_enum(self) |
634 | } |
635 | |
636 | forward_to_deserialize_any! { |
637 | bool i8 i16 i32 i64 i128 u8 u16 u32 u64 u128 f32 f64 char str string |
638 | bytes byte_buf option unit unit_struct newtype_struct seq tuple |
639 | tuple_struct map struct identifier ignored_any |
640 | } |
641 | } |
642 | |
643 | #[cfg (any(feature = "std" , feature = "alloc" ))] |
644 | impl<'de, E> de::EnumAccess<'de> for StringDeserializer<E> |
645 | where |
646 | E: de::Error, |
647 | { |
648 | type Error = E; |
649 | type Variant = private::UnitOnly<E>; |
650 | |
651 | fn variant_seed<T>(self, seed: T) -> Result<(T::Value, Self::Variant), Self::Error> |
652 | where |
653 | T: de::DeserializeSeed<'de>, |
654 | { |
655 | seed.deserialize(self).map(private::unit_only) |
656 | } |
657 | } |
658 | |
659 | #[cfg (any(feature = "std" , feature = "alloc" ))] |
660 | impl<E> Debug for StringDeserializer<E> { |
661 | fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result { |
662 | formatter |
663 | .debug_struct("StringDeserializer" ) |
664 | .field("value" , &self.value) |
665 | .finish() |
666 | } |
667 | } |
668 | |
669 | //////////////////////////////////////////////////////////////////////////////// |
670 | |
671 | /// A deserializer holding a `Cow<str>`. |
672 | #[cfg (any(feature = "std" , feature = "alloc" ))] |
673 | #[cfg_attr (doc_cfg, doc(cfg(any(feature = "std" , feature = "alloc" ))))] |
674 | pub struct CowStrDeserializer<'a, E> { |
675 | value: Cow<'a, str>, |
676 | marker: PhantomData<E>, |
677 | } |
678 | |
679 | #[cfg (any(feature = "std" , feature = "alloc" ))] |
680 | impl<'a, E> Clone for CowStrDeserializer<'a, E> { |
681 | fn clone(&self) -> Self { |
682 | CowStrDeserializer { |
683 | value: self.value.clone(), |
684 | marker: PhantomData, |
685 | } |
686 | } |
687 | } |
688 | |
689 | #[cfg (any(feature = "std" , feature = "alloc" ))] |
690 | #[cfg_attr (doc_cfg, doc(cfg(any(feature = "std" , feature = "alloc" ))))] |
691 | impl<'de, 'a, E> IntoDeserializer<'de, E> for Cow<'a, str> |
692 | where |
693 | E: de::Error, |
694 | { |
695 | type Deserializer = CowStrDeserializer<'a, E>; |
696 | |
697 | fn into_deserializer(self) -> CowStrDeserializer<'a, E> { |
698 | CowStrDeserializer::new(self) |
699 | } |
700 | } |
701 | |
702 | #[cfg (any(feature = "std" , feature = "alloc" ))] |
703 | impl<'a, E> CowStrDeserializer<'a, E> { |
704 | #[allow (missing_docs)] |
705 | pub fn new(value: Cow<'a, str>) -> Self { |
706 | CowStrDeserializer { |
707 | value, |
708 | marker: PhantomData, |
709 | } |
710 | } |
711 | } |
712 | |
713 | #[cfg (any(feature = "std" , feature = "alloc" ))] |
714 | impl<'de, 'a, E> de::Deserializer<'de> for CowStrDeserializer<'a, E> |
715 | where |
716 | E: de::Error, |
717 | { |
718 | type Error = E; |
719 | |
720 | fn deserialize_any<V>(self, visitor: V) -> Result<V::Value, Self::Error> |
721 | where |
722 | V: de::Visitor<'de>, |
723 | { |
724 | match self.value { |
725 | Cow::Borrowed(string) => visitor.visit_str(string), |
726 | Cow::Owned(string) => visitor.visit_string(string), |
727 | } |
728 | } |
729 | |
730 | fn deserialize_enum<V>( |
731 | self, |
732 | name: &str, |
733 | variants: &'static [&'static str], |
734 | visitor: V, |
735 | ) -> Result<V::Value, Self::Error> |
736 | where |
737 | V: de::Visitor<'de>, |
738 | { |
739 | let _ = name; |
740 | let _ = variants; |
741 | visitor.visit_enum(self) |
742 | } |
743 | |
744 | forward_to_deserialize_any! { |
745 | bool i8 i16 i32 i64 i128 u8 u16 u32 u64 u128 f32 f64 char str string |
746 | bytes byte_buf option unit unit_struct newtype_struct seq tuple |
747 | tuple_struct map struct identifier ignored_any |
748 | } |
749 | } |
750 | |
751 | #[cfg (any(feature = "std" , feature = "alloc" ))] |
752 | impl<'de, 'a, E> de::EnumAccess<'de> for CowStrDeserializer<'a, E> |
753 | where |
754 | E: de::Error, |
755 | { |
756 | type Error = E; |
757 | type Variant = private::UnitOnly<E>; |
758 | |
759 | fn variant_seed<T>(self, seed: T) -> Result<(T::Value, Self::Variant), Self::Error> |
760 | where |
761 | T: de::DeserializeSeed<'de>, |
762 | { |
763 | seed.deserialize(self).map(private::unit_only) |
764 | } |
765 | } |
766 | |
767 | #[cfg (any(feature = "std" , feature = "alloc" ))] |
768 | impl<'a, E> Debug for CowStrDeserializer<'a, E> { |
769 | fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result { |
770 | formatter |
771 | .debug_struct("CowStrDeserializer" ) |
772 | .field("value" , &self.value) |
773 | .finish() |
774 | } |
775 | } |
776 | |
777 | //////////////////////////////////////////////////////////////////////////////// |
778 | |
779 | /// A deserializer holding a `&[u8]`. Always calls [`Visitor::visit_bytes`]. |
780 | pub struct BytesDeserializer<'a, E> { |
781 | value: &'a [u8], |
782 | marker: PhantomData<E>, |
783 | } |
784 | |
785 | impl<'a, E> BytesDeserializer<'a, E> { |
786 | /// Create a new deserializer from the given bytes. |
787 | pub fn new(value: &'a [u8]) -> Self { |
788 | BytesDeserializer { |
789 | value, |
790 | marker: PhantomData, |
791 | } |
792 | } |
793 | } |
794 | |
795 | impl_copy_clone!(BytesDeserializer<'a>); |
796 | |
797 | impl<'de, 'a, E> IntoDeserializer<'de, E> for &'a [u8] |
798 | where |
799 | E: de::Error, |
800 | { |
801 | type Deserializer = BytesDeserializer<'a, E>; |
802 | |
803 | fn into_deserializer(self) -> BytesDeserializer<'a, E> { |
804 | BytesDeserializer::new(self) |
805 | } |
806 | } |
807 | |
808 | impl<'de, 'a, E> Deserializer<'de> for BytesDeserializer<'a, E> |
809 | where |
810 | E: de::Error, |
811 | { |
812 | type Error = E; |
813 | |
814 | fn deserialize_any<V>(self, visitor: V) -> Result<V::Value, Self::Error> |
815 | where |
816 | V: Visitor<'de>, |
817 | { |
818 | visitor.visit_bytes(self.value) |
819 | } |
820 | |
821 | forward_to_deserialize_any! { |
822 | bool i8 i16 i32 i64 i128 u8 u16 u32 u64 u128 f32 f64 char str string |
823 | bytes byte_buf option unit unit_struct newtype_struct seq tuple |
824 | tuple_struct map struct enum identifier ignored_any |
825 | } |
826 | } |
827 | |
828 | impl<'a, E> Debug for BytesDeserializer<'a, E> { |
829 | fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result { |
830 | formatter |
831 | .debug_struct("BytesDeserializer" ) |
832 | .field("value" , &self.value) |
833 | .finish() |
834 | } |
835 | } |
836 | |
837 | /// A deserializer holding a `&[u8]` with a lifetime tied to another |
838 | /// deserializer. Always calls [`Visitor::visit_borrowed_bytes`]. |
839 | pub struct BorrowedBytesDeserializer<'de, E> { |
840 | value: &'de [u8], |
841 | marker: PhantomData<E>, |
842 | } |
843 | |
844 | impl<'de, E> BorrowedBytesDeserializer<'de, E> { |
845 | /// Create a new borrowed deserializer from the given borrowed bytes. |
846 | pub fn new(value: &'de [u8]) -> Self { |
847 | BorrowedBytesDeserializer { |
848 | value, |
849 | marker: PhantomData, |
850 | } |
851 | } |
852 | } |
853 | |
854 | impl_copy_clone!(BorrowedBytesDeserializer<'de>); |
855 | |
856 | impl<'de, E> Deserializer<'de> for BorrowedBytesDeserializer<'de, E> |
857 | where |
858 | E: de::Error, |
859 | { |
860 | type Error = E; |
861 | |
862 | fn deserialize_any<V>(self, visitor: V) -> Result<V::Value, Self::Error> |
863 | where |
864 | V: Visitor<'de>, |
865 | { |
866 | visitor.visit_borrowed_bytes(self.value) |
867 | } |
868 | |
869 | forward_to_deserialize_any! { |
870 | bool i8 i16 i32 i64 i128 u8 u16 u32 u64 u128 f32 f64 char str string |
871 | bytes byte_buf option unit unit_struct newtype_struct seq tuple |
872 | tuple_struct map struct enum identifier ignored_any |
873 | } |
874 | } |
875 | |
876 | impl<'de, E> Debug for BorrowedBytesDeserializer<'de, E> { |
877 | fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result { |
878 | formatter |
879 | .debug_struct("BorrowedBytesDeserializer" ) |
880 | .field("value" , &self.value) |
881 | .finish() |
882 | } |
883 | } |
884 | |
885 | //////////////////////////////////////////////////////////////////////////////// |
886 | |
887 | /// A deserializer that iterates over a sequence. |
888 | #[derive(Clone)] |
889 | pub struct SeqDeserializer<I, E> { |
890 | iter: iter::Fuse<I>, |
891 | count: usize, |
892 | marker: PhantomData<E>, |
893 | } |
894 | |
895 | impl<I, E> SeqDeserializer<I, E> |
896 | where |
897 | I: Iterator, |
898 | { |
899 | /// Construct a new `SeqDeserializer<I, E>`. |
900 | pub fn new(iter: I) -> Self { |
901 | SeqDeserializer { |
902 | iter: iter.fuse(), |
903 | count: 0, |
904 | marker: PhantomData, |
905 | } |
906 | } |
907 | } |
908 | |
909 | impl<I, E> SeqDeserializer<I, E> |
910 | where |
911 | I: Iterator, |
912 | E: de::Error, |
913 | { |
914 | /// Check for remaining elements after passing a `SeqDeserializer` to |
915 | /// `Visitor::visit_seq`. |
916 | pub fn end(self) -> Result<(), E> { |
917 | let remaining = self.iter.count(); |
918 | if remaining == 0 { |
919 | Ok(()) |
920 | } else { |
921 | // First argument is the number of elements in the data, second |
922 | // argument is the number of elements expected by the Deserialize. |
923 | Err(de::Error::invalid_length( |
924 | self.count + remaining, |
925 | &ExpectedInSeq(self.count), |
926 | )) |
927 | } |
928 | } |
929 | } |
930 | |
931 | impl<'de, I, T, E> de::Deserializer<'de> for SeqDeserializer<I, E> |
932 | where |
933 | I: Iterator<Item = T>, |
934 | T: IntoDeserializer<'de, E>, |
935 | E: de::Error, |
936 | { |
937 | type Error = E; |
938 | |
939 | fn deserialize_any<V>(mut self, visitor: V) -> Result<V::Value, Self::Error> |
940 | where |
941 | V: de::Visitor<'de>, |
942 | { |
943 | let v = tri!(visitor.visit_seq(&mut self)); |
944 | tri!(self.end()); |
945 | Ok(v) |
946 | } |
947 | |
948 | forward_to_deserialize_any! { |
949 | bool i8 i16 i32 i64 i128 u8 u16 u32 u64 u128 f32 f64 char str string |
950 | bytes byte_buf option unit unit_struct newtype_struct seq tuple |
951 | tuple_struct map struct enum identifier ignored_any |
952 | } |
953 | } |
954 | |
955 | impl<'de, I, T, E> de::SeqAccess<'de> for SeqDeserializer<I, E> |
956 | where |
957 | I: Iterator<Item = T>, |
958 | T: IntoDeserializer<'de, E>, |
959 | E: de::Error, |
960 | { |
961 | type Error = E; |
962 | |
963 | fn next_element_seed<V>(&mut self, seed: V) -> Result<Option<V::Value>, Self::Error> |
964 | where |
965 | V: de::DeserializeSeed<'de>, |
966 | { |
967 | match self.iter.next() { |
968 | Some(value) => { |
969 | self.count += 1; |
970 | seed.deserialize(value.into_deserializer()).map(Some) |
971 | } |
972 | None => Ok(None), |
973 | } |
974 | } |
975 | |
976 | fn size_hint(&self) -> Option<usize> { |
977 | size_hint::from_bounds(&self.iter) |
978 | } |
979 | } |
980 | |
981 | struct ExpectedInSeq(usize); |
982 | |
983 | impl Expected for ExpectedInSeq { |
984 | fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result { |
985 | if self.0 == 1 { |
986 | write!(formatter, "1 element in sequence" ) |
987 | } else { |
988 | write!(formatter, "{} elements in sequence" , self.0) |
989 | } |
990 | } |
991 | } |
992 | |
993 | impl<I, E> Debug for SeqDeserializer<I, E> |
994 | where |
995 | I: Debug, |
996 | { |
997 | fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result { |
998 | formatter |
999 | .debug_struct("SeqDeserializer" ) |
1000 | .field("iter" , &self.iter) |
1001 | .field("count" , &self.count) |
1002 | .finish() |
1003 | } |
1004 | } |
1005 | |
1006 | //////////////////////////////////////////////////////////////////////////////// |
1007 | |
1008 | #[cfg (any(feature = "std" , feature = "alloc" ))] |
1009 | #[cfg_attr (doc_cfg, doc(cfg(any(feature = "std" , feature = "alloc" ))))] |
1010 | impl<'de, T, E> IntoDeserializer<'de, E> for Vec<T> |
1011 | where |
1012 | T: IntoDeserializer<'de, E>, |
1013 | E: de::Error, |
1014 | { |
1015 | type Deserializer = SeqDeserializer<<Self as IntoIterator>::IntoIter, E>; |
1016 | |
1017 | fn into_deserializer(self) -> Self::Deserializer { |
1018 | SeqDeserializer::new(self.into_iter()) |
1019 | } |
1020 | } |
1021 | |
1022 | #[cfg (any(feature = "std" , feature = "alloc" ))] |
1023 | #[cfg_attr (doc_cfg, doc(cfg(any(feature = "std" , feature = "alloc" ))))] |
1024 | impl<'de, T, E> IntoDeserializer<'de, E> for BTreeSet<T> |
1025 | where |
1026 | T: IntoDeserializer<'de, E> + Eq + Ord, |
1027 | E: de::Error, |
1028 | { |
1029 | type Deserializer = SeqDeserializer<<Self as IntoIterator>::IntoIter, E>; |
1030 | |
1031 | fn into_deserializer(self) -> Self::Deserializer { |
1032 | SeqDeserializer::new(self.into_iter()) |
1033 | } |
1034 | } |
1035 | |
1036 | #[cfg (feature = "std" )] |
1037 | #[cfg_attr (doc_cfg, doc(cfg(feature = "std" )))] |
1038 | impl<'de, T, S, E> IntoDeserializer<'de, E> for HashSet<T, S> |
1039 | where |
1040 | T: IntoDeserializer<'de, E> + Eq + Hash, |
1041 | S: BuildHasher, |
1042 | E: de::Error, |
1043 | { |
1044 | type Deserializer = SeqDeserializer<<Self as IntoIterator>::IntoIter, E>; |
1045 | |
1046 | fn into_deserializer(self) -> Self::Deserializer { |
1047 | SeqDeserializer::new(self.into_iter()) |
1048 | } |
1049 | } |
1050 | |
1051 | //////////////////////////////////////////////////////////////////////////////// |
1052 | |
1053 | /// A deserializer holding a `SeqAccess`. |
1054 | #[derive(Clone, Debug)] |
1055 | pub struct SeqAccessDeserializer<A> { |
1056 | seq: A, |
1057 | } |
1058 | |
1059 | impl<A> SeqAccessDeserializer<A> { |
1060 | /// Construct a new `SeqAccessDeserializer<A>`. |
1061 | pub fn new(seq: A) -> Self { |
1062 | SeqAccessDeserializer { seq } |
1063 | } |
1064 | } |
1065 | |
1066 | impl<'de, A> de::Deserializer<'de> for SeqAccessDeserializer<A> |
1067 | where |
1068 | A: de::SeqAccess<'de>, |
1069 | { |
1070 | type Error = A::Error; |
1071 | |
1072 | fn deserialize_any<V>(self, visitor: V) -> Result<V::Value, Self::Error> |
1073 | where |
1074 | V: de::Visitor<'de>, |
1075 | { |
1076 | visitor.visit_seq(self.seq) |
1077 | } |
1078 | |
1079 | forward_to_deserialize_any! { |
1080 | bool i8 i16 i32 i64 i128 u8 u16 u32 u64 u128 f32 f64 char str string |
1081 | bytes byte_buf option unit unit_struct newtype_struct seq tuple |
1082 | tuple_struct map struct enum identifier ignored_any |
1083 | } |
1084 | } |
1085 | |
1086 | //////////////////////////////////////////////////////////////////////////////// |
1087 | |
1088 | /// A deserializer that iterates over a map. |
1089 | pub struct MapDeserializer<'de, I, E> |
1090 | where |
1091 | I: Iterator, |
1092 | I::Item: private::Pair, |
1093 | { |
1094 | iter: iter::Fuse<I>, |
1095 | value: Option<Second<I::Item>>, |
1096 | count: usize, |
1097 | lifetime: PhantomData<&'de ()>, |
1098 | error: PhantomData<E>, |
1099 | } |
1100 | |
1101 | impl<'de, I, E> MapDeserializer<'de, I, E> |
1102 | where |
1103 | I: Iterator, |
1104 | I::Item: private::Pair, |
1105 | { |
1106 | /// Construct a new `MapDeserializer<I, E>`. |
1107 | pub fn new(iter: I) -> Self { |
1108 | MapDeserializer { |
1109 | iter: iter.fuse(), |
1110 | value: None, |
1111 | count: 0, |
1112 | lifetime: PhantomData, |
1113 | error: PhantomData, |
1114 | } |
1115 | } |
1116 | } |
1117 | |
1118 | impl<'de, I, E> MapDeserializer<'de, I, E> |
1119 | where |
1120 | I: Iterator, |
1121 | I::Item: private::Pair, |
1122 | E: de::Error, |
1123 | { |
1124 | /// Check for remaining elements after passing a `MapDeserializer` to |
1125 | /// `Visitor::visit_map`. |
1126 | pub fn end(self) -> Result<(), E> { |
1127 | let remaining = self.iter.count(); |
1128 | if remaining == 0 { |
1129 | Ok(()) |
1130 | } else { |
1131 | // First argument is the number of elements in the data, second |
1132 | // argument is the number of elements expected by the Deserialize. |
1133 | Err(de::Error::invalid_length( |
1134 | self.count + remaining, |
1135 | &ExpectedInMap(self.count), |
1136 | )) |
1137 | } |
1138 | } |
1139 | } |
1140 | |
1141 | impl<'de, I, E> MapDeserializer<'de, I, E> |
1142 | where |
1143 | I: Iterator, |
1144 | I::Item: private::Pair, |
1145 | { |
1146 | fn next_pair(&mut self) -> Option<(First<I::Item>, Second<I::Item>)> { |
1147 | match self.iter.next() { |
1148 | Some(kv) => { |
1149 | self.count += 1; |
1150 | Some(private::Pair::split(kv)) |
1151 | } |
1152 | None => None, |
1153 | } |
1154 | } |
1155 | } |
1156 | |
1157 | impl<'de, I, E> de::Deserializer<'de> for MapDeserializer<'de, I, E> |
1158 | where |
1159 | I: Iterator, |
1160 | I::Item: private::Pair, |
1161 | First<I::Item>: IntoDeserializer<'de, E>, |
1162 | Second<I::Item>: IntoDeserializer<'de, E>, |
1163 | E: de::Error, |
1164 | { |
1165 | type Error = E; |
1166 | |
1167 | fn deserialize_any<V>(mut self, visitor: V) -> Result<V::Value, Self::Error> |
1168 | where |
1169 | V: de::Visitor<'de>, |
1170 | { |
1171 | let value = tri!(visitor.visit_map(&mut self)); |
1172 | tri!(self.end()); |
1173 | Ok(value) |
1174 | } |
1175 | |
1176 | fn deserialize_seq<V>(mut self, visitor: V) -> Result<V::Value, Self::Error> |
1177 | where |
1178 | V: de::Visitor<'de>, |
1179 | { |
1180 | let value = tri!(visitor.visit_seq(&mut self)); |
1181 | tri!(self.end()); |
1182 | Ok(value) |
1183 | } |
1184 | |
1185 | fn deserialize_tuple<V>(self, len: usize, visitor: V) -> Result<V::Value, Self::Error> |
1186 | where |
1187 | V: de::Visitor<'de>, |
1188 | { |
1189 | let _ = len; |
1190 | self.deserialize_seq(visitor) |
1191 | } |
1192 | |
1193 | forward_to_deserialize_any! { |
1194 | bool i8 i16 i32 i64 i128 u8 u16 u32 u64 u128 f32 f64 char str string |
1195 | bytes byte_buf option unit unit_struct newtype_struct tuple_struct map |
1196 | struct enum identifier ignored_any |
1197 | } |
1198 | } |
1199 | |
1200 | impl<'de, I, E> de::MapAccess<'de> for MapDeserializer<'de, I, E> |
1201 | where |
1202 | I: Iterator, |
1203 | I::Item: private::Pair, |
1204 | First<I::Item>: IntoDeserializer<'de, E>, |
1205 | Second<I::Item>: IntoDeserializer<'de, E>, |
1206 | E: de::Error, |
1207 | { |
1208 | type Error = E; |
1209 | |
1210 | fn next_key_seed<T>(&mut self, seed: T) -> Result<Option<T::Value>, Self::Error> |
1211 | where |
1212 | T: de::DeserializeSeed<'de>, |
1213 | { |
1214 | match self.next_pair() { |
1215 | Some((key, value)) => { |
1216 | self.value = Some(value); |
1217 | seed.deserialize(key.into_deserializer()).map(Some) |
1218 | } |
1219 | None => Ok(None), |
1220 | } |
1221 | } |
1222 | |
1223 | fn next_value_seed<T>(&mut self, seed: T) -> Result<T::Value, Self::Error> |
1224 | where |
1225 | T: de::DeserializeSeed<'de>, |
1226 | { |
1227 | let value = self.value.take(); |
1228 | // Panic because this indicates a bug in the program rather than an |
1229 | // expected failure. |
1230 | let value = value.expect("MapAccess::next_value called before next_key" ); |
1231 | seed.deserialize(value.into_deserializer()) |
1232 | } |
1233 | |
1234 | fn next_entry_seed<TK, TV>( |
1235 | &mut self, |
1236 | kseed: TK, |
1237 | vseed: TV, |
1238 | ) -> Result<Option<(TK::Value, TV::Value)>, Self::Error> |
1239 | where |
1240 | TK: de::DeserializeSeed<'de>, |
1241 | TV: de::DeserializeSeed<'de>, |
1242 | { |
1243 | match self.next_pair() { |
1244 | Some((key, value)) => { |
1245 | let key = tri!(kseed.deserialize(key.into_deserializer())); |
1246 | let value = tri!(vseed.deserialize(value.into_deserializer())); |
1247 | Ok(Some((key, value))) |
1248 | } |
1249 | None => Ok(None), |
1250 | } |
1251 | } |
1252 | |
1253 | fn size_hint(&self) -> Option<usize> { |
1254 | size_hint::from_bounds(&self.iter) |
1255 | } |
1256 | } |
1257 | |
1258 | impl<'de, I, E> de::SeqAccess<'de> for MapDeserializer<'de, I, E> |
1259 | where |
1260 | I: Iterator, |
1261 | I::Item: private::Pair, |
1262 | First<I::Item>: IntoDeserializer<'de, E>, |
1263 | Second<I::Item>: IntoDeserializer<'de, E>, |
1264 | E: de::Error, |
1265 | { |
1266 | type Error = E; |
1267 | |
1268 | fn next_element_seed<T>(&mut self, seed: T) -> Result<Option<T::Value>, Self::Error> |
1269 | where |
1270 | T: de::DeserializeSeed<'de>, |
1271 | { |
1272 | match self.next_pair() { |
1273 | Some((k, v)) => { |
1274 | let de = PairDeserializer(k, v, PhantomData); |
1275 | seed.deserialize(de).map(Some) |
1276 | } |
1277 | None => Ok(None), |
1278 | } |
1279 | } |
1280 | |
1281 | fn size_hint(&self) -> Option<usize> { |
1282 | size_hint::from_bounds(&self.iter) |
1283 | } |
1284 | } |
1285 | |
1286 | // Cannot #[derive(Clone)] because of the bound `Second<I::Item>: Clone`. |
1287 | impl<'de, I, E> Clone for MapDeserializer<'de, I, E> |
1288 | where |
1289 | I: Iterator + Clone, |
1290 | I::Item: private::Pair, |
1291 | Second<I::Item>: Clone, |
1292 | { |
1293 | fn clone(&self) -> Self { |
1294 | MapDeserializer { |
1295 | iter: self.iter.clone(), |
1296 | value: self.value.clone(), |
1297 | count: self.count, |
1298 | lifetime: self.lifetime, |
1299 | error: self.error, |
1300 | } |
1301 | } |
1302 | } |
1303 | |
1304 | impl<'de, I, E> Debug for MapDeserializer<'de, I, E> |
1305 | where |
1306 | I: Iterator + Debug, |
1307 | I::Item: private::Pair, |
1308 | Second<I::Item>: Debug, |
1309 | { |
1310 | fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result { |
1311 | formatter |
1312 | .debug_struct("MapDeserializer" ) |
1313 | .field("iter" , &self.iter) |
1314 | .field("value" , &self.value) |
1315 | .field("count" , &self.count) |
1316 | .finish() |
1317 | } |
1318 | } |
1319 | |
1320 | // Used in the `impl SeqAccess for MapDeserializer` to visit the map as a |
1321 | // sequence of pairs. |
1322 | struct PairDeserializer<A, B, E>(A, B, PhantomData<E>); |
1323 | |
1324 | impl<'de, A, B, E> de::Deserializer<'de> for PairDeserializer<A, B, E> |
1325 | where |
1326 | A: IntoDeserializer<'de, E>, |
1327 | B: IntoDeserializer<'de, E>, |
1328 | E: de::Error, |
1329 | { |
1330 | type Error = E; |
1331 | |
1332 | forward_to_deserialize_any! { |
1333 | bool i8 i16 i32 i64 i128 u8 u16 u32 u64 u128 f32 f64 char str string |
1334 | bytes byte_buf option unit unit_struct newtype_struct tuple_struct map |
1335 | struct enum identifier ignored_any |
1336 | } |
1337 | |
1338 | fn deserialize_any<V>(self, visitor: V) -> Result<V::Value, Self::Error> |
1339 | where |
1340 | V: de::Visitor<'de>, |
1341 | { |
1342 | self.deserialize_seq(visitor) |
1343 | } |
1344 | |
1345 | fn deserialize_seq<V>(self, visitor: V) -> Result<V::Value, Self::Error> |
1346 | where |
1347 | V: de::Visitor<'de>, |
1348 | { |
1349 | let mut pair_visitor = PairVisitor(Some(self.0), Some(self.1), PhantomData); |
1350 | let pair = tri!(visitor.visit_seq(&mut pair_visitor)); |
1351 | if pair_visitor.1.is_none() { |
1352 | Ok(pair) |
1353 | } else { |
1354 | let remaining = pair_visitor.size_hint().unwrap(); |
1355 | // First argument is the number of elements in the data, second |
1356 | // argument is the number of elements expected by the Deserialize. |
1357 | Err(de::Error::invalid_length(2, &ExpectedInSeq(2 - remaining))) |
1358 | } |
1359 | } |
1360 | |
1361 | fn deserialize_tuple<V>(self, len: usize, visitor: V) -> Result<V::Value, Self::Error> |
1362 | where |
1363 | V: de::Visitor<'de>, |
1364 | { |
1365 | if len == 2 { |
1366 | self.deserialize_seq(visitor) |
1367 | } else { |
1368 | // First argument is the number of elements in the data, second |
1369 | // argument is the number of elements expected by the Deserialize. |
1370 | Err(de::Error::invalid_length(2, &ExpectedInSeq(len))) |
1371 | } |
1372 | } |
1373 | } |
1374 | |
1375 | struct PairVisitor<A, B, E>(Option<A>, Option<B>, PhantomData<E>); |
1376 | |
1377 | impl<'de, A, B, E> de::SeqAccess<'de> for PairVisitor<A, B, E> |
1378 | where |
1379 | A: IntoDeserializer<'de, E>, |
1380 | B: IntoDeserializer<'de, E>, |
1381 | E: de::Error, |
1382 | { |
1383 | type Error = E; |
1384 | |
1385 | fn next_element_seed<T>(&mut self, seed: T) -> Result<Option<T::Value>, Self::Error> |
1386 | where |
1387 | T: de::DeserializeSeed<'de>, |
1388 | { |
1389 | if let Some(k) = self.0.take() { |
1390 | seed.deserialize(k.into_deserializer()).map(Some) |
1391 | } else if let Some(v) = self.1.take() { |
1392 | seed.deserialize(v.into_deserializer()).map(Some) |
1393 | } else { |
1394 | Ok(None) |
1395 | } |
1396 | } |
1397 | |
1398 | fn size_hint(&self) -> Option<usize> { |
1399 | if self.0.is_some() { |
1400 | Some(2) |
1401 | } else if self.1.is_some() { |
1402 | Some(1) |
1403 | } else { |
1404 | Some(0) |
1405 | } |
1406 | } |
1407 | } |
1408 | |
1409 | struct ExpectedInMap(usize); |
1410 | |
1411 | impl Expected for ExpectedInMap { |
1412 | fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result { |
1413 | if self.0 == 1 { |
1414 | write!(formatter, "1 element in map" ) |
1415 | } else { |
1416 | write!(formatter, "{} elements in map" , self.0) |
1417 | } |
1418 | } |
1419 | } |
1420 | |
1421 | //////////////////////////////////////////////////////////////////////////////// |
1422 | |
1423 | #[cfg (any(feature = "std" , feature = "alloc" ))] |
1424 | #[cfg_attr (doc_cfg, doc(cfg(any(feature = "std" , feature = "alloc" ))))] |
1425 | impl<'de, K, V, E> IntoDeserializer<'de, E> for BTreeMap<K, V> |
1426 | where |
1427 | K: IntoDeserializer<'de, E> + Eq + Ord, |
1428 | V: IntoDeserializer<'de, E>, |
1429 | E: de::Error, |
1430 | { |
1431 | type Deserializer = MapDeserializer<'de, <Self as IntoIterator>::IntoIter, E>; |
1432 | |
1433 | fn into_deserializer(self) -> Self::Deserializer { |
1434 | MapDeserializer::new(self.into_iter()) |
1435 | } |
1436 | } |
1437 | |
1438 | #[cfg (feature = "std" )] |
1439 | #[cfg_attr (doc_cfg, doc(cfg(feature = "std" )))] |
1440 | impl<'de, K, V, S, E> IntoDeserializer<'de, E> for HashMap<K, V, S> |
1441 | where |
1442 | K: IntoDeserializer<'de, E> + Eq + Hash, |
1443 | V: IntoDeserializer<'de, E>, |
1444 | S: BuildHasher, |
1445 | E: de::Error, |
1446 | { |
1447 | type Deserializer = MapDeserializer<'de, <Self as IntoIterator>::IntoIter, E>; |
1448 | |
1449 | fn into_deserializer(self) -> Self::Deserializer { |
1450 | MapDeserializer::new(self.into_iter()) |
1451 | } |
1452 | } |
1453 | |
1454 | //////////////////////////////////////////////////////////////////////////////// |
1455 | |
1456 | /// A deserializer holding a `MapAccess`. |
1457 | #[derive(Clone, Debug)] |
1458 | pub struct MapAccessDeserializer<A> { |
1459 | map: A, |
1460 | } |
1461 | |
1462 | impl<A> MapAccessDeserializer<A> { |
1463 | /// Construct a new `MapAccessDeserializer<A>`. |
1464 | pub fn new(map: A) -> Self { |
1465 | MapAccessDeserializer { map } |
1466 | } |
1467 | } |
1468 | |
1469 | impl<'de, A> de::Deserializer<'de> for MapAccessDeserializer<A> |
1470 | where |
1471 | A: de::MapAccess<'de>, |
1472 | { |
1473 | type Error = A::Error; |
1474 | |
1475 | fn deserialize_any<V>(self, visitor: V) -> Result<V::Value, Self::Error> |
1476 | where |
1477 | V: de::Visitor<'de>, |
1478 | { |
1479 | visitor.visit_map(self.map) |
1480 | } |
1481 | |
1482 | fn deserialize_enum<V>( |
1483 | self, |
1484 | _name: &str, |
1485 | _variants: &'static [&'static str], |
1486 | visitor: V, |
1487 | ) -> Result<V::Value, Self::Error> |
1488 | where |
1489 | V: de::Visitor<'de>, |
1490 | { |
1491 | visitor.visit_enum(self) |
1492 | } |
1493 | |
1494 | forward_to_deserialize_any! { |
1495 | bool i8 i16 i32 i64 i128 u8 u16 u32 u64 u128 f32 f64 char str string |
1496 | bytes byte_buf option unit unit_struct newtype_struct seq tuple |
1497 | tuple_struct map struct identifier ignored_any |
1498 | } |
1499 | } |
1500 | |
1501 | impl<'de, A> de::EnumAccess<'de> for MapAccessDeserializer<A> |
1502 | where |
1503 | A: de::MapAccess<'de>, |
1504 | { |
1505 | type Error = A::Error; |
1506 | type Variant = private::MapAsEnum<A>; |
1507 | |
1508 | fn variant_seed<T>(mut self, seed: T) -> Result<(T::Value, Self::Variant), Self::Error> |
1509 | where |
1510 | T: de::DeserializeSeed<'de>, |
1511 | { |
1512 | match tri!(self.map.next_key_seed(seed)) { |
1513 | Some(key) => Ok((key, private::map_as_enum(self.map))), |
1514 | None => Err(de::Error::invalid_type(de::Unexpected::Map, &"enum" )), |
1515 | } |
1516 | } |
1517 | } |
1518 | |
1519 | //////////////////////////////////////////////////////////////////////////////// |
1520 | |
1521 | /// A deserializer holding an `EnumAccess`. |
1522 | #[derive(Clone, Debug)] |
1523 | pub struct EnumAccessDeserializer<A> { |
1524 | access: A, |
1525 | } |
1526 | |
1527 | impl<A> EnumAccessDeserializer<A> { |
1528 | /// Construct a new `EnumAccessDeserializer<A>`. |
1529 | pub fn new(access: A) -> Self { |
1530 | EnumAccessDeserializer { access } |
1531 | } |
1532 | } |
1533 | |
1534 | impl<'de, A> de::Deserializer<'de> for EnumAccessDeserializer<A> |
1535 | where |
1536 | A: de::EnumAccess<'de>, |
1537 | { |
1538 | type Error = A::Error; |
1539 | |
1540 | fn deserialize_any<V>(self, visitor: V) -> Result<V::Value, Self::Error> |
1541 | where |
1542 | V: de::Visitor<'de>, |
1543 | { |
1544 | visitor.visit_enum(self.access) |
1545 | } |
1546 | |
1547 | forward_to_deserialize_any! { |
1548 | bool i8 i16 i32 i64 i128 u8 u16 u32 u64 u128 f32 f64 char str string |
1549 | bytes byte_buf option unit unit_struct newtype_struct seq tuple |
1550 | tuple_struct map struct enum identifier ignored_any |
1551 | } |
1552 | } |
1553 | |
1554 | //////////////////////////////////////////////////////////////////////////////// |
1555 | |
1556 | mod private { |
1557 | use crate::lib::*; |
1558 | |
1559 | use crate::de::{ |
1560 | self, DeserializeSeed, Deserializer, MapAccess, Unexpected, VariantAccess, Visitor, |
1561 | }; |
1562 | |
1563 | pub struct UnitOnly<E> { |
1564 | marker: PhantomData<E>, |
1565 | } |
1566 | |
1567 | pub fn unit_only<T, E>(t: T) -> (T, UnitOnly<E>) { |
1568 | ( |
1569 | t, |
1570 | UnitOnly { |
1571 | marker: PhantomData, |
1572 | }, |
1573 | ) |
1574 | } |
1575 | |
1576 | impl<'de, E> de::VariantAccess<'de> for UnitOnly<E> |
1577 | where |
1578 | E: de::Error, |
1579 | { |
1580 | type Error = E; |
1581 | |
1582 | fn unit_variant(self) -> Result<(), Self::Error> { |
1583 | Ok(()) |
1584 | } |
1585 | |
1586 | fn newtype_variant_seed<T>(self, _seed: T) -> Result<T::Value, Self::Error> |
1587 | where |
1588 | T: de::DeserializeSeed<'de>, |
1589 | { |
1590 | Err(de::Error::invalid_type( |
1591 | Unexpected::UnitVariant, |
1592 | &"newtype variant" , |
1593 | )) |
1594 | } |
1595 | |
1596 | fn tuple_variant<V>(self, _len: usize, _visitor: V) -> Result<V::Value, Self::Error> |
1597 | where |
1598 | V: de::Visitor<'de>, |
1599 | { |
1600 | Err(de::Error::invalid_type( |
1601 | Unexpected::UnitVariant, |
1602 | &"tuple variant" , |
1603 | )) |
1604 | } |
1605 | |
1606 | fn struct_variant<V>( |
1607 | self, |
1608 | _fields: &'static [&'static str], |
1609 | _visitor: V, |
1610 | ) -> Result<V::Value, Self::Error> |
1611 | where |
1612 | V: de::Visitor<'de>, |
1613 | { |
1614 | Err(de::Error::invalid_type( |
1615 | Unexpected::UnitVariant, |
1616 | &"struct variant" , |
1617 | )) |
1618 | } |
1619 | } |
1620 | |
1621 | pub struct MapAsEnum<A> { |
1622 | map: A, |
1623 | } |
1624 | |
1625 | pub fn map_as_enum<A>(map: A) -> MapAsEnum<A> { |
1626 | MapAsEnum { map } |
1627 | } |
1628 | |
1629 | impl<'de, A> VariantAccess<'de> for MapAsEnum<A> |
1630 | where |
1631 | A: MapAccess<'de>, |
1632 | { |
1633 | type Error = A::Error; |
1634 | |
1635 | fn unit_variant(mut self) -> Result<(), Self::Error> { |
1636 | self.map.next_value() |
1637 | } |
1638 | |
1639 | fn newtype_variant_seed<T>(mut self, seed: T) -> Result<T::Value, Self::Error> |
1640 | where |
1641 | T: DeserializeSeed<'de>, |
1642 | { |
1643 | self.map.next_value_seed(seed) |
1644 | } |
1645 | |
1646 | fn tuple_variant<V>(mut self, len: usize, visitor: V) -> Result<V::Value, Self::Error> |
1647 | where |
1648 | V: Visitor<'de>, |
1649 | { |
1650 | self.map.next_value_seed(SeedTupleVariant { len, visitor }) |
1651 | } |
1652 | |
1653 | fn struct_variant<V>( |
1654 | mut self, |
1655 | _fields: &'static [&'static str], |
1656 | visitor: V, |
1657 | ) -> Result<V::Value, Self::Error> |
1658 | where |
1659 | V: Visitor<'de>, |
1660 | { |
1661 | self.map.next_value_seed(SeedStructVariant { visitor }) |
1662 | } |
1663 | } |
1664 | |
1665 | struct SeedTupleVariant<V> { |
1666 | len: usize, |
1667 | visitor: V, |
1668 | } |
1669 | |
1670 | impl<'de, V> DeserializeSeed<'de> for SeedTupleVariant<V> |
1671 | where |
1672 | V: Visitor<'de>, |
1673 | { |
1674 | type Value = V::Value; |
1675 | |
1676 | fn deserialize<D>(self, deserializer: D) -> Result<Self::Value, D::Error> |
1677 | where |
1678 | D: Deserializer<'de>, |
1679 | { |
1680 | deserializer.deserialize_tuple(self.len, self.visitor) |
1681 | } |
1682 | } |
1683 | |
1684 | struct SeedStructVariant<V> { |
1685 | visitor: V, |
1686 | } |
1687 | |
1688 | impl<'de, V> DeserializeSeed<'de> for SeedStructVariant<V> |
1689 | where |
1690 | V: Visitor<'de>, |
1691 | { |
1692 | type Value = V::Value; |
1693 | |
1694 | fn deserialize<D>(self, deserializer: D) -> Result<Self::Value, D::Error> |
1695 | where |
1696 | D: Deserializer<'de>, |
1697 | { |
1698 | deserializer.deserialize_map(self.visitor) |
1699 | } |
1700 | } |
1701 | |
1702 | /// Avoid having to restate the generic types on `MapDeserializer`. The |
1703 | /// `Iterator::Item` contains enough information to figure out K and V. |
1704 | pub trait Pair { |
1705 | type First; |
1706 | type Second; |
1707 | fn split(self) -> (Self::First, Self::Second); |
1708 | } |
1709 | |
1710 | impl<A, B> Pair for (A, B) { |
1711 | type First = A; |
1712 | type Second = B; |
1713 | fn split(self) -> (A, B) { |
1714 | self |
1715 | } |
1716 | } |
1717 | |
1718 | pub type First<T> = <T as Pair>::First; |
1719 | pub type Second<T> = <T as Pair>::Second; |
1720 | } |
1721 | |