musli_core/de/
entries_decoder.rs

1use crate::{Allocator, Context};
2
3use super::{Decoder, SizeHint};
4
5/// Trait governing how to decode a sequence of map pairs.
6///
7/// This trait exists so that decoders can implement a mode that is compatible
8/// with serde deserialization.
9///
10/// If you do not intend to implement this, then serde compatibility for your
11/// format might be degraded.
12#[must_use = "Must call end_entries to complete decoding"]
13pub trait EntriesDecoder<'de> {
14    /// Context associated with the decoder.
15    type Cx: Context<Error = Self::Error, Allocator = Self::Allocator>;
16    /// Error associated with decoding.
17    type Error;
18    /// The allocator associated with the decoder.
19    type Allocator: Allocator;
20    /// The mode of the decoder.
21    type Mode: 'static;
22    /// The decoder to use for a tuple field index.
23    type DecodeEntryKey<'this>: Decoder<
24        'de,
25        Cx = Self::Cx,
26        Error = Self::Error,
27        Allocator = Self::Allocator,
28        Mode = Self::Mode,
29    >
30    where
31        Self: 'this;
32    /// The decoder to use for a tuple field value.
33    type DecodeEntryValue<'this>: Decoder<
34        'de,
35        Cx = Self::Cx,
36        Error = Self::Error,
37        Allocator = Self::Allocator,
38        Mode = Self::Mode,
39    >
40    where
41        Self: 'this;
42
43    /// Access the context associated with the decoder.
44    fn cx(&self) -> Self::Cx;
45
46    /// Get a size hint for the size of the map being decoded.
47    #[inline]
48    fn size_hint(&self) -> SizeHint {
49        SizeHint::any()
50    }
51
52    /// Try to return the decoder for the first value in the pair.
53    ///
54    /// If this is a map the first value would be the key of the map, if this is
55    /// a struct the first value would be the field of the struct.
56    #[must_use = "Decoders must be consumed"]
57    fn decode_entry_key(&mut self) -> Result<Option<Self::DecodeEntryKey<'_>>, Self::Error>;
58
59    /// Decode the value in the map.
60    #[must_use = "Decoders must be consumed"]
61    fn decode_entry_value(&mut self) -> Result<Self::DecodeEntryValue<'_>, Self::Error>;
62
63    /// End entries decoding.
64    fn end_entries(self) -> Result<(), Self::Error>;
65}
musli_core/de/entries_decoder.rs

musli_core/de/
entries_decoder.rs
