musli_json/de/
variant_decoder.rs

1use musli::de::VariantDecoder;
2use musli::Context;
3
4use crate::parser::{Parser, Token};
5
6use super::{JsonDecoder, JsonKeyDecoder};
7
8pub(crate) struct JsonVariantDecoder<'a, P, C: ?Sized> {
9    cx: &'a C,
10    parser: P,
11}
12
13impl<'a, 'de, P, C> JsonVariantDecoder<'a, P, C>
14where
15    P: Parser<'de>,
16    C: ?Sized + Context,
17{
18    #[inline]
19    pub(super) fn new(cx: &'a C, mut parser: P) -> Result<Self, C::Error> {
20        let actual = parser.peek(cx)?;
21
22        if !matches!(actual, Token::OpenBrace) {
23            return Err(cx.message(format_args!("Expected open brace, was {actual}")));
24        }
25
26        parser.skip(cx, 1)?;
27        Ok(Self { cx, parser })
28    }
29
30    #[inline]
31    pub(super) fn end(mut self) -> Result<(), C::Error> {
32        let actual = self.parser.peek(self.cx)?;
33
34        if !matches!(actual, Token::CloseBrace) {
35            return Err(self.cx.message(format_args!(
36                "Expected closing brace for variant, was {actual}"
37            )));
38        }
39
40        self.parser.skip(self.cx, 1)?;
41        Ok(())
42    }
43}
44
45impl<'a, 'de, P, C> VariantDecoder<'de> for JsonVariantDecoder<'a, P, C>
46where
47    P: Parser<'de>,
48    C: ?Sized + Context,
49{
50    type Cx = C;
51    type DecodeTag<'this> = JsonKeyDecoder<'a, P::Mut<'this>, C>
52    where
53        Self: 'this;
54    type DecodeValue<'this> = JsonDecoder<'a, P::Mut<'this>, C> where Self: 'this;
55
56    #[inline]
57    fn decode_tag(&mut self) -> Result<Self::DecodeTag<'_>, C::Error> {
58        Ok(JsonKeyDecoder::new(self.cx, self.parser.borrow_mut()))
59    }
60
61    #[inline]
62    fn decode_value(&mut self) -> Result<Self::DecodeValue<'_>, C::Error> {
63        let actual = self.parser.peek(self.cx)?;
64
65        if !matches!(actual, Token::Colon) {
66            return Err(self
67                .cx
68                .message(format_args!("Expected colon, was {actual}")));
69        }
70
71        self.parser.skip(self.cx, 1)?;
72        Ok(JsonDecoder::new(self.cx, self.parser.borrow_mut()))
73    }
74}
musli_json/de/variant_decoder.rs

musli_json/de/
variant_decoder.rs
