diff options
Diffstat (limited to 'src/de.rs')
| -rw-r--r-- | src/de.rs | 135 |
1 files changed, 134 insertions, 1 deletions
@@ -11,6 +11,7 @@ use std::str; use std::vec; use serde::de; +use serde::de::IntoDeserializer; use tokens::{Tokenizer, Token, Error as TokenError}; use datetime::{SERDE_STRUCT_FIELD_NAME, SERDE_STRUCT_NAME}; @@ -121,6 +122,12 @@ enum ErrorKind { /// type. Custom, + /// TODO + ExpectedMapEnd, + ExpectedEnum, + ExpectedMapColon, + ExpectedString, + #[doc(hidden)] __Nonexhaustive, } @@ -145,6 +152,7 @@ impl<'de, 'b> de::Deserializer<'de> for &'b mut Deserializer<'de> { values: None, array: false, }; + while let Some(line) = self.line()? { match line { Line::Table { at, mut header, array } => { @@ -192,9 +200,40 @@ impl<'de, 'b> de::Deserializer<'de> for &'b mut Deserializer<'de> { }) } + fn deserialize_enum<V>( + self, + _name: &'static str, + _variants: &'static [&'static str], + visitor: V + ) -> Result<V::Value, Error> + where V: de::Visitor<'de> + { + if self.peek_char()? == '"' { + // Visit a unit variant. + match self.next()?.unwrap() { + Token::String { ref val, ..} => { + visitor.visit_enum(val.clone().into_deserializer()) + }, + _ => Err(Error::from_kind(ErrorKind::ExpectedString)) + } + } else if self.next_char()? == '{' { + // Visit a newtype variant, tuple variant, or struct variant. + let value = visitor.visit_enum(Enum::new(self))?; + // Parse the matching close brace. + if self.next_char()? == '}' { + Ok(value) + } else { + Err(Error::from_kind(ErrorKind::ExpectedMapEnd)) + } + } else { + Err(Error::from_kind(ErrorKind::ExpectedEnum)) + } + } + + forward_to_deserialize_any! { bool u8 u16 u32 u64 i8 i16 i32 i64 f32 f64 char str string seq - bytes byte_buf map struct unit enum newtype_struct + bytes byte_buf map struct unit newtype_struct ignored_any unit_struct tuple_struct tuple option identifier } } @@ -574,6 +613,82 @@ impl<'de> de::MapAccess<'de> for InlineTableDeserializer<'de> { } } +struct Enum<'a, 'de: 'a> { + de: &'a mut Deserializer<'de>, +} + +impl<'a, 'de> Enum<'a, 'de> { + fn new(de: &'a mut Deserializer<'de>) -> Self { + Enum { de: de } + } +} + +// `EnumAccess` is provided to the `Visitor` to give it the ability to determine +// which variant of the enum is supposed to be deserialized. +// +// Note that all enum deserialization methods in Serde refer exclusively to the +// "externally tagged" enum representation. +impl<'de, 'a> de::EnumAccess<'de> for Enum<'a, 'de> { + type Error = Error; + type Variant = Self; + + fn variant_seed<V>(self, seed: V) -> Result<(V::Value, Self::Variant), Error> + where V: de::DeserializeSeed<'de> + { + // The `deserialize_enum` method parsed a `{` character so we are + // currently inside of a map. The seed will be deserializing itself from + // the key of the map. + let val = seed.deserialize(&mut *self.de)?; + // Parse the colon separating map key from value. + if self.de.next_char()? == ':' { + Ok((val, self)) + } else { + Err(Error::from_kind(ErrorKind::ExpectedMapColon)) + } + } +} + +// `VariantAccess` is provided to the `Visitor` to give it the ability to see +// the content of the single variant that it decided to deserialize. +impl<'de, 'a> de::VariantAccess<'de> for Enum<'a, 'de> { + type Error = Error; + + // If the `Visitor` expected this variant to be a unit variant, the input + // should have been the plain string case handled in `deserialize_enum`. + fn unit_variant(self) -> Result<(), Error> { + Err(Error::from_kind(ErrorKind::ExpectedString)) + } + + // Newtype variants are represented in JSON as `{ NAME: VALUE }` so + // deserialize the value here. + fn newtype_variant_seed<T>(self, seed: T) -> Result<T::Value, Error> + where T: de::DeserializeSeed<'de> + { + seed.deserialize(self.de) + } + + // Tuple variants are represented in JSON as `{ NAME: [DATA...] }` so + // deserialize the sequence of data here. + fn tuple_variant<V>(self, _len: usize, visitor: V) -> Result<V::Value, Error> + where V: de::Visitor<'de> + { + de::Deserializer::deserialize_seq(self.de, visitor) + } + + // Struct variants are represented in JSON as `{ NAME: { K: V, ... } }` so + // deserialize the inner map here. + fn struct_variant<V>( + self, + _fields: &'static [&'static str], + visitor: V, + ) -> Result<V::Value, Error> + where V: de::Visitor<'de> + { + de::Deserializer::deserialize_map(self.de, visitor) + } +} + + impl<'a> Deserializer<'a> { /// Creates a new deserializer which will be deserializing the string /// provided. @@ -959,6 +1074,16 @@ impl<'a> Deserializer<'a> { self.tokens.peek().map_err(|e| self.token_error(e)) } + fn peek_char(&mut self) -> Result<char, Error> { + self.input.chars().next().ok_or(Error::from_kind(ErrorKind::UnexpectedEof)) + } + + fn next_char(&mut self) -> Result<char, Error> { + let ch = self.peek_char()?; + self.input = &self.input[ch.len_utf8()..]; + Ok(ch) + } + fn eof(&self) -> Error { self.error(self.input.len(), ErrorKind::UnexpectedEof) } @@ -1092,6 +1217,10 @@ impl fmt::Display for Error { ErrorKind::RedefineAsArray => "table redefined as array".fmt(f)?, ErrorKind::EmptyTableKey => "empty table key found".fmt(f)?, ErrorKind::Custom => self.inner.message.fmt(f)?, + ErrorKind::ExpectedMapEnd => "expected end of map".fmt(f)?, + ErrorKind::ExpectedEnum => "expected enum".fmt(f)?, + ErrorKind::ExpectedMapColon => "expected map colon".fmt(f)?, + ErrorKind::ExpectedString => "expected string".fmt(f)?, ErrorKind::__Nonexhaustive => panic!(), } @@ -1134,6 +1263,10 @@ impl error::Error for Error { ErrorKind::RedefineAsArray => "table redefined as array", ErrorKind::EmptyTableKey => "empty table key found", ErrorKind::Custom => "a custom error", + ErrorKind::ExpectedMapEnd => "expected end of map", + ErrorKind::ExpectedEnum => "expected enum", + ErrorKind::ExpectedMapColon => "expected map colon", + ErrorKind::ExpectedString => "expected string", ErrorKind::__Nonexhaustive => panic!(), } } |