diff options
Diffstat (limited to 'src/de/value.rs')
| -rw-r--r-- | src/de/value.rs | 252 |
1 files changed, 252 insertions, 0 deletions
diff --git a/src/de/value.rs b/src/de/value.rs new file mode 100644 index 0000000..3984287 --- /dev/null +++ b/src/de/value.rs @@ -0,0 +1,252 @@ +use serde::de::IntoDeserializer as _; + +use crate::de::DatetimeDeserializer; +use crate::de::Error; + +/// Deserialization implementation for TOML [values][crate::Value]. +/// +/// Can be creater either directly from TOML strings, using [`std::str::FromStr`], +/// or from parsed [values][crate::Value] using [`serde::de::IntoDeserializer::into_deserializer`]. +/// +/// # Example +/// +/// ``` +/// use serde::Deserialize; +/// +/// #[derive(Deserialize)] +/// struct Config { +/// title: String, +/// owner: Owner, +/// } +/// +/// #[derive(Deserialize)] +/// struct Owner { +/// name: String, +/// } +/// +/// let value = r#"{ title = 'TOML Example', owner = { name = 'Lisa' } }"#; +/// let deserializer = value.parse::<toml_edit::de::ValueDeserializer>().unwrap(); +/// let config = Config::deserialize(deserializer).unwrap(); +/// assert_eq!(config.title, "TOML Example"); +/// assert_eq!(config.owner.name, "Lisa"); +/// ``` +pub struct ValueDeserializer { + input: crate::Item, + validate_struct_keys: bool, +} + +impl ValueDeserializer { + pub(crate) fn new(input: crate::Item) -> Self { + Self { + input, + validate_struct_keys: false, + } + } + + pub(crate) fn with_struct_key_validation(mut self) -> Self { + self.validate_struct_keys = true; + self + } +} + +// Note: this is wrapped by `toml::de::ValueDeserializer` and any trait methods +// implemented here need to be wrapped there +impl<'de> serde::Deserializer<'de> for ValueDeserializer { + type Error = Error; + + fn deserialize_any<V>(self, visitor: V) -> Result<V::Value, Self::Error> + where + V: serde::de::Visitor<'de>, + { + let span = self.input.span(); + match self.input { + crate::Item::None => visitor.visit_none(), + crate::Item::Value(crate::Value::String(v)) => visitor.visit_string(v.into_value()), + crate::Item::Value(crate::Value::Integer(v)) => visitor.visit_i64(v.into_value()), + crate::Item::Value(crate::Value::Float(v)) => visitor.visit_f64(v.into_value()), + crate::Item::Value(crate::Value::Boolean(v)) => visitor.visit_bool(v.into_value()), + crate::Item::Value(crate::Value::Datetime(v)) => { + visitor.visit_map(DatetimeDeserializer::new(v.into_value())) + } + crate::Item::Value(crate::Value::Array(v)) => { + v.into_deserializer().deserialize_any(visitor) + } + crate::Item::Value(crate::Value::InlineTable(v)) => { + v.into_deserializer().deserialize_any(visitor) + } + crate::Item::Table(v) => v.into_deserializer().deserialize_any(visitor), + crate::Item::ArrayOfTables(v) => v.into_deserializer().deserialize_any(visitor), + } + .map_err(|mut e: Self::Error| { + if e.span().is_none() { + e.set_span(span); + } + e + }) + } + + // `None` is interpreted as a missing field so be sure to implement `Some` + // as a present field. + fn deserialize_option<V>(self, visitor: V) -> Result<V::Value, Error> + where + V: serde::de::Visitor<'de>, + { + let span = self.input.span(); + visitor.visit_some(self).map_err(|mut e: Self::Error| { + if e.span().is_none() { + e.set_span(span); + } + e + }) + } + + fn deserialize_newtype_struct<V>( + self, + _name: &'static str, + visitor: V, + ) -> Result<V::Value, Error> + where + V: serde::de::Visitor<'de>, + { + let span = self.input.span(); + visitor + .visit_newtype_struct(self) + .map_err(|mut e: Self::Error| { + if e.span().is_none() { + e.set_span(span); + } + e + }) + } + + fn deserialize_struct<V>( + self, + name: &'static str, + fields: &'static [&'static str], + visitor: V, + ) -> Result<V::Value, Error> + where + V: serde::de::Visitor<'de>, + { + if serde_spanned::__unstable::is_spanned(name, fields) { + if let Some(span) = self.input.span() { + return visitor.visit_map(super::SpannedDeserializer::new(self, span)); + } + } + + if name == toml_datetime::__unstable::NAME && fields == [toml_datetime::__unstable::FIELD] { + let span = self.input.span(); + if let crate::Item::Value(crate::Value::Datetime(d)) = self.input { + return visitor + .visit_map(DatetimeDeserializer::new(d.into_value())) + .map_err(|mut e: Self::Error| { + if e.span().is_none() { + e.set_span(span); + } + e + }); + } + } + + if self.validate_struct_keys { + let span = self.input.span(); + match &self.input { + crate::Item::Table(values) => super::validate_struct_keys(&values.items, fields), + crate::Item::Value(crate::Value::InlineTable(values)) => { + super::validate_struct_keys(&values.items, fields) + } + _ => Ok(()), + } + .map_err(|mut e: Self::Error| { + if e.span().is_none() { + e.set_span(span); + } + e + })? + } + + self.deserialize_any(visitor) + } + + // Called when the type to deserialize is an enum, as opposed to a field in the type. + fn deserialize_enum<V>( + self, + name: &'static str, + variants: &'static [&'static str], + visitor: V, + ) -> Result<V::Value, Error> + where + V: serde::de::Visitor<'de>, + { + let span = self.input.span(); + match self.input { + crate::Item::Value(crate::Value::String(v)) => { + visitor.visit_enum(v.into_value().into_deserializer()) + } + crate::Item::Value(crate::Value::InlineTable(v)) => { + if v.is_empty() { + Err(crate::de::Error::custom( + "wanted exactly 1 element, found 0 elements", + v.span(), + )) + } else if v.len() != 1 { + Err(crate::de::Error::custom( + "wanted exactly 1 element, more than 1 element", + v.span(), + )) + } else { + v.into_deserializer() + .deserialize_enum(name, variants, visitor) + } + } + crate::Item::Table(v) => v + .into_deserializer() + .deserialize_enum(name, variants, visitor), + e => Err(crate::de::Error::custom("wanted string or table", e.span())), + } + .map_err(|mut e: Self::Error| { + if e.span().is_none() { + e.set_span(span); + } + e + }) + } + + serde::forward_to_deserialize_any! { + bool u8 u16 u32 u64 i8 i16 i32 i64 f32 f64 char str string seq + bytes byte_buf map unit + ignored_any unit_struct tuple_struct tuple identifier + } +} + +impl<'de> serde::de::IntoDeserializer<'de, crate::de::Error> for ValueDeserializer { + type Deserializer = Self; + + fn into_deserializer(self) -> Self::Deserializer { + self + } +} + +impl<'de> serde::de::IntoDeserializer<'de, crate::de::Error> for crate::Value { + type Deserializer = ValueDeserializer; + + fn into_deserializer(self) -> Self::Deserializer { + ValueDeserializer::new(crate::Item::Value(self)) + } +} + +impl crate::Item { + pub(crate) fn into_deserializer(self) -> ValueDeserializer { + ValueDeserializer::new(self) + } +} + +impl std::str::FromStr for ValueDeserializer { + type Err = Error; + + /// Parses a value from a &str + fn from_str(s: &str) -> Result<Self, Self::Err> { + let v = crate::parser::parse_value(s).map_err(Error::from)?; + Ok(v.into_deserializer()) + } +} |