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use crate::{number, Error, Mapping, Sequence, Value};
use serde::de::{
self, Deserialize, DeserializeSeed, Deserializer, EnumAccess, Error as SError, Expected,
MapAccess, SeqAccess, Unexpected, VariantAccess, Visitor,
};
use serde::forward_to_deserialize_any;
use std::fmt;
use std::vec;
impl<'de> Deserialize<'de> for Value {
fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
where
D: Deserializer<'de>,
{
struct ValueVisitor;
impl<'de> Visitor<'de> for ValueVisitor {
type Value = Value;
fn expecting(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
formatter.write_str("any YAML value")
}
fn visit_bool<E>(self, b: bool) -> Result<Value, E>
where
E: SError,
{
Ok(Value::Bool(b))
}
fn visit_i64<E>(self, i: i64) -> Result<Value, E>
where
E: SError,
{
Ok(Value::Number(i.into()))
}
fn visit_u64<E>(self, u: u64) -> Result<Value, E>
where
E: SError,
{
Ok(Value::Number(u.into()))
}
fn visit_f64<E>(self, f: f64) -> Result<Value, E>
where
E: SError,
{
Ok(Value::Number(f.into()))
}
fn visit_str<E>(self, s: &str) -> Result<Value, E>
where
E: SError,
{
Ok(Value::String(s.to_owned()))
}
fn visit_string<E>(self, s: String) -> Result<Value, E>
where
E: SError,
{
Ok(Value::String(s))
}
fn visit_unit<E>(self) -> Result<Value, E>
where
E: SError,
{
Ok(Value::Null)
}
fn visit_none<E>(self) -> Result<Value, E>
where
E: SError,
{
Ok(Value::Null)
}
fn visit_some<D>(self, deserializer: D) -> Result<Value, D::Error>
where
D: Deserializer<'de>,
{
Deserialize::deserialize(deserializer)
}
fn visit_seq<V>(self, mut visitor: V) -> Result<Value, V::Error>
where
V: SeqAccess<'de>,
{
let mut vec = Vec::new();
while let Some(element) = visitor.next_element()? {
vec.push(element);
}
Ok(Value::Sequence(vec))
}
fn visit_map<V>(self, mut visitor: V) -> Result<Value, V::Error>
where
V: MapAccess<'de>,
{
let mut values = Mapping::new();
while let Some((key, value)) = visitor.next_entry()? {
values.insert(key, value);
}
Ok(Value::Mapping(values))
}
}
deserializer.deserialize_any(ValueVisitor)
}
}
impl Value {
fn deserialize_number<'de, V>(self, visitor: V) -> Result<V::Value, Error>
where
V: Visitor<'de>,
{
match self {
Value::Number(n) => n.deserialize_any(visitor),
_ => Err(self.invalid_type(&visitor)),
}
}
}
fn visit_sequence<'de, V>(sequence: Sequence, visitor: V) -> Result<V::Value, Error>
where
V: Visitor<'de>,
{
let len = sequence.len();
let mut deserializer = SeqDeserializer::new(sequence);
let seq = visitor.visit_seq(&mut deserializer)?;
let remaining = deserializer.iter.len();
if remaining == 0 {
Ok(seq)
} else {
Err(Error::invalid_length(len, &"fewer elements in sequence"))
}
}
fn visit_mapping<'de, V>(mapping: Mapping, visitor: V) -> Result<V::Value, Error>
where
V: Visitor<'de>,
{
let len = mapping.len();
let mut deserializer = MapDeserializer::new(mapping);
let map = visitor.visit_map(&mut deserializer)?;
let remaining = deserializer.iter.len();
if remaining == 0 {
Ok(map)
} else {
Err(Error::invalid_length(len, &"fewer elements in map"))
}
}
impl<'de> Deserializer<'de> for Value {
type Error = Error;
fn deserialize_any<V>(self, visitor: V) -> Result<V::Value, Error>
where
V: Visitor<'de>,
{
match self {
Value::Null => visitor.visit_unit(),
Value::Bool(v) => visitor.visit_bool(v),
Value::Number(n) => n.deserialize_any(visitor),
Value::String(v) => visitor.visit_string(v),
Value::Sequence(v) => visit_sequence(v, visitor),
Value::Mapping(v) => visit_mapping(v, visitor),
}
}
fn deserialize_bool<V>(self, visitor: V) -> Result<V::Value, Error>
where
V: Visitor<'de>,
{
match self {
Value::Bool(v) => visitor.visit_bool(v),
_ => Err(self.invalid_type(&visitor)),
}
}
fn deserialize_i8<V>(self, visitor: V) -> Result<V::Value, Error>
where
V: Visitor<'de>,
{
self.deserialize_number(visitor)
}
fn deserialize_i16<V>(self, visitor: V) -> Result<V::Value, Error>
where
V: Visitor<'de>,
{
self.deserialize_number(visitor)
}
fn deserialize_i32<V>(self, visitor: V) -> Result<V::Value, Error>
where
V: Visitor<'de>,
{
self.deserialize_number(visitor)
}
fn deserialize_i64<V>(self, visitor: V) -> Result<V::Value, Error>
where
V: Visitor<'de>,
{
self.deserialize_number(visitor)
}
fn deserialize_i128<V>(self, visitor: V) -> Result<V::Value, Error>
where
V: Visitor<'de>,
{
self.deserialize_number(visitor)
}
fn deserialize_u8<V>(self, visitor: V) -> Result<V::Value, Error>
where
V: Visitor<'de>,
{
self.deserialize_number(visitor)
}
fn deserialize_u16<V>(self, visitor: V) -> Result<V::Value, Error>
where
V: Visitor<'de>,
{
self.deserialize_number(visitor)
}
fn deserialize_u32<V>(self, visitor: V) -> Result<V::Value, Error>
where
V: Visitor<'de>,
{
self.deserialize_number(visitor)
}
fn deserialize_u64<V>(self, visitor: V) -> Result<V::Value, Error>
where
V: Visitor<'de>,
{
self.deserialize_number(visitor)
}
fn deserialize_u128<V>(self, visitor: V) -> Result<V::Value, Error>
where
V: Visitor<'de>,
{
self.deserialize_number(visitor)
}
fn deserialize_f32<V>(self, visitor: V) -> Result<V::Value, Error>
where
V: Visitor<'de>,
{
self.deserialize_number(visitor)
}
fn deserialize_f64<V>(self, visitor: V) -> Result<V::Value, Error>
where
V: Visitor<'de>,
{
self.deserialize_number(visitor)
}
fn deserialize_char<V>(self, visitor: V) -> Result<V::Value, Error>
where
V: Visitor<'de>,
{
self.deserialize_string(visitor)
}
fn deserialize_str<V>(self, visitor: V) -> Result<V::Value, Error>
where
V: Visitor<'de>,
{
self.deserialize_string(visitor)
}
fn deserialize_string<V>(self, visitor: V) -> Result<V::Value, Error>
where
V: Visitor<'de>,
{
match self {
Value::String(v) => visitor.visit_string(v),
_ => Err(self.invalid_type(&visitor)),
}
}
fn deserialize_bytes<V>(self, visitor: V) -> Result<V::Value, Error>
where
V: Visitor<'de>,
{
self.deserialize_byte_buf(visitor)
}
fn deserialize_byte_buf<V>(self, visitor: V) -> Result<V::Value, Error>
where
V: Visitor<'de>,
{
match self {
Value::String(v) => visitor.visit_string(v),
Value::Sequence(v) => visit_sequence(v, visitor),
_ => Err(self.invalid_type(&visitor)),
}
}
fn deserialize_option<V>(self, visitor: V) -> Result<V::Value, Error>
where
V: Visitor<'de>,
{
match self {
Value::Null => visitor.visit_none(),
_ => visitor.visit_some(self),
}
}
fn deserialize_unit<V>(self, visitor: V) -> Result<V::Value, Error>
where
V: Visitor<'de>,
{
match self {
Value::Null => visitor.visit_unit(),
_ => Err(self.invalid_type(&visitor)),
}
}
fn deserialize_unit_struct<V>(self, _name: &'static str, visitor: V) -> Result<V::Value, Error>
where
V: Visitor<'de>,
{
self.deserialize_unit(visitor)
}
fn deserialize_newtype_struct<V>(
self,
_name: &'static str,
visitor: V,
) -> Result<V::Value, Error>
where
V: Visitor<'de>,
{
visitor.visit_newtype_struct(self)
}
fn deserialize_seq<V>(self, visitor: V) -> Result<V::Value, Error>
where
V: Visitor<'de>,
{
match self {
Value::Sequence(v) => visit_sequence(v, visitor),
_ => Err(self.invalid_type(&visitor)),
}
}
fn deserialize_tuple<V>(self, _len: usize, visitor: V) -> Result<V::Value, Error>
where
V: Visitor<'de>,
{
self.deserialize_seq(visitor)
}
fn deserialize_tuple_struct<V>(
self,
_name: &'static str,
_len: usize,
visitor: V,
) -> Result<V::Value, Error>
where
V: Visitor<'de>,
{
self.deserialize_seq(visitor)
}
fn deserialize_map<V>(self, visitor: V) -> Result<V::Value, Error>
where
V: Visitor<'de>,
{
match self {
Value::Mapping(v) => visit_mapping(v, visitor),
_ => Err(self.invalid_type(&visitor)),
}
}
fn deserialize_struct<V>(
self,
_name: &'static str,
_fields: &'static [&'static str],
visitor: V,
) -> Result<V::Value, Error>
where
V: Visitor<'de>,
{
match self {
Value::Sequence(v) => visit_sequence(v, visitor),
Value::Mapping(v) => visit_mapping(v, visitor),
_ => Err(self.invalid_type(&visitor)),
}
}
fn deserialize_enum<V>(
self,
_name: &str,
_variants: &'static [&'static str],
visitor: V,
) -> Result<V::Value, Error>
where
V: Visitor<'de>,
{
let (variant, value) = match self {
Value::Mapping(value) => {
let mut iter = value.into_iter();
let (variant, value) = match iter.next() {
Some(v) => v,
None => {
return Err(Error::invalid_value(
Unexpected::Map,
&"map with a single key",
));
}
};
// enums are encoded in json as maps with a single key:value pair
if iter.next().is_some() {
return Err(Error::invalid_value(
Unexpected::Map,
&"map with a single key",
));
}
(variant, Some(value))
}
Value::String(variant) => (Value::String(variant), None),
other => {
return Err(Error::invalid_type(other.unexpected(), &"string or map"));
}
};
visitor.visit_enum(EnumDeserializer { variant, value })
}
fn deserialize_identifier<V>(self, visitor: V) -> Result<V::Value, Error>
where
V: Visitor<'de>,
{
self.deserialize_string(visitor)
}
fn deserialize_ignored_any<V>(self, visitor: V) -> Result<V::Value, Error>
where
V: Visitor<'de>,
{
drop(self);
visitor.visit_unit()
}
}
struct EnumDeserializer {
variant: Value,
value: Option<Value>,
}
impl<'de> EnumAccess<'de> for EnumDeserializer {
type Error = Error;
type Variant = VariantDeserializer;
fn variant_seed<V>(self, seed: V) -> Result<(V::Value, VariantDeserializer), Error>
where
V: DeserializeSeed<'de>,
{
let visitor = VariantDeserializer { value: self.value };
seed.deserialize(self.variant).map(|v| (v, visitor))
}
}
struct VariantDeserializer {
value: Option<Value>,
}
impl<'de> VariantAccess<'de> for VariantDeserializer {
type Error = Error;
fn unit_variant(self) -> Result<(), Error> {
match self.value {
Some(value) => Deserialize::deserialize(value),
None => Ok(()),
}
}
fn newtype_variant_seed<T>(self, seed: T) -> Result<T::Value, Error>
where
T: DeserializeSeed<'de>,
{
match self.value {
Some(value) => seed.deserialize(value),
None => Err(Error::invalid_type(
Unexpected::UnitVariant,
&"newtype variant",
)),
}
}
fn tuple_variant<V>(self, _len: usize, visitor: V) -> Result<V::Value, Error>
where
V: Visitor<'de>,
{
match self.value {
Some(Value::Sequence(v)) => {
Deserializer::deserialize_any(SeqDeserializer::new(v), visitor)
}
Some(other) => Err(Error::invalid_type(other.unexpected(), &"tuple variant")),
None => Err(Error::invalid_type(
Unexpected::UnitVariant,
&"tuple variant",
)),
}
}
fn struct_variant<V>(
self,
_fields: &'static [&'static str],
visitor: V,
) -> Result<V::Value, Error>
where
V: Visitor<'de>,
{
match self.value {
Some(Value::Mapping(v)) => {
Deserializer::deserialize_any(MapDeserializer::new(v), visitor)
}
Some(other) => Err(Error::invalid_type(other.unexpected(), &"struct variant")),
None => Err(Error::invalid_type(
Unexpected::UnitVariant,
&"struct variant",
)),
}
}
}
struct SeqDeserializer {
iter: vec::IntoIter<Value>,
}
impl SeqDeserializer {
fn new(vec: Vec<Value>) -> Self {
SeqDeserializer {
iter: vec.into_iter(),
}
}
}
impl<'de> Deserializer<'de> for SeqDeserializer {
type Error = Error;
#[inline]
fn deserialize_any<V>(mut self, visitor: V) -> Result<V::Value, Error>
where
V: Visitor<'de>,
{
let len = self.iter.len();
if len == 0 {
visitor.visit_unit()
} else {
let ret = visitor.visit_seq(&mut self)?;
let remaining = self.iter.len();
if remaining == 0 {
Ok(ret)
} else {
Err(Error::invalid_length(len, &"fewer elements in sequence"))
}
}
}
fn deserialize_ignored_any<V>(self, visitor: V) -> Result<V::Value, Error>
where
V: Visitor<'de>,
{
drop(self);
visitor.visit_unit()
}
forward_to_deserialize_any! {
bool i8 i16 i32 i64 u8 u16 u32 u64 f32 f64 char str string bytes
byte_buf option unit unit_struct newtype_struct seq tuple tuple_struct
map struct enum identifier
}
}
impl<'de> SeqAccess<'de> for SeqDeserializer {
type Error = Error;
fn next_element_seed<T>(&mut self, seed: T) -> Result<Option<T::Value>, Error>
where
T: DeserializeSeed<'de>,
{
match self.iter.next() {
Some(value) => seed.deserialize(value).map(Some),
None => Ok(None),
}
}
fn size_hint(&self) -> Option<usize> {
match self.iter.size_hint() {
(lower, Some(upper)) if lower == upper => Some(upper),
_ => None,
}
}
}
struct MapDeserializer {
iter: <Mapping as IntoIterator>::IntoIter,
value: Option<Value>,
}
impl MapDeserializer {
fn new(map: Mapping) -> Self {
MapDeserializer {
iter: map.into_iter(),
value: None,
}
}
}
impl<'de> MapAccess<'de> for MapDeserializer {
type Error = Error;
fn next_key_seed<T>(&mut self, seed: T) -> Result<Option<T::Value>, Error>
where
T: DeserializeSeed<'de>,
{
match self.iter.next() {
Some((key, value)) => {
self.value = Some(value);
seed.deserialize(key).map(Some)
}
None => Ok(None),
}
}
fn next_value_seed<T>(&mut self, seed: T) -> Result<T::Value, Error>
where
T: DeserializeSeed<'de>,
{
match self.value.take() {
Some(value) => seed.deserialize(value),
None => panic!("visit_value called before visit_key"),
}
}
fn size_hint(&self) -> Option<usize> {
match self.iter.size_hint() {
(lower, Some(upper)) if lower == upper => Some(upper),
_ => None,
}
}
}
impl<'de> Deserializer<'de> for MapDeserializer {
type Error = Error;
#[inline]
fn deserialize_any<V>(self, visitor: V) -> Result<V::Value, Error>
where
V: Visitor<'de>,
{
visitor.visit_map(self)
}
fn deserialize_ignored_any<V>(self, visitor: V) -> Result<V::Value, Error>
where
V: Visitor<'de>,
{
drop(self);
visitor.visit_unit()
}
forward_to_deserialize_any! {
bool i8 i16 i32 i64 u8 u16 u32 u64 f32 f64 char str string bytes
byte_buf option unit unit_struct newtype_struct seq tuple tuple_struct
map struct enum identifier
}
}
impl Value {
#[cold]
fn invalid_type<E>(&self, exp: &dyn Expected) -> E
where
E: de::Error,
{
de::Error::invalid_type(self.unexpected(), exp)
}
#[cold]
fn unexpected(&self) -> Unexpected {
match self {
Value::Null => Unexpected::Unit,
Value::Bool(b) => Unexpected::Bool(*b),
Value::Number(n) => number::unexpected(n),
Value::String(s) => Unexpected::Str(s),
Value::Sequence(_) => Unexpected::Seq,
Value::Mapping(_) => Unexpected::Map,
}
}
}