1use std::{2 collections::BTreeMap,3 convert::{TryFrom, TryInto},4};56use serde::{7 de::{self, MapAccess, SeqAccess},8 Deserializer,9};1011use crate::{Error, Value};1213struct ObjectAccess {14 iter: std::collections::btree_map::IntoIter<String, Value>,15 value: Option<Value>,16}17impl ObjectAccess {18 fn new(v: BTreeMap<String, Value>) -> Self {19 Self {20 iter: v.into_iter(),21 value: None,22 }23 }24}2526impl<'de> MapAccess<'de> for ObjectAccess {27 type Error = Error;2829 fn next_key_seed<K>(&mut self, seed: K) -> Result<Option<K::Value>, Self::Error>30 where31 K: de::DeserializeSeed<'de>,32 {33 if let Some((k, v)) = self.iter.next() {34 let _ = self.value.insert(v);35 Ok(Some(seed.deserialize(Value::String(k))?))36 } else {37 Ok(None)38 }39 }4041 fn next_value_seed<V>(&mut self, seed: V) -> Result<V::Value, Self::Error>42 where43 V: de::DeserializeSeed<'de>,44 {45 seed.deserialize(self.value.take().unwrap())46 }47}4849struct ArrayAccess {50 iter: std::vec::IntoIter<Value>,51}52impl ArrayAccess {53 fn new(v: Vec<Value>) -> Self {54 Self {55 iter: v.into_iter(),56 }57 }58}5960impl<'de> SeqAccess<'de> for ArrayAccess {61 type Error = Error;6263 fn next_element_seed<T>(&mut self, seed: T) -> Result<Option<T::Value>, Self::Error>64 where65 T: de::DeserializeSeed<'de>,66 {67 if let Some(v) = self.iter.next() {68 Ok(Some(seed.deserialize(v)?))69 } else {70 Ok(None)71 }72 }73}7475impl Value {76 fn parse_int<T: TryFrom<i64>>(&self) -> Result<T, Error> {77 match self {78 Value::Number(n) => Ok((*n).try_into().map_err(|_| Error::BadNumber)?),79 _ => Err(Error::Expected("integer")),80 }81 }82 fn parse_boolean(self) -> Result<bool, Error> {83 match self {84 Value::Boolean(b) => Ok(b),85 _ => Err(Error::Expected("boolean")),86 }87 }88 pub fn parse_string(&self) -> Result<&str, Error> {89 match self {90 Value::String(s) => Ok(s),91 _ => Err(Error::Expected("string")),92 }93 }94 fn parse_char(self) -> Result<char, Error> {95 match self {96 Value::String(s) if s.chars().count() == 1 => Ok(s.chars().next().unwrap()),97 _ => Err(Error::Expected("char")),98 }99 }100 fn parse_array(self) -> Result<Vec<Value>, Error> {101 match self {102 Value::Array(s) => Ok(s),103 _ => Err(Error::Expected("array")),104 }105 }106 fn parse_object(self) -> Result<BTreeMap<String, Value>, Error> {107 match self {108 Value::Object(s) => Ok(s),109 _ => Err(Error::Expected("object")),110 }111 }112 fn parse_null(self) -> Result<(), Error> {113 match self {114 Value::Null => Ok(()),115 _ => Err(Error::Expected("null")),116 }117 }118}119120impl de::Error for Error {121 fn custom<T>(msg: T) -> Self122 where123 T: std::fmt::Display,124 {125 Self::Custom(format!("{}", msg))126 }127}128129impl<'de> Deserializer<'de> for Value {130 type Error = Error;131132 fn deserialize_any<V>(self, visitor: V) -> Result<V::Value, Self::Error>133 where134 V: serde::de::Visitor<'de>,135 {136 match self {137 Value::Number(f) => visitor.visit_i64(f),138 Value::String(s) => visitor.visit_str(&s),139 Value::Boolean(b) => visitor.visit_bool(b),140 Value::Object(o) => visitor.visit_map(ObjectAccess::new(o)),141 Value::Array(a) => visitor.visit_seq(ArrayAccess::new(a)),142 Value::Null => visitor.visit_none(),143 }144 }145146 fn deserialize_bool<V>(self, visitor: V) -> Result<V::Value, Self::Error>147 where148 V: serde::de::Visitor<'de>,149 {150 visitor.visit_bool(self.parse_boolean()?)151 }152153 fn deserialize_i8<V>(self, visitor: V) -> Result<V::Value, Self::Error>154 where155 V: serde::de::Visitor<'de>,156 {157 visitor.visit_i8(self.parse_int()?)158 }159160 fn deserialize_i16<V>(self, visitor: V) -> Result<V::Value, Self::Error>161 where162 V: serde::de::Visitor<'de>,163 {164 visitor.visit_i16(self.parse_int()?)165 }166167 fn deserialize_i32<V>(self, visitor: V) -> Result<V::Value, Self::Error>168 where169 V: serde::de::Visitor<'de>,170 {171 visitor.visit_i32(self.parse_int()?)172 }173174 fn deserialize_i64<V>(self, visitor: V) -> Result<V::Value, Self::Error>175 where176 V: serde::de::Visitor<'de>,177 {178 visitor.visit_i64(self.parse_int()?)179 }180181 fn deserialize_u8<V>(self, visitor: V) -> Result<V::Value, Self::Error>182 where183 V: serde::de::Visitor<'de>,184 {185 visitor.visit_u8(self.parse_int()?)186 }187188 fn deserialize_u16<V>(self, visitor: V) -> Result<V::Value, Self::Error>189 where190 V: serde::de::Visitor<'de>,191 {192 visitor.visit_u16(self.parse_int()?)193 }194195 fn deserialize_u32<V>(self, visitor: V) -> Result<V::Value, Self::Error>196 where197 V: serde::de::Visitor<'de>,198 {199 visitor.visit_u32(self.parse_int()?)200 }201202 fn deserialize_u64<V>(self, visitor: V) -> Result<V::Value, Self::Error>203 where204 V: serde::de::Visitor<'de>,205 {206 visitor.visit_u64(self.parse_int()?)207 }208209 fn deserialize_f32<V>(self, _visitor: V) -> Result<V::Value, Self::Error>210 where211 V: serde::de::Visitor<'de>,212 {213 todo!()214 }215216 fn deserialize_f64<V>(self, _visitor: V) -> Result<V::Value, Self::Error>217 where218 V: serde::de::Visitor<'de>,219 {220 todo!()221 }222223 fn deserialize_char<V>(self, visitor: V) -> Result<V::Value, Self::Error>224 where225 V: serde::de::Visitor<'de>,226 {227 visitor.visit_char(self.parse_char()?)228 }229230 fn deserialize_str<V>(self, visitor: V) -> Result<V::Value, Self::Error>231 where232 V: serde::de::Visitor<'de>,233 {234 visitor.visit_str(self.parse_string()?)235 }236237 fn deserialize_string<V>(self, visitor: V) -> Result<V::Value, Self::Error>238 where239 V: serde::de::Visitor<'de>,240 {241 visitor.visit_string(self.parse_string()?.to_owned())242 }243244 fn deserialize_bytes<V>(self, _visitor: V) -> Result<V::Value, Self::Error>245 where246 V: serde::de::Visitor<'de>,247 {248 todo!()249 }250251 fn deserialize_byte_buf<V>(self, _visitor: V) -> Result<V::Value, Self::Error>252 where253 V: serde::de::Visitor<'de>,254 {255 todo!()256 }257258 fn deserialize_option<V>(self, visitor: V) -> Result<V::Value, Self::Error>259 where260 V: serde::de::Visitor<'de>,261 {262 match self {263 Value::Null => visitor.visit_none(),264 v => visitor.visit_some(v),265 }266 }267268 fn deserialize_unit<V>(self, visitor: V) -> Result<V::Value, Self::Error>269 where270 V: serde::de::Visitor<'de>,271 {272 self.parse_null()?;273 visitor.visit_unit()274 }275276 fn deserialize_unit_struct<V>(277 self,278 _name: &'static str,279 visitor: V,280 ) -> Result<V::Value, Self::Error>281 where282 V: serde::de::Visitor<'de>,283 {284 self.deserialize_unit(visitor)285 }286287 fn deserialize_newtype_struct<V>(288 self,289 _name: &'static str,290 visitor: V,291 ) -> Result<V::Value, Self::Error>292 where293 V: serde::de::Visitor<'de>,294 {295 visitor.visit_newtype_struct(self)296 }297298 fn deserialize_seq<V>(self, visitor: V) -> Result<V::Value, Self::Error>299 where300 V: serde::de::Visitor<'de>,301 {302 visitor.visit_seq(self.parse_array().map(ArrayAccess::new)?)303 }304305 fn deserialize_tuple<V>(self, _len: usize, visitor: V) -> Result<V::Value, Self::Error>306 where307 V: serde::de::Visitor<'de>,308 {309 self.deserialize_seq(visitor)310 }311312 fn deserialize_tuple_struct<V>(313 self,314 _name: &'static str,315 _len: usize,316 visitor: V,317 ) -> Result<V::Value, Self::Error>318 where319 V: serde::de::Visitor<'de>,320 {321 self.deserialize_seq(visitor)322 }323324 fn deserialize_map<V>(self, visitor: V) -> Result<V::Value, Self::Error>325 where326 V: serde::de::Visitor<'de>,327 {328 visitor.visit_map(self.parse_object().map(ObjectAccess::new)?)329 }330331 fn deserialize_struct<V>(332 self,333 _name: &'static str,334 _fields: &'static [&'static str],335 visitor: V,336 ) -> Result<V::Value, Self::Error>337 where338 V: serde::de::Visitor<'de>,339 {340 self.deserialize_map(visitor)341 }342343 fn deserialize_enum<V>(344 self,345 _name: &'static str,346 _variants: &'static [&'static str],347 _visitor: V,348 ) -> Result<V::Value, Self::Error>349 where350 V: serde::de::Visitor<'de>,351 {352 todo!()353 }354355 fn deserialize_identifier<V>(self, visitor: V) -> Result<V::Value, Self::Error>356 where357 V: serde::de::Visitor<'de>,358 {359 self.deserialize_str(visitor)360 }361362 fn deserialize_ignored_any<V>(self, visitor: V) -> Result<V::Value, Self::Error>363 where364 V: serde::de::Visitor<'de>,365 {366 self.deserialize_any(visitor)367 }368}