nushell/crates/nu-json/src/value.rs
2022-02-07 14:54:06 -05:00

1159 lines
31 KiB
Rust

#[cfg(not(feature = "preserve_order"))]
use std::collections::{btree_map, BTreeMap};
#[cfg(feature = "preserve_order")]
use linked_hash_map::{self, LinkedHashMap};
use std::fmt;
use std::io;
use std::str;
use std::vec;
use num_traits::NumCast;
use serde::de;
use serde::ser;
use crate::error::{Error, ErrorCode};
type Result<T, E = Error> = std::result::Result<T, E>;
/// Represents a key/value type.
#[cfg(not(feature = "preserve_order"))]
pub type Map<K, V> = BTreeMap<K, V>;
/// Represents a key/value type.
#[cfg(feature = "preserve_order")]
pub type Map<K, V> = LinkedHashMap<K, V>;
/// Represents the `IntoIter` type.
#[cfg(not(feature = "preserve_order"))]
pub type MapIntoIter<K, V> = btree_map::IntoIter<K, V>;
/// Represents the IntoIter type.
#[cfg(feature = "preserve_order")]
pub type MapIntoIter<K, V> = linked_hash_map::IntoIter<K, V>;
fn map_with_capacity<K: std::hash::Hash + Eq, V>(size: Option<usize>) -> Map<K, V> {
#[cfg(not(feature = "preserve_order"))]
{
let _ = size;
BTreeMap::new()
}
#[cfg(feature = "preserve_order")]
{
LinkedHashMap::with_capacity(size.unwrap_or(0))
}
}
/// Represents a Hjson/JSON value
#[derive(Clone, PartialEq)]
pub enum Value {
/// Represents a JSON null value
Null,
/// Represents a JSON Boolean
Bool(bool),
/// Represents a JSON signed integer
I64(i64),
/// Represents a JSON unsigned integer
U64(u64),
/// Represents a JSON floating point number
F64(f64),
/// Represents a JSON string
String(String),
/// Represents a JSON array
Array(Vec<Value>),
/// Represents a JSON object
Object(Map<String, Value>),
}
impl Value {
/// If the `Value` is an Object, returns the value associated with the provided key.
/// Otherwise, returns None.
pub fn find<'a>(&'a self, key: &str) -> Option<&'a Value> {
match *self {
Value::Object(ref map) => map.get(key),
_ => None,
}
}
/// Attempts to get a nested Value Object for each key in `keys`.
/// If any key is found not to exist, find_path will return None.
/// Otherwise, it will return the `Value` associated with the final key.
pub fn find_path<'a>(&'a self, keys: &[&str]) -> Option<&'a Value> {
let mut target = self;
for key in keys {
match target.find(key) {
Some(t) => {
target = t;
}
None => return None,
}
}
Some(target)
}
/// Looks up a value by a JSON Pointer.
///
/// JSON Pointer defines a string syntax for identifying a specific value
/// within a JavaScript Object Notation (JSON) document.
///
/// A Pointer is a Unicode string with the reference tokens separated by `/`.
/// Inside tokens `/` is replaced by `~1` and `~` is replaced by `~0`. The
/// addressed value is returned and if there is no such value `None` is
/// returned.
///
/// For more information read [RFC6901](https://tools.ietf.org/html/rfc6901).
pub fn pointer<'a>(&'a self, pointer: &str) -> Option<&'a Value> {
fn parse_index(s: &str) -> Option<usize> {
if s.starts_with('+') || (s.starts_with('0') && s.len() != 1) {
return None;
}
s.parse().ok()
}
if pointer.is_empty() {
return Some(self);
}
if !pointer.starts_with('/') {
return None;
}
let mut target = self;
for escaped_token in pointer.split('/').skip(1) {
let token = escaped_token.replace("~1", "/").replace("~0", "~");
let target_opt = match *target {
Value::Object(ref map) => map.get(&token[..]),
Value::Array(ref list) => parse_index(&token[..]).and_then(|x| list.get(x)),
_ => return None,
};
if let Some(t) = target_opt {
target = t;
} else {
return None;
}
}
Some(target)
}
/// If the `Value` is an Object, performs a depth-first search until
/// a value associated with the provided key is found. If no value is found
/// or the `Value` is not an Object, returns None.
pub fn search<'a>(&'a self, key: &str) -> Option<&'a Value> {
match self {
Value::Object(map) => map
.get(key)
.or_else(|| map.values().find_map(|v| v.search(key))),
_ => None,
}
}
/// Returns true if the `Value` is an Object. Returns false otherwise.
pub fn is_object(&self) -> bool {
self.as_object().is_some()
}
/// If the `Value` is an Object, returns the associated Map.
/// Returns None otherwise.
pub fn as_object(&self) -> Option<&Map<String, Value>> {
match *self {
Value::Object(ref map) => Some(map),
_ => None,
}
}
/// If the `Value` is an Object, returns the associated mutable Map.
/// Returns None otherwise.
pub fn as_object_mut(&mut self) -> Option<&mut Map<String, Value>> {
match *self {
Value::Object(ref mut map) => Some(map),
_ => None,
}
}
/// Returns true if the `Value` is an Array. Returns false otherwise.
pub fn is_array(&self) -> bool {
self.as_array().is_some()
}
/// If the `Value` is an Array, returns the associated vector.
/// Returns None otherwise.
pub fn as_array(&self) -> Option<&Vec<Value>> {
match self {
Value::Array(array) => Some(array),
_ => None,
}
}
/// If the `Value` is an Array, returns the associated mutable vector.
/// Returns None otherwise.
pub fn as_array_mut(&mut self) -> Option<&mut Vec<Value>> {
match self {
Value::Array(list) => Some(list),
_ => None,
}
}
/// Returns true if the `Value` is a String. Returns false otherwise.
pub fn is_string(&self) -> bool {
self.as_str().is_some()
}
/// If the `Value` is a String, returns the associated str.
/// Returns None otherwise.
pub fn as_str(&self) -> Option<&str> {
match self {
Value::String(s) => Some(s),
_ => None,
}
}
/// Returns true if the `Value` is a Number. Returns false otherwise.
pub fn is_number(&self) -> bool {
matches!(self, Value::I64(_) | Value::U64(_) | Value::F64(_))
}
/// Returns true if the `Value` is a i64. Returns false otherwise.
pub fn is_i64(&self) -> bool {
matches!(self, Value::I64(_))
}
/// Returns true if the `Value` is a u64. Returns false otherwise.
pub fn is_u64(&self) -> bool {
matches!(self, Value::U64(_))
}
/// Returns true if the `Value` is a f64. Returns false otherwise.
pub fn is_f64(&self) -> bool {
matches!(self, Value::F64(_))
}
/// If the `Value` is a number, return or cast it to a i64.
/// Returns None otherwise.
pub fn as_i64(&self) -> Option<i64> {
match *self {
Value::I64(n) => Some(n),
Value::U64(n) => NumCast::from(n),
_ => None,
}
}
/// If the `Value` is a number, return or cast it to a u64.
/// Returns None otherwise.
pub fn as_u64(&self) -> Option<u64> {
match *self {
Value::I64(n) => NumCast::from(n),
Value::U64(n) => Some(n),
_ => None,
}
}
/// If the `Value` is a number, return or cast it to a f64.
/// Returns None otherwise.
pub fn as_f64(&self) -> Option<f64> {
match *self {
Value::I64(n) => NumCast::from(n),
Value::U64(n) => NumCast::from(n),
Value::F64(n) => Some(n),
_ => None,
}
}
/// Returns true if the `Value` is a Boolean. Returns false otherwise.
pub fn is_boolean(&self) -> bool {
self.as_bool().is_some()
}
/// If the `Value` is a Boolean, returns the associated bool.
/// Returns None otherwise.
pub fn as_bool(&self) -> Option<bool> {
match *self {
Value::Bool(b) => Some(b),
_ => None,
}
}
/// Returns true if the `Value` is a Null. Returns false otherwise.
pub fn is_null(&self) -> bool {
self.as_null().is_some()
}
/// If the `Value` is a Null, returns ().
/// Returns None otherwise.
pub fn as_null(&self) -> Option<()> {
match self {
Value::Null => Some(()),
_ => None,
}
}
fn as_unexpected(&self) -> de::Unexpected<'_> {
match *self {
Value::Null => de::Unexpected::Unit,
Value::Bool(v) => de::Unexpected::Bool(v),
Value::I64(v) => de::Unexpected::Signed(v),
Value::U64(v) => de::Unexpected::Unsigned(v),
Value::F64(v) => de::Unexpected::Float(v),
Value::String(ref v) => de::Unexpected::Str(v),
Value::Array(_) => de::Unexpected::Seq,
Value::Object(_) => de::Unexpected::Map,
}
}
}
impl ser::Serialize for Value {
#[inline]
fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
where
S: ser::Serializer,
{
match *self {
Value::Null => serializer.serialize_unit(),
Value::Bool(v) => serializer.serialize_bool(v),
Value::I64(v) => serializer.serialize_i64(v),
Value::U64(v) => serializer.serialize_u64(v),
Value::F64(v) => serializer.serialize_f64(v),
Value::String(ref v) => serializer.serialize_str(v),
Value::Array(ref v) => v.serialize(serializer),
Value::Object(ref v) => v.serialize(serializer),
}
}
}
impl<'de> de::Deserialize<'de> for Value {
#[inline]
fn deserialize<D>(deserializer: D) -> Result<Value, D::Error>
where
D: de::Deserializer<'de>,
{
struct ValueVisitor;
impl<'de> de::Visitor<'de> for ValueVisitor {
type Value = Value;
fn expecting(&self, f: &mut fmt::Formatter) -> fmt::Result {
f.write_str("a json value")
}
#[inline]
fn visit_bool<E>(self, value: bool) -> Result<Value, E> {
Ok(Value::Bool(value))
}
#[inline]
fn visit_i64<E>(self, value: i64) -> Result<Value, E> {
if value < 0 {
Ok(Value::I64(value))
} else {
Ok(Value::U64(value as u64))
}
}
#[inline]
fn visit_u64<E>(self, value: u64) -> Result<Value, E> {
Ok(Value::U64(value))
}
#[inline]
fn visit_f64<E>(self, value: f64) -> Result<Value, E> {
Ok(Value::F64(value))
}
#[inline]
fn visit_str<E>(self, value: &str) -> Result<Value, E>
where
E: de::Error,
{
self.visit_string(String::from(value))
}
#[inline]
fn visit_string<E>(self, value: String) -> Result<Value, E> {
Ok(Value::String(value))
}
#[inline]
fn visit_none<E>(self) -> Result<Value, E> {
Ok(Value::Null)
}
#[inline]
fn visit_some<D>(self, deserializer: D) -> Result<Value, D::Error>
where
D: de::Deserializer<'de>,
{
de::Deserialize::deserialize(deserializer)
}
#[inline]
fn visit_unit<E>(self) -> Result<Value, E> {
Ok(Value::Null)
}
#[inline]
fn visit_seq<A>(self, mut seq: A) -> Result<Value, A::Error>
where
A: de::SeqAccess<'de>,
{
let mut v = match seq.size_hint() {
Some(cap) => Vec::with_capacity(cap),
None => Vec::new(),
};
while let Some(el) = seq.next_element()? {
v.push(el)
}
Ok(Value::Array(v))
}
#[inline]
fn visit_map<A>(self, mut map: A) -> Result<Value, A::Error>
where
A: de::MapAccess<'de>,
{
let mut values = map_with_capacity(map.size_hint());
while let Some((k, v)) = map.next_entry()? {
values.insert(k, v);
}
Ok(Value::Object(values))
}
}
deserializer.deserialize_any(ValueVisitor)
}
}
struct WriterFormatter<'a, 'b: 'a> {
inner: &'a mut fmt::Formatter<'b>,
}
impl<'a, 'b> io::Write for WriterFormatter<'a, 'b> {
fn write(&mut self, buf: &[u8]) -> io::Result<usize> {
fn io_error<E>(_: E) -> io::Error {
// Value does not matter because fmt::Debug and fmt::Display impls
// below just map it to fmt::Error
io::Error::new(io::ErrorKind::Other, "fmt error")
}
let s = str::from_utf8(buf).map_err(io_error)?;
self.inner.write_str(s).map_err(io_error)?;
Ok(buf.len())
}
fn flush(&mut self) -> io::Result<()> {
Ok(())
}
}
impl fmt::Debug for Value {
/// Serializes a Hjson value into a string
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
let mut wr = WriterFormatter { inner: f };
super::ser::to_writer(&mut wr, self).map_err(|_| fmt::Error)
}
}
impl fmt::Display for Value {
/// Serializes a Hjson value into a string
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
let mut wr = WriterFormatter { inner: f };
super::ser::to_writer(&mut wr, self).map_err(|_| fmt::Error)
}
}
impl str::FromStr for Value {
type Err = Error;
fn from_str(s: &str) -> Result<Value> {
super::de::from_str(s)
}
}
/// Create a `serde::Serializer` that serializes a `Serialize`e into a `Value`.
#[derive(Default)]
pub struct Serializer;
impl ser::Serializer for Serializer {
type Ok = Value;
type Error = Error;
type SerializeSeq = SerializeVec;
type SerializeTuple = SerializeVec;
type SerializeTupleStruct = SerializeVec;
type SerializeTupleVariant = SerializeTupleVariant;
type SerializeMap = SerializeMap;
type SerializeStruct = SerializeMap;
type SerializeStructVariant = SerializeStructVariant;
#[inline]
fn serialize_bool(self, value: bool) -> Result<Value> {
Ok(Value::Bool(value))
}
#[inline]
fn serialize_i8(self, value: i8) -> Result<Value> {
self.serialize_i64(value as i64)
}
#[inline]
fn serialize_i16(self, value: i16) -> Result<Value> {
self.serialize_i64(value as i64)
}
#[inline]
fn serialize_i32(self, value: i32) -> Result<Value> {
self.serialize_i64(value as i64)
}
fn serialize_i64(self, value: i64) -> Result<Value> {
let v = if value < 0 {
Value::I64(value)
} else {
Value::U64(value as u64)
};
Ok(v)
}
#[inline]
fn serialize_u8(self, value: u8) -> Result<Value> {
self.serialize_u64(value as u64)
}
#[inline]
fn serialize_u16(self, value: u16) -> Result<Value> {
self.serialize_u64(value as u64)
}
#[inline]
fn serialize_u32(self, value: u32) -> Result<Value> {
self.serialize_u64(value as u64)
}
#[inline]
fn serialize_u64(self, value: u64) -> Result<Value> {
Ok(Value::U64(value))
}
#[inline]
fn serialize_f32(self, value: f32) -> Result<Value> {
self.serialize_f64(value as f64)
}
#[inline]
fn serialize_f64(self, value: f64) -> Result<Value> {
Ok(Value::F64(value))
}
#[inline]
fn serialize_char(self, value: char) -> Result<Value> {
let mut s = String::new();
s.push(value);
self.serialize_str(&s)
}
#[inline]
fn serialize_str(self, value: &str) -> Result<Value> {
Ok(Value::String(String::from(value)))
}
fn serialize_bytes(self, value: &[u8]) -> Result<Value> {
let mut state = self.serialize_seq(Some(value.len()))?;
for byte in value {
ser::SerializeSeq::serialize_element(&mut state, byte)?;
}
ser::SerializeSeq::end(state)
}
#[inline]
fn serialize_unit(self) -> Result<Value> {
Ok(Value::Null)
}
#[inline]
fn serialize_unit_struct(self, _name: &'static str) -> Result<Value> {
self.serialize_unit()
}
#[inline]
fn serialize_unit_variant(
self,
_name: &'static str,
_variant_index: u32,
variant: &'static str,
) -> Result<Value> {
self.serialize_str(variant)
}
#[inline]
fn serialize_newtype_struct<T>(self, _name: &'static str, value: &T) -> Result<Value>
where
T: ?Sized + ser::Serialize,
{
value.serialize(self)
}
fn serialize_newtype_variant<T>(
self,
_name: &'static str,
_variant_index: u32,
variant: &'static str,
value: &T,
) -> Result<Value>
where
T: ?Sized + ser::Serialize,
{
let mut values = Map::new();
values.insert(String::from(variant), to_value(&value)?);
Ok(Value::Object(values))
}
#[inline]
fn serialize_none(self) -> Result<Value> {
self.serialize_unit()
}
#[inline]
fn serialize_some<V>(self, value: &V) -> Result<Value>
where
V: ?Sized + ser::Serialize,
{
value.serialize(self)
}
#[inline]
fn serialize_seq(self, len: Option<usize>) -> Result<Self::SerializeSeq, Self::Error> {
Ok(SerializeVec {
vec: Vec::with_capacity(len.unwrap_or(0)),
})
}
#[inline]
fn serialize_tuple(self, len: usize) -> Result<Self::SerializeTuple, Self::Error> {
self.serialize_seq(Some(len))
}
#[inline]
fn serialize_tuple_struct(
self,
_name: &'static str,
len: usize,
) -> Result<Self::SerializeTupleStruct, Self::Error> {
self.serialize_seq(Some(len))
}
#[inline]
fn serialize_tuple_variant(
self,
_name: &'static str,
_variant_index: u32,
variant: &'static str,
len: usize,
) -> Result<Self::SerializeTupleVariant, Self::Error> {
Ok(SerializeTupleVariant {
name: variant,
vec: Vec::with_capacity(len),
})
}
#[inline]
fn serialize_map(self, len: Option<usize>) -> Result<Self::SerializeMap, Self::Error> {
Ok(SerializeMap {
map: map_with_capacity(len),
next_key: None,
})
}
#[inline]
fn serialize_struct(
self,
_name: &'static str,
len: usize,
) -> Result<Self::SerializeStruct, Self::Error> {
self.serialize_map(Some(len))
}
#[inline]
fn serialize_struct_variant(
self,
_name: &'static str,
_variant_index: u32,
variant: &'static str,
len: usize,
) -> Result<Self::SerializeStructVariant, Self::Error> {
Ok(SerializeStructVariant {
name: variant,
map: map_with_capacity(Some(len)),
})
}
}
#[doc(hidden)]
pub struct SerializeVec {
vec: Vec<Value>,
}
#[doc(hidden)]
pub struct SerializeTupleVariant {
name: &'static str,
vec: Vec<Value>,
}
#[doc(hidden)]
pub struct SerializeMap {
map: Map<String, Value>,
next_key: Option<String>,
}
#[doc(hidden)]
pub struct SerializeStructVariant {
name: &'static str,
map: Map<String, Value>,
}
impl ser::SerializeSeq for SerializeVec {
type Ok = Value;
type Error = Error;
fn serialize_element<T>(&mut self, value: &T) -> Result<()>
where
T: ?Sized + ser::Serialize,
{
self.vec.push(to_value(&value)?);
Ok(())
}
fn end(self) -> Result<Value> {
Ok(Value::Array(self.vec))
}
}
impl ser::SerializeTuple for SerializeVec {
type Ok = Value;
type Error = Error;
fn serialize_element<T>(&mut self, value: &T) -> Result<()>
where
T: ?Sized + ser::Serialize,
{
ser::SerializeSeq::serialize_element(self, value)
}
fn end(self) -> Result<Value> {
ser::SerializeSeq::end(self)
}
}
impl ser::SerializeTupleStruct for SerializeVec {
type Ok = Value;
type Error = Error;
fn serialize_field<T>(&mut self, value: &T) -> Result<()>
where
T: ?Sized + ser::Serialize,
{
ser::SerializeSeq::serialize_element(self, value)
}
fn end(self) -> Result<Value> {
ser::SerializeSeq::end(self)
}
}
impl ser::SerializeTupleVariant for SerializeTupleVariant {
type Ok = Value;
type Error = Error;
fn serialize_field<T>(&mut self, value: &T) -> Result<()>
where
T: ?Sized + ser::Serialize,
{
self.vec.push(to_value(&value)?);
Ok(())
}
fn end(self) -> Result<Value> {
let mut object = Map::new();
object.insert(self.name.to_owned(), Value::Array(self.vec));
Ok(Value::Object(object))
}
}
impl ser::SerializeMap for SerializeMap {
type Ok = Value;
type Error = Error;
fn serialize_key<T>(&mut self, key: &T) -> Result<()>
where
T: ?Sized + ser::Serialize,
{
match to_value(key)? {
Value::String(s) => self.next_key = Some(s),
_ => return Err(Error::Syntax(ErrorCode::KeyMustBeAString, 0, 0)),
};
Ok(())
}
fn serialize_value<T>(&mut self, value: &T) -> Result<()>
where
T: ?Sized + ser::Serialize,
{
let key = self.next_key.take();
// Panic because this indicates a bug in the program rather than an
// expected failure.
let key = key.expect("serialize_value called before serialize_key");
self.map.insert(key, to_value(value)?);
Ok(())
}
fn end(self) -> Result<Value> {
Ok(Value::Object(self.map))
}
}
impl ser::SerializeStruct for SerializeMap {
type Ok = Value;
type Error = Error;
fn serialize_field<T>(&mut self, key: &'static str, value: &T) -> Result<()>
where
T: ?Sized + ser::Serialize,
{
ser::SerializeMap::serialize_entry(self, key, value)
}
fn end(self) -> Result<Value> {
ser::SerializeMap::end(self)
}
}
impl ser::SerializeStructVariant for SerializeStructVariant {
type Ok = Value;
type Error = Error;
fn serialize_field<T>(&mut self, key: &'static str, value: &T) -> Result<()>
where
T: ?Sized + ser::Serialize,
{
self.map.insert(key.to_owned(), to_value(&value)?);
Ok(())
}
fn end(self) -> Result<Value> {
let mut object = map_with_capacity(Some(1));
object.insert(self.name.to_owned(), Value::Object(self.map));
Ok(Value::Object(object))
}
}
impl<'de> de::Deserializer<'de> for Value {
type Error = Error;
#[inline]
fn deserialize_any<V>(self, visitor: V) -> Result<V::Value>
where
V: de::Visitor<'de>,
{
match self {
Value::Null => visitor.visit_unit(),
Value::Bool(v) => visitor.visit_bool(v),
Value::I64(v) => visitor.visit_i64(v),
Value::U64(v) => visitor.visit_u64(v),
Value::F64(v) => visitor.visit_f64(v),
Value::String(v) => visitor.visit_string(v),
Value::Array(v) => visitor.visit_seq(SeqDeserializer {
iter: v.into_iter(),
}),
Value::Object(v) => visitor.visit_map(MapDeserializer {
iter: v.into_iter(),
value: None,
}),
}
}
#[inline]
fn deserialize_option<V>(self, visitor: V) -> Result<V::Value>
where
V: de::Visitor<'de>,
{
match self {
Value::Null => visitor.visit_none(),
_ => visitor.visit_some(self),
}
}
#[inline]
fn deserialize_enum<V>(
self,
_name: &str,
_variants: &'static [&'static str],
visitor: V,
) -> Result<V::Value>
where
V: de::Visitor<'de>,
{
let (variant, value) = match self {
Value::Object(value) => {
let mut iter = value.into_iter();
let (variant, value) = match iter.next() {
Some(v) => v,
None => {
return Err(de::Error::invalid_type(
de::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(de::Error::invalid_type(
de::Unexpected::Map,
&"map with a single key",
));
}
(variant, Some(value))
}
Value::String(variant) => (variant, None),
val => {
return Err(de::Error::invalid_type(
val.as_unexpected(),
&"string or map",
))
}
};
visitor.visit_enum(EnumDeserializer { variant, value })
}
#[inline]
fn deserialize_newtype_struct<V>(
self,
_name: &'static str,
visitor: V,
) -> Result<V::Value, Self::Error>
where
V: de::Visitor<'de>,
{
visitor.visit_newtype_struct(self)
}
serde::forward_to_deserialize_any! {
bool i8 i16 i32 i64 i128 u8 u16 u32 u64 u128 f32 f64 char str string
bytes byte_buf unit unit_struct seq tuple
tuple_struct map struct identifier ignored_any
}
}
struct EnumDeserializer {
variant: String,
value: Option<Value>,
}
impl<'de> de::EnumAccess<'de> for EnumDeserializer {
type Error = Error;
type Variant = VariantDeserializer;
fn variant_seed<V>(self, seed: V) -> Result<(V::Value, Self::Variant), Self::Error>
where
V: de::DeserializeSeed<'de>,
{
let variant = de::IntoDeserializer::into_deserializer(self.variant);
let visitor = VariantDeserializer { val: self.value };
seed.deserialize(variant).map(|v| (v, visitor))
}
}
struct VariantDeserializer {
val: Option<Value>,
}
impl<'de, 'a> de::VariantAccess<'de> for VariantDeserializer {
type Error = Error;
fn unit_variant(self) -> Result<()> {
match self.val {
Some(val) => de::Deserialize::deserialize(val),
None => Ok(()),
}
}
fn newtype_variant_seed<T>(self, seed: T) -> Result<T::Value>
where
T: de::DeserializeSeed<'de>,
{
match self.val {
Some(value) => seed.deserialize(value),
None => Err(serde::de::Error::invalid_type(
de::Unexpected::UnitVariant,
&"newtype variant",
)),
}
}
fn tuple_variant<V>(self, _len: usize, visitor: V) -> Result<V::Value>
where
V: de::Visitor<'de>,
{
let val = self.val.expect("val is missing");
if let Value::Array(fields) = val {
visitor.visit_seq(SeqDeserializer {
iter: fields.into_iter(),
})
} else {
Err(de::Error::invalid_type(val.as_unexpected(), &visitor))
}
}
fn struct_variant<V>(self, _fields: &'static [&'static str], visitor: V) -> Result<V::Value>
where
V: de::Visitor<'de>,
{
match self.val {
Some(Value::Object(fields)) => visitor.visit_map(MapDeserializer {
iter: fields.into_iter(),
value: None,
}),
Some(other) => Err(de::Error::invalid_type(
other.as_unexpected(),
&"struct variant",
)),
None => Err(de::Error::invalid_type(
de::Unexpected::UnitVariant,
&"struct variant",
)),
}
}
}
struct SeqDeserializer {
iter: vec::IntoIter<Value>,
}
impl<'de> de::SeqAccess<'de> for SeqDeserializer {
type Error = Error;
fn next_element_seed<T>(&mut self, seed: T) -> Result<Option<T::Value>, Self::Error>
where
T: de::DeserializeSeed<'de>,
{
match self.iter.next() {
Some(value) => Ok(Some(seed.deserialize(value)?)),
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: MapIntoIter<String, Value>,
value: Option<Value>,
}
impl<'de, 'a> de::MapAccess<'de> for MapDeserializer {
type Error = Error;
fn next_key_seed<K>(&mut self, seed: K) -> Result<Option<K::Value>>
where
K: de::DeserializeSeed<'de>,
{
match self.iter.next() {
Some((key, value)) => {
self.value = Some(value);
Ok(Some(seed.deserialize(Value::String(key))?))
}
None => Ok(None),
}
}
fn next_value_seed<V>(&mut self, seed: V) -> Result<V::Value, Self::Error>
where
V: de::DeserializeSeed<'de>,
{
let value = self.value.take().expect("value is missing");
seed.deserialize(value)
}
fn size_hint(&self) -> Option<usize> {
match self.iter.size_hint() {
(lower, Some(upper)) if lower == upper => Some(upper),
_ => None,
}
}
}
pub fn to_value<T: ?Sized>(value: &T) -> Result<Value>
where
T: ser::Serialize,
{
value.serialize(Serializer)
}
/// Shortcut function to decode a Hjson `Value` into a `T`
pub fn from_value<T>(value: Value) -> Result<T>
where
T: de::DeserializeOwned,
{
de::Deserialize::deserialize(value)
}
/// A trait for converting values to Hjson
pub trait ToJson {
/// Converts the value of `self` to an instance of Hjson
fn to_json(&self) -> Value;
}
impl<T: ?Sized> ToJson for T
where
T: ser::Serialize,
{
fn to_json(&self) -> Value {
to_value(&self).expect("failed to serialize")
}
}
#[cfg(test)]
mod test {
use super::Value;
use crate::de::from_str;
#[test]
fn number_deserialize() {
let v: Value = from_str("{\"a\":1}").unwrap();
let vo = v.as_object().unwrap();
assert_eq!(vo["a"].as_u64().unwrap(), 1);
let v: Value = from_str("{\"a\":-1}").unwrap();
let vo = v.as_object().unwrap();
assert_eq!(vo["a"].as_i64().unwrap(), -1);
let v: Value = from_str("{\"a\":1.1}").unwrap();
let vo = v.as_object().unwrap();
assert!(vo["a"].as_f64().unwrap() - 1.1 < std::f64::EPSILON);
let v: Value = from_str("{\"a\":-1.1}").unwrap();
let vo = v.as_object().unwrap();
assert!(vo["a"].as_f64().unwrap() + 1.1 > -(std::f64::EPSILON));
let v: Value = from_str("{\"a\":1e6}").unwrap();
let vo = v.as_object().unwrap();
assert!(vo["a"].as_f64().unwrap() - 1e6 < std::f64::EPSILON);
let v: Value = from_str("{\"a\":-1e6}").unwrap();
let vo = v.as_object().unwrap();
assert!(vo["a"].as_f64().unwrap() + 1e6 > -(std::f64::EPSILON));
}
}