use std::mem;
use super::Value;
use indexmap::map::{IndexMap, IntoIter};
/// An Object value
#[derive(Debug, Clone, PartialEq)]
pub struct Object<S> {
key_value_list: IndexMap<String, Value<S>>,
}
impl<S> Object<S> {
/// Create a new Object value with a fixed number of
/// preallocated slots for field-value pairs
pub fn with_capacity(size: usize) -> Self {
Object {
key_value_list: IndexMap::with_capacity(size),
}
}
/// Add a new field with a value
///
/// If there is already a field for the given key
/// any both values are objects, they are merged.
///
/// Otherwise the existing value is replaced and
/// returned.
pub fn add_field<K>(&mut self, k: K, value: Value<S>) -> Option<Value<S>>
where
K: AsRef<str> + Into<String>,
{
if let Some(v) = self.key_value_list.get_mut(k.as_ref()) {
Some(mem::replace(v, value))
} else {
self.key_value_list.insert(k.into(), value)
}
}
/// Check if the object already contains a field with the given name
pub fn contains_field<K: AsRef<str>>(&self, k: K) -> bool {
self.key_value_list.contains_key(k.as_ref())
}
/// Get a iterator over all field value pairs
pub fn iter(&self) -> impl Iterator<Item = (&String, &Value<S>)> {
self.key_value_list.iter()
}
/// Get a iterator over all mutable field value pairs
pub fn iter_mut(&mut self) -> impl Iterator<Item = (&String, &mut Value<S>)> {
self.key_value_list.iter_mut()
}
/// Get the current number of fields
pub fn field_count(&self) -> usize {
self.key_value_list.len()
}
/// Get the value for a given field
pub fn get_field_value<K: AsRef<str>>(&self, key: K) -> Option<&Value<S>> {
self.key_value_list.get(key.as_ref())
}
/// Get the mutable value for a given field
pub fn get_mut_field_value<K: AsRef<str>>(&mut self, key: K) -> Option<&mut Value<S>> {
self.key_value_list.get_mut(key.as_ref())
}
}
impl<S> IntoIterator for Object<S> {
type Item = (String, Value<S>);
type IntoIter = IntoIter<String, Value<S>>;
fn into_iter(self) -> Self::IntoIter {
self.key_value_list.into_iter()
}
}
impl<S> From<Object<S>> for Value<S> {
fn from(o: Object<S>) -> Self {
Self::Object(o)
}
}
impl<K, S> FromIterator<(K, Value<S>)> for Object<S>
where
K: AsRef<str> + Into<String>,
{
fn from_iter<I>(iter: I) -> Self
where
I: IntoIterator<Item = (K, Value<S>)>,
{
let iter = iter.into_iter();
let mut ret = Self {
key_value_list: IndexMap::with_capacity(iter.size_hint().0),
};
for (k, v) in iter {
ret.add_field(k, v);
}
ret
}
}