eva/src/array.rs
2025-09-15 19:58:24 +03:00

146 lines
3.7 KiB
Rust

//! # Array utilities and types.
use std::{
borrow::{Borrow, Cow},
fmt,
ops::Deref,
sync::Arc,
};
use eva_macros::data;
use schemars::JsonSchema;
use serde::{Deserialize, Serialize, de};
#[data(copy, error, display("too big, expected array no bigger than {LIMIT}"), crate = crate)]
pub struct TooBig<const LIMIT: usize>;
#[crate::perfect_derive(Debug, Default, Clone, PartialEq, Eq, Hash)]
pub struct ImmutableHeap<T, const MAX: usize>(Arc<[T]>);
impl<T, const MAX: usize> Borrow<[T]> for ImmutableHeap<T, MAX> {
fn borrow(&self) -> &[T] {
self.0.as_ref()
}
}
impl<T, const MAX: usize> AsRef<[T]> for ImmutableHeap<T, MAX> {
fn as_ref(&self) -> &[T] {
self.0.as_ref()
}
}
impl<T, const MAX: usize> Deref for ImmutableHeap<T, MAX> {
type Target = [T];
fn deref(&self) -> &Self::Target {
self.0.as_ref()
}
}
impl<'a, T, const MAX: usize> IntoIterator for &'a ImmutableHeap<T, MAX> {
type IntoIter = <&'a [T] as IntoIterator>::IntoIter;
type Item = &'a T;
fn into_iter(self) -> Self::IntoIter {
self.0.into_iter()
}
}
impl<T, const MAX: usize> TryFrom<Vec<T>> for ImmutableHeap<T, MAX> {
type Error = TooBig<MAX>;
fn try_from(value: Vec<T>) -> Result<Self, Self::Error> {
if value.len() > MAX {
return Err(TooBig::<MAX>);
}
Ok(Self(value.into()))
}
}
impl<T, const MAX: usize, const N: usize> TryFrom<[T; N]> for ImmutableHeap<T, MAX> {
type Error = TooBig<MAX>;
fn try_from(value: [T; N]) -> Result<Self, Self::Error> {
if N > MAX {
return Err(TooBig::<MAX>);
}
Ok(Self(Arc::new(value)))
}
}
impl<'de, T: Deserialize<'de>, const MAX: usize> Deserialize<'de> for ImmutableHeap<T, MAX> {
fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
where
D: serde::Deserializer<'de>,
{
struct Visitor<T, const MAX: usize> {
v: Vec<T>,
}
impl<'d, T: Deserialize<'d>, const MAX: usize> de::Visitor<'d> for Visitor<T, MAX> {
type Value = Vec<T>;
fn expecting(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
write!(formatter, "array no bigger than {MAX}")
}
fn visit_seq<A>(self, mut seq: A) -> Result<Self::Value, A::Error>
where
A: de::SeqAccess<'d>,
{
let mut dst = self.v;
let mut fuel = MAX;
loop {
if fuel <= 0 {
return Err(de::Error::custom(TooBig::<MAX>));
}
let Some(element) = seq.next_element()? else {
break;
};
dst.push(element);
fuel -= 1;
}
Ok(dst)
}
}
let v = deserializer.deserialize_seq(Visitor::<T, MAX> {
v: Vec::with_capacity(MAX),
})?;
Ok(Self(v.into()))
}
}
impl<T: Serialize, const MAX: usize> Serialize for ImmutableHeap<T, MAX> {
fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
where
S: serde::Serializer,
{
self.0.serialize(serializer)
}
}
impl<T: JsonSchema, const MAX: usize> JsonSchema for ImmutableHeap<T, MAX> {
fn schema_id() -> Cow<'static, str> {
<Vec<T> as JsonSchema>::schema_id()
}
fn schema_name() -> Cow<'static, str> {
<Vec<T> as JsonSchema>::schema_name()
}
fn json_schema(generator: &mut schemars::SchemaGenerator) -> schemars::Schema {
schemars::json_schema!({
"type": "array",
"items": T::json_schema(generator),
"maxItems": MAX,
})
}
}