radn-rs/src/std/cast.rs
2023-04-21 17:23:01 +00:00

79 lines
2.4 KiB
Rust

use crate::core::*;
use crate::std::*;
struct CastResolver<'a, Ctx: 'a + Context> {
points: Vec<Point<'a, Ctx, TypelessMentionable<'a, Ctx>>>,
}
pub enum CastError<'a> {
Typeless(TypelessError<'a>),
AddressIndexOutOfBounds(usize),
AddressPointMismatch {
expected: Hash,
received: Hash,
index: usize,
},
}
impl<'a, Ctx: 'a + Context> Resolver<'a, Ctx> for CastResolver<'a, Ctx>
where
Ctx::LookupError: From<CastError<'a>>,
{
fn resolve(self: Rc<Self>, address: Address) -> HashResolution<'a, Ctx> {
let point = match self.points.get(address.index) {
Some(point) => point,
None => {
return Ctx::T::pure(Err(CastError::AddressIndexOutOfBounds(address.index).into()));
}
};
if point.point != address.point {
return Ctx::T::pure(Err(CastError::AddressPointMismatch {
expected: point.point,
received: address.point,
index: address.index,
}
.into()));
}
Ctx::T::fmap(
|resolved| match resolved {
Ok(mentionable) => {
let mut vec = Vec::new();
mentionable.serialize(&mut vec);
let resolver: Rc<dyn Resolver<'a, Ctx>> = Rc::new(CastResolver {
points: mentionable.points(),
});
Ok((vec, resolver))
}
Err(error) => Err(match error {
ResolutionError::Lookup(lookup_error) => lookup_error,
ResolutionError::Parse(parse_error) => CastError::Typeless(parse_error).into(),
}),
},
point.resolve(),
)
}
}
pub type CastResult<'a, Ctx, A> =
Result<A, <<A as Mentionable<'a, Ctx>>::Fctr as Factory<'a, Ctx>>::ParseError>;
impl<'a, Ctx: Context> TypelessMentionable<'a, Ctx>
where
Ctx::LookupError: From<CastError<'a>>,
{
/// .
///
/// # Errors
///
/// This function will return an error if .
pub fn cast<A: Mentionable<'a, Ctx>>(&self, factory: A::Fctr) -> CastResult<'a, Ctx, A> {
let mut vec = Vec::new();
self.serialize(&mut vec);
factory.parse_slice(
&vec,
Rc::new(CastResolver {
points: self.points(),
}),
)
}
}