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pub use crate::{
prelude_internal::*,
sub::{CowSub, Sub},
};
pub use std::{borrow::Cow, collections::HashMap};
pub trait Unify<K: Clone, V: Clone> {
type Error;
fn unify_with<'a>(&self, sub: CowSub<'a, K, V>, rhs: &Self) -> UResult<'a, K, V, Self::Error>;
fn unify(&self, rhs: &Self) -> UResult<K, V, Self::Error> {
self.unify_with(Cow::Owned(Sub::top()), rhs)
}
}
impl<K: Clone, V: Clone, E, T: Unify<K, V, Error = E>> Unify<K, V> for Option<T> {
type Error = E;
fn unify_with<'a>(&self, sub: CowSub<'a, K, V>, rhs: &Self) -> UResult<'a, K, V, Self::Error> {
match (self, rhs) {
(Some(l), Some(r)) => l.unify_with(sub, r),
(None, None) => UOk(sub),
_ => Bottom,
}
}
}
impl<K: Clone, V: Clone, E, T: Unify<K, V, Error = E>> Unify<K, V> for Vec<T> {
type Error = E;
fn unify_with<'a>(
&self,
mut sub: CowSub<'a, K, V>,
rhs: &Self,
) -> UResult<'a, K, V, Self::Error>
{
if self.len() != rhs.len() {
return Bottom;
}
for (l, r) in self.iter().zip(rhs.iter()) {
match l.unify_with(sub, r) {
UOk(s) => sub = s,
Bottom => return Bottom,
UErr(e) => return UErr(e),
}
}
UOk(sub)
}
}
impl<K: Clone, V: Clone, E, K2: Eq + Hash, V2: Unify<K, V, Error = E>> Unify<K, V>
for HashMap<K2, V2>
{
type Error = E;
fn unify_with<'a>(
&self,
mut sub: CowSub<'a, K, V>,
rhs: &Self,
) -> UResult<'a, K, V, Self::Error>
{
if self.len() != rhs.len() {
return Bottom;
}
for (l, r) in self.iter().map(|(k, v)| (v, rhs.get(k))) {
match r {
Some(r) => match l.unify_with(sub, r) {
UOk(s) => sub = s,
Bottom => return Bottom,
UErr(e) => return UErr(e),
},
None => return Bottom,
}
}
UOk(sub)
}
}