108 lines
2.9 KiB
Rust
108 lines
2.9 KiB
Rust
|
use {
|
|||
|
|
std::collections::HashMap,
|
|||
|
|
crate::{term::*, dict::*}
|
|||
|
|
};
|
|||
|
|
|
|||
|
|
//<<<<>>>><<>><><<>><<<*>>><<>><><<>><<<<>>>>\\
|
|||
|
|
|
|||
|
|
#[derive(Clone, Eq, PartialEq, Debug)]
|
|||
|
|
pub struct UnificationError {
|
|||
|
|
pub addr: Vec<usize>,
|
|||
|
|
pub t1: TypeTerm,
|
|||
|
|
pub t2: TypeTerm
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
impl UnificationError {
|
|||
|
|
pub fn new(t1: &TypeTerm, t2: &TypeTerm) -> Self {
|
|||
|
|
UnificationError {
|
|||
|
|
addr: vec![],
|
|||
|
|
t1: t1.clone(),
|
|||
|
|
t2: t2.clone()
|
|||
|
|
}
|
|||
|
|
}
|
|||
|
|
}
|
|||
|
|
/*
|
|||
|
|
struct UnificationProblem {
|
|||
|
|
eqs: Vec<(TypeTerm, TypeTerm)>,
|
|||
|
|
σ: HashMap<TypeID, TypeTerm>
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
impl UnificationProblem {
|
|||
|
|
pub fn new() -> Self {
|
|||
|
|
UnificationProblem {
|
|||
|
|
eqs: Vec::new(),
|
|||
|
|
σ: HashMap::new()
|
|||
|
|
}
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
pub fn eval_equation(&mut self, lhs: &TypeTerm, rhs: &TypeTerm) -> Option<UnificationError> {
|
|||
|
|
match (lhs, rhs) {
|
|||
|
|
|
|||
|
|
}
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
pub fn solve(self) -> Result<HashMap<TypeID, TypeTerm>, UnificationError> {
|
|||
|
|
|
|||
|
|
}
|
|||
|
|
}
|
|||
|
|
*/
|
|||
|
|
pub fn unify(
|
|||
|
|
t1: &TypeTerm,
|
|||
|
|
t2: &TypeTerm
|
|||
|
|
) -> Result<HashMap<TypeID, TypeTerm>, UnificationError> {
|
|||
|
|
let mut σ = HashMap::new();
|
|||
|
|
|
|||
|
|
match (t1, t2) {
|
|||
|
|
(TypeTerm::TypeID(TypeID::Var(varid)), t) |
|
|||
|
|
(t, TypeTerm::TypeID(TypeID::Var(varid))) => {
|
|||
|
|
σ.insert(TypeID::Var(*varid), t.clone());
|
|||
|
|
Ok(σ)
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
(TypeTerm::TypeID(a1), TypeTerm::TypeID(a2)) => {
|
|||
|
|
if a1 == a2 { Ok(σ) } else { Err(UnificationError::new(&t1, &t2)) }
|
|||
|
|
}
|
|||
|
|
(TypeTerm::Num(n1), TypeTerm::Num(n2)) => {
|
|||
|
|
if n1 == n2 { Ok(σ) } else { Err(UnificationError::new(&t1, &t2)) }
|
|||
|
|
}
|
|||
|
|
(TypeTerm::Char(c1), TypeTerm::Char(c2)) => {
|
|||
|
|
if c1 == c2 { Ok(σ) } else { Err(UnificationError::new(&t1, &t2)) }
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
(TypeTerm::Ladder(a1), TypeTerm::Ladder(a2)) |
|
|||
|
|
(TypeTerm::App(a1), TypeTerm::App(a2)) => {
|
|||
|
|
if a1.len() == a2.len() {
|
|||
|
|
for (i, (x, y)) in a1.iter().cloned().zip(a2.iter().cloned()).enumerate() {
|
|||
|
|
let (mut x, mut y) = (x.clone(), y.clone());
|
|||
|
|
x.apply_substitution(&|v| σ.get(v).cloned());
|
|||
|
|
y.apply_substitution(&|v| σ.get(v).cloned());
|
|||
|
|
|
|||
|
|
match unify(&x, &y) {
|
|||
|
|
Ok(τ) => {
|
|||
|
|
for (v,t) in τ {
|
|||
|
|
σ.insert(v,t);
|
|||
|
|
}
|
|||
|
|
}
|
|||
|
|
Err(mut err) => {
|
|||
|
|
err.addr.insert(0, i);
|
|||
|
|
return Err(err);
|
|||
|
|
}
|
|||
|
|
}
|
|||
|
|
}
|
|||
|
|
Ok(σ)
|
|||
|
|
} else {
|
|||
|
|
Err(UnificationError::new(&t1, &t2))
|
|||
|
|
}
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
(TypeTerm::Ladder(l1), TypeTerm::Ladder(l2)) => {
|
|||
|
|
Err(UnificationError::new(&t1, &t2))
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
_ => Err(UnificationError::new(t1, t2))
|
|||
|
|
}
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
//<<<<>>>><<>><><<>><<<*>>><<>><><<>><<<<>>>>\\
|
|||
|
|
|