Implement box pattern inference

This commit is contained in:
Jonas Schievink 2020-09-12 21:18:57 +02:00
parent 2de6eb7bc8
commit 07a704e31c
3 changed files with 20 additions and 2 deletions

View File

@ -835,8 +835,12 @@ impl ExprCollector<'_> {
Pat::Missing
}
ast::Pat::BoxPat(boxpat) => {
let inner = self.collect_pat_opt(boxpat.pat());
Pat::Box { inner }
}
// FIXME: implement
ast::Pat::BoxPat(_) | ast::Pat::RangePat(_) | ast::Pat::MacroPat(_) => Pat::Missing,
ast::Pat::RangePat(_) | ast::Pat::MacroPat(_) => Pat::Missing,
};
let ptr = AstPtr::new(&pat);
self.alloc_pat(pattern, Either::Left(ptr))

View File

@ -395,6 +395,7 @@ pub enum Pat {
Bind { mode: BindingAnnotation, name: Name, subpat: Option<PatId> },
TupleStruct { path: Option<Path>, args: Vec<PatId>, ellipsis: Option<usize> },
Ref { pat: PatId, mutability: Mutability },
Box { inner: PatId },
}
impl Pat {
@ -415,6 +416,7 @@ impl Pat {
Pat::Record { args, .. } => {
args.iter().map(|f| f.pat).for_each(f);
}
Pat::Box { inner } => f(*inner),
}
}
}

View File

@ -209,6 +209,18 @@ impl<'a> InferenceContext<'a> {
end_ty
}
Pat::Lit(expr) => self.infer_expr(*expr, &Expectation::has_type(expected.clone())),
Pat::Box { inner } => match self.resolve_boxed_box() {
Some(box_adt) => {
let inner_expected = match expected.as_adt() {
Some((adt, substs)) if adt == box_adt => substs.as_single(),
_ => &Ty::Unknown,
};
let inner_ty = self.infer_pat(*inner, inner_expected, default_bm);
Ty::apply_one(TypeCtor::Adt(box_adt), inner_ty)
}
None => Ty::Unknown,
},
Pat::Missing => Ty::Unknown,
};
// use a new type variable if we got Ty::Unknown here
@ -236,6 +248,6 @@ fn is_non_ref_pat(body: &hir_def::body::Body, pat: PatId) -> bool {
Expr::Literal(Literal::String(..)) => false,
_ => true,
},
Pat::Wild | Pat::Bind { .. } | Pat::Ref { .. } | Pat::Missing => false,
Pat::Wild | Pat::Bind { .. } | Pat::Ref { .. } | Pat::Box { .. } | Pat::Missing => false,
}
}