use super::{BindingMode, Expectation, InferenceContext, TypeMismatch};
use crate::{
- lower::lower_to_chalk_mutability, static_lifetime, Interner, Substitution, Ty, TyBuilder,
- TyExt, TyKind,
+ infer::{Adjust, Adjustment, AutoBorrow},
+ lower::lower_to_chalk_mutability,
+ static_lifetime, Interner, Substitution, Ty, TyBuilder, TyExt, TyKind,
};
impl<'a> InferenceContext<'a> {
id: PatId,
ellipsis: Option<usize>,
) -> Ty {
- let (ty, def) = self.resolve_variant(path);
+ let (ty, def) = self.resolve_variant(path, true);
let var_data = def.map(|it| it.variant_data(self.db.upcast()));
if let Some(variant) = def {
self.write_variant_resolution(id.into(), variant);
default_bm: BindingMode,
id: PatId,
) -> Ty {
- let (ty, def) = self.resolve_variant(path);
+ let (ty, def) = self.resolve_variant(path, false);
let var_data = def.map(|it| it.variant_data(self.db.upcast()));
if let Some(variant) = def {
self.write_variant_resolution(id.into(), variant);
pub(super) fn infer_pat(
&mut self,
pat: PatId,
- mut expected: &Ty,
+ expected: &Ty,
mut default_bm: BindingMode,
) -> Ty {
let body = Arc::clone(&self.body); // avoid borrow checker problem
+ let mut expected = self.resolve_ty_shallow(expected);
if is_non_ref_pat(&body, pat) {
+ let mut pat_adjustments = Vec::new();
while let Some((inner, _lifetime, mutability)) = expected.as_reference() {
- expected = inner;
+ pat_adjustments.push(Adjustment {
+ target: expected.clone(),
+ kind: Adjust::Borrow(AutoBorrow::Ref(mutability)),
+ });
+ expected = self.resolve_ty_shallow(inner);
default_bm = match default_bm {
BindingMode::Move => BindingMode::Ref(mutability),
BindingMode::Ref(Mutability::Not) => BindingMode::Ref(Mutability::Not),
BindingMode::Ref(Mutability::Mut) => BindingMode::Ref(mutability),
}
}
+
+ if !pat_adjustments.is_empty() {
+ pat_adjustments.shrink_to_fit();
+ self.result.pat_adjustments.insert(pat, pat_adjustments);
+ }
} else if let Pat::Ref { .. } = &body[pat] {
cov_mark::hit!(match_ergonomics_ref);
// When you encounter a `&pat` pattern, reset to Move.
}
Pat::Or(ref pats) => {
if let Some((first_pat, rest)) = pats.split_first() {
- let ty = self.infer_pat(*first_pat, expected, default_bm);
+ let ty = self.infer_pat(*first_pat, &expected, default_bm);
for pat in rest {
- self.infer_pat(*pat, expected, default_bm);
+ self.infer_pat(*pat, &expected, default_bm);
}
ty
} else {
Pat::TupleStruct { path: p, args: subpats, ellipsis } => self.infer_tuple_struct_pat(
p.as_deref(),
subpats,
- expected,
+ &expected,
default_bm,
pat,
*ellipsis,
),
Pat::Record { path: p, args: fields, ellipsis: _ } => {
- self.infer_record_pat(p.as_deref(), fields, expected, default_bm, pat)
+ self.infer_record_pat(p.as_deref(), fields, &expected, default_bm, pat)
}
Pat::Path(path) => {
// FIXME use correct resolver for the surrounding expression
let resolver = self.resolver.clone();
- self.infer_path(&resolver, &path, pat.into()).unwrap_or(self.err_ty())
+ self.infer_path(&resolver, path, pat.into()).unwrap_or_else(|| self.err_ty())
}
Pat::Bind { mode, name: _, subpat } => {
let mode = if mode == &BindingAnnotation::Unannotated {
BindingMode::convert(*mode)
};
let inner_ty = if let Some(subpat) = subpat {
- self.infer_pat(*subpat, expected, default_bm)
+ self.infer_pat(*subpat, &expected, default_bm)
} else {
- expected.clone()
+ expected
};
let inner_ty = self.insert_type_vars_shallow(inner_ty);
}
BindingMode::Move => inner_ty.clone(),
};
- let bound_ty = self.resolve_ty_as_possible(bound_ty);
self.write_pat_ty(pat, bound_ty);
return inner_ty;
}
};
// use a new type variable if we got error type here
let ty = self.insert_type_vars_shallow(ty);
- if !self.unify(&ty, expected) {
- self.result.type_mismatches.insert(
- pat.into(),
- TypeMismatch { expected: expected.clone(), actual: ty.clone() },
- );
+ if !self.unify(&ty, &expected) {
+ self.result
+ .type_mismatches
+ .insert(pat.into(), TypeMismatch { expected, actual: ty.clone() });
}
- let ty = self.resolve_ty_as_possible(ty);
self.write_pat_ty(pat, ty.clone());
ty
}
Expr::Literal(Literal::String(..)) => false,
_ => true,
},
+ Pat::Bind {
+ mode: BindingAnnotation::Mutable | BindingAnnotation::Unannotated,
+ subpat: Some(subpat),
+ ..
+ } => is_non_ref_pat(body, *subpat),
Pat::Wild | Pat::Bind { .. } | Pat::Ref { .. } | Pat::Box { .. } | Pat::Missing => false,
}
}