//! Type inference for patterns.
-use std::iter::repeat;
-use std::sync::Arc;
+use std::{iter::repeat, sync::Arc};
use chalk_ir::Mutability;
use hir_def::{
};
use hir_expand::name::Name;
-use super::{BindingMode, Expectation, InferenceContext};
use crate::{
- lower::lower_to_chalk_mutability, static_lifetime, Interner, Substitution, Ty, TyBuilder,
- TyExt, TyKind,
+ infer::{
+ Adjust, Adjustment, AutoBorrow, BindingMode, Expectation, InferenceContext, TypeMismatch,
+ },
+ 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.
let expected = expected;
let ty = match &body[pat] {
- &Pat::Tuple { ref args, ellipsis } => {
+ Pat::Tuple { args, ellipsis } => {
let expectations = match expected.as_tuple() {
Some(parameters) => &*parameters.as_slice(&Interner),
_ => &[],
};
- let (pre, post) = match ellipsis {
- Some(idx) => args.split_at(idx),
- None => (&args[..], &[][..]),
+ let ((pre, post), n_uncovered_patterns) = match ellipsis {
+ Some(idx) => {
+ (args.split_at(*idx), expectations.len().saturating_sub(args.len()))
+ }
+ None => ((&args[..], &[][..]), 0),
};
- let n_uncovered_patterns = expectations.len().saturating_sub(args.len());
let err_ty = self.err_ty();
let mut expectations_iter =
expectations.iter().map(|a| a.assert_ty_ref(&Interner)).chain(repeat(&err_ty));
TyKind::Tuple(inner_tys.len(), Substitution::from_iter(&Interner, inner_tys))
.intern(&Interner)
}
- Pat::Or(ref pats) => {
+ Pat::Or(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 {
} else {
BindingMode::convert(*mode)
};
- let inner_ty = if let Some(subpat) = subpat {
- self.infer_pat(*subpat, expected, default_bm)
- } else {
- expected.clone()
+ let inner_ty = match subpat {
+ Some(subpat) => self.infer_pat(*subpat, &expected, default_bm),
+ None => 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;
}
Pat::Wild => expected.clone(),
Pat::Range { start, end } => {
let start_ty = self.infer_expr(*start, &Expectation::has_type(expected.clone()));
- let end_ty = self.infer_expr(*end, &Expectation::has_type(start_ty));
- end_ty
+ self.infer_expr(*end, &Expectation::has_type(start_ty))
}
Pat::Lit(expr) => self.infer_expr(*expr, &Expectation::has_type(expected.clone())),
Pat::Box { inner } => match self.resolve_boxed_box() {
};
// use a new type variable if we got error type here
let ty = self.insert_type_vars_shallow(ty);
- if !self.unify(&ty, expected) {
- // FIXME record mismatch, we need to change the type of self.type_mismatches for that
+ 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
}
// FIXME: ConstBlock/Path/Lit might actually evaluate to ref, but inference is unimplemented.
Pat::Path(..) => true,
Pat::ConstBlock(..) => true,
- Pat::Lit(expr) => match body[*expr] {
- Expr::Literal(Literal::String(..)) => false,
- _ => true,
- },
+ Pat::Lit(expr) => !matches!(body[*expr], Expr::Literal(Literal::String(..))),
+ 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,
}
}
projects / rust.git / blobdiff