style: rename crates to kebab case

crates/hir-ty/src/lib.rs

@@ -0,0 +1,524 @@
+//! The type system. We currently use this to infer types for completion, hover
+//! information and various assists.
+
+#[allow(unused)]
+macro_rules! eprintln {
+    ($($tt:tt)*) => { stdx::eprintln!($($tt)*) };
+}
+
+mod autoderef;
+mod builder;
+mod chalk_db;
+mod chalk_ext;
+pub mod consteval;
+mod infer;
+mod interner;
+mod lower;
+mod mapping;
+mod tls;
+mod utils;
+mod walk;
+pub mod db;
+pub mod diagnostics;
+pub mod display;
+pub mod method_resolution;
+pub mod primitive;
+pub mod traits;
+
+#[cfg(test)]
+mod tests;
+#[cfg(test)]
+mod test_db;
+
+use std::sync::Arc;
+
+use chalk_ir::{
+    fold::{Fold, Shift},
+    interner::HasInterner,
+    NoSolution,
+};
+use hir_def::{expr::ExprId, type_ref::Rawness, TypeOrConstParamId};
+use itertools::Either;
+use utils::Generics;
+
+use crate::{consteval::unknown_const, db::HirDatabase, utils::generics};
+
+pub use autoderef::autoderef;
+pub use builder::{ParamKind, TyBuilder};
+pub use chalk_ext::*;
+pub use infer::{
+    could_coerce, could_unify, Adjust, Adjustment, AutoBorrow, InferenceDiagnostic, InferenceResult,
+};
+pub use interner::Interner;
+pub use lower::{
+    associated_type_shorthand_candidates, callable_item_sig, CallableDefId, ImplTraitLoweringMode,
+    TyDefId, TyLoweringContext, ValueTyDefId,
+};
+pub use mapping::{
+    from_assoc_type_id, from_chalk_trait_id, from_foreign_def_id, from_placeholder_idx,
+    lt_from_placeholder_idx, to_assoc_type_id, to_chalk_trait_id, to_foreign_def_id,
+    to_placeholder_idx,
+};
+pub use traits::TraitEnvironment;
+pub use utils::{all_super_traits, is_fn_unsafe_to_call};
+pub use walk::TypeWalk;
+
+pub use chalk_ir::{
+    cast::Cast, AdtId, BoundVar, DebruijnIndex, Mutability, Safety, Scalar, TyVariableKind,
+};
+
+pub type ForeignDefId = chalk_ir::ForeignDefId<Interner>;
+pub type AssocTypeId = chalk_ir::AssocTypeId<Interner>;
+pub type FnDefId = chalk_ir::FnDefId<Interner>;
+pub type ClosureId = chalk_ir::ClosureId<Interner>;
+pub type OpaqueTyId = chalk_ir::OpaqueTyId<Interner>;
+pub type PlaceholderIndex = chalk_ir::PlaceholderIndex;
+
+pub type VariableKind = chalk_ir::VariableKind<Interner>;
+pub type VariableKinds = chalk_ir::VariableKinds<Interner>;
+pub type CanonicalVarKinds = chalk_ir::CanonicalVarKinds<Interner>;
+pub type Binders<T> = chalk_ir::Binders<T>;
+pub type Substitution = chalk_ir::Substitution<Interner>;
+pub type GenericArg = chalk_ir::GenericArg<Interner>;
+pub type GenericArgData = chalk_ir::GenericArgData<Interner>;
+
+pub type Ty = chalk_ir::Ty<Interner>;
+pub type TyKind = chalk_ir::TyKind<Interner>;
+pub type DynTy = chalk_ir::DynTy<Interner>;
+pub type FnPointer = chalk_ir::FnPointer<Interner>;
+// pub type FnSubst = chalk_ir::FnSubst<Interner>;
+pub use chalk_ir::FnSubst;
+pub type ProjectionTy = chalk_ir::ProjectionTy<Interner>;
+pub type AliasTy = chalk_ir::AliasTy<Interner>;
+pub type OpaqueTy = chalk_ir::OpaqueTy<Interner>;
+pub type InferenceVar = chalk_ir::InferenceVar;
+
+pub type Lifetime = chalk_ir::Lifetime<Interner>;
+pub type LifetimeData = chalk_ir::LifetimeData<Interner>;
+pub type LifetimeOutlives = chalk_ir::LifetimeOutlives<Interner>;
+
+pub type Const = chalk_ir::Const<Interner>;
+pub type ConstData = chalk_ir::ConstData<Interner>;
+pub type ConstValue = chalk_ir::ConstValue<Interner>;
+pub type ConcreteConst = chalk_ir::ConcreteConst<Interner>;
+
+pub type ChalkTraitId = chalk_ir::TraitId<Interner>;
+pub type TraitRef = chalk_ir::TraitRef<Interner>;
+pub type QuantifiedWhereClause = Binders<WhereClause>;
+pub type QuantifiedWhereClauses = chalk_ir::QuantifiedWhereClauses<Interner>;
+pub type Canonical<T> = chalk_ir::Canonical<T>;
+
+pub type FnSig = chalk_ir::FnSig<Interner>;
+
+pub type InEnvironment<T> = chalk_ir::InEnvironment<T>;
+pub type Environment = chalk_ir::Environment<Interner>;
+pub type DomainGoal = chalk_ir::DomainGoal<Interner>;
+pub type Goal = chalk_ir::Goal<Interner>;
+pub type AliasEq = chalk_ir::AliasEq<Interner>;
+pub type Solution = chalk_solve::Solution<Interner>;
+pub type ConstrainedSubst = chalk_ir::ConstrainedSubst<Interner>;
+pub type Guidance = chalk_solve::Guidance<Interner>;
+pub type WhereClause = chalk_ir::WhereClause<Interner>;
+
+// FIXME: get rid of this
+pub fn subst_prefix(s: &Substitution, n: usize) -> Substitution {
+    Substitution::from_iter(
+        Interner,
+        s.as_slice(Interner)[..std::cmp::min(s.len(Interner), n)].iter().cloned(),
+    )
+}
+
+/// Return an index of a parameter in the generic type parameter list by it's id.
+pub fn param_idx(db: &dyn HirDatabase, id: TypeOrConstParamId) -> Option<usize> {
+    generics(db.upcast(), id.parent).param_idx(id)
+}
+
+pub(crate) fn wrap_empty_binders<T>(value: T) -> Binders<T>
+where
+    T: Fold<Interner, Result = T> + HasInterner<Interner = Interner>,
+{
+    Binders::empty(Interner, value.shifted_in_from(Interner, DebruijnIndex::ONE))
+}
+
+pub(crate) fn make_type_and_const_binders<T: HasInterner<Interner = Interner>>(
+    which_is_const: impl Iterator<Item = Option<Ty>>,
+    value: T,
+) -> Binders<T> {
+    Binders::new(
+        VariableKinds::from_iter(
+            Interner,
+            which_is_const.map(|x| {
+                if let Some(ty) = x {
+                    chalk_ir::VariableKind::Const(ty)
+                } else {
+                    chalk_ir::VariableKind::Ty(chalk_ir::TyVariableKind::General)
+                }
+            }),
+        ),
+        value,
+    )
+}
+
+pub(crate) fn make_single_type_binders<T: HasInterner<Interner = Interner>>(
+    value: T,
+) -> Binders<T> {
+    Binders::new(
+        VariableKinds::from_iter(
+            Interner,
+            std::iter::once(chalk_ir::VariableKind::Ty(chalk_ir::TyVariableKind::General)),
+        ),
+        value,
+    )
+}
+
+pub(crate) fn make_binders_with_count<T: HasInterner<Interner = Interner>>(
+    db: &dyn HirDatabase,
+    count: usize,
+    generics: &Generics,
+    value: T,
+) -> Binders<T> {
+    let it = generics.iter_id().take(count).map(|id| match id {
+        Either::Left(_) => None,
+        Either::Right(id) => Some(db.const_param_ty(id)),
+    });
+    crate::make_type_and_const_binders(it, value)
+}
+
+pub(crate) fn make_binders<T: HasInterner<Interner = Interner>>(
+    db: &dyn HirDatabase,
+    generics: &Generics,
+    value: T,
+) -> Binders<T> {
+    make_binders_with_count(db, usize::MAX, generics, value)
+}
+
+// FIXME: get rid of this
+pub fn make_canonical<T: HasInterner<Interner = Interner>>(
+    value: T,
+    kinds: impl IntoIterator<Item = TyVariableKind>,
+) -> Canonical<T> {
+    let kinds = kinds.into_iter().map(|tk| {
+        chalk_ir::CanonicalVarKind::new(
+            chalk_ir::VariableKind::Ty(tk),
+            chalk_ir::UniverseIndex::ROOT,
+        )
+    });
+    Canonical { value, binders: chalk_ir::CanonicalVarKinds::from_iter(Interner, kinds) }
+}
+
+// FIXME: get rid of this, just replace it by FnPointer
+/// A function signature as seen by type inference: Several parameter types and
+/// one return type.
+#[derive(Clone, PartialEq, Eq, Debug)]
+pub struct CallableSig {
+    params_and_return: Arc<[Ty]>,
+    is_varargs: bool,
+}
+
+has_interner!(CallableSig);
+
+/// A polymorphic function signature.
+pub type PolyFnSig = Binders<CallableSig>;
+
+impl CallableSig {
+    pub fn from_params_and_return(mut params: Vec<Ty>, ret: Ty, is_varargs: bool) -> CallableSig {
+        params.push(ret);
+        CallableSig { params_and_return: params.into(), is_varargs }
+    }
+
+    pub fn from_fn_ptr(fn_ptr: &FnPointer) -> CallableSig {
+        CallableSig {
+            // FIXME: what to do about lifetime params? -> return PolyFnSig
+            params_and_return: fn_ptr
+                .substitution
+                .clone()
+                .shifted_out_to(Interner, DebruijnIndex::ONE)
+                .expect("unexpected lifetime vars in fn ptr")
+                .0
+                .as_slice(Interner)
+                .iter()
+                .map(|arg| arg.assert_ty_ref(Interner).clone())
+                .collect(),
+            is_varargs: fn_ptr.sig.variadic,
+        }
+    }
+
+    pub fn to_fn_ptr(&self) -> FnPointer {
+        FnPointer {
+            num_binders: 0,
+            sig: FnSig { abi: (), safety: Safety::Safe, variadic: self.is_varargs },
+            substitution: FnSubst(Substitution::from_iter(
+                Interner,
+                self.params_and_return.iter().cloned(),
+            )),
+        }
+    }
+
+    pub fn params(&self) -> &[Ty] {
+        &self.params_and_return[0..self.params_and_return.len() - 1]
+    }
+
+    pub fn ret(&self) -> &Ty {
+        &self.params_and_return[self.params_and_return.len() - 1]
+    }
+}
+
+impl Fold<Interner> for CallableSig {
+    type Result = CallableSig;
+
+    fn fold_with<E>(
+        self,
+        folder: &mut dyn chalk_ir::fold::Folder<Interner, Error = E>,
+        outer_binder: DebruijnIndex,
+    ) -> Result<Self::Result, E> {
+        let vec = self.params_and_return.to_vec();
+        let folded = vec.fold_with(folder, outer_binder)?;
+        Ok(CallableSig { params_and_return: folded.into(), is_varargs: self.is_varargs })
+    }
+}
+
+#[derive(Copy, Clone, PartialEq, Eq, Debug, Hash)]
+pub enum ImplTraitId {
+    ReturnTypeImplTrait(hir_def::FunctionId, u16),
+    AsyncBlockTypeImplTrait(hir_def::DefWithBodyId, ExprId),
+}
+
+#[derive(Clone, PartialEq, Eq, Debug, Hash)]
+pub struct ReturnTypeImplTraits {
+    pub(crate) impl_traits: Vec<ReturnTypeImplTrait>,
+}
+
+has_interner!(ReturnTypeImplTraits);
+
+#[derive(Clone, PartialEq, Eq, Debug, Hash)]
+pub(crate) struct ReturnTypeImplTrait {
+    pub(crate) bounds: Binders<Vec<QuantifiedWhereClause>>,
+}
+
+pub fn static_lifetime() -> Lifetime {
+    LifetimeData::Static.intern(Interner)
+}
+
+pub(crate) fn fold_free_vars<T: HasInterner<Interner = Interner> + Fold<Interner>>(
+    t: T,
+    for_ty: impl FnMut(BoundVar, DebruijnIndex) -> Ty,
+    for_const: impl FnMut(Ty, BoundVar, DebruijnIndex) -> Const,
+) -> T::Result {
+    use chalk_ir::{fold::Folder, Fallible};
+    struct FreeVarFolder<F1, F2>(F1, F2);
+    impl<
+            'i,
+            F1: FnMut(BoundVar, DebruijnIndex) -> Ty + 'i,
+            F2: FnMut(Ty, BoundVar, DebruijnIndex) -> Const + 'i,
+        > Folder<Interner> for FreeVarFolder<F1, F2>
+    {
+        type Error = NoSolution;
+
+        fn as_dyn(&mut self) -> &mut dyn Folder<Interner, Error = Self::Error> {
+            self
+        }
+
+        fn interner(&self) -> Interner {
+            Interner
+        }
+
+        fn fold_free_var_ty(
+            &mut self,
+            bound_var: BoundVar,
+            outer_binder: DebruijnIndex,
+        ) -> Fallible<Ty> {
+            Ok(self.0(bound_var, outer_binder))
+        }
+
+        fn fold_free_var_const(
+            &mut self,
+            ty: Ty,
+            bound_var: BoundVar,
+            outer_binder: DebruijnIndex,
+        ) -> Fallible<Const> {
+            Ok(self.1(ty, bound_var, outer_binder))
+        }
+    }
+    t.fold_with(&mut FreeVarFolder(for_ty, for_const), DebruijnIndex::INNERMOST)
+        .expect("fold failed unexpectedly")
+}
+
+pub(crate) fn fold_tys<T: HasInterner<Interner = Interner> + Fold<Interner>>(
+    t: T,
+    mut for_ty: impl FnMut(Ty, DebruijnIndex) -> Ty,
+    binders: DebruijnIndex,
+) -> T::Result {
+    fold_tys_and_consts(
+        t,
+        |x, d| match x {
+            Either::Left(x) => Either::Left(for_ty(x, d)),
+            Either::Right(x) => Either::Right(x),
+        },
+        binders,
+    )
+}
+
+pub(crate) fn fold_tys_and_consts<T: HasInterner<Interner = Interner> + Fold<Interner>>(
+    t: T,
+    f: impl FnMut(Either<Ty, Const>, DebruijnIndex) -> Either<Ty, Const>,
+    binders: DebruijnIndex,
+) -> T::Result {
+    use chalk_ir::{
+        fold::{Folder, SuperFold},
+        Fallible,
+    };
+    struct TyFolder<F>(F);
+    impl<'i, F: FnMut(Either<Ty, Const>, DebruijnIndex) -> Either<Ty, Const> + 'i> Folder<Interner>
+        for TyFolder<F>
+    {
+        type Error = NoSolution;
+
+        fn as_dyn(&mut self) -> &mut dyn Folder<Interner, Error = Self::Error> {
+            self
+        }
+
+        fn interner(&self) -> Interner {
+            Interner
+        }
+
+        fn fold_ty(&mut self, ty: Ty, outer_binder: DebruijnIndex) -> Fallible<Ty> {
+            let ty = ty.super_fold_with(self.as_dyn(), outer_binder)?;
+            Ok(self.0(Either::Left(ty), outer_binder).left().unwrap())
+        }
+
+        fn fold_const(&mut self, c: Const, outer_binder: DebruijnIndex) -> Fallible<Const> {
+            Ok(self.0(Either::Right(c), outer_binder).right().unwrap())
+        }
+    }
+    t.fold_with(&mut TyFolder(f), binders).expect("fold failed unexpectedly")
+}
+
+/// 'Canonicalizes' the `t` by replacing any errors with new variables. Also
+/// ensures there are no unbound variables or inference variables anywhere in
+/// the `t`.
+pub fn replace_errors_with_variables<T>(t: &T) -> Canonical<T::Result>
+where
+    T: HasInterner<Interner = Interner> + Fold<Interner> + Clone,
+    T::Result: HasInterner<Interner = Interner>,
+{
+    use chalk_ir::{
+        fold::{Folder, SuperFold},
+        Fallible,
+    };
+    struct ErrorReplacer {
+        vars: usize,
+    }
+    impl Folder<Interner> for ErrorReplacer {
+        type Error = NoSolution;
+
+        fn as_dyn(&mut self) -> &mut dyn Folder<Interner, Error = Self::Error> {
+            self
+        }
+
+        fn interner(&self) -> Interner {
+            Interner
+        }
+
+        fn fold_ty(&mut self, ty: Ty, outer_binder: DebruijnIndex) -> Fallible<Ty> {
+            if let TyKind::Error = ty.kind(Interner) {
+                let index = self.vars;
+                self.vars += 1;
+                Ok(TyKind::BoundVar(BoundVar::new(outer_binder, index)).intern(Interner))
+            } else {
+                let ty = ty.super_fold_with(self.as_dyn(), outer_binder)?;
+                Ok(ty)
+            }
+        }
+
+        fn fold_inference_ty(
+            &mut self,
+            _var: InferenceVar,
+            _kind: TyVariableKind,
+            _outer_binder: DebruijnIndex,
+        ) -> Fallible<Ty> {
+            if cfg!(debug_assertions) {
+                // we don't want to just panic here, because then the error message
+                // won't contain the whole thing, which would not be very helpful
+                Err(NoSolution)
+            } else {
+                Ok(TyKind::Error.intern(Interner))
+            }
+        }
+
+        fn fold_free_var_ty(
+            &mut self,
+            _bound_var: BoundVar,
+            _outer_binder: DebruijnIndex,
+        ) -> Fallible<Ty> {
+            if cfg!(debug_assertions) {
+                // we don't want to just panic here, because then the error message
+                // won't contain the whole thing, which would not be very helpful
+                Err(NoSolution)
+            } else {
+                Ok(TyKind::Error.intern(Interner))
+            }
+        }
+
+        fn fold_inference_const(
+            &mut self,
+            ty: Ty,
+            _var: InferenceVar,
+            _outer_binder: DebruijnIndex,
+        ) -> Fallible<Const> {
+            if cfg!(debug_assertions) {
+                Err(NoSolution)
+            } else {
+                Ok(unknown_const(ty))
+            }
+        }
+
+        fn fold_free_var_const(
+            &mut self,
+            ty: Ty,
+            _bound_var: BoundVar,
+            _outer_binder: DebruijnIndex,
+        ) -> Fallible<Const> {
+            if cfg!(debug_assertions) {
+                Err(NoSolution)
+            } else {
+                Ok(unknown_const(ty))
+            }
+        }
+
+        fn fold_inference_lifetime(
+            &mut self,
+            _var: InferenceVar,
+            _outer_binder: DebruijnIndex,
+        ) -> Fallible<Lifetime> {
+            if cfg!(debug_assertions) {
+                Err(NoSolution)
+            } else {
+                Ok(static_lifetime())
+            }
+        }
+
+        fn fold_free_var_lifetime(
+            &mut self,
+            _bound_var: BoundVar,
+            _outer_binder: DebruijnIndex,
+        ) -> Fallible<Lifetime> {
+            if cfg!(debug_assertions) {
+                Err(NoSolution)
+            } else {
+                Ok(static_lifetime())
+            }
+        }
+    }
+    let mut error_replacer = ErrorReplacer { vars: 0 };
+    let value = match t.clone().fold_with(&mut error_replacer, DebruijnIndex::INNERMOST) {
+        Ok(t) => t,
+        Err(_) => panic!("Encountered unbound or inference vars in {:?}", t),
+    };
+    let kinds = (0..error_replacer.vars).map(|_| {
+        chalk_ir::CanonicalVarKind::new(
+            chalk_ir::VariableKind::Ty(TyVariableKind::General),
+            chalk_ir::UniverseIndex::ROOT,
+        )
+    });
+    Canonical { value, binders: chalk_ir::CanonicalVarKinds::from_iter(Interner, kinds) }
+}