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|
//! The type system. We currently use this to infer types for completion, hover
//! information and various assists.
macro_rules! impl_froms {
($e:ident: $($v:ident $(($($sv:ident),*))?),*) => {
$(
impl From<$v> for $e {
fn from(it: $v) -> $e {
$e::$v(it)
}
}
$($(
impl From<$sv> for $e {
fn from(it: $sv) -> $e {
$e::$v($v::$sv(it))
}
}
)*)?
)*
}
}
mod autoderef;
pub mod primitive;
pub mod traits;
pub mod method_resolution;
mod op;
mod lower;
mod infer;
pub mod display;
pub(crate) mod utils;
pub mod db;
pub mod diagnostics;
pub mod expr;
#[cfg(test)]
mod tests;
#[cfg(test)]
mod test_db;
mod marks;
use std::ops::Deref;
use std::sync::Arc;
use std::{fmt, iter, mem};
use hir_def::{
expr::ExprId, type_ref::Mutability, AdtId, ContainerId, DefWithBodyId,
GenericDefId, HasModule, Lookup, TraitId, TypeAliasId,
};
use hir_expand::name::Name;
use ra_db::{impl_intern_key, salsa, CrateId};
use crate::{
db::HirDatabase,
primitive::{FloatTy, IntTy, Uncertain},
utils::{generics, make_mut_slice, Generics},
};
use display::{HirDisplay, HirFormatter};
pub use autoderef::autoderef;
pub use infer::{infer_query, InferTy, InferenceResult};
pub use lower::CallableDef;
pub use lower::{callable_item_sig, TyDefId, ValueTyDefId};
pub use traits::{InEnvironment, Obligation, ProjectionPredicate, TraitEnvironment};
/// A type constructor or type name: this might be something like the primitive
/// type `bool`, a struct like `Vec`, or things like function pointers or
/// tuples.
#[derive(Copy, Clone, PartialEq, Eq, Debug, Hash)]
pub enum TypeCtor {
/// The primitive boolean type. Written as `bool`.
Bool,
/// The primitive character type; holds a Unicode scalar value
/// (a non-surrogate code point). Written as `char`.
Char,
/// A primitive integer type. For example, `i32`.
Int(Uncertain<IntTy>),
/// A primitive floating-point type. For example, `f64`.
Float(Uncertain<FloatTy>),
/// Structures, enumerations and unions.
Adt(AdtId),
/// The pointee of a string slice. Written as `str`.
Str,
/// The pointee of an array slice. Written as `[T]`.
Slice,
/// An array with the given length. Written as `[T; n]`.
Array,
/// A raw pointer. Written as `*mut T` or `*const T`
RawPtr(Mutability),
/// A reference; a pointer with an associated lifetime. Written as
/// `&'a mut T` or `&'a T`.
Ref(Mutability),
/// The anonymous type of a function declaration/definition. Each
/// function has a unique type, which is output (for a function
/// named `foo` returning an `i32`) as `fn() -> i32 {foo}`.
///
/// This includes tuple struct / enum variant constructors as well.
///
/// For example the type of `bar` here:
///
/// ```
/// fn foo() -> i32 { 1 }
/// let bar = foo; // bar: fn() -> i32 {foo}
/// ```
FnDef(CallableDef),
/// A pointer to a function. Written as `fn() -> i32`.
///
/// For example the type of `bar` here:
///
/// ```
/// fn foo() -> i32 { 1 }
/// let bar: fn() -> i32 = foo;
/// ```
FnPtr { num_args: u16 },
/// The never type `!`.
Never,
/// A tuple type. For example, `(i32, bool)`.
Tuple { cardinality: u16 },
/// Represents an associated item like `Iterator::Item`. This is used
/// when we have tried to normalize a projection like `T::Item` but
/// couldn't find a better representation. In that case, we generate
/// an **application type** like `(Iterator::Item)<T>`.
AssociatedType(TypeAliasId),
/// The type of a specific closure.
///
/// The closure signature is stored in a `FnPtr` type in the first type
/// parameter.
Closure { def: DefWithBodyId, expr: ExprId },
}
/// This exists just for Chalk, because Chalk just has a single `StructId` where
/// we have different kinds of ADTs, primitive types and special type
/// constructors like tuples and function pointers.
#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
pub struct TypeCtorId(salsa::InternId);
impl_intern_key!(TypeCtorId);
impl TypeCtor {
pub fn num_ty_params(self, db: &impl HirDatabase) -> usize {
match self {
TypeCtor::Bool
| TypeCtor::Char
| TypeCtor::Int(_)
| TypeCtor::Float(_)
| TypeCtor::Str
| TypeCtor::Never => 0,
TypeCtor::Slice
| TypeCtor::Array
| TypeCtor::RawPtr(_)
| TypeCtor::Ref(_)
| TypeCtor::Closure { .. } // 1 param representing the signature of the closure
=> 1,
TypeCtor::Adt(adt) => {
let generic_params = generics(db, AdtId::from(adt).into());
generic_params.len()
}
TypeCtor::FnDef(callable) => {
let generic_params = generics(db, callable.into());
generic_params.len()
}
TypeCtor::AssociatedType(type_alias) => {
let generic_params = generics(db, type_alias.into());
generic_params.len()
}
TypeCtor::FnPtr { num_args } => num_args as usize + 1,
TypeCtor::Tuple { cardinality } => cardinality as usize,
}
}
pub fn krate(self, db: &impl HirDatabase) -> Option<CrateId> {
match self {
TypeCtor::Bool
| TypeCtor::Char
| TypeCtor::Int(_)
| TypeCtor::Float(_)
| TypeCtor::Str
| TypeCtor::Never
| TypeCtor::Slice
| TypeCtor::Array
| TypeCtor::RawPtr(_)
| TypeCtor::Ref(_)
| TypeCtor::FnPtr { .. }
| TypeCtor::Tuple { .. } => None,
// Closure's krate is irrelevant for coherence I would think?
TypeCtor::Closure { .. } => None,
TypeCtor::Adt(adt) => Some(adt.module(db).krate),
TypeCtor::FnDef(callable) => Some(callable.krate(db)),
TypeCtor::AssociatedType(type_alias) => Some(type_alias.lookup(db).module(db).krate),
}
}
pub fn as_generic_def(self) -> Option<GenericDefId> {
match self {
TypeCtor::Bool
| TypeCtor::Char
| TypeCtor::Int(_)
| TypeCtor::Float(_)
| TypeCtor::Str
| TypeCtor::Never
| TypeCtor::Slice
| TypeCtor::Array
| TypeCtor::RawPtr(_)
| TypeCtor::Ref(_)
| TypeCtor::FnPtr { .. }
| TypeCtor::Tuple { .. }
| TypeCtor::Closure { .. } => None,
TypeCtor::Adt(adt) => Some(adt.into()),
TypeCtor::FnDef(callable) => Some(callable.into()),
TypeCtor::AssociatedType(type_alias) => Some(type_alias.into()),
}
}
}
/// A nominal type with (maybe 0) type parameters. This might be a primitive
/// type like `bool`, a struct, tuple, function pointer, reference or
/// several other things.
#[derive(Clone, PartialEq, Eq, Debug, Hash)]
pub struct ApplicationTy {
pub ctor: TypeCtor,
pub parameters: Substs,
}
/// A "projection" type corresponds to an (unnormalized)
/// projection like `<P0 as Trait<P1..Pn>>::Foo`. Note that the
/// trait and all its parameters are fully known.
#[derive(Clone, PartialEq, Eq, Debug, Hash)]
pub struct ProjectionTy {
pub associated_ty: TypeAliasId,
pub parameters: Substs,
}
impl ProjectionTy {
pub fn trait_ref(&self, db: &impl HirDatabase) -> TraitRef {
TraitRef { trait_: self.trait_(db).into(), substs: self.parameters.clone() }
}
fn trait_(&self, db: &impl HirDatabase) -> TraitId {
match self.associated_ty.lookup(db).container {
ContainerId::TraitId(it) => it,
_ => panic!("projection ty without parent trait"),
}
}
}
impl TypeWalk for ProjectionTy {
fn walk(&self, f: &mut impl FnMut(&Ty)) {
self.parameters.walk(f);
}
fn walk_mut_binders(&mut self, f: &mut impl FnMut(&mut Ty, usize), binders: usize) {
self.parameters.walk_mut_binders(f, binders);
}
}
/// A type.
///
/// See also the `TyKind` enum in rustc (librustc/ty/sty.rs), which represents
/// the same thing (but in a different way).
///
/// This should be cheap to clone.
#[derive(Clone, PartialEq, Eq, Debug, Hash)]
pub enum Ty {
/// A nominal type with (maybe 0) type parameters. This might be a primitive
/// type like `bool`, a struct, tuple, function pointer, reference or
/// several other things.
Apply(ApplicationTy),
/// A "projection" type corresponds to an (unnormalized)
/// projection like `<P0 as Trait<P1..Pn>>::Foo`. Note that the
/// trait and all its parameters are fully known.
Projection(ProjectionTy),
/// A type parameter; for example, `T` in `fn f<T>(x: T) {}
Param {
/// The index of the parameter (starting with parameters from the
/// surrounding impl, then the current function).
idx: u32,
/// The name of the parameter, for displaying.
// FIXME get rid of this
name: Name,
},
/// A bound type variable. Used during trait resolution to represent Chalk
/// variables, and in `Dyn` and `Opaque` bounds to represent the `Self` type.
Bound(u32),
/// A type variable used during type checking. Not to be confused with a
/// type parameter.
Infer(InferTy),
/// A trait object (`dyn Trait` or bare `Trait` in pre-2018 Rust).
///
/// The predicates are quantified over the `Self` type, i.e. `Ty::Bound(0)`
/// represents the `Self` type inside the bounds. This is currently
/// implicit; Chalk has the `Binders` struct to make it explicit, but it
/// didn't seem worth the overhead yet.
Dyn(Arc<[GenericPredicate]>),
/// An opaque type (`impl Trait`).
///
/// The predicates are quantified over the `Self` type; see `Ty::Dyn` for
/// more.
Opaque(Arc<[GenericPredicate]>),
/// A placeholder for a type which could not be computed; this is propagated
/// to avoid useless error messages. Doubles as a placeholder where type
/// variables are inserted before type checking, since we want to try to
/// infer a better type here anyway -- for the IDE use case, we want to try
/// to infer as much as possible even in the presence of type errors.
Unknown,
}
/// A list of substitutions for generic parameters.
#[derive(Clone, PartialEq, Eq, Debug, Hash)]
pub struct Substs(Arc<[Ty]>);
impl TypeWalk for Substs {
fn walk(&self, f: &mut impl FnMut(&Ty)) {
for t in self.0.iter() {
t.walk(f);
}
}
fn walk_mut_binders(&mut self, f: &mut impl FnMut(&mut Ty, usize), binders: usize) {
for t in make_mut_slice(&mut self.0) {
t.walk_mut_binders(f, binders);
}
}
}
impl Substs {
pub fn empty() -> Substs {
Substs(Arc::new([]))
}
pub fn single(ty: Ty) -> Substs {
Substs(Arc::new([ty]))
}
pub fn prefix(&self, n: usize) -> Substs {
Substs(self.0[..std::cmp::min(self.0.len(), n)].into())
}
pub fn as_single(&self) -> &Ty {
if self.0.len() != 1 {
panic!("expected substs of len 1, got {:?}", self);
}
&self.0[0]
}
/// Return Substs that replace each parameter by itself (i.e. `Ty::Param`).
pub(crate) fn identity(generic_params: &Generics) -> Substs {
Substs(
generic_params.iter().map(|(idx, p)| Ty::Param { idx, name: p.name.clone() }).collect(),
)
}
/// Return Substs that replace each parameter by a bound variable.
pub(crate) fn bound_vars(generic_params: &Generics) -> Substs {
Substs(generic_params.iter().map(|(idx, _p)| Ty::Bound(idx)).collect())
}
pub fn build_for_def(db: &impl HirDatabase, def: impl Into<GenericDefId>) -> SubstsBuilder {
let def = def.into();
let params = generics(db, def);
let param_count = params.len();
Substs::builder(param_count)
}
pub(crate) fn build_for_generics(generic_params: &Generics) -> SubstsBuilder {
Substs::builder(generic_params.len())
}
pub fn build_for_type_ctor(db: &impl HirDatabase, type_ctor: TypeCtor) -> SubstsBuilder {
Substs::builder(type_ctor.num_ty_params(db))
}
fn builder(param_count: usize) -> SubstsBuilder {
SubstsBuilder { vec: Vec::with_capacity(param_count), param_count }
}
}
#[derive(Debug, Clone)]
pub struct SubstsBuilder {
vec: Vec<Ty>,
param_count: usize,
}
impl SubstsBuilder {
pub fn build(self) -> Substs {
assert_eq!(self.vec.len(), self.param_count);
Substs(self.vec.into())
}
pub fn push(mut self, ty: Ty) -> Self {
self.vec.push(ty);
self
}
fn remaining(&self) -> usize {
self.param_count - self.vec.len()
}
pub fn fill_with_bound_vars(self, starting_from: u32) -> Self {
self.fill((starting_from..).map(Ty::Bound))
}
pub fn fill_with_params(self) -> Self {
let start = self.vec.len() as u32;
self.fill((start..).map(|idx| Ty::Param { idx, name: Name::missing() }))
}
pub fn fill_with_unknown(self) -> Self {
self.fill(iter::repeat(Ty::Unknown))
}
pub fn fill(mut self, filler: impl Iterator<Item = Ty>) -> Self {
self.vec.extend(filler.take(self.remaining()));
assert_eq!(self.remaining(), 0);
self
}
pub fn use_parent_substs(mut self, parent_substs: &Substs) -> Self {
assert!(self.vec.is_empty());
assert!(parent_substs.len() <= self.param_count);
self.vec.extend(parent_substs.iter().cloned());
self
}
}
impl Deref for Substs {
type Target = [Ty];
fn deref(&self) -> &[Ty] {
&self.0
}
}
/// A trait with type parameters. This includes the `Self`, so this represents a concrete type implementing the trait.
/// Name to be bikeshedded: TraitBound? TraitImplements?
#[derive(Clone, PartialEq, Eq, Debug, Hash)]
pub struct TraitRef {
/// FIXME name?
pub trait_: TraitId,
pub substs: Substs,
}
impl TraitRef {
pub fn self_ty(&self) -> &Ty {
&self.substs[0]
}
}
impl TypeWalk for TraitRef {
fn walk(&self, f: &mut impl FnMut(&Ty)) {
self.substs.walk(f);
}
fn walk_mut_binders(&mut self, f: &mut impl FnMut(&mut Ty, usize), binders: usize) {
self.substs.walk_mut_binders(f, binders);
}
}
/// Like `generics::WherePredicate`, but with resolved types: A condition on the
/// parameters of a generic item.
#[derive(Debug, Clone, PartialEq, Eq, Hash)]
pub enum GenericPredicate {
/// The given trait needs to be implemented for its type parameters.
Implemented(TraitRef),
/// An associated type bindings like in `Iterator<Item = T>`.
Projection(ProjectionPredicate),
/// We couldn't resolve the trait reference. (If some type parameters can't
/// be resolved, they will just be Unknown).
Error,
}
impl GenericPredicate {
pub fn is_error(&self) -> bool {
match self {
GenericPredicate::Error => true,
_ => false,
}
}
pub fn is_implemented(&self) -> bool {
match self {
GenericPredicate::Implemented(_) => true,
_ => false,
}
}
pub fn trait_ref(&self, db: &impl HirDatabase) -> Option<TraitRef> {
match self {
GenericPredicate::Implemented(tr) => Some(tr.clone()),
GenericPredicate::Projection(proj) => Some(proj.projection_ty.trait_ref(db)),
GenericPredicate::Error => None,
}
}
}
impl TypeWalk for GenericPredicate {
fn walk(&self, f: &mut impl FnMut(&Ty)) {
match self {
GenericPredicate::Implemented(trait_ref) => trait_ref.walk(f),
GenericPredicate::Projection(projection_pred) => projection_pred.walk(f),
GenericPredicate::Error => {}
}
}
fn walk_mut_binders(&mut self, f: &mut impl FnMut(&mut Ty, usize), binders: usize) {
match self {
GenericPredicate::Implemented(trait_ref) => trait_ref.walk_mut_binders(f, binders),
GenericPredicate::Projection(projection_pred) => {
projection_pred.walk_mut_binders(f, binders)
}
GenericPredicate::Error => {}
}
}
}
/// Basically a claim (currently not validated / checked) that the contained
/// type / trait ref contains no inference variables; any inference variables it
/// contained have been replaced by bound variables, and `num_vars` tells us how
/// many there are. This is used to erase irrelevant differences between types
/// before using them in queries.
#[derive(Debug, Clone, PartialEq, Eq, Hash)]
pub struct Canonical<T> {
pub value: T,
pub num_vars: usize,
}
/// A function signature as seen by type inference: Several parameter types and
/// one return type.
#[derive(Clone, PartialEq, Eq, Debug)]
pub struct FnSig {
params_and_return: Arc<[Ty]>,
}
impl FnSig {
pub fn from_params_and_return(mut params: Vec<Ty>, ret: Ty) -> FnSig {
params.push(ret);
FnSig { params_and_return: params.into() }
}
pub fn from_fn_ptr_substs(substs: &Substs) -> FnSig {
FnSig { params_and_return: Arc::clone(&substs.0) }
}
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 TypeWalk for FnSig {
fn walk(&self, f: &mut impl FnMut(&Ty)) {
for t in self.params_and_return.iter() {
t.walk(f);
}
}
fn walk_mut_binders(&mut self, f: &mut impl FnMut(&mut Ty, usize), binders: usize) {
for t in make_mut_slice(&mut self.params_and_return) {
t.walk_mut_binders(f, binders);
}
}
}
impl Ty {
pub fn simple(ctor: TypeCtor) -> Ty {
Ty::Apply(ApplicationTy { ctor, parameters: Substs::empty() })
}
pub fn apply_one(ctor: TypeCtor, param: Ty) -> Ty {
Ty::Apply(ApplicationTy { ctor, parameters: Substs::single(param) })
}
pub fn apply(ctor: TypeCtor, parameters: Substs) -> Ty {
Ty::Apply(ApplicationTy { ctor, parameters })
}
pub fn unit() -> Self {
Ty::apply(TypeCtor::Tuple { cardinality: 0 }, Substs::empty())
}
pub fn as_reference(&self) -> Option<(&Ty, Mutability)> {
match self {
Ty::Apply(ApplicationTy { ctor: TypeCtor::Ref(mutability), parameters }) => {
Some((parameters.as_single(), *mutability))
}
_ => None,
}
}
pub fn as_adt(&self) -> Option<(AdtId, &Substs)> {
match self {
Ty::Apply(ApplicationTy { ctor: TypeCtor::Adt(adt_def), parameters }) => {
Some((*adt_def, parameters))
}
_ => None,
}
}
pub fn as_tuple(&self) -> Option<&Substs> {
match self {
Ty::Apply(ApplicationTy { ctor: TypeCtor::Tuple { .. }, parameters }) => {
Some(parameters)
}
_ => None,
}
}
pub fn as_callable(&self) -> Option<(CallableDef, &Substs)> {
match self {
Ty::Apply(ApplicationTy { ctor: TypeCtor::FnDef(callable_def), parameters }) => {
Some((*callable_def, parameters))
}
_ => None,
}
}
fn builtin_deref(&self) -> Option<Ty> {
match self {
Ty::Apply(a_ty) => match a_ty.ctor {
TypeCtor::Ref(..) => Some(Ty::clone(a_ty.parameters.as_single())),
TypeCtor::RawPtr(..) => Some(Ty::clone(a_ty.parameters.as_single())),
_ => None,
},
_ => None,
}
}
fn callable_sig(&self, db: &impl HirDatabase) -> Option<FnSig> {
match self {
Ty::Apply(a_ty) => match a_ty.ctor {
TypeCtor::FnPtr { .. } => Some(FnSig::from_fn_ptr_substs(&a_ty.parameters)),
TypeCtor::FnDef(def) => {
let sig = db.callable_item_signature(def);
Some(sig.subst(&a_ty.parameters))
}
TypeCtor::Closure { .. } => {
let sig_param = &a_ty.parameters[0];
sig_param.callable_sig(db)
}
_ => None,
},
_ => None,
}
}
/// If this is a type with type parameters (an ADT or function), replaces
/// the `Substs` for these type parameters with the given ones. (So e.g. if
/// `self` is `Option<_>` and the substs contain `u32`, we'll have
/// `Option<u32>` afterwards.)
pub fn apply_substs(self, substs: Substs) -> Ty {
match self {
Ty::Apply(ApplicationTy { ctor, parameters: previous_substs }) => {
assert_eq!(previous_substs.len(), substs.len());
Ty::Apply(ApplicationTy { ctor, parameters: substs })
}
_ => self,
}
}
/// Returns the type parameters of this type if it has some (i.e. is an ADT
/// or function); so if `self` is `Option<u32>`, this returns the `u32`.
pub fn substs(&self) -> Option<Substs> {
match self {
Ty::Apply(ApplicationTy { parameters, .. }) => Some(parameters.clone()),
_ => None,
}
}
/// If this is an `impl Trait` or `dyn Trait`, returns that trait.
pub fn inherent_trait(&self) -> Option<TraitId> {
match self {
Ty::Dyn(predicates) | Ty::Opaque(predicates) => {
predicates.iter().find_map(|pred| match pred {
GenericPredicate::Implemented(tr) => Some(tr.trait_),
_ => None,
})
}
_ => None,
}
}
}
/// This allows walking structures that contain types to do something with those
/// types, similar to Chalk's `Fold` trait.
pub trait TypeWalk {
fn walk(&self, f: &mut impl FnMut(&Ty));
fn walk_mut(&mut self, f: &mut impl FnMut(&mut Ty)) {
self.walk_mut_binders(&mut |ty, _binders| f(ty), 0);
}
/// Walk the type, counting entered binders.
///
/// `Ty::Bound` variables use DeBruijn indexing, which means that 0 refers
/// to the innermost binder, 1 to the next, etc.. So when we want to
/// substitute a certain bound variable, we can't just walk the whole type
/// and blindly replace each instance of a certain index; when we 'enter'
/// things that introduce new bound variables, we have to keep track of
/// that. Currently, the only thing that introduces bound variables on our
/// side are `Ty::Dyn` and `Ty::Opaque`, which each introduce a bound
/// variable for the self type.
fn walk_mut_binders(&mut self, f: &mut impl FnMut(&mut Ty, usize), binders: usize);
fn fold(mut self, f: &mut impl FnMut(Ty) -> Ty) -> Self
where
Self: Sized,
{
self.walk_mut(&mut |ty_mut| {
let ty = mem::replace(ty_mut, Ty::Unknown);
*ty_mut = f(ty);
});
self
}
/// Replaces type parameters in this type using the given `Substs`. (So e.g.
/// if `self` is `&[T]`, where type parameter T has index 0, and the
/// `Substs` contain `u32` at index 0, we'll have `&[u32]` afterwards.)
fn subst(self, substs: &Substs) -> Self
where
Self: Sized,
{
self.fold(&mut |ty| match ty {
Ty::Param { idx, name } => {
substs.get(idx as usize).cloned().unwrap_or(Ty::Param { idx, name })
}
ty => ty,
})
}
/// Substitutes `Ty::Bound` vars (as opposed to type parameters).
fn subst_bound_vars(mut self, substs: &Substs) -> Self
where
Self: Sized,
{
self.walk_mut_binders(
&mut |ty, binders| match ty {
&mut Ty::Bound(idx) => {
if idx as usize >= binders && (idx as usize - binders) < substs.len() {
*ty = substs.0[idx as usize - binders].clone();
}
}
_ => {}
},
0,
);
self
}
/// Shifts up `Ty::Bound` vars by `n`.
fn shift_bound_vars(self, n: i32) -> Self
where
Self: Sized,
{
self.fold(&mut |ty| match ty {
Ty::Bound(idx) => {
assert!(idx as i32 >= -n);
Ty::Bound((idx as i32 + n) as u32)
}
ty => ty,
})
}
}
impl TypeWalk for Ty {
fn walk(&self, f: &mut impl FnMut(&Ty)) {
match self {
Ty::Apply(a_ty) => {
for t in a_ty.parameters.iter() {
t.walk(f);
}
}
Ty::Projection(p_ty) => {
for t in p_ty.parameters.iter() {
t.walk(f);
}
}
Ty::Dyn(predicates) | Ty::Opaque(predicates) => {
for p in predicates.iter() {
p.walk(f);
}
}
Ty::Param { .. } | Ty::Bound(_) | Ty::Infer(_) | Ty::Unknown => {}
}
f(self);
}
fn walk_mut_binders(&mut self, f: &mut impl FnMut(&mut Ty, usize), binders: usize) {
match self {
Ty::Apply(a_ty) => {
a_ty.parameters.walk_mut_binders(f, binders);
}
Ty::Projection(p_ty) => {
p_ty.parameters.walk_mut_binders(f, binders);
}
Ty::Dyn(predicates) | Ty::Opaque(predicates) => {
for p in make_mut_slice(predicates) {
p.walk_mut_binders(f, binders + 1);
}
}
Ty::Param { .. } | Ty::Bound(_) | Ty::Infer(_) | Ty::Unknown => {}
}
f(self, binders);
}
}
impl HirDisplay for &Ty {
fn hir_fmt(&self, f: &mut HirFormatter<impl HirDatabase>) -> fmt::Result {
HirDisplay::hir_fmt(*self, f)
}
}
impl HirDisplay for ApplicationTy {
fn hir_fmt(&self, f: &mut HirFormatter<impl HirDatabase>) -> fmt::Result {
if f.should_truncate() {
return write!(f, "…");
}
match self.ctor {
TypeCtor::Bool => write!(f, "bool")?,
TypeCtor::Char => write!(f, "char")?,
TypeCtor::Int(t) => write!(f, "{}", t)?,
TypeCtor::Float(t) => write!(f, "{}", t)?,
TypeCtor::Str => write!(f, "str")?,
TypeCtor::Slice => {
let t = self.parameters.as_single();
write!(f, "[{}]", t.display(f.db))?;
}
TypeCtor::Array => {
let t = self.parameters.as_single();
write!(f, "[{};_]", t.display(f.db))?;
}
TypeCtor::RawPtr(m) => {
let t = self.parameters.as_single();
write!(f, "*{}{}", m.as_keyword_for_ptr(), t.display(f.db))?;
}
TypeCtor::Ref(m) => {
let t = self.parameters.as_single();
write!(f, "&{}{}", m.as_keyword_for_ref(), t.display(f.db))?;
}
TypeCtor::Never => write!(f, "!")?,
TypeCtor::Tuple { .. } => {
let ts = &self.parameters;
if ts.len() == 1 {
write!(f, "({},)", ts[0].display(f.db))?;
} else {
write!(f, "(")?;
f.write_joined(&*ts.0, ", ")?;
write!(f, ")")?;
}
}
TypeCtor::FnPtr { .. } => {
let sig = FnSig::from_fn_ptr_substs(&self.parameters);
write!(f, "fn(")?;
f.write_joined(sig.params(), ", ")?;
write!(f, ") -> {}", sig.ret().display(f.db))?;
}
TypeCtor::FnDef(def) => {
let sig = f.db.callable_item_signature(def);
let name = match def {
CallableDef::FunctionId(ff) => f.db.function_data(ff).name.clone(),
CallableDef::StructId(s) => f.db.struct_data(s).name.clone(),
CallableDef::EnumVariantId(e) => {
let enum_data = f.db.enum_data(e.parent);
enum_data.variants[e.local_id].name.clone()
}
};
match def {
CallableDef::FunctionId(_) => write!(f, "fn {}", name)?,
CallableDef::StructId(_) | CallableDef::EnumVariantId(_) => {
write!(f, "{}", name)?
}
}
if self.parameters.len() > 0 {
write!(f, "<")?;
f.write_joined(&*self.parameters.0, ", ")?;
write!(f, ">")?;
}
write!(f, "(")?;
f.write_joined(sig.params(), ", ")?;
write!(f, ") -> {}", sig.ret().display(f.db))?;
}
TypeCtor::Adt(def_id) => {
let name = match def_id {
AdtId::StructId(it) => f.db.struct_data(it).name.clone(),
AdtId::UnionId(it) => f.db.union_data(it).name.clone(),
AdtId::EnumId(it) => f.db.enum_data(it).name.clone(),
};
write!(f, "{}", name)?;
if self.parameters.len() > 0 {
write!(f, "<")?;
f.write_joined(&*self.parameters.0, ", ")?;
write!(f, ">")?;
}
}
TypeCtor::AssociatedType(type_alias) => {
let trait_ = match type_alias.lookup(f.db).container {
ContainerId::TraitId(it) => it,
_ => panic!("not an associated type"),
};
let trait_name = f.db.trait_data(trait_).name.clone();
let name = f.db.type_alias_data(type_alias).name.clone();
write!(f, "{}::{}", trait_name, name)?;
if self.parameters.len() > 0 {
write!(f, "<")?;
f.write_joined(&*self.parameters.0, ", ")?;
write!(f, ">")?;
}
}
TypeCtor::Closure { .. } => {
let sig = self.parameters[0]
.callable_sig(f.db)
.expect("first closure parameter should contain signature");
write!(f, "|")?;
f.write_joined(sig.params(), ", ")?;
write!(f, "| -> {}", sig.ret().display(f.db))?;
}
}
Ok(())
}
}
impl HirDisplay for ProjectionTy {
fn hir_fmt(&self, f: &mut HirFormatter<impl HirDatabase>) -> fmt::Result {
if f.should_truncate() {
return write!(f, "…");
}
let trait_name = f.db.trait_data(self.trait_(f.db)).name.clone();
write!(f, "<{} as {}", self.parameters[0].display(f.db), trait_name,)?;
if self.parameters.len() > 1 {
write!(f, "<")?;
f.write_joined(&self.parameters[1..], ", ")?;
write!(f, ">")?;
}
write!(f, ">::{}", f.db.type_alias_data(self.associated_ty).name)?;
Ok(())
}
}
impl HirDisplay for Ty {
fn hir_fmt(&self, f: &mut HirFormatter<impl HirDatabase>) -> fmt::Result {
if f.should_truncate() {
return write!(f, "…");
}
match self {
Ty::Apply(a_ty) => a_ty.hir_fmt(f)?,
Ty::Projection(p_ty) => p_ty.hir_fmt(f)?,
Ty::Param { name, .. } => write!(f, "{}", name)?,
Ty::Bound(idx) => write!(f, "?{}", idx)?,
Ty::Dyn(predicates) | Ty::Opaque(predicates) => {
match self {
Ty::Dyn(_) => write!(f, "dyn ")?,
Ty::Opaque(_) => write!(f, "impl ")?,
_ => unreachable!(),
};
// Note: This code is written to produce nice results (i.e.
// corresponding to surface Rust) for types that can occur in
// actual Rust. It will have weird results if the predicates
// aren't as expected (i.e. self types = $0, projection
// predicates for a certain trait come after the Implemented
// predicate for that trait).
let mut first = true;
let mut angle_open = false;
for p in predicates.iter() {
match p {
GenericPredicate::Implemented(trait_ref) => {
if angle_open {
write!(f, ">")?;
}
if !first {
write!(f, " + ")?;
}
// We assume that the self type is $0 (i.e. the
// existential) here, which is the only thing that's
// possible in actual Rust, and hence don't print it
write!(f, "{}", f.db.trait_data(trait_ref.trait_).name.clone())?;
if trait_ref.substs.len() > 1 {
write!(f, "<")?;
f.write_joined(&trait_ref.substs[1..], ", ")?;
// there might be assoc type bindings, so we leave the angle brackets open
angle_open = true;
}
}
GenericPredicate::Projection(projection_pred) => {
// in types in actual Rust, these will always come
// after the corresponding Implemented predicate
if angle_open {
write!(f, ", ")?;
} else {
write!(f, "<")?;
angle_open = true;
}
let name =
f.db.type_alias_data(projection_pred.projection_ty.associated_ty)
.name
.clone();
write!(f, "{} = ", name)?;
projection_pred.ty.hir_fmt(f)?;
}
GenericPredicate::Error => {
if angle_open {
// impl Trait<X, {error}>
write!(f, ", ")?;
} else if !first {
// impl Trait + {error}
write!(f, " + ")?;
}
p.hir_fmt(f)?;
}
}
first = false;
}
if angle_open {
write!(f, ">")?;
}
}
Ty::Unknown => write!(f, "{{unknown}}")?,
Ty::Infer(..) => write!(f, "_")?,
}
Ok(())
}
}
impl TraitRef {
fn hir_fmt_ext(&self, f: &mut HirFormatter<impl HirDatabase>, use_as: bool) -> fmt::Result {
if f.should_truncate() {
return write!(f, "…");
}
self.substs[0].hir_fmt(f)?;
if use_as {
write!(f, " as ")?;
} else {
write!(f, ": ")?;
}
write!(f, "{}", f.db.trait_data(self.trait_).name.clone())?;
if self.substs.len() > 1 {
write!(f, "<")?;
f.write_joined(&self.substs[1..], ", ")?;
write!(f, ">")?;
}
Ok(())
}
}
impl HirDisplay for TraitRef {
fn hir_fmt(&self, f: &mut HirFormatter<impl HirDatabase>) -> fmt::Result {
self.hir_fmt_ext(f, false)
}
}
impl HirDisplay for &GenericPredicate {
fn hir_fmt(&self, f: &mut HirFormatter<impl HirDatabase>) -> fmt::Result {
HirDisplay::hir_fmt(*self, f)
}
}
impl HirDisplay for GenericPredicate {
fn hir_fmt(&self, f: &mut HirFormatter<impl HirDatabase>) -> fmt::Result {
if f.should_truncate() {
return write!(f, "…");
}
match self {
GenericPredicate::Implemented(trait_ref) => trait_ref.hir_fmt(f)?,
GenericPredicate::Projection(projection_pred) => {
write!(f, "<")?;
projection_pred.projection_ty.trait_ref(f.db).hir_fmt_ext(f, true)?;
write!(
f,
">::{} = {}",
f.db.type_alias_data(projection_pred.projection_ty.associated_ty).name,
projection_pred.ty.display(f.db)
)?;
}
GenericPredicate::Error => write!(f, "{{error}}")?,
}
Ok(())
}
}
impl HirDisplay for Obligation {
fn hir_fmt(&self, f: &mut HirFormatter<impl HirDatabase>) -> fmt::Result {
match self {
Obligation::Trait(tr) => write!(f, "Implements({})", tr.display(f.db)),
Obligation::Projection(proj) => write!(
f,
"Normalize({} => {})",
proj.projection_ty.display(f.db),
proj.ty.display(f.db)
),
}
}
}
|