use smallvec::SmallVec;
use std::fmt::Debug;
use std::hash::Hash;
use crate::fold::TypeSuperFoldable;
use crate::visit::{Flags, TypeSuperVisitable, TypeVisitable};
use crate::{
new, BoundVar, BoundVars, CanonicalVarInfo, ConstKind, DebugWithInfcx, RegionKind, TyKind,
UniverseIndex,
};
pub trait Interner: Sized + Copy {
type DefId: Copy + Debug + Hash + Eq;
type DefiningOpaqueTypes: Copy + Debug + Hash + Default + Eq + TypeVisitable<Self>;
type AdtDef: Copy + Debug + Hash + Eq;
type GenericArgs: Copy
+ DebugWithInfcx<Self>
+ Hash
+ Eq
+ IntoIterator<Item = Self::GenericArg>;
type GenericArg: Copy + DebugWithInfcx<Self> + Hash + Eq;
type Term: Copy + Debug + Hash + Eq;
type Binder<T: TypeVisitable<Self>>: BoundVars<Self> + TypeSuperVisitable<Self>;
type BoundVars: IntoIterator<Item = Self::BoundVar>;
type BoundVar;
type CanonicalVars: Copy + Debug + Hash + Eq + IntoIterator<Item = CanonicalVarInfo<Self>>;
type Ty: Copy
+ DebugWithInfcx<Self>
+ Hash
+ Eq
+ Into<Self::GenericArg>
+ IntoKind<Kind = TyKind<Self>>
+ TypeSuperVisitable<Self>
+ TypeSuperFoldable<Self>
+ Flags
+ new::Ty<Self>;
type Tys: Copy + Debug + Hash + Eq + IntoIterator<Item = Self::Ty>;
type AliasTy: Copy + DebugWithInfcx<Self> + Hash + Eq;
type ParamTy: Copy + Debug + Hash + Eq;
type BoundTy: Copy + Debug + Hash + Eq;
type PlaceholderTy: Copy + Debug + Hash + Eq + PlaceholderLike;
type ErrorGuaranteed: Copy + Debug + Hash + Eq;
type BoundExistentialPredicates: Copy + DebugWithInfcx<Self> + Hash + Eq;
type PolyFnSig: Copy + DebugWithInfcx<Self> + Hash + Eq;
type AllocId: Copy + Debug + Hash + Eq;
type Pat: Copy + Debug + Hash + Eq + DebugWithInfcx<Self>;
type Const: Copy
+ DebugWithInfcx<Self>
+ Hash
+ Eq
+ Into<Self::GenericArg>
+ IntoKind<Kind = ConstKind<Self>>
+ ConstTy<Self>
+ TypeSuperVisitable<Self>
+ TypeSuperFoldable<Self>
+ Flags
+ new::Const<Self>;
type AliasConst: Copy + DebugWithInfcx<Self> + Hash + Eq;
type PlaceholderConst: Copy + Debug + Hash + Eq + PlaceholderLike;
type ParamConst: Copy + Debug + Hash + Eq;
type BoundConst: Copy + Debug + Hash + Eq;
type ValueConst: Copy + Debug + Hash + Eq;
type ExprConst: Copy + DebugWithInfcx<Self> + Hash + Eq;
type Region: Copy
+ DebugWithInfcx<Self>
+ Hash
+ Eq
+ Into<Self::GenericArg>
+ IntoKind<Kind = RegionKind<Self>>
+ Flags
+ new::Region<Self>;
type EarlyParamRegion: Copy + Debug + Hash + Eq;
type LateParamRegion: Copy + Debug + Hash + Eq;
type BoundRegion: Copy + Debug + Hash + Eq;
type InferRegion: Copy + DebugWithInfcx<Self> + Hash + Eq;
type PlaceholderRegion: Copy + Debug + Hash + Eq + PlaceholderLike;
type Predicate: Copy
+ Debug
+ Hash
+ Eq
+ TypeSuperVisitable<Self>
+ TypeSuperFoldable<Self>
+ Flags;
type TraitPredicate: Copy + Debug + Hash + Eq;
type RegionOutlivesPredicate: Copy + Debug + Hash + Eq;
type TypeOutlivesPredicate: Copy + Debug + Hash + Eq;
type ProjectionPredicate: Copy + Debug + Hash + Eq;
type NormalizesTo: Copy + Debug + Hash + Eq;
type SubtypePredicate: Copy + Debug + Hash + Eq;
type CoercePredicate: Copy + Debug + Hash + Eq;
type ClosureKind: Copy + Debug + Hash + Eq;
type Clauses: Copy + Debug + Hash + Eq + TypeSuperVisitable<Self> + Flags;
fn mk_canonical_var_infos(self, infos: &[CanonicalVarInfo<Self>]) -> Self::CanonicalVars;
}
pub trait PlaceholderLike {
fn universe(self) -> UniverseIndex;
fn var(self) -> BoundVar;
fn with_updated_universe(self, ui: UniverseIndex) -> Self;
fn new(ui: UniverseIndex, var: BoundVar) -> Self;
}
pub trait IntoKind {
type Kind;
fn kind(self) -> Self::Kind;
}
pub trait ConstTy<I: Interner> {
fn ty(self) -> I::Ty;
}
pub trait CollectAndApply<T, R>: Sized {
type Output;
fn collect_and_apply<I, F>(iter: I, f: F) -> Self::Output
where
I: Iterator<Item = Self>,
F: FnOnce(&[T]) -> R;
}
impl<T, R> CollectAndApply<T, R> for T {
type Output = R;
fn collect_and_apply<I, F>(mut iter: I, f: F) -> R
where
I: Iterator<Item = T>,
F: FnOnce(&[T]) -> R,
{
match iter.size_hint() {
(0, Some(0)) => {
assert!(iter.next().is_none());
f(&[])
}
(1, Some(1)) => {
let t0 = iter.next().unwrap();
assert!(iter.next().is_none());
f(&[t0])
}
(2, Some(2)) => {
let t0 = iter.next().unwrap();
let t1 = iter.next().unwrap();
assert!(iter.next().is_none());
f(&[t0, t1])
}
_ => f(&iter.collect::<SmallVec<[_; 8]>>()),
}
}
}
impl<T, R, E> CollectAndApply<T, R> for Result<T, E> {
type Output = Result<R, E>;
fn collect_and_apply<I, F>(mut iter: I, f: F) -> Result<R, E>
where
I: Iterator<Item = Result<T, E>>,
F: FnOnce(&[T]) -> R,
{
Ok(match iter.size_hint() {
(0, Some(0)) => {
assert!(iter.next().is_none());
f(&[])
}
(1, Some(1)) => {
let t0 = iter.next().unwrap()?;
assert!(iter.next().is_none());
f(&[t0])
}
(2, Some(2)) => {
let t0 = iter.next().unwrap()?;
let t1 = iter.next().unwrap()?;
assert!(iter.next().is_none());
f(&[t0, t1])
}
_ => f(&iter.collect::<Result<SmallVec<[_; 8]>, _>>()?),
})
}
}