flux_rustc_bridge/ty/
subst.rs

1use flux_arc_interner::{Internable, List};
2
3use super::{
4    Binder, Const, ConstKind, ExistentialPredicate, ExistentialProjection, ExistentialTraitRef,
5    FnSig, GenericArg, Region, Ty, TyKind,
6};
7use crate::ty::TraitRef;
8
9pub(super) trait Subst {
10    fn subst(&self, args: &[GenericArg]) -> Self;
11}
12
13impl<T> Subst for Binder<T>
14where
15    T: Subst,
16{
17    fn subst(&self, args: &[GenericArg]) -> Self {
18        Binder(self.0.subst(args), self.1.clone())
19    }
20}
21
22impl Subst for FnSig {
23    fn subst(&self, args: &[GenericArg]) -> Self {
24        FnSig {
25            safety: self.safety,
26            abi: self.abi,
27            inputs_and_output: self.inputs_and_output.subst(args),
28        }
29    }
30}
31
32impl Subst for Ty {
33    fn subst(&self, args: &[GenericArg]) -> Ty {
34        match self.kind() {
35            TyKind::Adt(adt_def, args2) => Ty::mk_adt(adt_def.clone(), args2.subst(args)),
36            TyKind::FnDef(def_id, args2) => Ty::mk_fn_def(*def_id, args2.subst(args)),
37            TyKind::Array(ty, len) => Ty::mk_array(ty.subst(args), len.clone()),
38            TyKind::Ref(re, ty, mutbl) => Ty::mk_ref(*re, ty.subst(args), *mutbl),
39            TyKind::Tuple(tys) => Ty::mk_tuple(tys.subst(args)),
40            TyKind::Slice(ty) => Ty::mk_slice(ty.subst(args)),
41            TyKind::Closure(def_id, args2) => Ty::mk_closure(*def_id, args2.subst(args)),
42            TyKind::Coroutine(def_id, args2) => Ty::mk_coroutine(*def_id, args2.subst(args)),
43            TyKind::CoroutineWitness(def_id, args2) => {
44                Ty::mk_generator_witness(*def_id, args2.subst(args))
45            }
46            TyKind::Alias(alias_ty) => Ty::mk_alias(alias_ty.kind, alias_ty.args.subst(args)),
47            TyKind::RawPtr(ty, mutbl) => Ty::mk_raw_ptr(ty.subst(args), *mutbl),
48            TyKind::Param(param_ty) => args[param_ty.index as usize].expect_type().clone(),
49            TyKind::FnPtr(fn_sig) => Ty::mk_fn_ptr(fn_sig.subst(args)),
50            TyKind::Dynamic(exi_preds, re) => Ty::mk_dynamic(exi_preds.subst(args), *re),
51            TyKind::Foreign(def_id) => Ty::mk_foreign(*def_id),
52            TyKind::Pat => todo!(),
53            TyKind::Bool
54            | TyKind::Uint(_)
55            | TyKind::Str
56            | TyKind::Char
57            | TyKind::Float(_)
58            | TyKind::Int(_)
59            | TyKind::Never => self.clone(),
60        }
61    }
62}
63
64impl Subst for TraitRef {
65    fn subst(&self, args: &[GenericArg]) -> Self {
66        let def_id = self.def_id;
67        TraitRef { def_id, args: self.args.subst(args) }
68    }
69}
70
71impl Subst for ExistentialTraitRef {
72    fn subst(&self, args: &[GenericArg]) -> Self {
73        ExistentialTraitRef { def_id: self.def_id, args: self.args.subst(args) }
74    }
75}
76
77impl Subst for ExistentialProjection {
78    fn subst(&self, args: &[GenericArg]) -> Self {
79        ExistentialProjection {
80            def_id: self.def_id,
81            args: self.args.subst(args),
82            term: self.term.subst(args),
83        }
84    }
85}
86
87impl Subst for ExistentialPredicate {
88    fn subst(&self, args: &[GenericArg]) -> Self {
89        match self {
90            ExistentialPredicate::Trait(exi_trait_ref) => {
91                ExistentialPredicate::Trait(exi_trait_ref.subst(args))
92            }
93            ExistentialPredicate::Projection(exi_proj_pred) => {
94                ExistentialPredicate::Projection(exi_proj_pred.subst(args))
95            }
96            ExistentialPredicate::AutoTrait(def_id) => ExistentialPredicate::AutoTrait(*def_id),
97        }
98    }
99}
100
101impl Subst for GenericArg {
102    fn subst(&self, args: &[GenericArg]) -> Self {
103        match self {
104            GenericArg::Ty(ty) => GenericArg::Ty(ty.subst(args)),
105            GenericArg::Lifetime(re) => GenericArg::Lifetime(re.subst(args)),
106            GenericArg::Const(c) => GenericArg::Const(c.subst(args)),
107        }
108    }
109}
110
111impl Subst for Const {
112    fn subst(&self, args: &[GenericArg]) -> Self {
113        if let ConstKind::Param(param_const) = &self.kind {
114            args[param_const.index as usize].expect_const().clone()
115        } else {
116            self.clone()
117        }
118    }
119}
120
121impl Subst for Region {
122    fn subst(&self, args: &[GenericArg]) -> Self {
123        match self {
124            Region::ReEarlyParam(ebr) => args[ebr.index as usize].expect_lifetime(),
125            Region::ReLateParam(..)
126            | Region::ReBound(_, _)
127            | Region::ReStatic
128            | Region::ReErased
129            | Region::ReVar(_) => *self,
130        }
131    }
132}
133
134impl<T> Subst for List<T>
135where
136    T: Subst,
137    [T]: Internable,
138{
139    fn subst(&self, args: &[GenericArg]) -> Self {
140        self.iter().map(|t| t.subst(args)).collect()
141    }
142}
flux_rustc_bridge/ty/subst.rs

flux_rustc_bridge/ty/
subst.rs
