Cleanup substitutions and treatment of generics around traits in a number of ways.
- In a TraitRef, use the self type consistently to refer to the Self type:
- trait ref in `impl Trait<A,B,C> for S` has a self type of `S`.
- trait ref in `A:Trait` has the self type `A`
- trait ref associated with a trait decl has self type `Self`
- trait ref associated with a supertype has self type `Self`
- trait ref in an object type `@Trait` has no self type
- Rewrite `each_bound_traits_and_supertraits` to perform
substitutions as it goes, and thus yield a series of trait refs
that are always in the same 'namespace' as the type parameter
bound given as input. Before, we left this to the caller, but
this doesn't work because the caller lacks adequare information
to perform the type substitutions correctly.
- For provided methods, substitute the generics involved in the provided
method correctly.
- Introduce TypeParameterDef, which tracks the bounds declared on a type
parameter and brings them together with the def_id and (in the future)
other information (maybe even the parameter's name!).
- Introduce Subst trait, which helps to cleanup a lot of the
repetitive code involved with doing type substitution.
- Introduce Repr trait, which makes debug printouts far more convenient.
Fixes #4183. Needed for #5656.
2013-04-09 00:54:49 -05:00
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// Copyright 2012 The Rust Project Developers. See the COPYRIGHT
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// file at the top-level directory of this distribution and at
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// http://rust-lang.org/COPYRIGHT.
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//
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// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
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// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
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// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
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// option. This file may not be copied, modified, or distributed
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// except according to those terms.
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// Type substitutions.
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use core::prelude::*;
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use middle::ty;
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use util::ppaux::Repr;
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///////////////////////////////////////////////////////////////////////////
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// Public trait `Subst`
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//
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// Just call `foo.subst(tcx, substs)` to perform a substitution across
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// `foo`.
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pub trait Subst {
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fn subst(&self, tcx: ty::ctxt, substs: &ty::substs) -> Self;
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}
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///////////////////////////////////////////////////////////////////////////
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// Substitution over types
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//
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// Because this is so common, we make a special optimization to avoid
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2013-04-09 14:33:18 -05:00
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// doing anything if `substs` is a no-op. I tried to generalize these
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Cleanup substitutions and treatment of generics around traits in a number of ways.
- In a TraitRef, use the self type consistently to refer to the Self type:
- trait ref in `impl Trait<A,B,C> for S` has a self type of `S`.
- trait ref in `A:Trait` has the self type `A`
- trait ref associated with a trait decl has self type `Self`
- trait ref associated with a supertype has self type `Self`
- trait ref in an object type `@Trait` has no self type
- Rewrite `each_bound_traits_and_supertraits` to perform
substitutions as it goes, and thus yield a series of trait refs
that are always in the same 'namespace' as the type parameter
bound given as input. Before, we left this to the caller, but
this doesn't work because the caller lacks adequare information
to perform the type substitutions correctly.
- For provided methods, substitute the generics involved in the provided
method correctly.
- Introduce TypeParameterDef, which tracks the bounds declared on a type
parameter and brings them together with the def_id and (in the future)
other information (maybe even the parameter's name!).
- Introduce Subst trait, which helps to cleanup a lot of the
repetitive code involved with doing type substitution.
- Introduce Repr trait, which makes debug printouts far more convenient.
Fixes #4183. Needed for #5656.
2013-04-09 00:54:49 -05:00
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// to all subst methods but ran into trouble due to the limitations of
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// our current method/trait matching algorithm. - Niko
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2013-04-09 14:33:18 -05:00
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trait EffectfulSubst {
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fn effectfulSubst(&self, tcx: ty::ctxt, substs: &ty::substs) -> Self;
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Cleanup substitutions and treatment of generics around traits in a number of ways.
- In a TraitRef, use the self type consistently to refer to the Self type:
- trait ref in `impl Trait<A,B,C> for S` has a self type of `S`.
- trait ref in `A:Trait` has the self type `A`
- trait ref associated with a trait decl has self type `Self`
- trait ref associated with a supertype has self type `Self`
- trait ref in an object type `@Trait` has no self type
- Rewrite `each_bound_traits_and_supertraits` to perform
substitutions as it goes, and thus yield a series of trait refs
that are always in the same 'namespace' as the type parameter
bound given as input. Before, we left this to the caller, but
this doesn't work because the caller lacks adequare information
to perform the type substitutions correctly.
- For provided methods, substitute the generics involved in the provided
method correctly.
- Introduce TypeParameterDef, which tracks the bounds declared on a type
parameter and brings them together with the def_id and (in the future)
other information (maybe even the parameter's name!).
- Introduce Subst trait, which helps to cleanup a lot of the
repetitive code involved with doing type substitution.
- Introduce Repr trait, which makes debug printouts far more convenient.
Fixes #4183. Needed for #5656.
2013-04-09 00:54:49 -05:00
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}
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impl Subst for ty::t {
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fn subst(&self, tcx: ty::ctxt, substs: &ty::substs) -> ty::t {
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if ty::substs_is_noop(substs) {
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return *self;
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} else {
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2013-04-09 14:33:18 -05:00
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return self.effectfulSubst(tcx, substs);
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Cleanup substitutions and treatment of generics around traits in a number of ways.
- In a TraitRef, use the self type consistently to refer to the Self type:
- trait ref in `impl Trait<A,B,C> for S` has a self type of `S`.
- trait ref in `A:Trait` has the self type `A`
- trait ref associated with a trait decl has self type `Self`
- trait ref associated with a supertype has self type `Self`
- trait ref in an object type `@Trait` has no self type
- Rewrite `each_bound_traits_and_supertraits` to perform
substitutions as it goes, and thus yield a series of trait refs
that are always in the same 'namespace' as the type parameter
bound given as input. Before, we left this to the caller, but
this doesn't work because the caller lacks adequare information
to perform the type substitutions correctly.
- For provided methods, substitute the generics involved in the provided
method correctly.
- Introduce TypeParameterDef, which tracks the bounds declared on a type
parameter and brings them together with the def_id and (in the future)
other information (maybe even the parameter's name!).
- Introduce Subst trait, which helps to cleanup a lot of the
repetitive code involved with doing type substitution.
- Introduce Repr trait, which makes debug printouts far more convenient.
Fixes #4183. Needed for #5656.
2013-04-09 00:54:49 -05:00
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}
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}
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}
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2013-04-09 14:33:18 -05:00
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impl EffectfulSubst for ty::t {
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fn effectfulSubst(&self, tcx: ty::ctxt, substs: &ty::substs) -> ty::t {
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Cleanup substitutions and treatment of generics around traits in a number of ways.
- In a TraitRef, use the self type consistently to refer to the Self type:
- trait ref in `impl Trait<A,B,C> for S` has a self type of `S`.
- trait ref in `A:Trait` has the self type `A`
- trait ref associated with a trait decl has self type `Self`
- trait ref associated with a supertype has self type `Self`
- trait ref in an object type `@Trait` has no self type
- Rewrite `each_bound_traits_and_supertraits` to perform
substitutions as it goes, and thus yield a series of trait refs
that are always in the same 'namespace' as the type parameter
bound given as input. Before, we left this to the caller, but
this doesn't work because the caller lacks adequare information
to perform the type substitutions correctly.
- For provided methods, substitute the generics involved in the provided
method correctly.
- Introduce TypeParameterDef, which tracks the bounds declared on a type
parameter and brings them together with the def_id and (in the future)
other information (maybe even the parameter's name!).
- Introduce Subst trait, which helps to cleanup a lot of the
repetitive code involved with doing type substitution.
- Introduce Repr trait, which makes debug printouts far more convenient.
Fixes #4183. Needed for #5656.
2013-04-09 00:54:49 -05:00
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if !ty::type_needs_subst(*self) {
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return *self;
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}
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match ty::get(*self).sty {
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2013-04-09 14:33:18 -05:00
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ty::ty_param(p) => {
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substs.tps[p.idx]
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}
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ty::ty_self(_) => {
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substs.self_ty.expect("ty_self not found in substs")
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}
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Cleanup substitutions and treatment of generics around traits in a number of ways.
- In a TraitRef, use the self type consistently to refer to the Self type:
- trait ref in `impl Trait<A,B,C> for S` has a self type of `S`.
- trait ref in `A:Trait` has the self type `A`
- trait ref associated with a trait decl has self type `Self`
- trait ref associated with a supertype has self type `Self`
- trait ref in an object type `@Trait` has no self type
- Rewrite `each_bound_traits_and_supertraits` to perform
substitutions as it goes, and thus yield a series of trait refs
that are always in the same 'namespace' as the type parameter
bound given as input. Before, we left this to the caller, but
this doesn't work because the caller lacks adequare information
to perform the type substitutions correctly.
- For provided methods, substitute the generics involved in the provided
method correctly.
- Introduce TypeParameterDef, which tracks the bounds declared on a type
parameter and brings them together with the def_id and (in the future)
other information (maybe even the parameter's name!).
- Introduce Subst trait, which helps to cleanup a lot of the
repetitive code involved with doing type substitution.
- Introduce Repr trait, which makes debug printouts far more convenient.
Fixes #4183. Needed for #5656.
2013-04-09 00:54:49 -05:00
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_ => {
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ty::fold_regions_and_ty(
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tcx, *self,
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|r| match r {
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ty::re_bound(ty::br_self) => {
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match substs.self_r {
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None => {
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tcx.sess.bug(
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fmt!("ty::subst: \
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Reference to self region when \
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given substs with no self region, \
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ty = %s",
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self.repr(tcx)));
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}
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Some(self_r) => self_r
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}
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}
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_ => r
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},
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2013-04-09 14:33:18 -05:00
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|t| t.effectfulSubst(tcx, substs),
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|t| t.effectfulSubst(tcx, substs))
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Cleanup substitutions and treatment of generics around traits in a number of ways.
- In a TraitRef, use the self type consistently to refer to the Self type:
- trait ref in `impl Trait<A,B,C> for S` has a self type of `S`.
- trait ref in `A:Trait` has the self type `A`
- trait ref associated with a trait decl has self type `Self`
- trait ref associated with a supertype has self type `Self`
- trait ref in an object type `@Trait` has no self type
- Rewrite `each_bound_traits_and_supertraits` to perform
substitutions as it goes, and thus yield a series of trait refs
that are always in the same 'namespace' as the type parameter
bound given as input. Before, we left this to the caller, but
this doesn't work because the caller lacks adequare information
to perform the type substitutions correctly.
- For provided methods, substitute the generics involved in the provided
method correctly.
- Introduce TypeParameterDef, which tracks the bounds declared on a type
parameter and brings them together with the def_id and (in the future)
other information (maybe even the parameter's name!).
- Introduce Subst trait, which helps to cleanup a lot of the
repetitive code involved with doing type substitution.
- Introduce Repr trait, which makes debug printouts far more convenient.
Fixes #4183. Needed for #5656.
2013-04-09 00:54:49 -05:00
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}
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}
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}
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}
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///////////////////////////////////////////////////////////////////////////
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// Other types
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impl<T:Subst> Subst for ~[T] {
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fn subst(&self, tcx: ty::ctxt, substs: &ty::substs) -> ~[T] {
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self.map(|t| t.subst(tcx, substs))
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}
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}
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impl<T:Subst> Subst for @~[T] {
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fn subst(&self, tcx: ty::ctxt, substs: &ty::substs) -> @~[T] {
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@(**self).subst(tcx, substs)
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}
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}
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impl<T:Subst> Subst for Option<T> {
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fn subst(&self, tcx: ty::ctxt, substs: &ty::substs) -> Option<T> {
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self.map(|t| t.subst(tcx, substs))
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}
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}
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impl Subst for ty::TraitRef {
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fn subst(&self, tcx: ty::ctxt, substs: &ty::substs) -> ty::TraitRef {
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ty::TraitRef {
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def_id: self.def_id,
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substs: self.substs.subst(tcx, substs)
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}
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}
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}
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impl Subst for ty::substs {
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fn subst(&self, tcx: ty::ctxt, substs: &ty::substs) -> ty::substs {
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ty::substs {
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self_r: self.self_r,
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self_ty: self.self_ty.map(|typ| typ.subst(tcx, substs)),
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tps: self.tps.map(|typ| typ.subst(tcx, substs))
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}
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}
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}
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impl Subst for ty::BareFnTy {
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fn subst(&self, tcx: ty::ctxt, substs: &ty::substs) -> ty::BareFnTy {
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ty::fold_bare_fn_ty(self, |t| t.subst(tcx, substs))
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}
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}
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impl Subst for ty::param_bound {
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fn subst(&self, tcx: ty::ctxt, substs: &ty::substs) -> ty::param_bound {
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match self {
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&ty::bound_copy |
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&ty::bound_durable |
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&ty::bound_owned |
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&ty::bound_const => {
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*self
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}
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&ty::bound_trait(tref) => {
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ty::bound_trait(@tref.subst(tcx, substs))
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}
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}
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}
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}
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impl Subst for ty::TypeParameterDef {
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fn subst(&self, tcx: ty::ctxt, substs: &ty::substs) -> ty::TypeParameterDef {
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ty::TypeParameterDef {
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def_id: self.def_id,
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bounds: self.bounds.subst(tcx, substs)
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}
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}
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}
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impl Subst for ty::Generics {
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fn subst(&self, tcx: ty::ctxt, substs: &ty::substs) -> ty::Generics {
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ty::Generics {
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type_param_defs: self.type_param_defs.subst(tcx, substs),
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region_param: self.region_param
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}
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}
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}
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impl Subst for ty::ty_param_bounds_and_ty {
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fn subst(&self, tcx: ty::ctxt, substs: &ty::substs) -> ty::ty_param_bounds_and_ty {
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ty::ty_param_bounds_and_ty {
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generics: self.generics.subst(tcx, substs),
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ty: self.ty.subst(tcx, substs)
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}
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}
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}
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