use super::program_clauses::ToProgramClauses;
use crate::clauses::builder::ClauseBuilder;
use crate::clauses::{match_alias_ty, match_ty};
use crate::DomainGoal;
use crate::FromEnv;
use crate::ProgramClause;
use crate::RustIrDatabase;
use crate::Ty;
use crate::{debug_span, TyKind};
use chalk_ir::interner::Interner;
use chalk_ir::visit::{Visit, Visitor};
use chalk_ir::{DebruijnIndex, Environment};
use rustc_hash::FxHashSet;
use tracing::instrument;
pub(super) fn elaborate_env_clauses<I: Interner>(
db: &dyn RustIrDatabase<I>,
in_clauses: &[ProgramClause<I>],
out: &mut FxHashSet<ProgramClause<I>>,
environment: &Environment<I>,
) {
let mut this_round = vec![];
in_clauses.visit_with(
&mut EnvElaborator::new(db, &mut this_round, environment),
DebruijnIndex::INNERMOST,
);
out.extend(this_round);
}
struct EnvElaborator<'me, I: Interner> {
db: &'me dyn RustIrDatabase<I>,
builder: ClauseBuilder<'me, I>,
environment: &'me Environment<I>,
}
impl<'me, I: Interner> EnvElaborator<'me, I> {
fn new(
db: &'me dyn RustIrDatabase<I>,
out: &'me mut Vec<ProgramClause<I>>,
environment: &'me Environment<I>,
) -> Self {
EnvElaborator {
db,
builder: ClauseBuilder::new(db, out),
environment,
}
}
}
impl<'me, I: Interner> Visitor<'me, I> for EnvElaborator<'me, I> {
type Result = ();
fn as_dyn(&mut self) -> &mut dyn Visitor<'me, I, Result = Self::Result> {
self
}
fn interner(&self) -> &'me I {
self.db.interner()
}
#[instrument(level = "debug", skip(self, _outer_binder))]
fn visit_ty(&mut self, ty: &Ty<I>, _outer_binder: DebruijnIndex) {
match ty.kind(self.interner()) {
TyKind::Alias(alias_ty) => {
match_alias_ty(&mut self.builder, self.environment, alias_ty)
}
TyKind::Placeholder(_) => {}
TyKind::Dyn(_) => (),
TyKind::Function(_) | TyKind::BoundVar(_) | TyKind::InferenceVar(_, _) => (),
_ => {
match_ty(&mut self.builder, self.environment, &ty)
.map_err(|_| ())
.unwrap()
}
}
}
fn visit_domain_goal(&mut self, domain_goal: &DomainGoal<I>, outer_binder: DebruijnIndex) {
if let DomainGoal::FromEnv(from_env) = domain_goal {
debug_span!("visit_domain_goal", ?from_env);
match from_env {
FromEnv::Trait(trait_ref) => {
let trait_datum = self.db.trait_datum(trait_ref.trait_id);
trait_datum.to_program_clauses(&mut self.builder, self.environment);
for &associated_ty_id in &trait_datum.associated_ty_ids {
self.db
.associated_ty_data(associated_ty_id)
.to_program_clauses(&mut self.builder, self.environment);
}
}
FromEnv::Ty(ty) => ty.visit_with(self, outer_binder),
}
}
}
}