bool expr_eq_fn::apply(expr const & a, expr const & b) {
if (is_eqp(a, b)) return true;
if (a.hash() != b.hash()) return false;
if (a.kind() != b.kind()) return false;
if (is_var(a)) return var_idx(a) == var_idx(b);
if (m_counter >= LEAN_EQ_CACHE_THRESHOLD && is_shared(a) && is_shared(b)) {
auto p = std::make_pair(a.raw(), b.raw());
if (!m_eq_visited)
m_eq_visited.reset(new expr_cell_pair_set);
if (m_eq_visited->find(p) != m_eq_visited->end())
return true;
m_eq_visited->insert(p);
}
check_system("expression equality test");
switch (a.kind()) {
case expr_kind::Var:
lean_unreachable(); // LCOV_EXCL_LINE
case expr_kind::Constant:
return
const_name(a) == const_name(b) &&
compare(const_levels(a), const_levels(b), [](level const & l1, level const & l2) { return l1 == l2; });
case expr_kind::Local: case expr_kind::Meta:
return
mlocal_name(a) == mlocal_name(b) &&
apply(mlocal_type(a), mlocal_type(b));
case expr_kind::App:
m_counter++;
return
apply(app_fn(a), app_fn(b)) &&
apply(app_arg(a), app_arg(b));
case expr_kind::Lambda: case expr_kind::Pi:
m_counter++;
return
apply(binding_domain(a), binding_domain(b)) &&
apply(binding_body(a), binding_body(b)) &&
(!m_compare_binder_info || binding_info(a) == binding_info(b));
case expr_kind::Sort:
return sort_level(a) == sort_level(b);
case expr_kind::Macro:
m_counter++;
if (macro_def(a) != macro_def(b) || macro_num_args(a) != macro_num_args(b))
return false;
for (unsigned i = 0; i < macro_num_args(a); i++) {
if (!apply(macro_arg(a, i), macro_arg(b, i)))
return false;
}
return true;
case expr_kind::Let:
m_counter++;
return
apply(let_type(a), let_type(b)) &&
apply(let_value(a), let_value(b)) &&
apply(let_body(a), let_body(b));
}
lean_unreachable(); // LCOV_EXCL_LINE
}
bool is_arrow(expr const & t) {
optional<bool> r = t.raw()->is_arrow();
if (r) {
return *r;
} else {
bool res = is_pi(t) && !has_free_var(binding_body(t), 0);
t.raw()->set_is_arrow(res);
return res;
}
}
bool check(expr const & a, expr const & b) {
if (!is_shared(a) || !is_shared(b))
return false;
unsigned i = hash(a.hash_alloc(), b.hash_alloc()) % m_capacity;
if (m_cache[i].m_a == a.raw() && m_cache[i].m_b == b.raw()) {
return true;
} else {
if (m_cache[i].m_a == nullptr)
m_used.push_back(i);
m_cache[i].m_a = a.raw();
m_cache[i].m_b = b.raw();
return false;
}
}
unsigned get_weight(expr const & e) {
switch (e.kind()) {
case expr_kind::Var: case expr_kind::Constant: case expr_kind::Sort:
case expr_kind::Meta: case expr_kind::Local:
return 1;
case expr_kind::Lambda: case expr_kind::Pi: case expr_kind::Macro:
case expr_kind::App: case expr_kind::Let:
return static_cast<expr_composite*>(e.raw())->m_weight;
}
lean_unreachable(); // LCOV_EXCL_LINE
}
expr apply(expr const & a) {
auto r = m_cache.find(a);
if (r != m_cache.end()) {
lean_assert((*r).raw()->max_shared());
return *r;
}
if (a.raw()->max_shared()) {
m_cache.insert(a);
return a;
}
switch (a.kind()) {
case expr_kind::Var: case expr_kind::Constant: case expr_kind::Type: case expr_kind::Value:
cache(a);
return a;
case expr_kind::App: {
expr r = update_app(a, [=](expr const & c){ return apply(c); });
cache(r);
return r;
}
case expr_kind::Eq : {
expr r = update_eq(a, [=](expr const & l, expr const & r){ return std::make_pair(apply(l), apply(r)); });
cache(r);
return r;
}
case expr_kind::Lambda:
case expr_kind::Pi: {
expr r = update_abst(a, [=](expr const & t, expr const & b) { return std::make_pair(apply(t), apply(b)); });
cache(r);
return r;
}
case expr_kind::Let: {
expr r = update_let(a, [=](expr const & t, expr const & v, expr const & b) {
expr new_t = t ? apply(t) : expr();
return std::make_tuple(new_t, apply(v), apply(b));
});
cache(r);
return r;
}
case expr_kind::MetaVar: {
expr r = update_metavar(a, [=](meta_entry const & e) -> meta_entry {
if (e.is_inst())
return mk_inst(e.s(), apply(e.v()));
else
return e;
});
cache(r);
return r;
}}
lean_unreachable();
}
expr copy(expr const & a) {
switch (a.kind()) {
case expr_kind::Var: return mk_var(var_idx(a));
case expr_kind::Constant: return mk_constant(const_name(a));
case expr_kind::Type: return mk_type(ty_level(a));
case expr_kind::Value: return mk_value(static_cast<expr_value*>(a.raw())->m_val);
case expr_kind::App: return mk_app(num_args(a), begin_args(a));
case expr_kind::Eq: return mk_eq(eq_lhs(a), eq_rhs(a));
case expr_kind::Lambda: return mk_lambda(abst_name(a), abst_domain(a), abst_body(a));
case expr_kind::Pi: return mk_pi(abst_name(a), abst_domain(a), abst_body(a));
case expr_kind::Let: return mk_let(let_name(a), let_type(a), let_value(a), let_body(a));
case expr_kind::MetaVar: return mk_metavar(metavar_idx(a), metavar_ctx(a));
}
lean_unreachable();
}
expr apply(expr const & a) {
bool sh = false;
if (is_shared(a)) {
auto r = m_cache.find(a.raw());
if (r != m_cache.end())
return r->second;
sh = true;
}
switch (a.kind()) {
case expr_kind::Var: case expr_kind::Constant: case expr_kind::Type: case expr_kind::Value:
return save_result(a, copy(a), sh);
case expr_kind::App: {
buffer<expr> new_args;
for (expr const & old_arg : args(a))
new_args.push_back(apply(old_arg));
return save_result(a, mk_app(new_args), sh);
}
case expr_kind::HEq: return save_result(a, mk_heq(apply(heq_lhs(a)), apply(heq_rhs(a))), sh);
case expr_kind::Pair: return save_result(a, mk_pair(apply(pair_first(a)), apply(pair_second(a)), apply(pair_type(a))), sh);
case expr_kind::Proj: return save_result(a, mk_proj(proj_first(a), apply(proj_arg(a))), sh);
case expr_kind::Lambda: return save_result(a, mk_lambda(abst_name(a), apply(abst_domain(a)), apply(abst_body(a))), sh);
case expr_kind::Pi: return save_result(a, mk_pi(abst_name(a), apply(abst_domain(a)), apply(abst_body(a))), sh);
case expr_kind::Sigma: return save_result(a, mk_sigma(abst_name(a), apply(abst_domain(a)), apply(abst_body(a))), sh);
case expr_kind::Let: return save_result(a, mk_let(let_name(a), apply(let_type(a)), apply(let_value(a)), apply(let_body(a))), sh);
case expr_kind::MetaVar:
return save_result(a,
update_metavar(a, [&](local_entry const & e) -> local_entry {
if (e.is_inst())
return mk_inst(e.s(), apply(e.v()));
else
return e;
}),
sh);
}
lean_unreachable(); // LCOV_EXCL_LINE
}
expr max_sharing(expr const & a) {
if (a.raw()->max_shared())
return a;
else
return max_sharing_fn::imp()(a);
}
void cache(expr const & a) {
a.raw()->set_max_shared();
m_cache.insert(a);
}
expr save_result(expr const & a, expr && r, bool shared) {
if (shared)
m_cache.insert(std::make_pair(a.raw(), r));
return r;
}
