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; }