lean2/src/library/noncomputable.cpp

114 lines
3.7 KiB
C++

/*
Copyright (c) 2015 Microsoft Corporation. All rights reserved.
Released under Apache 2.0 license as described in the file LICENSE.
Author: Leonardo de Moura
*/
#include <utility>
#include <string>
#include "util/sstream.h"
#include "kernel/for_each_fn.h"
#include "kernel/type_checker.h"
#include "library/module.h"
#include "library/util.h"
#include "library/fingerprint.h"
namespace lean {
struct noncomputable_ext : public environment_extension {
name_set m_noncomputable;
noncomputable_ext() {}
};
struct noncomputable_ext_reg {
unsigned m_ext_id;
noncomputable_ext_reg() {
m_ext_id = environment::register_extension(std::make_shared<noncomputable_ext>());
}
};
static noncomputable_ext_reg * g_ext = nullptr;
static noncomputable_ext const & get_extension(environment const & env) {
return static_cast<noncomputable_ext const &>(env.get_extension(g_ext->m_ext_id));
}
static environment update(environment const & env, noncomputable_ext const & ext) {
return env.update(g_ext->m_ext_id, std::make_shared<noncomputable_ext>(ext));
}
static name * g_noncomputable = nullptr;
static std::string * g_key = nullptr;
static void noncomputable_reader(deserializer & d, shared_environment & senv,
std::function<void(asynch_update_fn const &)> &,
std::function<void(delayed_update_fn const &)> &) {
name n;
d >> n;
senv.update([=](environment const & env) -> environment {
noncomputable_ext ext = get_extension(env);
ext.m_noncomputable.insert(n);
return update(env, ext);
});
}
static bool is_noncomputable(type_checker & tc, noncomputable_ext const & ext, name const & n) {
if (ext.m_noncomputable.contains(n))
return true;
declaration const & d = tc.env().get(n);
return d.is_axiom() && !tc.is_prop(d.get_type()).first;
}
bool is_noncomputable(environment const & env, name const & n) {
type_checker tc(env);
auto ext = get_extension(env);
return is_noncomputable(tc, ext, n);
}
bool is_marked_noncomputable(environment const & env, name const & n) {
auto ext = get_extension(env);
return ext.m_noncomputable.contains(n);
}
environment mark_noncomputable(environment const & env, name const & n) {
auto ext = get_extension(env);
ext.m_noncomputable.insert(n);
environment new_env = update(env, ext);
return module::add(new_env, *g_key, [=](environment const &, serializer & s) { s << n; });
}
optional<name> get_noncomputable_reason(environment const & env, name const & n) {
if (!is_standard(env))
return optional<name>(); // do nothing if it is not a standard kernel
declaration const & d = env.get(n);
if (!d.is_definition())
return optional<name>();
type_checker tc(env);
if (tc.is_prop(d.get_type()).first)
return optional<name>(); // definition is a proposition, then do nothing
expr const & v = d.get_value();
auto ext = get_extension(env);
optional<name> r;
for_each(v, [&](expr const & e, unsigned) {
if (is_constant(e) && is_noncomputable(tc, ext, const_name(e))) {
r = const_name(e);
}
return true;
});
return r;
}
bool check_computable(environment const & env, name const & n) {
return !get_noncomputable_reason(env, n);
}
void initialize_noncomputable() {
g_ext = new noncomputable_ext_reg();
g_noncomputable = new name("noncomputable");
g_key = new std::string("ncomp");
register_module_object_reader(*g_key, noncomputable_reader);
}
void finalize_noncomputable() {
delete g_key;
delete g_noncomputable;
delete g_ext;
}
}