lean2/src/library/relation_manager.cpp

278 lines
10 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 <string>
#include "util/optional.h"
#include "util/name.h"
#include "util/rb_map.h"
#include "util/sstream.h"
#include "library/constants.h"
#include "library/scoped_ext.h"
#include "library/relation_manager.h"
namespace lean {
// Check whether e is of the form (f ...) where f is a constant. If it is return f.
static name const & get_fn_const(expr const & e, char const * msg) {
expr const & fn = get_app_fn(e);
if (!is_constant(fn))
throw exception(msg);
return const_name(fn);
}
static pair<expr, unsigned> extract_arg_types_core(environment const & env, name const & f, buffer<expr> & arg_types) {
declaration d = env.get(f);
expr f_type = d.get_type();
while (is_pi(f_type)) {
arg_types.push_back(binding_domain(f_type));
f_type = binding_body(f_type);
}
return mk_pair(f_type, d.get_num_univ_params());
}
enum class op_kind { Relation, Subst, Trans, Refl, Symm };
struct rel_entry {
op_kind m_kind;
name m_name;
rel_entry() {}
rel_entry(op_kind k, name const & n):m_kind(k), m_name(n) {}
};
struct rel_state {
typedef name_map<refl_info> refl_table;
typedef name_map<subst_info> subst_table;
typedef name_map<symm_info> symm_table;
typedef rb_map<name_pair, trans_info, name_pair_quick_cmp> trans_table;
typedef name_map<relation_info> rop_table;
trans_table m_trans_table;
refl_table m_refl_table;
subst_table m_subst_table;
symm_table m_symm_table;
rop_table m_rop_table;
rel_state() {}
bool is_equivalence(name const & rop) const {
return m_trans_table.contains(mk_pair(rop, rop)) && m_refl_table.contains(rop) && m_symm_table.contains(rop);
}
static void throw_invalid_relation(name const & rop) {
throw exception(sstream() << "invalid binary relation declaration, relation '" << rop
<< "' must have two explicit parameters");
}
void register_rop(environment const & env, name const & rop) {
if (m_rop_table.contains(rop))
return;
declaration const & d = env.get(rop);
optional<unsigned> lhs_pos;
optional<unsigned> rhs_pos;
unsigned i = 0;
expr type = d.get_type();
while (is_pi(type)) {
if (is_explicit(binding_info(type))) {
if (!lhs_pos) {
lhs_pos = i;
} else if (!rhs_pos) {
rhs_pos = i;
} else {
lhs_pos = rhs_pos;
rhs_pos = i;
}
}
type = binding_body(type);
i++;
}
if (lhs_pos && rhs_pos) {
m_rop_table.insert(rop, relation_info(i, *lhs_pos, *rhs_pos));
} else {
throw_invalid_relation(rop);
}
}
void add_subst(environment const & env, name const & subst) {
buffer<expr> arg_types;
auto p = extract_arg_types_core(env, subst, arg_types);
expr r_type = p.first;
unsigned nunivs = p.second;
unsigned nargs = arg_types.size();
if (nargs < 2)
throw exception("invalid substitution theorem, it must have at least 2 arguments");
name const & rop = get_fn_const(arg_types[nargs-2], "invalid substitution theorem, penultimate argument must be an operator application");
m_subst_table.insert(rop, subst_info(subst, nunivs, nargs));
}
void add_refl(environment const & env, name const & refl) {
buffer<expr> arg_types;
auto p = extract_arg_types_core(env, refl, arg_types);
expr r_type = p.first;
unsigned nunivs = p.second;
unsigned nargs = arg_types.size();
if (nargs < 1)
throw exception("invalid reflexivity rule, it must have at least 1 argument");
name const & rop = get_fn_const(r_type, "invalid reflexivity rule, result type must be an operator application");
register_rop(env, rop);
m_refl_table.insert(rop, refl_info(refl, nunivs, nargs));
}
void add_trans(environment const & env, name const & trans) {
buffer<expr> arg_types;
auto p = extract_arg_types_core(env, trans, arg_types);
expr r_type = p.first;
unsigned nunivs = p.second;
unsigned nargs = arg_types.size();
if (nargs < 5)
throw exception("invalid transitivity rule, it must have at least 5 arguments");
name const & rop = get_fn_const(r_type, "invalid transitivity rule, result type must be an operator application");
name const & op1 = get_fn_const(arg_types[nargs-2], "invalid transitivity rule, penultimate argument must be an operator application");
name const & op2 = get_fn_const(arg_types[nargs-1], "invalid transitivity rule, last argument must be an operator application");
register_rop(env, rop);
m_trans_table.insert(name_pair(op1, op2), trans_info(trans, nunivs, nargs, rop));
}
void add_symm(environment const & env, name const & symm) {
buffer<expr> arg_types;
auto p = extract_arg_types_core(env, symm, arg_types);
expr r_type = p.first;
unsigned nunivs = p.second;
unsigned nargs = arg_types.size();
if (nargs < 1)
throw exception("invalid symmetry rule, it must have at least 1 argument");
name const & rop = get_fn_const(r_type, "invalid symmetry rule, result type must be an operator application");
register_rop(env, rop);
m_symm_table.insert(rop, symm_info(symm, nunivs, nargs));
}
};
static name * g_rel_name = nullptr;
static std::string * g_key = nullptr;
struct rel_config {
typedef rel_state state;
typedef rel_entry entry;
static void add_entry(environment const & env, io_state const &, state & s, entry const & e) {
switch (e.m_kind) {
case op_kind::Relation: s.register_rop(env, e.m_name); break;
case op_kind::Refl: s.add_refl(env, e.m_name); break;
case op_kind::Subst: s.add_subst(env, e.m_name); break;
case op_kind::Trans: s.add_trans(env, e.m_name); break;
case op_kind::Symm: s.add_symm(env, e.m_name); break;
}
}
static name const & get_class_name() {
return *g_rel_name;
}
static std::string const & get_serialization_key() {
return *g_key;
}
static void write_entry(serializer & s, entry const & e) {
s << static_cast<char>(e.m_kind) << e.m_name;
}
static entry read_entry(deserializer & d) {
entry e;
char cmd;
d >> cmd >> e.m_name;
e.m_kind = static_cast<op_kind>(cmd);
return e;
}
static optional<unsigned> get_fingerprint(entry const &) {
return optional<unsigned>();
}
};
template class scoped_ext<rel_config>;
typedef scoped_ext<rel_config> rel_ext;
environment add_relation(environment const & env, name const & n, bool persistent) {
return rel_ext::add_entry(env, get_dummy_ios(), rel_entry(op_kind::Relation, n), persistent);
}
environment add_subst(environment const & env, name const & n, bool persistent) {
return rel_ext::add_entry(env, get_dummy_ios(), rel_entry(op_kind::Subst, n), persistent);
}
environment add_refl(environment const & env, name const & n, bool persistent) {
return rel_ext::add_entry(env, get_dummy_ios(), rel_entry(op_kind::Refl, n), persistent);
}
environment add_symm(environment const & env, name const & n, bool persistent) {
return rel_ext::add_entry(env, get_dummy_ios(), rel_entry(op_kind::Symm, n), persistent);
}
environment add_trans(environment const & env, name const & n, bool persistent) {
return rel_ext::add_entry(env, get_dummy_ios(), rel_entry(op_kind::Trans, n), persistent);
}
static optional<relation_lemma_info> get_info(name_map<relation_lemma_info> const & table, name const & op) {
if (auto it = table.find(op)) {
return optional<relation_lemma_info>(*it);
} else {
return optional<relation_lemma_info>();
}
}
optional<refl_info> get_refl_extra_info(environment const & env, name const & op) {
return get_info(rel_ext::get_state(env).m_refl_table, op);
}
optional<subst_info> get_subst_extra_info(environment const & env, name const & op) {
return get_info(rel_ext::get_state(env).m_subst_table, op);
}
optional<symm_info> get_symm_extra_info(environment const & env, name const & op) {
return get_info(rel_ext::get_state(env).m_symm_table, op);
}
optional<trans_info> get_trans_extra_info(environment const & env, name const & op1, name const & op2) {
if (auto it = rel_ext::get_state(env).m_trans_table.find(mk_pair(op1, op2))) {
return optional<trans_info>(*it);
} else {
return optional<trans_info>();
}
}
bool is_subst_relation(environment const & env, name const & op) {
return rel_ext::get_state(env).m_subst_table.contains(op);
}
optional<name> get_refl_info(environment const & env, name const & op) {
if (auto it = get_refl_extra_info(env, op))
return optional<name>(it->m_name);
else
return optional<name>();
}
optional<name> get_symm_info(environment const & env, name const & op) {
if (auto it = get_symm_extra_info(env, op))
return optional<name>(it->m_name);
else
return optional<name>();
}
optional<name> get_trans_info(environment const & env, name const & op) {
if (auto it = get_trans_extra_info(env, op, op))
return optional<name>(it->m_name);
else
return optional<name>();
}
bool is_equivalence(environment const & env, name const & rop) {
return rel_ext::get_state(env).is_equivalence(rop);
}
relation_info const * get_relation_info(environment const & env, name const & rop) {
return rel_ext::get_state(env).m_rop_table.find(rop);
}
void initialize_relation_manager() {
g_rel_name = new name("rel");
g_key = new std::string("rel");
rel_ext::initialize();
}
void finalize_relation_manager() {
rel_ext::finalize();
delete g_key;
delete g_rel_name;
}
}