lean2/src/frontends/lean/proof_qed_elaborator.cpp
Leonardo de Moura 0a288aec40 chore(frontends/lean/proof_qed_elaborator): remove obsolete comment
Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
2014-10-04 09:19:33 -07:00

58 lines
2.5 KiB
C++

/*
Copyright (c) 2014 Microsoft Corporation. All rights reserved.
Released under Apache 2.0 license as described in the file LICENSE.
Author: Leonardo de Moura
*/
#include "library/unifier.h"
#include "library/reducible.h"
#include "library/metavar_closure.h"
#include "frontends/lean/util.h"
#include "frontends/lean/info_manager.h"
namespace lean {
/** \brief Create a "choice" constraint that postpone the
solving the constraints <tt>(cs union (m =?= e))</tt>.
*/
constraint mk_proof_qed_cnstr(environment const & env, expr const & m, expr const & e,
constraint_seq const & cs, unifier_config const & cfg,
info_manager * im, bool relax) {
justification j = mk_failed_to_synthesize_jst(env, m);
auto choice_fn = [=](expr const & meta, expr const & meta_type, substitution const & s,
name_generator const & _ngen) {
name_generator ngen(_ngen);
type_checker_ptr tc(mk_type_checker(env, ngen.mk_child(), relax));
pair<expr, constraint_seq> tcs = tc->infer(e);
expr e_type = tcs.first;
justification new_j = mk_type_mismatch_jst(e, e_type, meta_type);
pair<bool, constraint_seq> dcs = tc->is_def_eq(e_type, meta_type, new_j);
if (!dcs.first)
throw unifier_exception(new_j, s);
constraint_seq new_cs = cs + tcs.second + dcs.second;
buffer<constraint> cs_buffer;
new_cs.linearize(cs_buffer);
metavar_closure cls(meta);
cls.add(meta_type);
cls.mk_constraints(s, j, relax, cs_buffer);
cs_buffer.push_back(mk_eq_cnstr(meta, e, j, relax));
unifier_config new_cfg(cfg);
new_cfg.m_discard = false;
unify_result_seq seq = unify(env, cs_buffer.size(), cs_buffer.data(), ngen, new_cfg);
auto p = seq.pull();
lean_assert(p);
substitution new_s = p->first.first;
constraints postponed = map(p->first.second,
[&](constraint const & c) {
// we erase internal justifications
return update_justification(c, j);
});
if (im)
im->instantiate(new_s);
constraints r = cls.mk_constraints(new_s, j, relax);
return append(r, postponed);
};
bool owner = false;
return mk_choice_cnstr(m, choice_fn, to_delay_factor(cnstr_group::Epilogue), owner, j, relax);
}
}