lean2/src/library/reducible.h

/*
Copyright (c) 2014 Microsoft Corporation. All rights reserved.
Released under Apache 2.0 license as described in the file LICENSE.

Author: Leonardo de Moura
*/
#pragma once
#include <memory>
#include "kernel/type_checker.h"
#include "library/util.h"

namespace lean {
enum class reducible_status { Reducible, Quasireducible, Semireducible, Irreducible };
/** \brief Mark the definition named \c n as reducible or not.

    The method throws an exception if \c n is
      - not a definition
      - a theorem
      - an opaque definition that was not defined in main module

    "Reducible" definitions can be freely unfolded by automation (i.e., elaborator, simplifier, etc).
    We should view it as a hint to automation.
*/
environment set_reducible(environment const & env, name const & n, reducible_status s, bool persistent = true);

reducible_status get_reducible_status(environment const & env, name const & n);

bool is_at_least_quasireducible(environment const & env, name const & n);

/* \brief Execute the given function for each declaration explicitly marked with a reducibility annotation */
void for_each_reducible(environment const & env, std::function<void(name const &, reducible_status)> const & fn);

/** \brief Create a predicate that returns true for all non reducible constants in \c env */
name_predicate mk_not_reducible_pred(environment const & env);
/** \brief Create a predicate that returns true for all non reducible and non quasireducible constants in \c env */
name_predicate mk_not_quasireducible_pred(environment const & env);
/** \brief Create a predicate that returns true for irreducible constants  in \c env */
name_predicate mk_irreducible_pred(environment const & env);

enum reducible_behavior { UnfoldReducible, UnfoldQuasireducible, UnfoldSemireducible };

/** \brief Create a type checker that takes the "reducibility" hints into account. */
type_checker_ptr mk_type_checker(environment const & env, name_generator && ngen,
                                 reducible_behavior r = UnfoldSemireducible);
type_checker_ptr mk_type_checker(environment const & env, reducible_behavior r = UnfoldSemireducible);

/** \brief Create a type checker that treats all definitions as opaque. */
type_checker_ptr mk_opaque_type_checker(environment const & env, name_generator && ngen);

void initialize_reducible();
void finalize_reducible();
void open_reducible(lua_State * L);
}