48 lines
1.9 KiB
C++
48 lines
1.9 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
|
|
*/
|
|
#pragma once
|
|
#include "kernel/expr.h"
|
|
#include "kernel/type_checker.h"
|
|
#include "library/choice_iterator.h"
|
|
|
|
namespace lean {
|
|
/** \brief Abstract class for hiding details of the info_manager from the coercion_elaborator */
|
|
class coercion_info_manager {
|
|
public:
|
|
virtual void erase_coercion_info(expr const & e) = 0;
|
|
virtual void save_coercion_info(expr const & e, expr const & c) = 0;
|
|
};
|
|
|
|
class coercion_elaborator : public choice_iterator {
|
|
coercion_info_manager & m_info;
|
|
expr m_arg;
|
|
bool m_id; // true if identity was not tried yet
|
|
list<constraints> m_choices;
|
|
list<expr> m_coercions;
|
|
public:
|
|
coercion_elaborator(coercion_info_manager & info, expr const & arg,
|
|
list<constraints> const & choices, list<expr> const & coes,
|
|
bool use_id = true);
|
|
optional<constraints> next();
|
|
};
|
|
|
|
/** \brief Given a term <tt>a : a_type</tt>, and a metavariable \c m, creates a constraint
|
|
that considers coercions from a_type to the type assigned to \c m.
|
|
|
|
This function is used when the types \c a_type and/or the type of \c m
|
|
are not known at preprocessing time, and a choice function is used to
|
|
enumerate coercion functions \c f. By "not known", we mean the type is a
|
|
metavariable application.
|
|
|
|
\see coercion_info_manager
|
|
*/
|
|
constraint mk_coercion_cnstr(type_checker & tc, coercion_info_manager & infom,
|
|
expr const & m, expr const & a, expr const & a_type,
|
|
justification const & j, unsigned delay_factor);
|
|
|
|
list<expr> get_coercions_from_to(type_checker & tc, expr const & from_type, expr const & to_type, constraint_seq & cs);
|
|
}
|