lean2/src/frontends/lean/lean_elaborator.h

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/*
Copyright (c) 2013 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 "environment.h"
#include "formatter.h"
namespace lean {
class frontend;
/**
\brief Expression elaborator, it is responsible for "filling" holes
in terms left by the user. This is the main module resposible for computing
the value of implicit arguments.
*/
class elaborator {
class imp;
std::shared_ptr<imp> m_ptr;
static void print(imp * ptr);
public:
explicit elaborator(frontend const & fe);
~elaborator();
expr operator()(expr const & e);
expr operator()(expr const & e, expr const & expected_type);
/**
\brief If \c e is an expression instantiated by the elaborator, then it
returns the expression (the one with "holes") used to generate \c e.
Otherwise, it just returns \c e.
*/
expr const & get_original(expr const & e) const;
void set_interrupt(bool flag);
void interrupt() { set_interrupt(true); }
void reset_interrupt() { set_interrupt(false); }
void clear();
environment const & get_environment() const;
void display(std::ostream & out) const;
format pp(formatter & f, options const & o) const;
bool has_constraints() const;
};
/**
\brief Create a choice expression for the given functions.
It is used to mark which functions can be used in a particular application.
The elaborator decides which one should be used based on the type of the arguments.
\pre num_fs >= 2
*/
expr mk_choice(unsigned num_fs, expr const * fs);
/**
\brief Return true iff \c e is an expression created using \c mk_choice.
*/
bool is_choice(expr const & e);
/**
\brief Return the number of alternatives in a choice expression.
We have that <tt>get_num_choices(mk_choice(n, fs)) == n</tt>.
\pre is_choice(e)
*/
unsigned get_num_choices(expr const & e);
/**
\brief Return the (i+1)-th alternative of a choice expression.
\pre is_choice(e)
\pre i < get_num_choices(e)
*/
expr const & get_choice(expr const & e, unsigned i);
}