f97c260b0b
The environment object is a "smart-pointer".
Before this commit, the use of "const &" for environment objects was broken.
For example, suppose we have a function f that should not modify the input environment.
Before this commit, its signature would be
void f(environment const & env)
This is broken, f's implementation can easilty convert it to a read-write pointer by using
the copy constructor.
environment rw_env(env);
Now, f can use rw_env to update env.
To fix this issue, we now have ro_environment. It is a shared *const* pointer.
We can convert an environment into a ro_environment, but not the other way around.
ro_environment can also be seen as a form of documentation.
For example, now it is clear that type_inferer is not updating the environment, since its constructor takes a ro_environment.
Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
25 lines
871 B
C++
25 lines
871 B
C++
/*
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Copyright (c) 2013 Microsoft Corporation. All rights reserved.
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Released under Apache 2.0 license as described in the file LICENSE.
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Author: Leonardo de Moura
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*/
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#pragma once
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#include <iostream>
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#include <utility>
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#include "kernel/expr.h"
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#include "kernel/context.h"
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namespace lean {
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class ro_environment;
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std::ostream & operator<<(std::ostream & out, context const & ctx);
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std::ostream & operator<<(std::ostream & out, expr const & e);
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std::ostream & operator<<(std::ostream & out, std::pair<expr const &, context const &> const & p);
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class object;
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std::ostream & operator<<(std::ostream & out, object const & obj);
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std::ostream & operator<<(std::ostream & out, ro_environment const & env);
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}
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void print(lean::expr const & a);
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void print(lean::expr const & a, lean::context const & c);
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void print(lean::context const & c);
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void print(lean::ro_environment const & e);
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