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>
38 lines
1.2 KiB
C++
38 lines
1.2 KiB
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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#include <sstream>
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#include "kernel/kernel_exception.h"
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#include "kernel/printer.h"
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#include "kernel/formatter.h"
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namespace lean {
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class simple_formatter_cell : public formatter_cell {
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public:
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virtual format operator()(expr const & e, options const &) {
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std::ostringstream s; s << e; return format(s.str());
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}
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virtual format operator()(context const & c, options const &) {
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std::ostringstream s; s << c; return format(s.str());
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}
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virtual format operator()(context const & c, expr const & e, bool format_ctx, options const &) {
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std::ostringstream s;
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if (format_ctx)
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s << c << " |- ";
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s << mk_pair(e, c);
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return format(s.str());
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}
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virtual format operator()(object const & obj, options const &) {
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std::ostringstream s; s << obj; return format(s.str());
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}
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virtual format operator()(ro_environment const & env, options const &) {
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std::ostringstream s; s << env; return format(s.str());
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}
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};
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formatter mk_simple_formatter() {
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return mk_formatter(simple_formatter_cell());
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}
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}
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