lean4-htt/src/util/fresh_name.cpp
2019-08-24 07:40:38 -07:00

94 lines
2.5 KiB
C++

/*
Copyright (c) 2016 Microsoft Corporation. All rights reserved.
Released under Apache 2.0 license as described in the file LICENSE.
Author: Leonardo de Moura
*/
#include <limits>
#include "runtime/thread.h"
#include "runtime/sstream.h"
#include "util/name_set.h"
#include "util/fresh_name.h"
namespace lean {
static name * g_fresh = nullptr;
MK_THREAD_LOCAL_GET_DEF(std::unique_ptr<name_generator>, get_name_generator_ptr);
name mk_fresh_name() {
std::unique_ptr<name_generator> & ngen = get_name_generator_ptr();
if (!ngen) {
name unique = name::mk_internal_unique_name();
ngen.reset(new name_generator(*g_fresh + unique));
}
return ngen->next();
}
bool is_fresh_name(name const & n) {
if (n.is_anonymous() || !n.is_numeral())
return false;
else if (n.get_prefix() == *g_fresh)
return true;
else
return is_fresh_name(n.get_prefix());
}
static void sanitize_fresh(sstream & strm, name const & n) {
if (n.is_anonymous() || n == *g_fresh) {
strm << "_fresh";
} else if (n.is_numeral()) {
sanitize_fresh(strm, n.get_prefix());
strm << "_" << n.get_numeral().to_std_string();
} else {
lean_unreachable();
}
}
name sanitize_if_fresh(name const & n) {
if (!is_fresh_name(n))
return n;
sstream strm;
sanitize_fresh(strm, n);
return name(strm.str().c_str());
}
name mk_tagged_fresh_name(name const & tag) {
lean_assert(tag.is_atomic());
return tag + mk_fresh_name();
}
bool is_tagged_by(name const & n, name const & tag) {
lean_assert(tag.is_atomic());
if (n.is_atomic())
return false;
name t = n;
while (!t.is_atomic())
t = t.get_prefix();
return t == tag;
}
/* A tagged name is of the form tag.unique_id.suffix */
optional<name> get_tagged_name_suffix(name const & n, name const & tag) {
if (n.is_atomic()) {
return optional<name>();
} else if (n.get_prefix() == tag) {
return optional<name>(name());
} else if (auto new_prefix = get_tagged_name_suffix(n.get_prefix(), tag)) {
if (n.is_string()) {
return optional<name>(name(*new_prefix, n.get_string()));
} else {
return optional<name>(name(*new_prefix, n.get_numeral()));
}
} else {
return optional<name>();
}
}
void initialize_fresh_name() {
g_fresh = new name("_fresh");
register_name_generator_prefix(*g_fresh);
}
void finalize_fresh_name() {
delete g_fresh;
}
}