lean4-htt/src/util/fresh_name.cpp

132 lines
3.6 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 "util/sstream.h"
#include "util/name_set.h"
#include "util/fresh_name.h"
#include "util/thread.h"
#include "util/shared_mutex.h"
namespace lean {
static name_set * g_fresh_name_prefixes = nullptr;
static shared_mutex * g_fresh_name_prefixes_guard = nullptr;
static void register_fresh_name_prefix(name const & p) {
exclusive_lock lock(*g_fresh_name_prefixes_guard);
g_fresh_name_prefixes->insert(p);
}
MK_THREAD_LOCAL_GET_DEF(name, get_prefix);
LEAN_THREAD_VALUE(unsigned, g_next_idx, 0);
static bool is_fresh_prefix(name const & p) {
if (p == get_prefix())
return true;
shared_lock lock(*g_fresh_name_prefixes_guard);
return g_fresh_name_prefixes->contains(p);
};
name mk_fresh_name() {
name & prefix = get_prefix();
if (prefix.is_anonymous()) {
// prefix has not been initialized for this thread yet.
prefix = name::mk_internal_unique_name();
register_fresh_name_prefix(prefix);
}
if (g_next_idx == std::numeric_limits<unsigned>::max()) {
// avoid overflow
prefix = name(prefix, g_next_idx);
register_fresh_name_prefix(prefix);
g_next_idx = 0;
}
name r(prefix, g_next_idx);
g_next_idx++;
return r;
}
bool is_fresh_name(name const & n) {
if (n.is_anonymous() || !n.is_numeral())
return false;
else if (is_fresh_prefix(n.get_prefix()))
return true;
else
return is_fresh_name(n.get_prefix());
}
static void sanitize_fresh(sstream & strm, name const & n) {
if (n.is_anonymous()) {
strm << "_fresh";
} else if (n.is_numeral()) {
sanitize_fresh(strm, n.get_prefix());
strm << "_" << n.get_numeral();
} 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());
}
name mk_tagged_fresh_name(name const & tag) {
lean_assert(tag.is_atomic());
name & prefix = get_prefix();
if (prefix.is_anonymous()) {
// prefix has not been initialized for this thread yet.
prefix = name::mk_internal_unique_name();
}
if (g_next_idx == std::numeric_limits<unsigned>::max()) {
// avoid overflow
prefix = name(prefix, g_next_idx);
g_next_idx = 0;
}
name r(tag + prefix, g_next_idx);
g_next_idx++;
return r;
}
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_name_prefixes = new name_set();
g_fresh_name_prefixes_guard = new shared_mutex();
}
void finalize_fresh_name() {
delete g_fresh_name_prefixes;
delete g_fresh_name_prefixes_guard;
}
}