lean2/src/util/name_generator.cpp

66 lines
2.1 KiB
C++

/*
Copyright (c) 2013 Microsoft Corporation. All rights reserved.
Released under Apache 2.0 license as described in the file LICENSE.
Author: Leonardo de Moura
*/
#include <limits>
#include <algorithm>
#include "util/name_generator.h"
namespace lean {
static name * g_tmp_prefix = nullptr;
name_generator::name_generator():name_generator(*g_tmp_prefix) {}
name name_generator::next() {
if (m_next_idx == std::numeric_limits<unsigned>::max()) {
// avoid overflow
m_prefix = name(m_prefix, m_next_idx);
m_next_idx = 0;
}
name r(m_prefix, m_next_idx);
m_next_idx++;
return r;
}
void swap(name_generator & a, name_generator & b) {
swap(a.m_prefix, b.m_prefix);
std::swap(a.m_next_idx, b.m_next_idx);
}
DECL_UDATA(name_generator)
static int mk_name_generator(lua_State * L) {
if (lua_gettop(L) == 0)
return push_name_generator(L, name_generator(*g_tmp_prefix));
else
return push_name_generator(L, name_generator(to_name_ext(L, 1)));
}
static int name_generator_next(lua_State * L) { return push_name(L, to_name_generator(L, 1).next()); }
static int name_generator_prefix(lua_State * L) { return push_name(L, to_name_generator(L, 1).prefix()); }
static int name_generator_mk_child(lua_State * L) { return push_name_generator(L, to_name_generator(L, 1).mk_child()); }
static const struct luaL_Reg name_generator_m[] = {
{"__gc", name_generator_gc}, // never throws
{"next", safe_function<name_generator_next>},
{"prefix", safe_function<name_generator_prefix>},
{"mk_child", safe_function<name_generator_mk_child>},
{0, 0}
};
void open_name_generator(lua_State * L) {
luaL_newmetatable(L, name_generator_mt);
lua_pushvalue(L, -1);
lua_setfield(L, -2, "__index");
setfuncs(L, name_generator_m, 0);
SET_GLOBAL_FUN(mk_name_generator, "name_generator");
SET_GLOBAL_FUN(name_generator_pred, "is_name_generator");
}
void initialize_name_generator() {
g_tmp_prefix = new name(name::mk_internal_unique_name());
}
void finalize_name_generator() {
delete g_tmp_prefix;
}
}