lean2/src/frontends/lean/local_decls.h
2014-10-10 16:16:19 -07:00

56 lines
1.9 KiB
C++

/*
Copyright (c) 2014 Microsoft Corporation. All rights reserved.
Released under Apache 2.0 license as described in the file LICENSE.
Author: Leonardo de Moura
*/
#pragma once
#include <utility>
#include "util/rb_map.h"
#include "util/name.h"
#include "util/list.h"
#include "util/pair.h"
namespace lean {
/**
\brief A "scoped" map from name to values.
It also supports the operation \c find_idx that returns "when a declaration was inserted into the map".
*/
template<typename V>
class local_decls {
typedef name_map<pair<V, unsigned>> map;
typedef list<pair<name, V>> entries;
typedef std::tuple<map, unsigned, entries> scope;
typedef list<scope> scopes;
map m_map;
unsigned m_counter;
scopes m_scopes;
entries m_entries;
public:
local_decls():m_counter(1) {}
local_decls(local_decls const & d):
m_map(d.m_map), m_counter(d.m_counter), m_scopes(d.m_scopes), m_entries(d.m_entries) {}
void insert(name const & k, V const & v) {
m_map.insert(k, mk_pair(v, m_counter));
m_counter++;
m_entries = cons(mk_pair(k, v), m_entries);
}
V const * find(name const & k) const { auto it = m_map.find(k); return it ? &(it->first) : nullptr; }
unsigned find_idx(name const & k) const { auto it = m_map.find(k); return it ? it->second : 0; }
bool contains(name const & k) const { return m_map.contains(k); }
entries const & get_entries() const { return m_entries; }
void push() { m_scopes = cons(scope(m_map, m_counter, m_entries), m_scopes); }
void pop() {
lean_assert(!is_nil(m_scopes));
std::tie(m_map, m_counter, m_entries) = head(m_scopes);
m_scopes = tail(m_scopes);
}
bool empty() const { return m_map.empty(); }
struct mk_scope {
local_decls & m_d;
mk_scope(local_decls & d):m_d(d) { m_d.push(); }
~mk_scope() { m_d.pop(); }
};
};
}