gecko-dev/xpcom/ds/Dafsa.h

56 строки
1.4 KiB
C++

/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
#ifndef mozilla_Dafsa_h
#define mozilla_Dafsa_h
#include "stdint.h"
#include "mozilla/Span.h"
#include "nsStringFwd.h"
namespace mozilla {
/**
* A deterministic acyclic finite state automaton suitable for storing static
* dictionaries of tagged ascii strings. Consider using this if you have a very
* large set of strings that need an associated enum value.
*
* Currently the string tag is limited by `make_dafsa.py` to a value of [0-4].
* In theory [0-15] can easily be supported.
*
* See `make_dafsa.py` for more details.
*/
class Dafsa
{
public:
using Graph = Span<const uint8_t>;
/**
* Initializes the DAFSA with a binary encoding generated by `make_dafsa.py`.
*/
explicit Dafsa(const Graph& aData) : mData(aData) {}
~Dafsa() = default;
/**
* Searches for the given string in the DAFSA.
*
* @param aKey The string to search for.
* @returns kKeyNotFound if not found, otherwise the associated tag.
*/
int Lookup(const nsACString& aKey) const;
static const int kKeyNotFound;
private:
const Graph mData;
};
} // namespace mozilla
#endif // mozilla_Dafsa_h