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//
/// @file memdict.hpp
/// @brief Simple dictionary implementation using a large memory block.
//
// Alee Forth: A portable and concise Forth implementation in modern C++.
// Copyright (C) 2023 Clyne Sullivan <clyne@bitgloo.com>
//
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU Lesser General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public License
// along with this program. If not, see <https://www.gnu.org/licenses/>.
#ifndef ALEEFORTH_MEMDICT_HPP
#define ALEEFORTH_MEMDICT_HPP
#include "libalee/alee.hpp"
#ifndef MEMDICTSIZE
/** Default dictionary size in bytes. */
#define MEMDICTSIZE (65536)
#endif
/** Size in bytes of a MemDict. */
constexpr unsigned long int MemDictSize = MEMDICTSIZE;
/**
* @class MemDict
* Dictionary implementation that uses a large block of memory.
*/
class MemDict : public Dictionary
{
/** Block of memory to contain dictionary's contents. */
uint8_t dict[MemDictSize] = {0};
public:
/** Returns the value of the cell at the given address. */
virtual Cell read(Addr addr) const noexcept final {
return *reinterpret_cast<const Cell *>(dict + addr);
}
/** Writes the given value to the cell at the given address. */
virtual void write(Addr addr, Cell value) noexcept final {
*reinterpret_cast<Cell *>(dict + addr) = value;
}
/** Returns the value of the byte at the given address. */
virtual uint8_t readbyte(Addr addr) const noexcept final {
return dict[addr];
}
/** Writes the given value to the byte at the given address. */
virtual void writebyte(Addr addr, uint8_t value) noexcept final {
dict[addr] = value;
}
/** Returns the size of the dictionary's memory block. */
virtual unsigned long int capacity() const noexcept final {
return sizeof(dict);
}
};
#endif // ALEEFORTH_MEMDICT_HPP
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