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alee-forth/libalee/corewords.hpp

84 lines
2.3 KiB
C++

/**
* 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_COREWORDS_HPP
#define ALEEFORTH_COREWORDS_HPP
#include "types.hpp"
#include "state.hpp"
#include <cstring>
/**
* To be implemented by the user, this function is called when the `sys` word
* is executed.
*/
void user_sys(State&);
class CoreWords
{
public:
constexpr static Cell WordCount = 37;
constexpr static Cell Semicolon = 26;
/**
* Finds execution token that corresponds to the given word.
* Returns -1 if not found.
*/
static Cell findi(State&, Word);
consteval static Cell findi(const char *word) {
return findi(word, std::strlen(word));
}
/**
* Executes the given CoreWord execution token using the given state.
*/
static void run(Cell, State&);
constexpr static char wordsarr[] =
"_lit\0drop\0dup\0swap\0pick\0sys\0"
"+\0-\0m*\0_/\0_%\0"
"_@\0_!\0>r\0r>\0=\0"
"<\0&\0|\0^\0"
"<<\0>>\0:\0_'\0execute\0"
"exit\0;\0_jmp0\0_jmp\0"
"depth\0_rdepth\0_in\0_ev\0find\0"
"_uma\0u<\0um/mod\0";
private:
template<typename Iter>
constexpr static Cell findi(Iter it, std::size_t size)
{
const char *ptr = CoreWords::wordsarr;
for (Cell wordsi = 0; wordsi < WordCount; ++wordsi) {
std::size_t wordsize = std::strlen(ptr);
if (wordsize == size && Dictionary::equal(ptr, ptr + wordsize, it))
return wordsi;
ptr += wordsize + 1;
}
return -1;
}
};
#endif // ALEEFORTH_COREWORDS_HPP