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/**
* 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/>.
*/
#include "corewords.hpp"
#include "parser.hpp"
#include <cctype>
#include <cstdlib>
ParseStatus Parser::parse(State& state, std::string_view& str)
{
auto addr = Dictionary::Input;
state.dict.write(addr, str.size() + 1);
addr += sizeof(Cell) + Dictionary::InputCells - str.size() - 1;
for (char c : str)
state.dict.writebyte(addr++, c);
state.dict.writebyte(addr, '\0');
return parseSource(state);
}
ParseStatus Parser::parseSource(State& state)
{
auto word = state.dict.input();
while (word.size() > 0) {
if (auto ret = parseWord(state, word); ret != ParseStatus::Finished)
return ret;
word = state.dict.input();
}
return ParseStatus::Finished;
}
ParseStatus Parser::parseWord(State& state, Word word)
{
if (auto i = CoreWords::findi(state, word); i >= 0) {
if (state.compiling())
state.dict.add(i & ~CoreWords::CoreImmediate);
else if (state.dict.equal(word, ":"))
state.compiling(true);
if (!state.compiling() || (i & CoreWords::CoreImmediate))
CoreWords::run(i & ~CoreWords::CoreImmediate, state);
} else if (auto j = state.dict.find(word); j > 0) {
auto e = state.dict.getexec(j);
if (state.compiling()) {
if (state.dict.read(j) & CoreWords::Immediate) {
state.compiling(false);
state.execute(e);
state.compiling(true);
} else {
state.dict.add(CoreWords::HiddenWordJump);
state.dict.add(e);
}
} else {
state.execute(e);
}
} else {
char buf[word.size() + 1];
for (unsigned i = 0; i < word.size(); ++i)
buf[i] = state.dict.readbyte(word.start + i);
buf[word.size()] = '\0';
char *p;
const auto base = state.dict.read(0);
const Cell l = std::strtol(buf, &p, base);
if (std::distance(buf, p) == word.size()) {
if (state.compiling()) {
state.dict.add(CoreWords::HiddenWordLiteral);
state.dict.add(l);
} else {
state.push(l);
}
} else {
return ParseStatus::NotAWord;
}
}
return ParseStatus::Finished;
}
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