You cannot select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
119 lines
3.1 KiB
C++
119 lines
3.1 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/>.
|
|
*/
|
|
|
|
#include "corewords.hpp"
|
|
#include "parser.hpp"
|
|
|
|
#include <charconv>
|
|
#include <cstring>
|
|
|
|
int Parser::parse(State& state, const char *str)
|
|
{
|
|
const auto size = std::strlen(str);
|
|
|
|
auto addr = Dictionary::Input;
|
|
state.dict.write(addr, size + 1);
|
|
|
|
addr += sizeof(Cell) + Dictionary::InputCells - size - 1;
|
|
while (*str)
|
|
state.dict.writebyte(addr++, *str++);
|
|
state.dict.writebyte(addr, ' ');
|
|
|
|
return parseSource(state);
|
|
}
|
|
|
|
int Parser::parseSource(State& state)
|
|
{
|
|
auto word = state.dict.input();
|
|
while (word.size() > 0) {
|
|
if (auto ret = parseWord(state, word); ret)
|
|
return ret;
|
|
|
|
word = state.dict.input();
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
int Parser::parseWord(State& state, Word word)
|
|
{
|
|
int ins, imm;
|
|
|
|
ins = state.dict.find(word);
|
|
|
|
if (ins <= 0) {
|
|
ins = CoreWords::findi(state, word);
|
|
|
|
if (ins < 0) {
|
|
return parseNumber(state, word);
|
|
} else {
|
|
imm = ins == CoreWords::Semicolon;
|
|
ins &= ~CoreWords::Immediate;
|
|
ins = (ins << 1) | 1;
|
|
}
|
|
} else {
|
|
imm = state.dict.read(ins) & CoreWords::Immediate;
|
|
ins = state.dict.getexec(ins);
|
|
}
|
|
|
|
if (state.dict.read(Dictionary::Postpone)) {
|
|
state.dict.add(ins);
|
|
state.dict.write(Dictionary::Postpone, 0);
|
|
} else if (state.compiling() && !imm) {
|
|
state.dict.add(ins);
|
|
} else {
|
|
if (auto stat = state.execute(ins); stat != State::Error::none)
|
|
return static_cast<int>(stat);
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
int Parser::parseNumber(State& state, Word word)
|
|
{
|
|
char buf[MaxCellNumberChars + 1];
|
|
unsigned i;
|
|
for (i = 0; i < std::min(MaxCellNumberChars, word.size()); ++i)
|
|
buf[i] = state.dict.readbyte(word.start + i);
|
|
buf[i] = '\0';
|
|
|
|
auto base = state.dict.read(0);
|
|
Cell l;
|
|
auto [ptr, ec] = std::from_chars(buf, buf + i, l, base);
|
|
|
|
if (ec == std::errc() && ptr == buf + i) {
|
|
if (state.compiling()) {
|
|
auto ins = (CoreWords::findi("_lit") << 1) | 1;
|
|
|
|
if (l >= 0 && l < 0xFF) {
|
|
state.dict.add(ins | ((l + 1) << 8));
|
|
} else {
|
|
state.dict.add(ins);
|
|
state.dict.add(l);
|
|
}
|
|
} else {
|
|
state.push(l);
|
|
}
|
|
|
|
return 0;
|
|
} else {
|
|
return UnknownWord;
|
|
}
|
|
}
|
|
|