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.
109 lines
3.6 KiB
C++
109 lines
3.6 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 "executor.hpp"
|
|
#include "parser.hpp"
|
|
|
|
#include <cstdlib>
|
|
|
|
ParseStatus Parser::parse(State& state, std::string_view& str)
|
|
{
|
|
const auto end = str.find_first_of(" \t\n\r");
|
|
const auto sub = str.substr(0, end);
|
|
if (sub.empty())
|
|
return ParseStatus::Finished;
|
|
|
|
if (state.pass != Pass::None) {
|
|
switch (state.pass) {
|
|
case Pass::Comment:
|
|
if (str.front() == ')')
|
|
state.pass = Pass::None;
|
|
|
|
str = str.substr(1);
|
|
break;
|
|
case Pass::Colon:
|
|
state.pass = Pass::None;
|
|
state.compiling(true);
|
|
state.dict.addDefinition(sub);
|
|
break;
|
|
case Pass::Constant:
|
|
state.pass = Pass::None;
|
|
state.compiling(true);
|
|
state.dict.addDefinition(sub);
|
|
state.dict.add(CoreWords::HiddenWordLiteral);
|
|
state.dict.add(state.pop());
|
|
state.dict.add(CoreWords::findi(";"));
|
|
CoreWords::run(CoreWords::findi(";"), state);
|
|
break;
|
|
default:
|
|
break;
|
|
}
|
|
} else {
|
|
if (auto i = CoreWords::findi(sub); i >= 0) {
|
|
if (state.compiling())
|
|
state.dict.add(i & ~CoreWords::CoreImmediate);
|
|
if (!state.compiling() || (i & CoreWords::CoreImmediate))
|
|
CoreWords::run(i & ~CoreWords::CoreImmediate, state);
|
|
} else if (auto j = state.dict.find(sub); j > 0) {
|
|
auto e = state.dict.getexec(j);
|
|
|
|
if (state.compiling()) {
|
|
if (state.dict.read(j) & CoreWords::Immediate) {
|
|
state.compiling(false);
|
|
Executor::fullexec(state, e);
|
|
state.compiling(true);
|
|
} else {
|
|
state.dict.add(CoreWords::HiddenWordJump);
|
|
state.dict.add(e);
|
|
}
|
|
} else {
|
|
Executor::fullexec(state, e);
|
|
}
|
|
} else {
|
|
char *p;
|
|
const auto base = state.dict.read(0);
|
|
const auto l = static_cast<Cell>(std::strtol(sub.data(), &p, base));
|
|
|
|
if (p != sub.data()) {
|
|
if (state.compiling()) {
|
|
state.dict.add(CoreWords::HiddenWordLiteral);
|
|
state.dict.add(l);
|
|
} else {
|
|
state.push(l);
|
|
}
|
|
} else {
|
|
return ParseStatus::Error;
|
|
}
|
|
}
|
|
|
|
if (end == std::string_view::npos)
|
|
return ParseStatus::Finished;
|
|
}
|
|
|
|
const auto next = str.find_first_not_of(" \t\n\r", end);
|
|
|
|
if (next == std::string_view::npos) {
|
|
return ParseStatus::Finished;
|
|
} else {
|
|
str = str.substr(next);
|
|
return ParseStatus::Continue;
|
|
}
|
|
}
|
|
|