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.
127 lines
3.2 KiB
C++
127 lines
3.2 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 "ctype.hpp"
|
|
#include "parser.hpp"
|
|
|
|
#include <cstring>
|
|
|
|
int Parser::parse(State& state, const char *str)
|
|
{
|
|
auto addr = Dictionary::Input;
|
|
state.dict.write(addr, 0);
|
|
state.dict.write(Dictionary::SourceLen, std::strlen(str));
|
|
|
|
addr += sizeof(Cell);
|
|
while (*str)
|
|
state.dict.writebyte(addr++, *str++);
|
|
|
|
while (addr < Dictionary::Input + Dictionary::InputCells)
|
|
state.dict.writebyte(addr++, '\0');
|
|
|
|
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;
|
|
} else {
|
|
imm = state.dict.read(ins) & CoreWords::Immediate;
|
|
ins = state.dict.getexec(ins);
|
|
}
|
|
|
|
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)
|
|
{
|
|
const auto base = state.dict.read(Dictionary::Base);
|
|
DoubleCell result = 0;
|
|
auto i = word.start;
|
|
bool inv;
|
|
char c;
|
|
|
|
c = state.dict.readbyte(i);
|
|
if (inv = c == '-'; inv)
|
|
c = state.dict.readbyte(++i);
|
|
|
|
do {
|
|
if (isdigit(c)) {
|
|
result *= base;
|
|
result += c - '0';
|
|
} else if (isalpha(c) && base > 10) {
|
|
result *= base;
|
|
result += 10 + (c > 'a' ? c - 'a' : c - 'A');
|
|
} else {
|
|
return UnknownWord;
|
|
}
|
|
|
|
if (++i < word.wend)
|
|
c = state.dict.readbyte(i);
|
|
} while (i < word.wend);
|
|
|
|
if (inv)
|
|
result *= -1;
|
|
|
|
Cell value = static_cast<Cell>(result);
|
|
if (state.compiling()) {
|
|
auto ins = CoreWords::findi("_lit");
|
|
|
|
if (value >= 0 && value < static_cast<Cell>(Dictionary::Begin - CoreWords::WordCount)) {
|
|
state.dict.add(value + CoreWords::WordCount);
|
|
} else {
|
|
state.dict.add(ins);
|
|
state.dict.add(value);
|
|
}
|
|
} else {
|
|
state.push(value);
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|