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alee-forth/libalee/dictionary.cpp

178 lines
3.9 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 "ctype.hpp"
#include "dictionary.hpp"
#include <cstring>
void Dictionary::initialize()
{
write(Base, 10);
write(Here, Begin);
write(Latest, Begin);
write(Compiling, 0);
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write(Source, Input + sizeof(Cell));
}
Addr Dictionary::allot(Cell amount) noexcept
{
Addr old = here();
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decltype(capacity()) neww = old + amount;
if (neww < capacity()) {
write(Here, static_cast<Addr>(neww));
} else {
// TODO
}
return old;
}
void Dictionary::add(Cell value) noexcept
{
write(allot(sizeof(Cell)), value);
}
Addr Dictionary::aligned(Addr addr) const noexcept
{
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Addr unaligned = addr & (sizeof(Cell) - sizeof(uint8_t));
if (unaligned) {
addr += sizeof(Cell);
addr -= unaligned;
}
return addr;
}
Addr Dictionary::alignhere() noexcept
{
here(aligned(here()));
return here();
}
void Dictionary::addDefinition(Word word) noexcept
{
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Cell wsize = word.size();
add(wsize);
auto it = word.begin(this);
const auto end = word.end(this);
while (it != end)
writebyte(allot(1), *it++);
alignhere();
}
Addr Dictionary::find(Word word) noexcept
{
Addr lt = latest();
for (;;) {
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const Addr l = read(lt);
const Addr len = l & 0x1F;
const auto lw = Word::fromLength(lt + sizeof(Cell), len);
if (equal(word, lw))
return lt;
else if (lt == Begin)
break;
else
lt -= l >> 6;
}
return 0;
}
Addr Dictionary::getexec(Addr addr) noexcept
{
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const Addr len = read(addr) & 0x1Fu;
addr += sizeof(Cell);
addr += len;
return aligned(addr);
}
bool Dictionary::hasInput() const noexcept
{
const Addr src = read(Dictionary::Source);
const Addr end = read(Dictionary::SourceLen);
uint8_t idx = read(Dictionary::Input) & 0xFFu;
while (idx < end) {
auto ch = readbyte(src + idx);
if (ch == '\0') {
break;
} else if (!isspace(ch)) {
return true;
}
++idx;
}
return false;
}
Word Dictionary::input() noexcept
{
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const Addr src = read(Dictionary::Source);
const Addr end = read(Dictionary::SourceLen);
uint8_t idx = read(Dictionary::Input) & 0xFFu;
Addr wstart = src + idx;
Addr wend = wstart;
while (idx < end) {
auto ch = readbyte(wend);
if (isspace(ch)) {
if (wend - wstart > 0)
break;
++wstart;
} else if (ch == '\0') {
break;
}
++wend;
++idx;
}
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writebyte(Dictionary::Input, ++idx);
return Word(wstart, wend);
}
bool Dictionary::equal(Word word, const char *str, unsigned len) const noexcept
{
return word.size() == len &&
equal(word.begin(this), word.end(this), str);
}
bool Dictionary::equal(Word word, Word other) const noexcept
{
return word.size() == other.size() &&
equal(word.begin(this), word.end(this), other.begin(this));
}
bool Dictionary::eqchars(char c1, char c2)
{
return c1 == c2 ||
(isalpha(c1) && isalpha(c2) && (c1 | 32) == (c2 | 32));
}