1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
|
/**
* 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>
#include <iostream>
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, ' ');
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)
{
int ins, imm;
ins = CoreWords::findi(state, word);
if (ins < 0) {
ins = state.dict.find(word);
if (ins <= 0) {
return parseNumber(state, word);
} else {
imm = state.dict.read(ins) & CoreWords::Immediate;
ins = state.dict.getexec(ins);
}
} else {
imm = ins & CoreWords::Compiletime;
ins &= ~CoreWords::Compiletime;
}
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 {
state.execute(ins);
}
return ParseStatus::Finished;
}
ParseStatus Parser::parseNumber(State& state, Word word)
{
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::findi("_lit"));
state.dict.add(l);
} else {
state.push(l);
}
return ParseStatus::Finished;
} else {
std::cout << "word not found: " << buf << std::endl;
return ParseStatus::NotAWord;
}
}
|
