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// Copyright (C) Filippo Cucchetto <filippocucchetto@gmail.com>
// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR GPL-3.0+ OR GPL-3.0 WITH Qt-GPL-exception-1.0
#pragma once
#include <cstdint>
#include <cstring>
#include <string>
#include <vector>
#include "sexprlexer.h"
namespace Nim {
struct SExprParser {
enum NodeType : uint8_t {
ATOM_STRING = 1,
ATOM_NUMBER = 2,
ATOM_IDENTIFIER = 4,
LIST = 8
};
struct Node {
NodeType kind;
std::size_t from;
std::size_t end;
std::vector<Node> nodes;
std::string value;
};
SExprParser(const std::string &str)
: SExprParser(str.data(), str.length())
{}
SExprParser(const char *data)
: SExprParser(data, ::strlen(data))
{}
SExprParser(const char *data, std::size_t length)
: m_lexer(SExprLexer(data, length))
{}
bool parse(Node &node)
{
SExprLexer::Token token;
if (m_lexer.next(token) != SExprLexer::Result::TokenAvailable
|| token.type != SExprLexer::OPEN_BRACE)
return false;
node = Node {LIST, token.start, token.start, {}, {}};
return parseList(node);
}
private:
bool parseList(Node &node)
{
while (true) {
SExprLexer::Token token;
if (m_lexer.next(token) != SExprLexer::Result::TokenAvailable)
return false;
switch (token.type) {
case SExprLexer::STRING: {
std::string value = m_lexer.tokenValue(token);
value.pop_back();
value.erase(value.begin());
node.nodes.emplace_back(Node{ATOM_STRING, token.start, token.end, {}, std::move(value)});
break;
}
case SExprLexer::NUMBER: {
node.nodes.emplace_back(Node{ATOM_NUMBER, token.start, token.end, {}, m_lexer.tokenValue(token)});
break;
}
case SExprLexer::IDENTIFIER: {
node.nodes.emplace_back(Node{ATOM_IDENTIFIER, token.start, token.end, {}, m_lexer.tokenValue(token)});
break;
}
case SExprLexer::OPEN_BRACE: {
Node list {LIST, token.start, token.start, {}, {}};
if (!parseList(list)) {
return false;
}
node.nodes.emplace_back(std::move(list));
break;
}
case SExprLexer::CLOSE_BRACE: {
node.end = token.end;
return true;
}
}
}
}
SExprLexer m_lexer;
};
} // namespace Nim
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