Lisp: Add source

src/reader.cpp

@@ -0,0 +1,161 @@
+/*
+ * Copyright (C) 2023 Riyyi
+ *
+ * SPDX-License-Identifier: MIT
+ */
+
+#include <cstddef> // size_t
+#include <cstdint> // uint64_t
+#include <cstdlib> // std::strtoll
+#include <utility> // std::move
+
+#include "ruc/format/color.h"
+#include "ruc/meta/assert.h"
+
+#include "ast.h"
+#include "reader.h"
+#include "types.h"
+
+namespace blaze {
+
+Reader::Reader(std::vector<Token>&& tokens) noexcept
+	: m_tokens(std::move(tokens))
+{
+}
+
+Reader::~Reader()
+{
+}
+
+// -----------------------------------------
+
+void Reader::read()
+{
+	if (m_node != nullptr) {
+		return;
+	}
+
+	m_node = readImpl();
+	VERIFY(m_index > m_tokens.size() - 1, "more than one sexp in input");
+}
+
+ASTNode* Reader::readImpl()
+{
+	switch (peek().type) {
+	case Token::Type::ParenOpen:
+		return readList();
+		break;
+	case Token::Type::String:
+		return readString();
+		break;
+	case Token::Type::Value:
+		return readValue();
+	default:
+		// Unimplemented token
+		VERIFY_NOT_REACHED();
+		return nullptr;
+	}
+}
+
+ASTNode* Reader::readList()
+{
+	ignore(); // (
+
+	List* list = new List();
+	while (m_index < m_tokens.size() && peek().type != Token::Type::ParenClose) {
+		list->addNode(readImpl());
+	}
+
+	VERIFY(m_index != m_tokens.size(), "missing closing ')'");
+
+	ignore(); // )
+
+	return list;
+}
+
+ASTNode* Reader::readString()
+{
+	Token token = consume();
+	return new String(token.symbol);
+}
+
+ASTNode* Reader::readValue()
+{
+	Token token = consume();
+	char* endPtr = nullptr;
+	int64_t result = std::strtoll(token.symbol.c_str(), &endPtr, 10);
+	if (endPtr == token.symbol.c_str() + token.symbol.size()) {
+		return new Number(result);
+	}
+
+	return new Symbol(token.symbol);
+}
+
+// -----------------------------------------
+
+bool Reader::isEOF() const
+{
+	return m_index >= m_tokens.size();
+}
+
+Token Reader::peek() const
+{
+	VERIFY(!isEOF());
+	return m_tokens[m_index];
+}
+
+Token Reader::consume()
+{
+	VERIFY(!isEOF());
+	return m_tokens[m_index++];
+}
+
+void Reader::ignore()
+{
+	m_index++;
+}
+
+// -----------------------------------------
+
+void Reader::dump()
+{
+	dumpImpl(m_node);
+}
+
+void Reader::dumpImpl(ASTNode* node)
+{
+	std::string indentation = std::string(m_indentation * 2, ' ');
+
+	if (is<List>(node)) {
+		List* list = static_cast<List*>(node);
+		print("{}", indentation);
+		print(fg(ruc::format::TerminalColor::Blue), "ListContainer");
+		print(" <");
+		print(fg(ruc::format::TerminalColor::Blue), "()");
+		print(">\n");
+		m_indentation++;
+		for (size_t i = 0; i < list->nodes().size(); ++i) {
+			dumpImpl(list->nodes()[i]);
+		}
+		m_indentation--;
+		return;
+	}
+	else if (is<String>(node)) {
+		print("{}", indentation);
+		print(fg(ruc::format::TerminalColor::Yellow), "StringNode");
+		print(" <{}>", static_cast<String*>(node)->data());
+	}
+	else if (is<Number>(node)) {
+		print("{}", indentation);
+		print(fg(ruc::format::TerminalColor::Yellow), "NumberNode");
+		print(" <{}>", static_cast<Number*>(node)->number());
+	}
+	else if (is<Symbol>(node)) {
+		print("{}", indentation);
+		print(fg(ruc::format::TerminalColor::Yellow), "SymbolNode");
+		print(" <{}>", static_cast<Symbol*>(node)->symbol());
+	}
+	print("\n");
+}
+
+} // namespace blaze