Core: Add generic ParameterConfig

This still needs to be improved

src/Nazara/Core/ParameterFile.cpp

@@ -0,0 +1,110 @@
+// Copyright (C) 2023 Jérôme "Lynix" Leclercq (lynix680@gmail.com)
+// This file is part of the "Nazara Engine - Core module"
+// For conditions of distribution and use, see copyright notice in Config.hpp
+
+#include <Nazara/Core/ParameterFile.hpp>
+#include <Nazara/Core/Error.hpp>
+#include <Nazara/Core/Stream.hpp>
+#include <Nazara/Core/Debug.hpp>
+
+namespace Nz
+{
+	bool ParameterFile::EnsureLine(bool peek)
+	{
+		while (m_currentLine.find_first_not_of(" \r\t\n") == m_currentLine.npos)
+		{
+			m_currentLine.clear();
+			m_stream.ReadLine(m_currentLine);
+			if (m_currentLine.empty())
+			{
+				if (!peek)
+					throw std::runtime_error("unexpected end of file");
+
+				return false;
+			}
+		}
+
+		return true;
+	}
+
+	std::string ParameterFile::ReadKeyword(bool peek)
+	{
+		std::size_t beginOffset;
+		do
+		{
+			if (!EnsureLine(peek))
+				return {};
+
+			beginOffset = m_currentLine.find_first_not_of(" \r\t\n");
+		} while (beginOffset == m_currentLine.npos);
+
+		if (m_currentLine[beginOffset] == '"')
+			throw std::runtime_error("expected a keyword, got a string");
+
+		std::size_t endOffset = m_currentLine.find_first_of(" \r\t\n", beginOffset + 1);
+		if (endOffset == m_currentLine.npos)
+			endOffset = m_currentLine.size();
+
+		std::string currentToken = std::string(m_currentLine.substr(beginOffset, endOffset - beginOffset));
+		if (!peek)
+			m_currentLine.erase(m_currentLine.begin(), m_currentLine.begin() + endOffset);
+
+		return currentToken;
+	}
+
+	std::string ParameterFile::ReadString()
+	{
+		std::size_t beginOffset;
+		do
+		{
+			EnsureLine();
+			beginOffset = m_currentLine.find_first_not_of(" \r\t\n");
+		} while (beginOffset == m_currentLine.npos);
+
+		if (m_currentLine[beginOffset] != '"')
+			throw std::runtime_error("expected a string, got a keyword");
+
+		std::string str;
+		for (std::size_t i = beginOffset + 1; i < m_currentLine.size(); ++i)
+		{
+			switch (m_currentLine[i])
+			{
+				case '\0':
+				case '\n':
+				case '\r':
+					throw std::runtime_error("expected a string, got a keyword");
+
+				case '"':
+				{
+					m_currentLine.erase(m_currentLine.begin(), m_currentLine.begin() + beginOffset + i);
+
+					return str;
+				}
+
+				case '\\':
+				{
+					i++;
+					char character;
+					switch (m_currentLine[i])
+					{
+						case 'n': character = '\n'; break;
+						case 'r': character = '\r'; break;
+						case 't': character = '\t'; break;
+						case '"': character = '"'; break;
+						case '\\': character = '\\'; break;
+						default:
+							throw std::runtime_error(Format("unrecognized character {}", character));
+					}
+
+					str.push_back(character);
+					break;
+				}
+
+				default:
+					str.push_back(m_currentLine[i]);
+			}
+		}
+
+		throw std::runtime_error("unfinished string");
+	}
+}