rework

lib/importer.cpp

@@ -0,0 +1,73 @@
+#include "autoopt/importer.hpp"
+
+namespace autoopt {
+std::generator<std::pair<double, double>> parse_dat_file(
+    const std::filesystem::path& filename) {
+  // check if file exists
+  if (!std::filesystem::exists(filename)) {
+    throw std::runtime_error("File does not exist: " + filename.string());
+  }
+
+  std::fstream file(filename, std::ios::in);
+
+  std::string line;
+  while (std::getline(file, line)) {
+    if (line.empty() || line == "\r" || line[0] == '#') {
+      continue;
+    }
+    std::istringstream iss(line);
+    double x, y;
+    iss >> x;
+    for (size_t i = 1; i < 5; ++i) {
+      iss >> y;  // skip unused columns
+    }
+
+    co_yield {x, -y};
+  }
+  co_return;
+}
+
+std::pair<std::vector<double>, std::vector<double>> parse_row(auto& iter,
+                                                              auto sentinel) {
+  std::vector<double> xs;
+  std::vector<double> ys;
+  xs.push_back((*iter).first);
+  ys.push_back((*iter).second);
+  ++iter;
+  double last_x = xs[0];
+  bool forward = last_x < (*iter).first;
+  while (iter != sentinel && ((forward && last_x < (*iter).first) ||
+                              (!forward && last_x > (*iter).first))) {
+    xs.push_back((*iter).first);
+    ys.push_back((*iter).second);
+    last_x = (*iter).first;
+    ++iter;
+  }
+  if (!forward) {
+    std::reverse(xs.begin(), xs.end());
+    std::reverse(ys.begin(), ys.end());
+  }
+  return std::make_pair(std::move(xs), std::move(ys));
+}
+
+raw_data read_data(const std::filesystem::path &filename){
+  auto lines = parse_dat_file(filename);
+
+  raw_data result;
+
+  auto it = lines.begin();
+  while (it != lines.end()) {
+    auto [xs, ys] = parse_row(it, lines.end());
+    if (result._xs.rows() == 0) {
+      result._xs = Eigen::VectorXd(xs.size());
+      std::copy(xs.begin(), xs.end(), result._xs.begin());
+    }
+    Eigen::VectorXd ys_vec = Eigen::VectorXd(ys.size());
+    std::copy(ys.begin(), ys.end(), ys_vec.begin());
+    result._yss.push_back(ys_vec);
+  }
+
+  return result;
+}
+
+}  // namespace autoopt