Sequence.h

// Copyright 2023, UChicago Argonne, LLC
// All Rights Reserved
// Software Name: NEML2 -- the New Engineering material Model Library, version 2
// By: Argonne National Laboratory
// OPEN SOURCE LICENSE (MIT)
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
// THE SOFTWARE.
 
#pragma once
 
#include <vector>
#include <string>
 
#include "neml2/misc/parser_utils.h"
#include "csvparser/csv.hpp"
 
namespace neml2
{
// Forward decl
template <typename T>
class Sequence;
template <typename T>
std::stringstream & operator>>(std::stringstream &, Sequence<T> &);
 
template <typename T>
class Sequence
{
public:
  Sequence() = default;
 
  Sequence<T> & operator=(const std::string & other);
 
  operator std::vector<T>() const;
 
  std::vector<T> vec() const;
 
  bool operator==(const Sequence<T> & other) const { return _raw_str == other.raw(); }
 
  const std::string & raw() const { return _raw_str; }
 
  friend std::stringstream & operator>> <>(std::stringstream & in, Sequence<T> &);
 
private:
  std::string _raw_str;
};
} // namespace neml2
 
// Implementations
 
namespace neml2
{
template <typename T>
Sequence<T> &
Sequence<T>::operator=(const std::string & other)
{
  _raw_str = other;
  return *this;
}
 
template <typename T>
Sequence<T>::operator std::vector<T>() const
{
  return vec();
}
 
template <typename T>
std::vector<T>
Sequence<T>::vec() const
{
  // If the string is empty, just return an empty vector
  if (_raw_str.empty())
    return std::vector<T>();
 
  // Parse into a vector of string, and if the vector has length greater than one, then this
  // must be a vector instead of a CSV file column.
  auto str_vec = utils::parse_vector<std::string>(_raw_str);
  if (str_vec.size() > 1)
  {
    std::vector<T> v;
    for (const auto & s : str_vec)
      v.push_back(utils::parse<T>(s));
    return v;
  }
 
  // If the string vector has exactly one element, we need to check if it conforms with our CSV
  // file column schema
 
  // Case 1: It doesn't conform the the CSV column schema, then just parse it normally
  if (str_vec[0].find(".csv:") == std::string::npos)
    return {utils::parse<T>(str_vec[0])};
 
  // Case 2: Invoke the 3rd party csv reader
  // Remove white space
  const auto str_trimmed = utils::trim(_raw_str);
 
  // Find file name and column identifier
  const auto pos = str_trimmed.find(".csv:");
  const auto filename = str_trimmed.substr(0, pos + 4);
  const auto col_id = str_trimmed.substr(pos + 5);
 
  std::vector<T> v;
  try
  {
    // Open the CSV
    csv::CSVReader reader(filename);
 
    // Get the column index
    int col;
    if (col_id.front() == '[' && col_id.back() == ']')
      col = utils::parse<int>(col_id.substr(1, col_id.length() - 2));
    else
      col = reader.index_of(col_id);
 
    // Loop through rows to fill the vector
    for (const auto & row : reader)
      v.push_back(utils::parse<T>(row[col].get<std::string>()));
  }
  catch (std::exception & e)
  {
    throw NEMLException("The following error was thrown while reading the CSV column '" + _raw_str +
                        "':\n" + e.what());
  }
 
  return v;
}
 
template <typename T>
std::ostream &
operator<<(std::ostream & os, const Sequence<T> & seq)
{
  os << seq.raw();
  return os;
}
 
template <typename T>
std::stringstream &
operator>>(std::stringstream & ss, Sequence<T> & seq)
{
  // This is special -- we have to eat the entire stream
  seq._raw_str = ss.str();
  ss.setstate(std::ios_base::eofbit);
  return ss;
}
} // namespace neml2