A CSV parser.

Author: dkorolev

Utils/CSV/Makefile

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+../../scripts/Makefile

Utils/CSV/csv.h

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+/*******************************************************************************
+The MIT License (MIT)
+
+Copyright (c) 2016 Dmitry "Dima" Korolev <[email protected]>
+
+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.
+*******************************************************************************/
+
+#ifndef CURRENT_UTILS_CSV_CSV_H
+#define CURRENT_UTILS_CSV_CSV_H
+
+#include "../../port.h"
+
+#include <fstream>
+
+#include "../../TypeSystem/struct.h"
+#include "../../Bricks/strings/strings.h"
+#include "../../Bricks/exception.h"
+
+namespace current {
+
+struct CSVException : Exception {
+  using Exception::Exception;
+};
+
+struct CSVFileNotFoundException : CSVException {
+  using CSVException::CSVException;
+};
+
+struct CSVFileFormatException : CSVException {
+  using CSVException::CSVException;
+};
+
+CURRENT_STRUCT_T(CSV) {
+  CURRENT_FIELD(header, std::vector<std::string>);
+  CURRENT_FIELD(data, std::vector<std::vector<T>>);
+  static CSV<T> ReadFile(const std::string& filename) {
+    CSV<T> csv;
+    std::ifstream fi(filename);
+    if (!fi.good()) {
+      CURRENT_THROW(CSVFileNotFoundException("The CSV file `" + filename + "` could not be opened."));
+    }
+    std::string line;
+    if (!std::getline(fi, line)) {
+      CURRENT_THROW(CSVFileFormatException("The CSV file `" + filename + "` is empty."));
+    }
+    if (!line.empty() && line.back() == '\r') {
+      line.resize(line.size() - 1u);  // NOTE(dkorolev): This may look like a hack, but I'd rather stay safe.
+    }
+    csv.header = current::strings::Split(line, ',');
+    if (csv.header.empty()) {
+      CURRENT_THROW(CSVFileFormatException("The CSV file `" + filename + "` does not even contain the header."));
+    }
+    while (std::getline(fi, line)) {
+      if (!line.empty() && line.back() == '\r') {
+        line.resize(line.size() - 1u);  // NOTE(dkorolev): This may look like a hack, but I'd rather stay safe.
+      }
+      std::vector<T> row;
+      for (const auto& field : current::strings::Split(line, ',')) {
+        row.push_back(current::FromString<T>(field));
+      }
+      if (row.size() != csv.header.size()) {
+        CURRENT_THROW(CSVFileFormatException("Column number mismatch in CSV file `" + filename + "`."));
+      }
+      csv.data.emplace_back(std::move(row));
+    }
+    return csv;
+  }
+};
+
+}  // namespace current
+
+#endif  // CURRENT_UTILS_CSV_CSV_H

Utils/CSV/test.cc

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+/*******************************************************************************
+The MIT License (MIT)
+
+Copyright (c) 2016 Dmitry "Dima" Korolev <[email protected]>
+
+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.
+*******************************************************************************/
+
+#include "csv.h"
+
+#include "../../Bricks/file/file.h"
+#include "../../Bricks/dflags/dflags.h"
+#include "../../TypeSystem/Serialization/json.h"
+#include "../../3rdparty/gtest/gtest-main-with-dflags.h"
+
+DEFINE_string(csv_test_tmpdir, ".current", "Local path for the test to create temporary files in.");
+
+TEST(CSV, Smoke) {
+  current::FileSystem::MkDir(FLAGS_csv_test_tmpdir, current::FileSystem::MkDirParameters::Silent);
+  const std::string fn = current::FileSystem::JoinPath(FLAGS_csv_test_tmpdir, "test.csv");
+  const auto persistence_file_remover = current::FileSystem::ScopedRmFile(fn);
+
+  ASSERT_THROW(current::CSV<double>::ReadFile(fn), current::CSVFileNotFoundException);
+
+  {
+    current::FileSystem::WriteStringToFile("", fn.c_str());
+    ASSERT_THROW(current::CSV<double>::ReadFile(fn), current::CSVFileFormatException);
+    current::FileSystem::WriteStringToFile("\n", fn.c_str());
+    ASSERT_THROW(current::CSV<double>::ReadFile(fn), current::CSVFileFormatException);
+  }
+
+  {
+    current::FileSystem::WriteStringToFile("A,B,C\n1,2,3\n4,5,6\n7,8,9\n", fn.c_str());
+    const auto csv = current::CSV<double>::ReadFile(fn);
+    EXPECT_EQ("[\"A\",\"B\",\"C\"]", JSON(csv.header));
+    EXPECT_EQ(3u, csv.data.size());
+    EXPECT_EQ(3u, csv.data[0].size());
+    EXPECT_EQ(3u, csv.data[1].size());
+    EXPECT_EQ(3u, csv.data[2].size());
+    EXPECT_EQ(1, csv.data[0][0]);
+    EXPECT_EQ(2, csv.data[0][1]);
+    EXPECT_EQ(3, csv.data[0][2]);
+    EXPECT_EQ(4, csv.data[1][0]);
+    EXPECT_EQ(5, csv.data[1][1]);
+    EXPECT_EQ(6, csv.data[1][2]);
+    EXPECT_EQ(7, csv.data[2][0]);
+    EXPECT_EQ(8, csv.data[2][1]);
+    EXPECT_EQ(9, csv.data[2][2]);
+  }
+
+  {
+    current::FileSystem::WriteStringToFile("no,data,in,this,file\n", fn.c_str());
+    const auto csv = current::CSV<double>::ReadFile(fn);
+    EXPECT_EQ("[\"no\",\"data\",\"in\",\"this\",\"file\"]", JSON(csv.header));
+    EXPECT_EQ(0u, csv.data.size());
+  }
+
+  {
+    current::FileSystem::WriteStringToFile("wrong,number,of,columns\n1,2,3\n", fn.c_str());
+    ASSERT_THROW(current::CSV<double>::ReadFile(fn), current::CSVFileFormatException);
+  }
+
+  {
+    current::FileSystem::WriteStringToFile("X\r\n 1.0  \r\n  20e-1  \r\n  \t\t3\t\t \n", fn.c_str());
+    const auto csv = current::CSV<double>::ReadFile(fn);
+    EXPECT_EQ("[\"X\"]", JSON(csv.header));
+    EXPECT_EQ(3u, csv.data.size());
+    EXPECT_EQ(1u, csv.data[0].size());
+    EXPECT_EQ(1u, csv.data[1].size());
+    EXPECT_EQ(1u, csv.data[2].size());
+    EXPECT_EQ(1, csv.data[0][0]);
+    EXPECT_EQ(2, csv.data[1][0]);
+    EXPECT_EQ(3, csv.data[2][0]);
+  }
+
+  {
+    current::FileSystem::WriteStringToFile("just,a,header,with,no,newline,is,ok", fn.c_str());
+    const auto csv = current::CSV<double>::ReadFile(fn);
+    EXPECT_EQ("[\"just\",\"a\",\"header\",\"with\",\"no\",\"newline\",\"is\",\"ok\"]", JSON(csv.header));
+  }
+}