C++ SourcePtr::begin方法代码示例

// [[Rcpp::export]]
CharacterVector read_file_(List sourceSpec) {
  SourcePtr source = Source::create(sourceSpec);

  CharacterVector out(1);
  out[0] = Rf_mkCharLen(source->begin(), source->end() - source->begin());
  return out;
}

// [[Rcpp::export]]
RObject tokenize_(List sourceSpec, List tokenizerSpec, int n_max) {
  Warnings warnings;

  SourcePtr source = Source::create(sourceSpec);
  TokenizerPtr tokenizer = Tokenizer::create(tokenizerSpec);
  tokenizer->tokenize(source->begin(), source->end());
  tokenizer->setWarnings(&warnings);

  std::vector<std::vector<std::string> > rows;

  for (Token t = tokenizer->nextToken(); t.type() != TOKEN_EOF; t = tokenizer->nextToken()) {
    if (n_max > 0 && t.row() >= (size_t) n_max)
      break;

    if (t.row() >= rows.size()) {
      rows.resize(t.row() + 1);
    }

    std::vector<std::string>& row = rows[t.row()];
    if (t.col() >= row.size())
      row.resize(t.col() + 1);

    row[t.col()] = t.asString();
  }

  RObject out = wrap(rows);
  return warnings.addAsAttribute(out);
}

// [[Rcpp::export]]
RObject guess_header_(List sourceSpec, List tokenizerSpec, List locale_) {
  Warnings warnings;
  LocaleInfo locale(locale_);
  SourcePtr source = Source::create(sourceSpec);
  TokenizerPtr tokenizer = Tokenizer::create(tokenizerSpec);
  tokenizer->tokenize(source->begin(), source->end());
  tokenizer->setWarnings(&warnings);

  CollectorCharacter out(&locale.encoder_);
  out.setWarnings(&warnings);

  for (Token t = tokenizer->nextToken(); t.type() != TOKEN_EOF; t = tokenizer->nextToken()) {
    if (t.row() > (size_t) 0) // only read one row
      break;

    if (t.col() >= (size_t) out.size()) {
      out.resize(t.col() + 1);
    }

    if (t.type() == TOKEN_STRING) {
      out.setValue(t.col(), t);
    }
  }

  return out.vector();
}

// [[Rcpp::export]]
std::vector<std::vector<std::string> > tokenize_(List sourceSpec, List tokenizerSpec, int n) {
  SourcePtr source = Source::create(sourceSpec);
  TokenizerPtr tokenizer = Tokenizer::create(tokenizerSpec);
  tokenizer->tokenize(source->begin(), source->end());

  std::vector<std::vector<std::string> > rows;

  int i = 0;
  for (Token t = tokenizer->nextToken(); t.type() != TOKEN_EOF; t = tokenizer->nextToken()) {
    if (n > 0 && i > n)
      break;

    if (t.row() >= rows.size()) {
      rows.resize(t.row() + 1);
    }

    std::vector<std::string>& row = rows[t.row()];
    if (t.col() >= row.size())
      row.resize(t.col() + 1);
    row[t.col()] = t.asString();

    ++i;
  }

  return rows;
}

// [[Rcpp::export]]
CharacterVector read_lines_(List sourceSpec, int n_max = -1) {
  SourcePtr source = Source::create(sourceSpec);
  TokenizerLine tokenizer;
  tokenizer.tokenize(source->begin(), source->end());

  int n = (n_max < 0) ? 1000 : n_max;
  CharacterVector out(n);

  int i = 0;
  for (Token t = tokenizer.nextToken(); t.type() != TOKEN_EOF; t = tokenizer.nextToken()) {
    if (i >= n) {
      if (n_max < 0) {
        n = (n * 3)/2 + 1;
        out = Rf_lengthgets(out, n);
      } else {
        break;
      }
    }

    if (t.type() == TOKEN_STRING)
      out[i] = t.asString();

    ++i;
  }

  if (i < n) {
    out = Rf_lengthgets(out, i);
  }

  return out;
}

// [[Rcpp::export]]
std::vector<std::string> collectorsGuess(List sourceSpec, List tokenizerSpec, int n = 100) {
  Warnings warnings;
  SourcePtr source = Source::create(sourceSpec);
  TokenizerPtr tokenizer = Tokenizer::create(tokenizerSpec);
  tokenizer->tokenize(source->begin(), source->end());
  tokenizer->setWarnings(&warnings); // silence warnings

  std::vector<CollectorCharacter> collectors;
  for (Token t = tokenizer->nextToken(); t.type() != TOKEN_EOF; t = tokenizer->nextToken()) {
    if (t.row() >= (size_t) n)
      break;

    // Add new collectors, if needed
    if (t.col() >= collectors.size()) {
      int old_p = collectors.size();
      collectors.resize(t.col() + 1);
      for (size_t j = old_p; j < collectors.size(); ++j) {
        collectors[j].resize(n);
      }
    }

    collectors[t.col()].setValue(t.row(), t);
  }

  std::vector<std::string> out;
  for (size_t j = 0; j < collectors.size(); ++j) {
    CharacterVector col = as<CharacterVector>(collectors[j].vector());
    out.push_back(collectorGuess(col));
  }

  return out;
}

// [[Rcpp::export]]
CharacterVector read_file_(List sourceSpec, List locale_) {
  SourcePtr source = Source::create(sourceSpec);
  LocaleInfo locale(locale_);

  return CharacterVector::create(
    locale.encoder_.makeSEXP(source->begin(), source->end())
  );
}

// [[Rcpp::export]]
IntegerVector dim_tokens_(List sourceSpec, List tokenizerSpec) {
  SourcePtr source = Source::create(sourceSpec);
  TokenizerPtr tokenizer = Tokenizer::create(tokenizerSpec);
  tokenizer->tokenize(source->begin(), source->end());

  size_t rows = -1, cols = -1;

  for (Token t = tokenizer->nextToken(); t.type() != TOKEN_EOF; t = tokenizer->nextToken()) {
    rows = t.row();
    if (t.col() > cols)
      cols = t.col();
  }

  return IntegerVector::create(rows + 1, cols + 1);
}

// [[Rcpp::export]]
CharacterVector read_lines_(List sourceSpec, List locale_, int n_max = -1,
                            bool progress = true) {

  SourcePtr source = Source::create(sourceSpec);
  TokenizerLine tokenizer;
  tokenizer.tokenize(source->begin(), source->end());
  LocaleInfo locale(locale_);
  Progress progressBar;

  int n = (n_max < 0) ? 10000 : n_max;
  CharacterVector out(n);

  int i = 0;
  for (Token t = tokenizer.nextToken(); t.type() != TOKEN_EOF; t = tokenizer.nextToken()) {
    if (progress && (i + 1) % 25000 == 0)
      progressBar.show(tokenizer.progress());

    if (i >= n) {
      if (n_max < 0) {
        // Estimate rows in full dataset
        n = (i / tokenizer.progress().first) * 1.2;
        out = Rf_lengthgets(out, n);
      } else {
        break;
      }
    }

    if (t.type() == TOKEN_STRING)
      out[i] = t.asSEXP(&locale.encoder_);

    ++i;
  }

  if (i < n) {
    out = Rf_lengthgets(out, i);
  }

  if (progress)
    progressBar.show(tokenizer.progress());
  progressBar.stop();

  return out;
}

// [[Rcpp::export]]
SEXP parse_(List sourceSpec, List tokenizerSpec, List collectorSpec) {
  SourcePtr source = Source::create(sourceSpec);
  TokenizerPtr tokenizer = Tokenizer::create(tokenizerSpec);
  tokenizer->tokenize(source->begin(), source->end());

  boost::shared_ptr<Collector> out = Collector::create(collectorSpec);
  out->resize(100);

  int i = 0;
  for (Token t = tokenizer->nextToken(); t.type() != TOKEN_EOF; t = tokenizer->nextToken()) {
    if (i >= out->size())
      out->resize(i * 2);

    out->setValue(i, t);
    ++i;
  }

  if (i != out->size()) {
    out->resize(i);
  }

  return out->vector();
}

// [[Rcpp::export]]
std::vector<std::string> guess_types_(List sourceSpec, List tokenizerSpec,
                                      Rcpp::List locale_, int n = 100) {
  Warnings warnings;
  SourcePtr source = Source::create(sourceSpec);
  TokenizerPtr tokenizer = Tokenizer::create(tokenizerSpec);
  tokenizer->tokenize(source->begin(), source->end());
  tokenizer->setWarnings(&warnings); // silence warnings

  LocaleInfo locale(locale_);

  std::vector<CollectorPtr> collectors;
  for (Token t = tokenizer->nextToken(); t.type() != TOKEN_EOF; t = tokenizer->nextToken()) {
    if (t.row() >= (size_t) n)
      break;

    // Add new collectors, if needed
    if (t.col() >= collectors.size()) {
      int p = collectors.size() - t.col() + 1;
      for (int j = 0; j < p; ++j) {
        CollectorPtr col = CollectorPtr(new CollectorCharacter(&locale.encoder_));
        col->setWarnings(&warnings);
        col->resize(n);
        collectors.push_back(col);
      }
    }

    collectors[t.col()]->setValue(t.row(), t);
  }

  std::vector<std::string> out;
  for (size_t j = 0; j < collectors.size(); ++j) {
    CharacterVector col = as<CharacterVector>(collectors[j]->vector());
    out.push_back(collectorGuess(col, locale_));
  }

  return out;
}

// [[Rcpp::export]]
RObject read_tokens(List sourceSpec, List tokenizerSpec, ListOf<List> colSpecs,
                    CharacterVector colNames, List locale_, int n_max = -1,
                    bool progress = true) {

  Warnings warnings;
  LocaleInfo locale(locale_);

  SourcePtr source = Source::create(sourceSpec);

  TokenizerPtr tokenizer = Tokenizer::create(tokenizerSpec);
  tokenizer->tokenize(source->begin(), source->end());
  tokenizer->setWarnings(&warnings);

  std::vector<CollectorPtr> collectors = collectorsCreate(colSpecs, &locale, &warnings);

  Progress progressBar;

  // Work out how many output columns we have
  size_t p = collectors.size();
  size_t pOut = 0;
  for (size_t j = 0; j < p; ++j) {
    if (collectors[j]->skip())
      continue;
    pOut++;
  }

  // Match colNames to with non-skipped collectors
  if (p != (size_t) colNames.size())
    stop("colSpec and colNames must be same size");

  CharacterVector outNames(pOut);
  int cj = 0;
  for (size_t j = 0; j < p; ++j) {
    if (collectors[j]->skip())
      continue;

    outNames[cj] = colNames[j];
    cj++;
  }

  size_t n = (n_max < 0) ? 1000 : n_max;
  collectorsResize(collectors, n);

  int i = -1, j = -1, cells = 0;
  for (Token t = tokenizer->nextToken(); t.type() != TOKEN_EOF; t = tokenizer->nextToken()) {
    if (progress && (cells++) % 250000 == 0)
      progressBar.show(tokenizer->progress());

    if (t.col() == 0 && i != -1)
      checkColumns(&warnings, i, j, p);

    if (t.row() >= n) {
      if (n_max >= 0)
        break;

      // Estimate rows in full dataset
      n = (i / tokenizer->progress().first) * 1.2;
      collectorsResize(collectors, n);
    }

    if (t.col() < p)
      collectors[t.col()]->setValue(t.row(), t);

    i = t.row();
    j = t.col();
  }
  if (i != -1)
    checkColumns(&warnings, i, j, p);

  if (progress)
    progressBar.show(tokenizer->progress());
  progressBar.stop();

  if (i != (int) n - 1) {
    collectorsResize(collectors, i + 1);
  }

  // Save individual columns into a data frame
  List out(pOut);
  j = 0;
  for(CollectorItr cur = collectors.begin(); cur != collectors.end(); ++cur) {
    if ((*cur)->skip())
      continue;

    out[j] = (*cur)->vector();
    j++;
  }

  out.attr("class") = CharacterVector::create("tbl_df", "tbl", "data.frame");
  out.attr("row.names") = IntegerVector::create(NA_INTEGER, -(i + 1));
  out.attr("names") = outNames;

  return warnings.addAsAttribute(out);
}

// [[Rcpp::export]]
RObject read_tokens(List sourceSpec, List tokenizerSpec, ListOf<List> colSpecs,
                    CharacterVector col_names, int n_max = -1,
                    bool progress = true) {
  Warnings warnings;

  SourcePtr source = Source::create(sourceSpec);

  TokenizerPtr tokenizer = Tokenizer::create(tokenizerSpec);
  tokenizer->tokenize(source->begin(), source->end());
  tokenizer->setWarnings(&warnings);

  std::vector<CollectorPtr> collectors = collectorsCreate(colSpecs, &warnings);

  Progress progressBar;

  size_t p = collectors.size();
  // Work out how many output columns we have
  size_t pOut = 0;
  for(CollectorItr cur = collectors.begin(); cur != collectors.end(); ++cur) {
    if (!(*cur)->skip())
      pOut++;
  }

  // Allow either one name for column, or one name per output col
  if (p != pOut && (size_t) col_names.size() == p) {
    CharacterVector col_names2(pOut);
    int cj = 0;
    for (size_t j = 0; j < p; ++j) {
      if (collectors[j]->skip())
        continue;
      col_names2[cj++] = col_names[j];
    }
    col_names = col_names2;
  }

  if (pOut != (size_t) col_names.size()) {
    Rcpp::stop("You have %i column names, but %i columns",
      col_names.size(), pOut);
  }

  size_t n = (n_max < 0) ? 1000 : n_max;
  collectorsResize(collectors, n);

  size_t i = 0, cells = 0;
  for (Token t = tokenizer->nextToken(); t.type() != TOKEN_EOF; t = tokenizer->nextToken()) {
    if (progress && (cells++) % 250000 == 0)
      progressBar.show(tokenizer->progress());

    if (t.col() >= p) {
      warnings.addWarning(t.row(), t.col(), tfm::format("Only %i columns", p), "");
      continue;
    }

    if (t.row() >= n) {
      if (n_max >= 0)
        break;

      // Estimate rows in full dataset
      n = (i / tokenizer->progress().first) * 1.2;
      collectorsResize(collectors, n);
    }

    collectors[t.col()]->setValue(t.row(), t);
    i = t.row();
  }
  progressBar.show(tokenizer->progress());
  progressBar.stop();

  if (i <= n) {
    collectorsResize(collectors, i + 1);
  }


  // Save individual columns into a data frame
  List out(pOut);
  int j = 0;
  for(CollectorItr cur = collectors.begin(); cur != collectors.end(); ++cur) {
    if ((*cur)->skip())
      continue;

    out[j] = (*cur)->vector();
    j++;
  }

  out.attr("class") = CharacterVector::create("tbl_df", "tbl", "data.frame");
  out.attr("row.names") = IntegerVector::create(NA_INTEGER, -(i + 1));
  out.attr("names") = col_names;

  return warnings.addAsAttribute(out);
}