/// <summary>
/// Create a text loader <see cref="TextLoader"/> by inferencing the dataset schema from a data model type.
/// </summary>
/// <param name="catalog">The <see cref="DataOperationsCatalog"/> catalog.</param>
/// <param name="hasHeader">Does the file contains header?</param>
/// <param name="separatorChar">Column separator character. Default is '\t'</param>
/// <param name="allowQuotedStrings">Whether the input may include quoted values,
/// which can contain separator characters, colons,
/// and distinguish empty values from missing values. When true, consecutive separators
/// denote a missing value and an empty value is denoted by \"\".
/// When false, consecutive separators denote an empty value.</param>
/// <param name="supportSparse">Whether the input may include sparse representations for example,
/// if one of the row contains "5 2:6 4:3" that's mean there are 5 columns all zero
/// except for 3rd and 5th columns which have values 6 and 3</param>
/// <param name="trimWhitespace">Remove trailing whitespace from lines</param>
public static TextLoader CreateTextLoader <TInput>(this DataOperationsCatalog catalog,
bool hasHeader = TextLoader.DefaultArguments.HasHeader,
char separatorChar = TextLoader.DefaultArguments.Separator,
bool allowQuotedStrings = TextLoader.DefaultArguments.AllowQuoting,
bool supportSparse = TextLoader.DefaultArguments.AllowSparse,
bool trimWhitespace = TextLoader.DefaultArguments.TrimWhitespace)
=> TextLoader.CreateTextReader <TInput>(CatalogUtils.GetEnvironment(catalog), hasHeader, separatorChar, allowQuotedStrings, supportSparse, trimWhitespace);
/// <summary>
/// Read a data view from a text file using <see cref="TextLoader"/>.
/// </summary>
/// <param name="catalog">The <see cref="DataOperationsCatalog"/> catalog.</param>
/// <param name="hasHeader">Does the file contains header?</param>
/// <param name="separatorChar">Column separator character. Default is '\t'</param>
/// <param name="allowQuotedStrings">Whether the input may include quoted values,
/// which can contain separator characters, colons,
/// and distinguish empty values from missing values. When true, consecutive separators
/// denote a missing value and an empty value is denoted by \"\".
/// When false, consecutive separators denote an empty value.</param>
/// <param name="supportSparse">Whether the input may include sparse representations for example,
/// if one of the row contains "5 2:6 4:3" that's mean there are 5 columns all zero
/// except for 3rd and 5th columns which have values 6 and 3</param>
/// <param name="trimWhitespace">Remove trailing whitespace from lines</param>
/// <param name="path">The path to the file.</param>
/// <returns>The data view.</returns>
public static IDataView ReadFromTextFile <TInput>(this DataOperationsCatalog catalog,
string path,
bool hasHeader = TextLoader.DefaultArguments.HasHeader,
char separatorChar = TextLoader.DefaultArguments.Separator,
bool allowQuotedStrings = TextLoader.DefaultArguments.AllowQuoting,
bool supportSparse = TextLoader.DefaultArguments.AllowSparse,
bool trimWhitespace = TextLoader.DefaultArguments.TrimWhitespace)
{
Contracts.CheckNonEmpty(path, nameof(path));
// REVIEW: it is almost always a mistake to have a 'trainable' text loader here.
// Therefore, we are going to disallow data sample.
return(TextLoader.CreateTextReader <TInput>(CatalogUtils.GetEnvironment(catalog), hasHeader, separatorChar, allowQuotedStrings, supportSparse, trimWhitespace)
.Read(new MultiFileSource(path)));
}