static async IAsyncEnumerable <ICsvLine> Impl(Stream stream, CsvOptions?options)
{
using var reader = new StreamReader(stream);
await foreach (var line in ReadImplAsync(reader, options))
{
yield return(line);
}
}
/// <summary>
/// Reads the lines from the csv string.
/// </summary>
/// <param name="csv">The csv string to read the data from.</param>
/// <param name="options">The optional options to use when reading.</param>
public static IEnumerable <ICsvLine> ReadFromText(string csv, CsvOptions?options = null)
{
if (csv == null)
{
throw new ArgumentNullException(nameof(csv));
}
return(ReadFromTextImpl(csv, options));
}
/// <summary>
/// Reads the lines from the stream.
/// </summary>
/// <param name="stream">The stream to read the data from.</param>
/// <param name="options">The optional options to use when reading.</param>
public static IEnumerable <ICsvLine> ReadFromStream(Stream stream, CsvOptions?options = null)
{
if (stream == null)
{
throw new ArgumentNullException(nameof(stream));
}
return(ReadFromStreamImpl(stream, options));
}
/// <summary>
/// Reads the lines from the reader.
/// </summary>
/// <param name="reader">The text reader to read the data from.</param>
/// <param name="options">The optional options to use when reading.</param>
public static IEnumerable <ICsvLine> Read(TextReader reader, CsvOptions?options = null)
{
if (reader == null)
{
throw new ArgumentNullException(nameof(reader));
}
return(ReadImpl(reader, options));
}
private static IEnumerable <ICsvLine> ReadFromTextImpl(string csv, CsvOptions?options)
{
using (var reader = new StringReader(csv))
{
foreach (var line in ReadImpl(reader, options))
{
yield return(line);
}
}
}
private static IEnumerable <ICsvLine> ReadFromStreamImpl(Stream stream, CsvOptions?options)
{
using (var reader = new StreamReader(stream))
{
foreach (var line in ReadImpl(reader, options))
{
yield return(line);
}
}
}
/// <summary>
/// Reads the lines from the csv string.
/// </summary>
/// <param name="csv">The csv string to read the data from.</param>
/// <param name="options">The optional options to use when reading.</param>
public static IEnumerable <ICsvLineFromMemory> ReadFromMemory(MemoryText csv, CsvOptions?options = null)
{
// NOTE: Logic is copied in ReadImpl/ReadImplAsync/ReadFromMemory
options ??= new CsvOptions();
MemoryText line;
var index = 0;
var position = 0;
MemoryText[]? headers = null;
Dictionary <string, int>?headerLookup = null;
while (!(line = csv.ReadLine(ref position)).IsEmpty)
{
index++;
if (index <= options.RowsToSkip || options.SkipRow?.Invoke(line, index) == true)
{
continue;
}
if (headers == null || headerLookup == null)
{
InitializeOptions(line.Span, options);
var skipInitialLine = options.HeaderMode == HeaderMode.HeaderPresent;
headers = skipInitialLine ? GetHeaders(line, options) : CreateDefaultHeaders(line, options);
try
{
headerLookup = headers
.Select((h, idx) => (h, idx))
.ToDictionary(h => h.Item1.AsString(), h => h.Item2, options.Comparer);
}
catch (ArgumentException)
{
throw new InvalidOperationException("Duplicate headers detected in HeaderPresent mode. If you don't have a header you can set the HeaderMode to HeaderAbsent.");
}
var aliases = options.Aliases;
if (aliases != null)
{
// NOTE: For each group we need at most 1 match (i.e. SingleOrDefault)
foreach (var aliasGroup in aliases)
{
var groupIndex = -1;
foreach (var alias in aliasGroup)
{
if (headerLookup.TryGetValue(alias, out var aliasIndex))
{
if (groupIndex != -1)
{
throw new InvalidOperationException("Found multiple matches within alias group: " + string.Join(";", aliasGroup));
}
groupIndex = aliasIndex;
}
}
if (groupIndex != -1)
{
foreach (var alias in aliasGroup)
{
headerLookup[alias] = groupIndex;
}
}
}
}
if (skipInitialLine)
{
continue;
}
}
var record = new ReadLineFromMemory(headers, headerLookup, index, line, options);
if (options.AllowNewLineInEnclosedFieldValues)
{
while (record.RawSplitLine.Any(f => CsvLineSplitter.IsUnterminatedQuotedValue(f.AsSpan(), options)))
{
var nextLine = csv.ReadLine(ref position);
if (nextLine.IsEmpty)
{
break;
}
line = StringHelpers.Concat(line, options.NewLine, nextLine);
record = new ReadLineFromMemory(headers, headerLookup, index, line, options);
}
}
yield return(record);
}
}
/// <summary>
/// Reads the lines from the stream.
/// </summary>
/// <param name="stream">The stream to read the data from.</param>
/// <param name="options">The optional options to use when reading.</param>
public static IAsyncEnumerable <ICsvLine> ReadFromStreamAsync(Stream stream, CsvOptions?options = null)
{
if (stream == null)
{
throw new ArgumentNullException(nameof(stream));
}