public static TextParser <object> NonGreedyContent(params PatternElement[] following)
{
if (following.Length == 0)
{
return(SpanEx.MatchedBy(Character.AnyChar.Many())
.Select(span => span.Length > 0 ? (object)span : null));
}
var rest = following[0].Match;
for (var i = 1; i < following.Length; ++i)
{
rest = rest.IgnoreThen(following[i].Match);
}
return(i =>
{
var remainder = i;
var attempt = rest(remainder);
while (!attempt.HasValue || attempt.Remainder == remainder) // A zero-length match doesn't tell us anything
{
remainder = remainder.ConsumeChar().Remainder;
attempt = rest(remainder);
}
var span = i.Until(remainder);
return Result.Value(span.Length > 0 ? (object)span : null, i, remainder);
});
}
public async Task SplitsLinesIntoFrames()
{
var source = new StringBuilder();
source.AppendLine("first");
source.AppendLine("second");
var reader = new FrameReader(
new StringReader(source.ToString()),
SpanEx.MatchedBy(Character.Letter),
TimeSpan.FromMilliseconds(100));
var first = await reader.TryReadAsync();
Assert.True(first.HasValue);
Assert.Equal("first" + Environment.NewLine, first.Value);
var second = await reader.TryReadAsync();
Assert.True(second.HasValue);
Assert.Equal("second" + Environment.NewLine, second.Value);
var empty = await reader.TryReadAsync();
Assert.False(empty.HasValue);
}
public PlainTextLogEventReader(TextReader input, string extractionPattern)
{
if (extractionPattern == null)
{
throw new ArgumentNullException(nameof(extractionPattern));
}
_nameValueExtractor = ExtractionPatternInterpreter.CreateNameValueExtractor(ExtractionPatternParser.Parse(extractionPattern));
_reader = new FrameReader(input, SpanEx.MatchedBy(_nameValueExtractor.StartMarker), TrailingLineArrivalDeadline);
}
public async Task TerminatesWhenNoLinesArePresent()
{
var reader = new FrameReader(
new StringReader(""),
SpanEx.MatchedBy(Character.Letter),
TimeSpan.FromMilliseconds(100));
var none = await reader.TryReadAsync();
Assert.False(none.HasValue);
}
public async Task CollectsTrailingLines()
{
var source = new StringBuilder();
source.AppendLine("first");
source.AppendLine(" some more");
source.AppendLine(" and more");
source.AppendLine("second");
source.AppendLine("third");
source.AppendLine(" and yet more");
var frames = await ReadAllFrames(source.ToString(), SpanEx.MatchedBy(Character.Letter));
Assert.Equal(3, frames.Length);
Assert.StartsWith("first", frames[0].Value);
Assert.EndsWith("and more" + Environment.NewLine, frames[0].Value);
}
