public static TextPosition ToPosition(this TextOffset offset, string data)
{
if (string.IsNullOrEmpty(data))
{
throw new ArgumentNullException(data);
}
var lines = data.Replace("\r", "").Split("\n");
var numLinesBeforeOffset = 0;
var pos = 0;
for (var i = 0; i < lines.Length; ++i)
{
if (offset < pos + lines[i].Length + 1)
{
break;
}
++numLinesBeforeOffset;
pos += lines[i].Length + 1;
}
var character = offset - pos;
return(new TextPosition(
new LineNumber(numLinesBeforeOffset + 1),
new CharacterNumber(character + 1)));
}
public string ReadTo(TextOffset end)
{
var text = _text.Substring(Position, end - Position);
Position = new TextOffset(end);
return(text);
}
public Optional <TextOffset> ScanToAny(char [] patterns)
{
var index = _text.IndexOfAny(patterns, Position);
if (index == -1)
{
return(Optional.None());
}
Position = new TextOffset(index + 1);
return(new TextOffset(index));
}
public Optional <TextOffset> ScanTo(string pattern)
{
var index = _text.IndexOf(pattern, Position, StringComparison.Ordinal);
if (index == -1)
{
return(Optional.None());
}
Position = new TextOffset(index + pattern.Length);
return(new TextOffset(index));
}
public Optional <TextOffset> PeekToAnyPattern(string[] patterns)
{
var endIndex = new TextOffset(End + 1);
var currentIndex = endIndex;
foreach (var pattern in patterns)
{
var index = PeekTo(pattern);
if (index.HasValue && index.Value < currentIndex)
{
currentIndex = index.Value;
}
}
return(currentIndex < endIndex?Optional.Some(currentIndex) : Optional.None());
}
public string GetLineContaining(TextOffset offset)
{
var lastLineStart = 0;
var currentLineStart = 0;
for (var i = 0; i < _text.Length; ++i)
{
if (_text[i] == '\n')
{
lastLineStart = currentLineStart;
currentLineStart = i;
}
if (offset <= currentLineStart && offset >= lastLineStart)
{
return(_text.Substring(lastLineStart, currentLineStart - lastLineStart));
}
}
throw new ArgumentOutOfRangeException("offset");
}
public TextScanner(string text)
{
_text = text;
Position = new TextOffset(0);
}
