Alright, because I was bored, here's a class that extracts strings from a file on whitespace boundaries, in a similar way that C++ iostreams do.
class WordReader : IDisposable
{
private StreamReader _reader;
private char[] _buffer = new char[1024];
private int _bufferPos;
private int _bufferSize;
public WordReader(string file)
{
_reader = File.OpenText(file);
}
public string ReadWord()
{
// Possible optimization: reuse the StringBuilder
StringBuilder result = new StringBuilder(80);
// Skip whitespace
while( (_bufferPos < _bufferSize || FillBuffer()) && char.IsWhiteSpace(_buffer[_bufferPos]) )
{
++_bufferPos;
}
// Read word
while( (_bufferPos < _bufferSize || FillBuffer()) && !char.IsWhiteSpace(_buffer[_bufferPos]) )
{
result.Append(_buffer[_bufferPos]);
++_bufferPos;
}
if( result.Length == 0 )
return null;
else
return result.ToString();
}
public IEnumerable<string> ReadWords()
{
string value;
while( (value = ReadWord()) != null )
yield return value;
}
public void Dispose()
{
Dispose(true);
GC.SuppressFinalize(this);
}
protected virtual void Dispose(bool disposing)
{
if( disposing )
_reader.Dispose();
}
private bool FillBuffer()
{
_bufferSize = _reader.Read(_buffer, 0, _buffer.Length);
_bufferPos = 0;
return _bufferSize > 0;
}
}
Which can then be used like this:
int[] values;
using( WordReader reader = new WordReader(fileName) )
{
values = reader.ReadWords().Select(word => Convert.ToInt32(word)).ToArray();
}
