/// <summary>
/// Extracts a collection of field values from the supplied text record.
/// </summary>
/// <param name="line">The text record to extract field values from.</param>
/// <param name="context">The current parser context.</param>
/// <returns>A collection of string values corresponding to the fields in the file definition.</returns>
public IEnumerable<string> ReadValues(string line, ParserContext context)
{
var recordSpec = (FixedRecordSpec)context.RecordSpec;
for( int ix = 0; ix < recordSpec.FieldCount; ix++ ) {
var fieldSpec = (FixedFieldSpec)recordSpec[ix];
yield return line.Substring(fieldSpec.Start, fieldSpec.Length);
}
}
internal void Validate(ParserContext context)
{
if( ! _context.RecordSpec.IsValid(context) )
{
throw new InvalidOperationException("Invalid!");
}
}
internal void Initialize(ParserContext context)
{
_context = context;
_values.Clear();
}
/// <summary>
/// Extracts a collection of field values from the supplied text record.
/// </summary>
/// <param name="line">The text record to extract field values from.</param>
/// <param name="context">The current parser context.</param>
/// <returns>A collection of string values corresponding to the fields in the file definition.</returns>
public IEnumerable<string> ReadValues(string line, ParserContext context)
{
_parseStrategy.Reset();
var value = new StringBuilder(line);
for( int ix = 0; ix < line.Length; ix++ ) {
char current = line[ix];
char? next = ix == line.Length - 1 ? default(char?) : line[ix + 1];
if( _parseStrategy.IncludeChar(current, next) ) {
value.Append(current);
if( ! _parseStrategy.Escaped && value.EndsWith(_fieldDelimiter) ) {
value.Length -= _fieldDelimiter.Length;
yield return value.ToString();
value.Length = 0;
}
}
}
yield return value.ToString();
}
/// <summary>
/// Creates a new record.
/// </summary>
/// <param name="context">The current parser context</param>
/// <returns></returns>
public Record CreateRecord(ParserContext context)
{
_record.Initialize(context);
return _record;
}
/// <summary>
/// Creates a new record.
/// </summary>
/// <param name="context">The current parser context</param>
/// <returns></returns>
public Record CreateRecord(ParserContext context)
{
var record = new Record();
record.Initialize(context);
return record;
}
private void ParseRecord(ParserContext context)
{
int ix = 0;
foreach (var value in _recordReader.ReadValues(context.LineValue, context)) {
context.Current.Add(context.RecordSpec[ix].ConvertText(value));
ix++;
}
}
private RecordSpec FindRecordSpec(ParserContext context)
{
return _records.FirstOrDefault(rs => rs.IsMatch(context));
}
/// <summary>
/// Parse records from the supplied text reader.
/// </summary>
/// <param name="reader">The text reader to read records from.</param>
/// <returns>A collection records</returns>
public IEnumerable<Record> Parse(TextReader reader)
{
var context = new ParserContext
{
Parser = this,
FirstRecord = true
};
var currentLine = ReadLine(reader);
var nextLine = ReadLine(reader);
while( currentLine != null )
{
context.LineValue = currentLine;
context.LastRecord = nextLine == null;
context.RecordSpec = FindRecordSpec(context);
context.Current = _recordFactory.CreateRecord(context);
ParseRecord(context);
context.Current.Validate(context);
yield return context.Current;
context.FirstRecord = false;
currentLine = nextLine;
nextLine = ReadLine(reader);
}
}
