/// <summary>
/// Parse using a state machine, does not use the call stack.
/// </summary>
public SearchResult Search(Parser <TInput> parser, int start, bool initialPrevWasMissing)
{
this.prevWasMissing = initialPrevWasMissing;
Push(parser, start, initialPrevWasMissing);
Parser <TInput> nextParser = null;
while (true)
{
if (this.state.Parser.IsHidden)
{
this.state.InputLength = SafeScanner.ScanSafe(this.state.Parser, source, this.state.InputStart);
nextParser = null;
}
else
{
if (this.state.State == 0)
{
beforeAction(this.state.Parser, source, this.state.InputStart, this.prevWasMissing);
}
nextParser = this.state.Parser.Accept(this);
}
if (nextParser != null)
{
Push(nextParser, inputStart: this.state.InputStart + this.state.InputLength, prevWasMissing: this.prevWasMissing);
}
else
{
var length = this.state.InputLength;
this.afterAction?.Invoke(this.state.Parser);
if (this.stackPosition == 0)
{
return(new SearchResult(length, this.prevWasMissing));
}
else
{
Pop();
this.state.LastResult = length;
}
}
}
}
private static int Scan(Parser <TInput> parser, Source <TInput> source, int start)
{
return(SafeScanner.ScanSafe(parser, source, start));
}