static string _ParseIdentifier(ParseContext pc)
{
pc.TrySkipCCommentsAndWhiteSpace();
if (-1 == pc.Current)
{
pc.Expecting();
return(null);
}
var l = pc.CaptureBuffer.Length;
if ('_' != pc.Current && !char.IsLetter((char)pc.Current))
{
pc.Expecting("ABCDEFGHIJKLMNOPQRSTUVWXYZ_abcdefghijklmnopqrstuvwxyz".ToCharArray().Convert <int>().ToArray());
}
pc.CaptureCurrent();
while (-1 != pc.Advance() && ('_' == pc.Current || '-' == pc.Current || char.IsLetterOrDigit((char)pc.Current)))
{
pc.CaptureCurrent();
}
pc.TrySkipCCommentsAndWhiteSpace();
return(pc.GetCapture(l));
}
static bool _DoMatchDfa(CharDfaEntry[] dfaTable, ParseContext context)
{
// track our current state
var state = 0;
// prepare the parse context
context.EnsureStarted();
while (true)
{
// if no more input
if (-1 == context.Current)
{
// if we accept, return that
return(-1 != dfaTable[state].AcceptSymbolId);
}
// move by current character
var newState = MoveDfa(dfaTable, state, (char)context.Current);
// we couldn't match anything
if (-1 == newState)
{
// if we accept, return that
if (-1 != dfaTable[state].AcceptSymbolId)
{
return(true);
}
// otherwise error
// advance the input
context.Advance();
return(false);
}
// store the current character
context.CaptureCurrent();
// advance the input
context.Advance();
// iterate to our next states
state = newState;
}
}
bool _DoMatchDfa(ParseContext context)
{
// track the current state
var state = this;
while (true)
{
// if no more input
if (-1 == context.Current)
{
// if we accept, return that
return(state.IsAccepting);
}
// move by current character
var newState = state.MoveDfa((char)context.Current);
// we couldn't match anything
if (null == newState)
{
// if we accept, return that
if (state.IsAccepting)
{
return(true);
}
// otherwise error
// advance the input
context.Advance();
return(false);
}
// store the current character
context.CaptureCurrent();
// advance the input
context.Advance();
// iterate to our next state
state = newState;
}
}
// almost the same as our lex methods
bool _DoMatch(ParseContext context)
{
// get the initial states
var states = FillEpsilonClosure();
while (true)
{
// if no more input
if (-1 == context.Current)
{
// if we accept, return that
return(IsAnyAccepting(states));
}
// move by current character
var newStates = FillMove(states, (char)context.Current);
// we couldn't match anything
if (0 == newStates.Count)
{
// if we accept, return that
if (IsAnyAccepting(states))
{
return(true);
}
// otherwise error
// advance the input
context.Advance();
return(false);
}
// store the current character
context.CaptureCurrent();
// advance the input
context.Advance();
// iterate to our next states
states = newStates;
}
}
