internal static RE.CharFAMatch Match(RE.ParseContext context)
{
context.EnsureStarted();
int line = context.Line;
int column = context.Column;
long position = context.Position;
int l = context.CaptureBuffer.Length;
bool success = false;
for ( //
; ((false == success) &&
(-1 != context.Current)); //
)
{
// q0
if ((((context.Current >= 'A') &&
(context.Current <= 'Z')) ||
((context.Current >= 'a') &&
(context.Current <= 'z'))))
{
context.CaptureCurrent();
context.Advance();
goto q1;
}
goto error;
q1:
if ((((context.Current >= 'A') &&
(context.Current <= 'Z')) ||
((context.Current >= 'a') &&
(context.Current <= 'z'))))
{
context.CaptureCurrent();
context.Advance();
goto q1;
}
success = true;
goto done;
error:
success = false;
context.Advance();
done:
if ((false == success))
{
line = context.Line;
column = context.Column;
position = context.Position;
l = context.CaptureBuffer.Length;
}
}
if (success)
{
return(new RE.CharFAMatch(line, column, position, context.GetCapture(l)));
}
return(null);
}
/// <summary>
/// Lexes the next input from the parse context.
/// </summary>
/// <param name="context">The <see cref="ParseContext"/> to use.</param>
/// <param name="errorSymbol">The symbol to report in the case of an error</param>
/// <returns>The next symbol matched - <paramref name="context"/> contains the capture and line information</returns>
public TAccept Lex(ParseContext context, TAccept errorSymbol = default(TAccept))
{
TAccept acc;
// get the initial states
var states = FillEpsilonClosure();
// prepare the parse context
context.EnsureStarted();
while (true)
{
// if no more input
if (-1 == context.Current)
{
// if we accept, return that
if (TryGetAnyAcceptSymbol(states, out acc))
{
return(acc);
}
// otherwise return error
return(errorSymbol);
}
// 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 (TryGetAnyAcceptSymbol(states, out acc))
{
return(acc);
}
// otherwise error
// store the current character
context.CaptureCurrent();
// advance the input
context.Advance();
return(errorSymbol);
}
// store the current character
context.CaptureCurrent();
// advance the input
context.Advance();
// iterate to our next states
states = newStates;
}
}
/// <summary>
/// Lexes the next input from the parse context.
/// </summary>
/// <param name="dfaTable">The DFA state table to use</param>
/// <param name="context">The <see cref="ParseContext"/> to use.</param>
/// <param name="errorSymbol">The symbol id to report in the case of an error</param>
/// <returns>The next symbol id matched - <paramref name="context"/> contains the capture and line information</returns>
public static int LexDfa(CharDfaEntry[] dfaTable, ParseContext context, int errorSymbol = -1)
{
// track our current state
var state = 0;
// prepare the parse context
context.EnsureStarted();
while (true)
{
// if no more input
if (-1 == context.Current)
{
var sid = dfaTable[state].AcceptSymbolId;
// if we accept, return that
if (-1 != sid)
{
return(sid);
}
// otherwise return error
return(errorSymbol);
}
// 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(dfaTable[state].AcceptSymbolId);
}
// otherwise error
// store the current character
context.CaptureCurrent();
// advance the input
context.Advance();
return(errorSymbol);
}
// store the current character
context.CaptureCurrent();
// advance the input
context.Advance();
// iterate to our next states
state = newState;
}
}
/// <summary>
/// Lexes the next input from the parse context.
/// </summary>
/// <param name="context">The <see cref="ParseContext"/> to use.</param>
/// <param name="errorSymbol">The symbol to report in the case of an error</param>
/// <returns>The next symbol matched - <paramref name="context"/> contains the capture and line information</returns>
/// <remarks>This method will not work properly on an NFA but will not error in that case, so take care to only use this with a DFA</remarks>
public TAccept LexDfa(ParseContext context, TAccept errorSymbol = default(TAccept))
{
// track our current state
var state = this;
// prepare the parse context
context.EnsureStarted();
while (true)
{
// if no more input
if (-1 == context.Current)
{
// if we accept, return that
if (state.IsAccepting)
{
return(state.AcceptSymbol);
}
// otherwise return error
return(errorSymbol);
}
// 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(state.AcceptSymbol);
}
// otherwise error
// store the current character
context.CaptureCurrent();
// advance the input
context.Advance();
return(errorSymbol);
}
// store the current character
context.CaptureCurrent();
// advance the input
context.Advance();
// iterate to our next states
state = newState;
}
}
internal static int Lex(RE.ParseContext context)
{
context.EnsureStarted();
// q0
if (((context.Current >= '0') &&
(context.Current <= '9')))
{
context.CaptureCurrent();
context.Advance();
goto q1;
}
if ((((context.Current >= 'A') &&
(context.Current <= 'Z')) ||
((context.Current >= 'a') &&
(context.Current <= 'z'))))
{
context.CaptureCurrent();
context.Advance();
goto q2;
}
if (((((context.Current == '\t') ||
((context.Current >= '\n') &&
(context.Current <= ' '))) ||
(context.Current == '\r')) ||
(context.Current == ' ')))
{
context.CaptureCurrent();
context.Advance();
goto q3;
}
goto error;
q1:
if (((context.Current >= '0') &&
(context.Current <= '9')))
{
context.CaptureCurrent();
context.Advance();
goto q1;
}
return(0);
q2:
if ((((context.Current >= 'A') &&
(context.Current <= 'Z')) ||
((context.Current >= 'a') &&
(context.Current <= 'z'))))
{
context.CaptureCurrent();
context.Advance();
goto q2;
}
return(1);
q3:
if (((((context.Current == '\t') ||
((context.Current >= '\n') &&
(context.Current <= ' '))) ||
(context.Current == '\r')) ||
(context.Current == ' ')))
{
context.CaptureCurrent();
context.Advance();
goto q3;
}
return(2);
error:
context.CaptureCurrent();
context.Advance();
return(3);
}
