public void Push(char c)
{
try {
//track line, column
if (c == '\n')
{
location.Line++;
location.Column = 1;
}
else
{
location.Column++;
}
position++;
for (int loopLimit = 0; loopLimit < 10; loopLimit++)
{
currentStateLength++;
string rollback = null;
State nextState = currentState.PushChar(c, this, ref rollback);
// no state change
if (nextState == currentState || nextState == null)
{
return;
}
// state changed; reset stuff
previousState = currentState;
currentState = nextState;
stateTag = 0;
currentStateLength = 0;
if (keywordBuilder.Length < 50)
{
keywordBuilder.Length = 0;
}
else
{
keywordBuilder = new StringBuilder();
}
// only loop if the same char should be run through the new state
if (rollback == null)
{
return;
}
//"complex" rollbacks require actually skipping backwards.
//Note the previous state is invalid for this operation.
else if (rollback.Length > 0)
{
position -= (rollback.Length + 1);
foreach (char rollChar in rollback)
{
Push(rollChar);
}
position++;
}
}
throw new InvalidOperationException("Too many state changes for char '" + c + "'. Current state is " + currentState.ToString() + ".");
} catch (Exception ex) {
//attach parser state to exceptions
throw new Exception(ToString(), ex);
}
}
public void Push(char c)
{
try {
//FIXME: position/location should be at current char, not after it
position++;
if (c == '\n')
{
previousLineEnd = new TextLocation(location.Line, location.Column + 1);
location = new TextLocation(location.Line + 1, 1);
}
else
{
location = new TextLocation(location.Line, location.Column + 1);
}
for (int loopLimit = 0; loopLimit < 10; loopLimit++)
{
currentStateLength++;
string rollback = null;
if (currentState == null)
{
return;
}
State nextState = currentState.PushChar(c, this, ref rollback);
// no state change
if (nextState == currentState || nextState == null)
{
return;
}
// state changed; reset stuff
previousState = currentState;
currentState = nextState;
stateTag = 0;
currentStateLength = 0;
if (keywordBuilder.Length < 50)
{
keywordBuilder.Length = 0;
}
else
{
keywordBuilder = new StringBuilder();
}
// only loop if the same char should be run through the new state
if (rollback == null)
{
return;
}
//simple rollback, just run same char through again
if (rollback.Length == 0)
{
continue;
}
//"complex" rollbacks require actually skipping backwards.
//Note the previous state is invalid for this operation.
//rollback position and location so they're valid
position -= (rollback.Length + 1);
location = new TextLocation(location.Line, location.Column - (rollback.Length + 1));
if (location.Column < 0)
{
throw new InvalidOperationException("Can't roll back across line boundary");
}
foreach (char rollChar in rollback)
{
Push(rollChar);
}
//restore position and location
position++;
location = new TextLocation(location.Line, location.Column + 1);
}
throw new InvalidOperationException("Too many state changes for char '" + c + "'. Current state is " + currentState.ToString() + ".");
} catch (Exception ex) {
//attach parser state to exceptions
throw new Exception(ToString(), ex);
}
}