public void Parse()
{
(SourceCode.NotEmpty()).OrThrows("Null Source Code");
// avoid re-parse
if (state_ == State.Finished)
{
return;
}
while (currentIdx_ < SourceCode.Length)
{
var ch = SourceCode[currentIdx_];
switch (state_)
{
case State.Start:
parseStart(ch);
break; // start
case State.InComment:
if (ch == '\n')
{
resetState();
lineCount_++;
currentLineIdx_ = currentIdx_ + 1;
}
break;
case State.InNote:
if (ch == '\n')
{
currentIdx_--;
addToken(TokenType.Note);
currentIdx_++;
resetState();
}
break;
case State.InInteger:
if (currentIdx_ != SourceCode.Count() - 1)
{
var next = SourceCode[currentIdx_ + 1];
if (ch == '.' && next.IsDigit())
{
state_ = State.InFloat;
}
else if (ch == 'E' || ch == 'e')
{
state_ = State.InSciNumber;
}
else if (!ch.IsDigit())
{
currentIdx_--;
addToken(TokenType.Integer);
resetState();
}
}
else if (ch.IsDigit()) // last char
{
addToken(TokenType.Integer);
resetState();
}
else // last char is not digit
{
currentIdx_--;
addToken(TokenType.Integer);
currentIdx_++;
if (tryAddSingle(ch))
{
resetState();
}
else
{
addError("Illegal Ending Char[" + ch + "] Following Integer");
}
}
break;
case State.InFloat:
if (currentIdx_ != SourceCode.Count() - 1)
{
var next = SourceCode[currentIdx_ + 1];
if (next == 'E' || next == 'e')
{
state_ = State.InSciNumber;
currentIdx_++;
}
if (!ch.IsDigit())
{
currentIdx_--;
addToken(TokenType.Float);
resetState();
}
}
else if (ch.IsDigit()) // last char
{
addToken(TokenType.Float);
resetState();
}
else // last char is not digit
{
currentIdx_--;
addToken(TokenType.Float);
currentIdx_++;
if (tryAddSingle(ch))
{
resetState();
}
else
{
addError("Illegal Ending Char[" + ch + "] Following Integer");
}
}
break;
case State.InSciNumber:
if (ch == '+' || ch == '-')
{
var prev = SourceCode[currentIdx_ - 1];
if (prev != 'E' && prev != 'e')
{
currentIdx_--;
addToken(TokenType.SciNumber);
resetState();
Console.WriteLine(" cur idx{0}", currentIdx_);
}
}
else if (!ch.IsDigit())
{
currentIdx_--;
addToken(TokenType.SciNumber);
resetState();
}
break;
case State.InIdentifier:
if (!ch.IsValidTailingIdCh())
{
currentIdx_--;
addToken(TokenType.Identifier);
resetState();
}
break;
case State.InString:
{
if (ch == '\"')
{
currentIdx_--; // skip "
addToken(TokenType.String);
currentIdx_++;
resetState();
break;
}
else if (ch == '\\')
{
state_ = State.InEscapingString;
Console.WriteLine("escape");
}
else if (ch == '\n')
{
addError("Multi-line string");
}
}
break;
case State.InEscapingString: // next char after
if (ch == '\n')
{
addError("Multi-line string");
resetState();
}
else
{
state_ = State.InString;
}
break;
} // while: foreach ch
currentIdx_++;
}
currentIdx_--;
switch (state_)
{
case State.InInteger:
addToken(TokenType.Integer);
break;
case State.InFloat:
addToken(TokenType.Float);
break;
case State.InSciNumber:
addToken(TokenType.SciNumber);
break;
case State.InIdentifier:
addToken(TokenType.Identifier);
break;
case State.InString:
case State.InEscapingString:
addError("Multi-Line String!");
break;
}
// ok we are done
// mark as finished to prevent reparse
// to re do parsing, see Reparse();
state_ = State.Finished;
}