private static void ResolveWhitespace(LexerContext context)
{
while (!context.IsEnded() && (context.GetCurrentChar().Equals(' ') || ResolveNewLine(context)))
{
context.IncIndex();
}
}
private static IToken Resolve(LexerContext context)
{
if (CommentToken.IsCommentBegin(context))
{
return(ResolveComment(context));
}
else if (NumberToken.IsNumberBegin(context))
{
return(ResolveNumber(context));
}
else if (StringToken.IsStringBegin(context))
{
return(ResolveString(context));
}
else if (SpecialSymbolToken.IsSpecial(context))
{
return(ResolveSpecial(context));
}
else if (IdentifierToken.IsIdentifierBegin(context))
{
return(ResolveIdentifier(context));
}
else
{
throw new SyntaxErrorException();
}
}
private static CommentToken ResolveDelphiComment(LexerContext context)
{
var begin = context.GetIndex();
context.IncIndex();
context.IncIndex();
var inners = new List <CommentToken>();
while (!context.IsEnded() && !context.IsNewLineNow())
{
if (CommentToken.IsOldStyleCommentBegin(context))
{
inners.Add(ResolveOldStyleComment(context));
continue;
}
if (CommentToken.IsTurboPascalCommentBegin(context))
{
inners.Add(ResolveTurboPascalComment(context));
continue;
}
context.IncIndex();
}
var isSingleLine = inners.All(c => c.IsSingleLineComment);
if (!isSingleLine)
{
throw new SyntaxErrorException();
}
return(new CommentToken(true, inners, begin, context.GetIndex()));
}
public List <IToken> Run(string str)
{
var context = new LexerContext(str);
var res = new List <IToken>();
ResolveWhitespace(context);
while (!context.IsEnded())
{
res.Add(Resolve(context));
ResolveWhitespace(context);
}
return(res);
}
private static CommentToken ResolveTurboPascalComment(LexerContext context)
{
var begin = context.GetIndex();
context.IncIndex();
var inners = new List <CommentToken>();
var isOneLine = true;
while (!context.IsEnded())
{
if (CommentToken.IsOldStyleCommentBegin(context))
{
inners.Add(ResolveOldStyleComment(context));
continue;
}
if (CommentToken.IsDelphiCommentBegin(context))
{
inners.Add(ResolveDelphiComment(context));
continue;
}
if (context.IsNewLineNow())
{
isOneLine = false;
for (var i = 0; i < Environment.NewLine.Length; i++)
{
context.IncIndex();
}
}
if (context.IsNewLineNow())
{
isOneLine = false;
for (var i = 0; i < Environment.NewLine.Length; i++)
{
context.IncIndex();
}
}
if (CommentToken.IsTurboPascalCommentEnd(context))
{
context.IncIndex();
break;
}
context.IncIndex();
}
return(new CommentToken(isOneLine && inners.All(c => c.IsSingleLineComment), inners,
begin, context.GetIndex()));
}
private static bool ResolveNewLine(LexerContext context)
{
var stringSep = Environment.NewLine;
if (stringSep.Length == 1 && stringSep.Equals(context.GetCurrentCharByString()))
{
return(true);
}
else if (stringSep.Length == 2 && !context.IsLast() && stringSep.Equals(context.GetCharPair()))
{
context.IncIndex();
return(true);
}
return(false);
}
private static CommentToken ResolveComment(LexerContext context)
{
if (CommentToken.IsOldStyleCommentBegin(context))
{
return(ResolveOldStyleComment(context));
}
else if (CommentToken.IsTurboPascalCommentBegin(context))
{
return(ResolveTurboPascalComment(context));
}
else
{
return(ResolveDelphiComment(context));
}
}
private static void ResolveControlString(LexerContext context, StringBuilder builder)
{
context.IncIndex();
var numberBuilder = new StringBuilder();
while (!context.IsEnded() && Char.IsDigit(context.GetCurrentChar()))
{
numberBuilder.Append(context.GetCurrentChar());
context.IncIndex();
}
var num = Int32.Parse(numberBuilder.ToString());
builder.Append((char)num);
}
private static IdentifierToken ResolveIdentifier(LexerContext context)
{
var builder = new StringBuilder();
var begin = context.GetIndex();
builder.Append(context.GetCurrentChar());
context.IncIndex();
while (!context.IsEnded() &&
(Char.IsDigit(context.GetCurrentChar()) ||
Char.IsLetter(context.GetCurrentChar())))
{
builder.Append(context.GetCurrentChar());
context.IncIndex();
}
return(new IdentifierToken(builder.ToString(), begin, context.GetIndex()));
}
private static SpecialSymbolToken ResolveSpecial(LexerContext context)
{
var begin = context.GetIndex();
if (!context.IsLast() && SpecialSymbolToken.IsSpecialPair(context))
{
var pair = context.GetCharPair();
context.IncIndex();
context.IncIndex();
return(new SpecialSymbolToken(pair, begin));
}
else
{
var ch = context.GetCurrentChar();
context.IncIndex();
return(new SpecialSymbolToken(ch, begin));
}
}
private static StringToken ResolveString(LexerContext context)
{
var begin = context.GetIndex();
var builder = new StringBuilder();
while (StringToken.IsStringBegin(context))
{
if (context.GetCurrentChar().Equals('\''))
{
ResolveQuotedString(context, builder);
}
else
{
ResolveControlString(context, builder);
}
}
return(new StringToken(builder.ToString(), begin, context.GetIndex()));
}
private static NumberToken ResolveNumber(LexerContext context)
{
var begin = context.GetIndex();
var builder = new StringBuilder();
if (NumberToken.IsDecimalNumberBegin(context))
{
while (!context.IsEnded() && NumberToken.IsDecimalDigit(context))
{
builder.Append(context.GetCurrentChar());
context.IncIndex();
}
}
else if (NumberToken.IsHexNumberBegin(context))
{
context.IncIndex();
while (!context.IsEnded() && NumberToken.IsHexadecimalDigit(context))
{
builder.Append(context.GetCurrentChar());
context.IncIndex();
}
}
else if (NumberToken.IsOctalNumberBegin(context))
{
context.IncIndex();
while (!context.IsEnded() && NumberToken.IsOctalDigit(context))
{
builder.Append(context.GetCurrentChar());
context.IncIndex();
}
}
else
{
context.IncIndex();
while (!context.IsEnded() && NumberToken.IsBinaryDigit(context))
{
builder.Append(context.GetCurrentChar());
context.IncIndex();
}
}
return(new NumberToken(builder.ToString(), begin, context.GetIndex()));
}
private static void ResolveQuotedString(LexerContext context, StringBuilder builder)
{
context.IncIndex();
while (!context.IsEnded() && StringToken.IsStringSymbol(context.GetCurrentChar()))
{
if (context.GetCurrentChar().Equals('\''))
{
if (StringToken.IsDoubleQuote(context))
{
builder.Append('\'');
context.IncIndex();
context.IncIndex();
}
else
{
context.IncIndex();
return;
}
}
builder.Append(context.GetCurrentChar());
context.IncIndex();
}
}
