private LexResult LexString(string typeName)
{
Debug.Assert(Buffer.Peek(0) == '"' || Buffer.Peek(0) == '\'');
char quoteChar = Buffer.Peek();
Buffer.AdvanceColumn();
bool isComplete = false;
CppTokenKind kind = quoteChar == '\'' ? CppTokenKind.CharLiteral : CppTokenKind.StringLiteral;
int maxCount = (kind == CppTokenKind.CharLiteral) ? 1 : -1;
int minCount = (kind == CppTokenKind.CharLiteral) ? 1 : 0;
int count = 0;
while (!Buffer.IsEOF)
{
char first = Buffer.Peek();
char second = Buffer.Peek(1);
if (first == quoteChar)
{
isComplete = true;
break;
}
else if (first == '\\')
{
switch (second)
{
case '\'':
case '"':
case '?':
case '\\':
case 'a':
case 'b':
case 'f':
case 'n':
case 'e':
case 'r':
case 't':
case 'v':
{
Buffer.AdvanceColumns(2);
++count;
continue;
}
case 'x':
case 'X':
case 'u':
case 'U':
{
Buffer.AdvanceColumns(2);
if (SyntaxUtils.IsHex(Buffer.Peek()))
{
int len = 0;
while (!Buffer.IsEOF)
{
if (!SyntaxUtils.IsHex(Buffer.Peek()))
{
break;
}
else
{
++len;
Buffer.AdvanceColumn();
}
}
}
else
{
AddError(Buffer.TextPosition, $"Unsupported hex escape character '{Buffer.Peek()}'!", typeName);
break;
}
++count;
continue;
}
default:
if (SyntaxUtils.IsOctal(second))
{
Buffer.AdvanceColumn();
while (!Buffer.IsEOF)
{
if (!SyntaxUtils.IsOctal(Buffer.Peek()))
{
break;
}
else
{
Buffer.AdvanceColumn();
}
}
++count;
continue;
}
else
{
AddError(Buffer.TextPosition, $"Not supported escape character '{Buffer.Peek()}'!", typeName);
break;
}
}
}
else if (SyntaxUtils.IsLineBreak(first))
{
break;
}
else if (char.IsWhiteSpace(first))
{
Buffer.AdvanceManual(first, second);
}
else
{
Buffer.AdvanceColumn();
}
++count;
}
// Skip over quote char
if (isComplete)
{
Debug.Assert(Buffer.Peek() == quoteChar);
Buffer.AdvanceColumn();
}
if (!isComplete)
{
AddError(Buffer.LexemeStart, $"Unterminated {typeName} literal!", typeName);
}
else
{
if (minCount > 0 && count < minCount)
{
AddError(Buffer.LexemeStart, $"Not enough characters for {typeName} literal, expect {minCount} but got {count}!", typeName);
}
else if (maxCount > -1 && (count > maxCount))
{
AddError(Buffer.LexemeStart, $"Too many characters for {typeName} literal, expect {maxCount} but got {count}!", typeName);
}
}
return(new LexResult(kind, isComplete));
}