static int ScanIdentifier()
{
unsigned char* start = CURSOR;
if('L' == *CURSOR)
{
if('\'' == CURSOR[1])
{
return ScanCharLiteral();
}
else if('\"' == CURSOR[1])
{
return ScanStringLiteral();
}
}
CURSOR++;
while(IsLetterOrDigit(*CURSOR))
{
CURSOR++;
}
return FindKeyword((char *)start, (int)(CURSOR - start));
}
/* 标示符扫描函数 */
static int ScanIdentifierOR (int def)
{
unsigned char *start = CURRENT;
int tok;
/* 处理宽字符或宽字符串 */
if ('L' == *CURRENT) {
/* 处理字符 */
if ('\'' == CURRENT[1])
return ScanCharLiteral ();
/* 处理宽字符串 */
if ('"' == CURRENT[1])
return ScanStringLiteral ();
}
if ( !IsLetterOrDigit (*CURRENT) )
return TK_BEGIN;
CURRENT++;
/* 字母和数字下画线都符合标示符的要求 */
while (IsLetterOrDigit (*CURRENT)) CURRENT++;
/* 判断是否是关键字 */
tok = FindKeyword ((char*)start, (int)(CURRENT - start));
if (TK_ID == tok) {
Symbol p;
/* 将字符串的值保存在字符串池中 */
TokenValue.p = InternStr ((char*)start, (int)(CURRENT - start));
// 该符号是define
if (!def && (p = LookupDefine (TokenValue.p))) {
LoadDefine (p);
return GetNextToken ();
}
} else
TokenValue.p = TokenString[tok];
return tok;
}
TokenPtr SLScanner::ScanToken()
{
std::string spell;
/* Scan directive (beginning with '#') */
if (Is('#'))
return ScanDirective();
/* Scan identifier */
if (std::isalpha(UChr()) || Is('_'))
return ScanIdentifier();
/* Scan number */
if (Is('.'))
return ScanNumberOrDot();
if (std::isdigit(UChr()))
return ScanNumber();
/* Scan string literal */
if (Is('\"'))
return ScanStringLiteral();
/* Scan operators */
if (Is('='))
{
spell += TakeIt();
if (Is('='))
return Make(Tokens::BinaryOp, spell, true);
return Make(Tokens::AssignOp, spell);
}
if (Is('~'))
return Make(Tokens::UnaryOp, spell, true);
if (Is('!'))
{
spell += TakeIt();
if (Is('='))
return Make(Tokens::BinaryOp, spell, true);
return Make(Tokens::UnaryOp, spell);
}
if (Is('%'))
{
spell += TakeIt();
if (Is('='))
return Make(Tokens::AssignOp, spell, true);
return Make(Tokens::BinaryOp, spell);
}
if (Is('*'))
{
spell += TakeIt();
if (Is('='))
return Make(Tokens::AssignOp, spell, true);
return Make(Tokens::BinaryOp, spell);
}
if (Is('^'))
{
spell += TakeIt();
if (Is('='))
return Make(Tokens::AssignOp, spell, true);
return Make(Tokens::BinaryOp, spell);
}
if (Is('+'))
return ScanPlusOp();
if (Is('-'))
return ScanMinusOp();
if (Is('<') || Is('>'))
return ScanAssignShiftRelationOp(Chr());
if (Is('&'))
{
spell += TakeIt();
if (Is('='))
return Make(Tokens::AssignOp, spell, true);
if (Is('&'))
return Make(Tokens::BinaryOp, spell, true);
return Make(Tokens::BinaryOp, spell);
}
if (Is('|'))
{
spell += TakeIt();
if (Is('='))
return Make(Tokens::AssignOp, spell, true);
if (Is('|'))
return Make(Tokens::BinaryOp, spell, true);
return Make(Tokens::BinaryOp, spell);
}
if (Is(':'))
{
spell += TakeIt();
if (Is(':'))
return Make(Tokens::DColon, spell, true);
return Make(Tokens::Colon, spell);
}
/* Scan punctuation, special characters and brackets */
switch (Chr())
{
case ';': return Make(Tokens::Semicolon, true); break;
case ',': return Make(Tokens::Comma, true); break;
case '?': return Make(Tokens::TernaryOp, true); break;
case '(': return Make(Tokens::LBracket, true); break;
case ')': return Make(Tokens::RBracket, true); break;
case '{': return Make(Tokens::LCurly, true); break;
case '}': return Make(Tokens::RCurly, true); break;
case '[': return Make(Tokens::LParen, true); break;
case ']': return Make(Tokens::RParen, true); break;
}
ErrorUnexpected();
return nullptr;
}
