// ScanNextToken
// . The main scanning function; here we branch out and
// scan whatever the next token should be.
void Scanner::ScanNextToken()
{
if(m_endedStream)
return;
if(!m_startedStream)
return StartStream();
// get rid of whitespace, etc. (in between tokens it should be irrelevent)
ScanToNextToken();
// check the latest simple key
VerifySimpleKey();
// maybe need to end some blocks
PopIndentTo(INPUT.column);
// *****
// And now branch based on the next few characters!
// *****
// end of stream
if(INPUT.peek() == EOF)
return EndStream();
if(INPUT.column == 0 && INPUT.peek() == Keys::Directive)
return ScanDirective();
// document token
if(INPUT.column == 0 && Exp::DocStart.Matches(INPUT))
return ScanDocStart();
if(INPUT.column == 0 && Exp::DocEnd.Matches(INPUT))
return ScanDocEnd();
// flow start/end/entry
if(INPUT.peek() == Keys::FlowSeqStart || INPUT.peek() == Keys::FlowMapStart)
return ScanFlowStart();
if(INPUT.peek() == Keys::FlowSeqEnd || INPUT.peek() == Keys::FlowMapEnd)
return ScanFlowEnd();
if(INPUT.peek() == Keys::FlowEntry)
return ScanFlowEntry();
// block/map stuff
if(Exp::BlockEntry.Matches(INPUT))
return ScanBlockEntry();
if((m_flowLevel == 0 ? Exp::Key : Exp::KeyInFlow).Matches(INPUT))
return ScanKey();
if((m_flowLevel == 0 ? Exp::Value : Exp::ValueInFlow).Matches(INPUT))
return ScanValue();
// alias/anchor
if(INPUT.peek() == Keys::Alias || INPUT.peek() == Keys::Anchor)
return ScanAnchorOrAlias();
// tag
if(INPUT.peek() == Keys::Tag)
return ScanTag();
// special scalars
if(m_flowLevel == 0 && (INPUT.peek() == Keys::LiteralScalar || INPUT.peek() == Keys::FoldedScalar))
return ScanBlockScalar();
if(INPUT.peek() == '\'' || INPUT.peek() == '\"')
return ScanQuotedScalar();
// plain scalars
if((m_flowLevel == 0 ? Exp::PlainScalar : Exp::PlainScalarInFlow).Matches(INPUT))
return ScanPlainScalar();
// don't know what it is!
throw ParserException(INPUT.line, INPUT.column, ErrorMsg::UNKNOWN_TOKEN);
}
void Scanner::ScanNextToken() {
if (m_endedStream) {
return;
}
if (!m_startedStream) {
return StartStream();
}
// get rid of whitespace, etc. (in between tokens it should be irrelevent)
ScanToNextToken();
// maybe need to end some blocks
PopIndentToHere();
// *****
// And now branch based on the next few characters!
// *****
// end of stream
if (!INPUT) {
return EndStream();
}
if (INPUT.column() == 0 && INPUT.peek() == Keys::Directive) {
return ScanDirective();
}
// document token
if (INPUT.column() == 0 && Exp::DocStart().Matches(INPUT)) {
return ScanDocStart();
}
if (INPUT.column() == 0 && Exp::DocEnd().Matches(INPUT)) {
return ScanDocEnd();
}
// flow start/end/entry
if (INPUT.peek() == Keys::FlowSeqStart ||
INPUT.peek() == Keys::FlowMapStart) {
return ScanFlowStart();
}
if (INPUT.peek() == Keys::FlowSeqEnd || INPUT.peek() == Keys::FlowMapEnd) {
return ScanFlowEnd();
}
if (INPUT.peek() == Keys::FlowEntry) {
return ScanFlowEntry();
}
// block/map stuff
if (Exp::BlockEntry().Matches(INPUT)) {
return ScanBlockEntry();
}
if ((InBlockContext() ? Exp::Key() : Exp::KeyInFlow()).Matches(INPUT)) {
return ScanKey();
}
if (GetValueRegex().Matches(INPUT)) {
return ScanValue();
}
// alias/anchor
if (INPUT.peek() == Keys::Alias || INPUT.peek() == Keys::Anchor) {
return ScanAnchorOrAlias();
}
// tag
if (INPUT.peek() == Keys::Tag) {
return ScanTag();
}
// special scalars
if (InBlockContext() && (INPUT.peek() == Keys::LiteralScalar ||
INPUT.peek() == Keys::FoldedScalar)) {
return ScanBlockScalar();
}
if (INPUT.peek() == '\'' || INPUT.peek() == '\"') {
return ScanQuotedScalar();
}
// plain scalars
if ((InBlockContext() ? Exp::PlainScalar() : Exp::PlainScalarInFlow())
.Matches(INPUT)) {
return ScanPlainScalar();
}
// don't know what it is!
throw ParserException(INPUT.mark(), ErrorMsg::UNKNOWN_TOKEN);
}
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;
}
