// Value
void Scanner::ScanValue()
{
// and check that simple key
bool isSimpleKey = VerifySimpleKey();
m_canBeJSONFlow = false;
if(isSimpleKey) {
// can't follow a simple key with another simple key (dunno why, though - it seems fine)
m_simpleKeyAllowed = false;
} else {
// handle values diffently in the block context (and manage indents)
if(InBlockContext()) {
if(!m_simpleKeyAllowed)
throw ParserException(INPUT.mark(), ErrorMsg::MAP_VALUE);
PushIndentTo(INPUT.column(), IndentMarker::MAP);
}
// can only put a simple key here if we're in block context
m_simpleKeyAllowed = InBlockContext();
}
// eat
Mark mark = INPUT.mark();
INPUT.eat(1);
m_tokens.push(Token(Token::VALUE, mark));
}
// ScanToNextToken
// . Eats input until we reach the next token-like thing.
void Scanner::ScanToNextToken() {
while (1) {
// first eat whitespace
while (INPUT && IsWhitespaceToBeEaten(INPUT.peek())) {
if (InBlockContext() && Exp::Tab().Matches(INPUT))
m_simpleKeyAllowed = false;
INPUT.eat(1);
}
// then eat a comment
if (Exp::Comment().Matches(INPUT)) {
// eat until line break
while (INPUT && !Exp::Break().Matches(INPUT))
INPUT.eat(1);
}
// if it's NOT a line break, then we're done!
if (!Exp::Break().Matches(INPUT))
break;
// otherwise, let's eat the line break and keep going
int n = Exp::Break().Match(INPUT);
INPUT.eat(n);
// oh yeah, and let's get rid of that simple key
InvalidateSimpleKey();
// new line - we may be able to accept a simple key now
if (InBlockContext())
m_simpleKeyAllowed = true;
}
}
const RegEx& Scanner::GetValueRegex() const {
if (InBlockContext()) {
return Exp::Value();
}
return m_canBeJSONFlow ? Exp::ValueInJSONFlow() : Exp::ValueInFlow();
}
// FlowEnd
void Scanner::ScanFlowEnd()
{
if(InBlockContext())
throw ParserException(INPUT.mark(), ErrorMsg::FLOW_END);
// we might have a solo entry in the flow context
if(InFlowContext()) {
if(m_flows.top() == FLOW_MAP && VerifySimpleKey())
m_tokens.push(Token(Token::VALUE, INPUT.mark()));
else if(m_flows.top() == FLOW_SEQ)
InvalidateSimpleKey();
}
m_simpleKeyAllowed = false;
m_canBeJSONFlow = true;
// eat
Mark mark = INPUT.mark();
char ch = INPUT.get();
// check that it matches the start
FLOW_MARKER flowType = (ch == Keys::FlowSeqEnd ? FLOW_SEQ : FLOW_MAP);
if(m_flows.top() != flowType)
throw ParserException(mark, ErrorMsg::FLOW_END);
m_flows.pop();
Token::TYPE type = (flowType ? Token::FLOW_SEQ_END : Token::FLOW_MAP_END);
m_tokens.push(Token(type, mark));
}
// Key
void Scanner::ScanKey() {
// handle keys diffently in the block context (and manage indents)
if (InBlockContext()) {
if (!m_simpleKeyAllowed)
throw ParserException(INPUT.mark(), ErrorMsg::MAP_KEY);
PushIndentTo(INPUT.column(), IndentMarker::MAP);
}
// can only put a simple key here if we're in block context
m_simpleKeyAllowed = InBlockContext();
// eat
Mark mark = INPUT.mark();
INPUT.eat(1);
m_tokens.push(Token(Token::KEY, mark));
}
// InsertPotentialSimpleKey
// . If we can, add a potential simple key to the queue,
// and save it on a stack.
void Scanner::InsertPotentialSimpleKey()
{
if(!CanInsertPotentialSimpleKey())
return;
SimpleKey key(INPUT.mark(), GetFlowLevel());
// first add a map start, if necessary
if(InBlockContext()) {
key.pIndent = PushIndentTo(INPUT.column(), IndentMarker::MAP);
if(key.pIndent) {
key.pIndent->status = IndentMarker::UNKNOWN;
key.pMapStart = key.pIndent->pStartToken;
key.pMapStart->status = Token::UNVERIFIED;
}
}
// then add the (now unverified) key
m_tokens.push(Token(Token::KEY, INPUT.mark()));
key.pKey = &m_tokens.back();
key.pKey->status = Token::UNVERIFIED;
m_simpleKeys.push(key);
}
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);
}