intermediate changes

ref:cde9a383711a11544ce7e107a78147fb96cc4029

1 files changed, 386 insertions, 0 deletions

diff --git a/contrib/libs/yaml-cpp/src/scanner.cpp b/contrib/libs/yaml-cpp/src/scanner.cpp
new file mode 100644
index 0000000000..b5cfcc12b2
--- /dev/null
+++ b/contrib/libs/yaml-cpp/src/scanner.cpp
@@ -0,0 +1,386 @@
+#include <cassert>
+#include <memory>
+
+#include "exp.h"
+#include "scanner.h"
+#include "token.h"
+#include "yaml-cpp/exceptions.h"  // IWYU pragma: keep
+
+namespace YAML {
+Scanner::Scanner(std::istream& in)
+    : INPUT(in),
+      m_startedStream(false),
+      m_endedStream(false),
+      m_simpleKeyAllowed(false),
+      m_canBeJSONFlow(false) {}
+
+Scanner::~Scanner() {}
+
+bool Scanner::empty() {
+  EnsureTokensInQueue();
+  return m_tokens.empty();
+}
+
+void Scanner::pop() {
+  EnsureTokensInQueue();
+  if (!m_tokens.empty())
+    m_tokens.pop();
+}
+
+Token& Scanner::peek() {
+  EnsureTokensInQueue();
+  assert(!m_tokens.empty());  // should we be asserting here? I mean, we really
+                              // just be checking
+                              // if it's empty before peeking.
+
+#if 0
+		static Token *pLast = 0;
+		if(pLast != &m_tokens.front())
+			std::cerr << "peek: " << m_tokens.front() << "\n";
+		pLast = &m_tokens.front();
+#endif
+
+  return m_tokens.front();
+}
+
+Mark Scanner::mark() const { return INPUT.mark(); }
+
+void Scanner::EnsureTokensInQueue() {
+  while (1) {
+    if (!m_tokens.empty()) {
+      Token& token = m_tokens.front();
+
+      // if this guy's valid, then we're done
+      if (token.status == Token::VALID) {
+        return;
+      }
+
+      // here's where we clean up the impossible tokens
+      if (token.status == Token::INVALID) {
+        m_tokens.pop();
+        continue;
+      }
+
+      // note: what's left are the unverified tokens
+    }
+
+    // no token? maybe we've actually finished
+    if (m_endedStream) {
+      return;
+    }
+
+    // no? then scan...
+    ScanNextToken();
+  }
+}
+
+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);
+}
+
+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;
+    }
+  }
+}
+
+///////////////////////////////////////////////////////////////////////
+// Misc. helpers
+
+// IsWhitespaceToBeEaten
+// . We can eat whitespace if it's a space or tab
+// . Note: originally tabs in block context couldn't be eaten
+//         "where a simple key could be allowed
+//         (i.e., not at the beginning of a line, or following '-', '?', or
+// ':')"
+//   I think this is wrong, since tabs can be non-content whitespace; it's just
+//   that they can't contribute to indentation, so once you've seen a tab in a
+//   line, you can't start a simple key
+bool Scanner::IsWhitespaceToBeEaten(char ch) {
+  if (ch == ' ') {
+    return true;
+  }
+
+  if (ch == '\t') {
+    return true;
+  }
+
+  return false;
+}
+
+const RegEx& Scanner::GetValueRegex() const {
+  if (InBlockContext()) {
+    return Exp::Value();
+  }
+
+  return m_canBeJSONFlow ? Exp::ValueInJSONFlow() : Exp::ValueInFlow();
+}
+
+void Scanner::StartStream() {
+  m_startedStream = true;
+  m_simpleKeyAllowed = true;
+  std::unique_ptr<IndentMarker> pIndent(
+      new IndentMarker(-1, IndentMarker::NONE));
+  m_indentRefs.push_back(std::move(pIndent));
+  m_indents.push(&m_indentRefs.back());
+}
+
+void Scanner::EndStream() {
+  // force newline
+  if (INPUT.column() > 0) {
+    INPUT.ResetColumn();
+  }
+
+  PopAllIndents();
+  PopAllSimpleKeys();
+
+  m_simpleKeyAllowed = false;
+  m_endedStream = true;
+}
+
+Token* Scanner::PushToken(Token::TYPE type) {
+  m_tokens.push(Token(type, INPUT.mark()));
+  return &m_tokens.back();
+}
+
+Token::TYPE Scanner::GetStartTokenFor(IndentMarker::INDENT_TYPE type) const {
+  switch (type) {
+    case IndentMarker::SEQ:
+      return Token::BLOCK_SEQ_START;
+    case IndentMarker::MAP:
+      return Token::BLOCK_MAP_START;
+    case IndentMarker::NONE:
+      assert(false);
+      break;
+  }
+  assert(false);
+  throw std::runtime_error("yaml-cpp: internal error, invalid indent type");
+}
+
+Scanner::IndentMarker* Scanner::PushIndentTo(int column,
+                                             IndentMarker::INDENT_TYPE type) {
+  // are we in flow?
+  if (InFlowContext()) {
+    return 0;
+  }
+
+  std::unique_ptr<IndentMarker> pIndent(new IndentMarker(column, type));
+  IndentMarker& indent = *pIndent;
+  const IndentMarker& lastIndent = *m_indents.top();
+
+  // is this actually an indentation?
+  if (indent.column < lastIndent.column) {
+    return 0;
+  }
+  if (indent.column == lastIndent.column &&
+      !(indent.type == IndentMarker::SEQ &&
+        lastIndent.type == IndentMarker::MAP)) {
+    return 0;
+  }
+
+  // push a start token
+  indent.pStartToken = PushToken(GetStartTokenFor(type));
+
+  // and then the indent
+  m_indents.push(&indent);
+  m_indentRefs.push_back(std::move(pIndent));
+  return &m_indentRefs.back();
+}
+
+void Scanner::PopIndentToHere() {
+  // are we in flow?
+  if (InFlowContext()) {
+    return;
+  }
+
+  // now pop away
+  while (!m_indents.empty()) {
+    const IndentMarker& indent = *m_indents.top();
+    if (indent.column < INPUT.column()) {
+      break;
+    }
+    if (indent.column == INPUT.column() &&
+        !(indent.type == IndentMarker::SEQ &&
+          !Exp::BlockEntry().Matches(INPUT))) {
+      break;
+    }
+
+    PopIndent();
+  }
+
+  while (!m_indents.empty() &&
+         m_indents.top()->status == IndentMarker::INVALID) {
+    PopIndent();
+  }
+}
+
+void Scanner::PopAllIndents() {
+  // are we in flow?
+  if (InFlowContext()) {
+    return;
+  }
+
+  // now pop away
+  while (!m_indents.empty()) {
+    const IndentMarker& indent = *m_indents.top();
+    if (indent.type == IndentMarker::NONE) {
+      break;
+    }
+
+    PopIndent();
+  }
+}
+
+void Scanner::PopIndent() {
+  const IndentMarker& indent = *m_indents.top();
+  m_indents.pop();
+
+  if (indent.status != IndentMarker::VALID) {
+    InvalidateSimpleKey();
+    return;
+  }
+
+  if (indent.type == IndentMarker::SEQ) {
+    m_tokens.push(Token(Token::BLOCK_SEQ_END, INPUT.mark()));
+  } else if (indent.type == IndentMarker::MAP) {
+    m_tokens.push(Token(Token::BLOCK_MAP_END, INPUT.mark()));
+  }
+}
+
+int Scanner::GetTopIndent() const {
+  if (m_indents.empty()) {
+    return 0;
+  }
+  return m_indents.top()->column;
+}
+
+void Scanner::ThrowParserException(const std::string& msg) const {
+  Mark mark = Mark::null_mark();
+  if (!m_tokens.empty()) {
+    const Token& token = m_tokens.front();
+    mark = token.mark;
+  }
+  throw ParserException(mark, msg);
+}
+}  // namespace YAML