fix parsing of ternary operator

src/Parsers/CommonParsers.cpp

@@ -65,4 +65,17 @@ bool ParserKeyword::parseImpl(Pos & pos, ASTPtr & /*node*/, Expected & expected)
     return true;
 }
 
+bool ParserDoubleColon::parseImpl(Pos & pos, ASTPtr & /*node*/, Expected & expected)
+{
+    /// Do not move position if only one colon mathced.
+    Pos begin = pos;
+    if (parser_colon.ignore(begin, expected) && parser_colon.ignore(begin, expected))
+    {
+        pos = begin;
+        return true;
+    }
+
+    return false;
+}
+
 }

src/Parsers/CommonParsers.h

@@ -56,4 +56,15 @@ public:
     bool parseImpl(Pos & /*pos*/, ASTPtr & /*node*/, Expected & /*expected*/) override { return true; }
 };
 
+class ParserDoubleColon : public IParserBase
+{
+public:
+    const char * getName() const override { return "double colon"; }
+
+    bool parseImpl(Pos & pos, ASTPtr & node, Expected & expected) override;
+
+private:
+    ParserToken parser_colon{TokenType::Colon};
+};
+
 }

src/Parsers/ExpressionElementParsers.cpp

@@ -866,11 +866,9 @@ bool ParserCastOperator::parseImpl(Pos & pos, ASTPtr & node, Expected & expected
         return false;
 
     ASTPtr type_ast;
-    ParserToken parser_colon(TokenType::Colon);
     const char * data_end = pos->begin;
 
-    if (parser_colon.ignore(pos, expected)
+    if (ParserDoubleColon().ignore(pos, expected)
-        && parser_colon.ignore(pos, expected)
         && ParserDataType().parse(pos, type_ast, expected))
     {
         auto type = DataTypeFactory::instance().get(type_ast);

src/Parsers/ExpressionListParsers.cpp

@@ -564,9 +564,7 @@ bool ParserCastExpression::parseImpl(Pos & pos, ASTPtr & node, Expected & expect
         return false;
 
     ASTPtr type_ast;
-    ParserToken parser_colon(TokenType::Colon);
+    if (ParserDoubleColon().ignore(pos, expected)
-    if (parser_colon.ignore(pos, expected)
-        && parser_colon.ignore(pos, expected)
         && ParserDataType().parse(pos, type_ast, expected))
     {
         node = createFunctionCast(expr_ast, type_ast);