```
$ echo '20210101,A' | clickhouse-local --input-format CSV --structure 'd Date, s String' --query "SELECT * FROM table"
Code: 27. DB::Exception: Cannot parse input: expected ',' before: '20210101,A\n': 
Row 1:
Column 0,   name: d, type: Date,   ERROR: text "20210101,A" is not like Date

: While executing ParallelParsingBlockInputFormat: While executing File. (CANNOT_PARSE_INPUT_ASSERTION_FAILED)
```

**How to solve**

Disambiguate while parsing by absense of separators between YYYY-MM-DD.
{
    while (!buf.eof())
    {
        char * next_pos = find_first_symbols<chars...>(buf.position(), buf.buffer().end());
        appendToStringOrVector(s, buf, next_pos);
        buf.position() = next_pos;
        if (buf.hasPendingData())
            return;
    }
}
template <typename Vector>
void readStringInto(Vector & s, ReadBuffer & buf)
{
    readStringUntilCharsInto<'\t', '\n'>(s, buf);
}
template <typename Vector>
void readStringUntilWhitespaceInto(Vector & s, ReadBuffer & buf)
{
    readStringUntilCharsInto<' '>(s, buf);
}
template <typename Vector>
void readNullTerminated(Vector & s, ReadBuffer & buf)
{
    readStringUntilCharsInto<'\0'>(s, buf);
    buf.ignore();
}
void readStringUntilWhitespace(String & s, ReadBuffer & buf)