syntax error - What is unexpected T_VARIABLE in PHP?

I get this PHP error:

Parse error: syntax error, unexpected
T_VARIABLE

From this line:

$list[$i][$docinfo['attrs']['@groupby']] = $docinfo['attrs']['@count'];

Is there anything wrong with this line?

Answer

There might be a semicolon or bracket missing a line before your pasted line. It seems fine to me, every string is allowed as array index.