A bug of the gramma. (the sign)

[vrbvillor]

input
    &:focus ~{
         button{}
         ul{}
    }

will be compiled into

input:focus button{}
input:focus ul{}

why not

input:focus~button{}
input:focus~ul{}

Please help me, thanks. Not the wave sign cause the problem, but the gramma does. Though I change the wave to a plus+, it also compiles missing the sign.