Right now, everything is assumed left associative at equal operator precedence. We'll have to transform the grammar to be a cascading one in order to enforce precedence. I'll have to figure out how we want to implement left/right associativity, but that's not a big problem.
We should special case 0 explicitly; currently, we are setting the exponent bit with its bias even when we don't need it, which causes it to get compiled to 0.5.