This allows putting a scalar as the first argument of a binary operator
in which the second argument is a vector:
<scalar> <binop> <vector>
For example,
1 / http_requests_total
...will output a vector in which every sample value is 1 divided by the
respective input vector element.
This even works for filter binary operators now:
1 == http_requests_total
Returns a vector with all values set to 1 for every element in
http_requests_total whose initial value was 1.
Note: For filter binary operators, the resulting values are always taken
from the left-hand-side of the operation, no matter whether the scalar
or the vector argument is the left-hand-side. That is,
1 != http_requests_total
...will set all result vector sample values to 1, although these are
exactly the sample elements that were != 1 in the input vector.
If you want to just filter elements without changing their sample
values, you still need to do:
http_requests_total != 1
The new filter form is a bit exotic, and so probably won't be used
often. But it was easier to implement it than disallow it completely or
change its behavior.
Change-Id: Idd083f2bd3a1219ba1560cf4ace42f5b82e797a5
d411a7d810