5f11b29a

Created Started Finished

By: Tom Sydney Kerckhove <syd@cs-syd.eu>

Name each call and each filtering comparison

The selector layer already has smart constructors, so nobody writes a
Matcher record by hand, but there were none for Call: every call site wrote
the Apply that puts one back into an expression.  The filtering half of the
comparison table had the same problem, spelled Compare GreaterThan AsAFilter
at each use.

Named after the constructors rather than after PromQL, which spells four of
these abs, ceil, sgn and sort_desc: the renderer is where the spellings
belong, and ceiling, floor, round and sort would each have shadowed
something a caller is likely to have imported.