why add attributes to interface elements?

[Thien-Thi Nguyen]

because such tags are useful to track the school as it swims through
time, changing affiliation and meaning.

the inverted view is to work w/ all elements having a tag, aka a group.
this can be used to communicate 1.4.1 "lt_*" removal in a codified way,
for example.

groups can be used for factoring by identifying congruency.

compilation systems that can express what their requirements are can
share validation code by adding it to groupings.alist.

to experiment w/ grouping, see previous mail on how to reproduce guile
hack environment, then do something like:

  cd hack/core-1-4.b
  ../scripts/update-guile-api.alist -n my-proj-groupings my-groupings ...

where my-proj-groupings, my-groupings, ... might be files that contain
grouping defs, for example:

(
(z (description "has z")
   (grok () (lambda (x)
              (name-prefix? x ".*z"))))
)

see hack/core/scripts/scan-api for more info.

thi