tree 02facdb0155091f347b9bc49c2d219a6e39e56d0
parent 08e814f8e10192d5443991ca8f13b2e4de02b837
author Marcel van Lohuizen <mpvl@golang.org> 1611083358 +0100
committer Marcel van Lohuizen <mpvl@golang.org> 1611156813 +0000

tools/trim: implement using adt

The data structures (adt) of the new evaluator make
implementing trim a lot easier than it was before.

The new evaluator tracks all conjuncts in a Vertex.
It now also marks whether a value originated from
a comprehension, definition, embedding, etc. This
means that the trim implemenation no longer needs to
maintain parallel data structures, which is hard and
error prone.

It also allows the right level of pre-evaluation,
so that the right values can be used to determine
whether a field is subsumed. This was hard in the
old implementation.

Ultimately it would be good if these kind of tools
could be build on a public API, but let's first try
to understand, building tools like trim, what would
be a good API.

Fixes #643
Fixes #626
Fixes #558
Closes #548

This fixes several other issues that were noted in
the tests and issues that were not explicitly marked
as issues.

Change-Id: I2a8cf6933288fbfa427792e536fbca030a04b3b2
Reviewed-on: https://cue-review.googlesource.com/c/cue/+/8238
Reviewed-by: CUE cueckoo <cueckoo@gmail.com>
Reviewed-by: Paul Jolly <paul@myitcv.org.uk>
Reviewed-by: Marcel van Lohuizen <mpvl@golang.org>