The test substructuralTS_indirectResourceDependency is not doing what it's intended
to be doing b/c of apparenly wrongly understood contract of the `also()` method.
It is not supposed to pass the result of the computation to the "chained" method.
Compare `T.also(block: (T) -> Unit): T` and `T.let(block: (T) -> R): R`.
After having fixed the code, the test no longer passes.
Previously only logicals directly used ar occurrence args
were observed. Now terms in occurrence args are traversed
recursively and all contained logicals are observed.
Also clear occurrence contract observers on discarding occ-s.
Introduce a generic way to clear observers in LogicalState.
Instead of simple allowed/not option sometimes Unsafe
is useful. 'Unsafe' status may be present when there're
few "bad" rules.
With this level end code may resolve to go with
incrementality without strict guarantees.
It seems to reflect the exact information needed: there's
one-to-one correspondence between feedback and its match.
While using rule unique tag as feedback key in TypesIndex
relied on several assumptions.
Also there's less use of MatchJournal information with this.
Previously parent principal match was passed to FeedbackConsumer.
Fixes IncrClassHierarchy.modifyClsHierarchyTypeParams test.
Key point is that changes to rules causing their
regeneration must be reflected in program.
There appeared to be cases when it's not true.
It's a case of non-principal rules with origins.
Such rules are called "weak principal" rules.
Matches of weak principal rules are not recorded
in Journal (as is for principal rules), but instead
they become part of their parent MatchChunk.
(In essense, tags of weak principal rules are
recorded in parent chunk).
With this, when a weak principal rule changes,
matches of all principal rules whose computation
depends on them are correctly invalidated.
(Example rules: findHierarchy_Classifier)
Relevant for MPSCR-62.
Now Evidence isn't unique for each Chunk: Occurrence Chunks fully
share evidence and justifications with their activating match.
So, less collections of justifications are created, approx. 2 times less.
Relates to machinery introduced in MPSCR-47.
Previously parent match was maintained in Controller on Java call stack.
Now this stack of parent matches is maintained manually in MatchJournal.
So MatchJournal gains new invariant: parentChunk()
returns correct parent after each logMatch() call.
Several tests fail, also need to maintain this
invariant after logActivation() calls.
Invariant ensures that retroactively added justifications
(added on past parent chunk, see fix commit) are propagated
for all relevant children of justified parent chunk.
Such machinery is needed inside ControllerImpl.processBody
to provide nearest relevant match to feedback handling.
Also required for a fix for MPSCR-47.
Also enables back one assertion in incremental processing on rm stage.
Make Occurrence a Justified entity and drop .justifications() from
ConstraintOccurrence.java because justifications are used only internally.
A single justification is now called Evidence (typealias to Int),
so Justified entities are justified by Evidence-s.
Tests are structured similar to how occurrences are processes with ExecQueue
and its 'postponedFutureMatches' in incremental processing in ConstraintProcessing.
Also don't ignore one old test.
StateFrameStack adds no functionality but requires too much processing.
Rename StateFrameStack -> LogicalState.
Rename ProcessingStateImpl -> ConstraintsProcessing.
Simplify occurrence's logical observer.
Introduce transient dependency on controller to LogicalState.
Keep logical state as part of session token, avoid re-initializing
all logical observers.
Make replaying of match journal independent of controller.
Drop layer prototype, make layer mutable.
Keep nodes in a layer in a linked list with fail-safe iterator.
Introduce update queue for update blocks.
Update blocks run incrementally unless reset.
Maintain trail of introduced and dropped occurrences.
Generation iterates over nodes in the last (final) layer incrementally,
unless reset.
Introduce new test.
Fedor Isakov