Some constraints could be missed: those which
are activated and discarded in the same Chunk.
Dispatcher weren't cleared from them
and stale matches could remain in its state.
Through these matches their invalidated heads
could get into incremental execution queue
which led to assert violation in MatchJournalImpl.reset
It was aimed at precluding cascading typechecking failures.
(There was some case with typechecking 'hasBound' after incorrect bind.)
It seems controversial. Typechecking with it is no more predictable
than with free variables left unbound in case of error.
With current tests almost nothing changes after removing it.
These unused in bodies constraints were for tracking certain
cases of incremental dependencies. Now it's handled by minor
algorithm extension introduced in several previous commits.
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.
To fix them need either extending incr algo to handle rules which
postpone binding logicals in principal constraints (i.e. typeOf)
(see rules in Closures for 'invoke' expression)
or rewriting these rules to not produce typeOf with free logicals.
Fixes IncrClosureInference.changeFunctionalInterfaceParam test.
Temporary rules built as macro applications weren't computing hash
due to origin!=null condition. Also macro inputs weren't processed.
Stable hash for TypeVarSubstitution is defined because it's used in macro args.
In general, any classes used as constraint/predicate/macro args
must adhere to stable hashCode() contract: hash should change
if there're important changes that may influence typechecking result.
Otherwise there may be unnecessary incremental recomputations.
Relevant for MPSCR-62
Add 'genDecl' constraint in heads of toFunctionalCls* rules
to handle incremental changes to respective classifier.
Also fail instead of just reporting error to break execution and
report on correct node according to calling rule.
UndefinedType should leave the logical variable unassigned.
Type is an abstract superconcept, so reaching it means
there should have an override for lift macro.
DataFormPrinter is hardcoded to support _term and _subterm
hacks and present the terms in a readable way.
Memoizer is searched for an implementation of
NodePresentable, which helps with visualization of SNode
and SNodeReference.
Replace unification with the intent of capturing term feature
with match constraint.
Drop unused term feature from head pattern.
Provide better context for failed class inheritance test.
Fedor Isakov