Separate

Add element to hidden set, recording it in elemsMap, return whether this was allowed. By default, recording is allowed but the special state VarState.Separate overrides this.

Record elements, return whether this was allowed. By default, recording is allowed in regular but not in frozen states.

Run test pred unless ref was seen in an enclosing ifNotSeen operation

Does this state allow additions of elements to capture set variables?

Returns a string representation of the object.

The default representation is platform dependent.

If root1 and root2 belong to the same binder but have different originalBinders it means that one of the roots was mapped to the binder of the other by a substBinder when comparing two method types. In that case we can unify the two roots1, provided none of the two roots have already been unified themselves. So unification must be 1-1.

Note, see (**) below: We also allow unifications of results that have different ExprType binders. This is necessary because ExprTypes don't get updated with SubstBindingMaps. It's sound since ExprTypes always appear alone and at the top-level, so there is no problem with confusing results at different levels. See pos-customargs/captures/overrides.scala for a test case.