scala/scala — pull request #1100 by adriaanm (2012-08-09 12:29:07+00:00)
Title: SI-6022 cleaner model of variable equality modulo <:

centralized and improved the construction of the information needed to construct the boolean proposition that encodes the equality proposition (V = C) that models a type test pattern `_: C` or constant pattern `C`, where the type test gives rise to a TypeConst C, and the constant pattern yields a ValueConst C

for exhaustivity, we really only need implication (e.g., V = 1 implies that V = 1 /\ V = Int, if both tests occur in the match, and thus in this variable's equality symbols), but reachability also requires us to model things like V = 1 precluding V = "1"