Change the return type of StandardVisitor.VisitExistsExpr() from

ExistsExpr to Expr. Enforcing the return type be ExistsExpr is
too restrictive. For example it prevents anyone from implementing
a visitor that does constant folding of an Expr tree.

There is precedence for this. For example VisitNAryExpr() returns
an Expr not an NAryExpr.

Unfortunately this a breaking API change so anyone who subclasses
the StandardVisitor (or one of its sub classes) and overrides this
method will get compilation errors until they change the return type.
a visitor that does constant folding of an Expr tree

0 files changed, 0 insertions, 0 deletions