Modifying emptyset.h and sexpr. Adding SetLanguage.

- Modifies expr/emptyset.h to use SetType only as an incomplete type within expr/emptyset.h. This breaks the include cycle between expr/emptyset.h, expr/expr.h and expr/type.h.
- Refactors SExpr to avoid a potentially infinite cycle. This is likely overkill, but it works.
- Moving Expr::setlanguage and related utilities out of the Expr class and into their own file. This allows files in util/ to know the output language set on an ostream.

1 files changed, 1 insertions, 1 deletions

diff --git a/doc/libcvc4.3_template.in b/doc/libcvc4.3_template.in
index 2ff96eb5a..f85a909dd 100644
--- a/doc/libcvc4.3_template.in
+++ b/doc/libcvc4.3_template.in
@@ -22,7 +22,7 @@ int main() {
   Expr onePlusTwo = em.mkExpr(kind::PLUS,
                               em.mkConst(Rational(1)),
                               em.mkConst(Rational(2)));
-  std::cout << Expr::setlanguage(language::output::LANG_CVC4)
+  std::cout << language::SetLanguage(language::output::LANG_CVC4)
             << smt.getInfo("name")
             << " says that 1 + 2 = "
             << smt.simplify(onePlusTwo)