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, 2 insertions, 1 deletions

diff --git a/test/system/smt2_compliance.cpp b/test/system/smt2_compliance.cpp
index 108e30b5c..99b4c625c 100644
--- a/test/system/smt2_compliance.cpp
+++ b/test/system/smt2_compliance.cpp
@@ -19,6 +19,7 @@
 #include <sstream>
 
 #include "expr/expr_manager.h"
+#include "options/set_language.h"
 #include "options/smt_options.h"
 #include "parser/parser.h"
 #include "parser/parser_builder.h"
@@ -36,7 +37,7 @@ int main() {
   opts.set(options::inputLanguage, language::input::LANG_SMTLIB_V2);
   opts.set(options::outputLanguage, language::output::LANG_SMTLIB_V2);
 
-  cout << Expr::setlanguage(language::output::LANG_SMTLIB_V2);
+  cout << language::SetLanguage(language::output::LANG_SMTLIB_V2);
 
   ExprManager em(opts);
   SmtEngine smt(&em);