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, 81 insertions, 0 deletions

diff --git a/src/options/set_language.cpp b/src/options/set_language.cpp
new file mode 100644
index 000000000..db0275e04
--- /dev/null
+++ b/src/options/set_language.cpp
@@ -0,0 +1,81 @@
+/*********************                                                        */
+/*! \file language.h
+ ** \verbatim
+ ** Original author: Morgan Deters
+ ** Major contributors: none
+ ** Minor contributors (to current version): Francois Bobot, Andrew Reynolds
+ ** This file is part of the CVC4 project.
+ ** Copyright (c) 2009-2014  New York University and The University of Iowa
+ ** See the file COPYING in the top-level source directory for licensing
+ ** information.\endverbatim
+ **
+ ** \brief Definition of input and output languages
+ **
+ ** Definition of input and output languages.
+ **/
+#include "options/set_language.h"
+
+#include <iosfwd>
+#include <iomanip>
+
+#include "options/language.h"
+#include "options/options.h"
+
+namespace CVC4 {
+namespace language {
+
+const int SetLanguage::s_iosIndex = std::ios_base::xalloc();
+
+SetLanguage::Scope::Scope(std::ostream& out, OutputLanguage language)
+  : d_out(out)
+  , d_oldLanguage(SetLanguage::getLanguage(out))
+{
+  SetLanguage::setLanguage(out, language);
+}
+
+SetLanguage::Scope::~Scope(){
+  SetLanguage::setLanguage(d_out, d_oldLanguage);
+}
+
+
+SetLanguage::SetLanguage(OutputLanguage l)
+  : d_language(l)
+{}
+
+void SetLanguage::applyLanguage(std::ostream& out) {
+  // (offset by one to detect whether default has been set yet)
+  out.iword(s_iosIndex) = int(d_language) + 1;
+}
+
+OutputLanguage SetLanguage::getLanguage(std::ostream& out) {
+  long& l = out.iword(s_iosIndex);
+  if(l == 0) {
+    // set the default language on this ostream
+    // (offset by one to detect whether default has been set yet)
+    if(not Options::isCurrentNull()) {
+      l = options::outputLanguage() + 1;
+    }
+    if(l <= 0 || l > language::output::LANG_MAX) {
+      // if called from outside the library, we may not have options
+      // available to us at this point (or perhaps the output language
+      // is not set in Options).  Default to something reasonable, but
+      // don't set "l" since that would make it "sticky" for this
+      // stream.
+      return OutputLanguage(s_defaultOutputLanguage);
+    }
+  }
+  return OutputLanguage(l - 1);
+}
+
+void SetLanguage::setLanguage(std::ostream& out, OutputLanguage l) {
+  // (offset by one to detect whether default has been set yet)
+  out.iword(s_iosIndex) = int(l) + 1;
+}
+
+std::ostream& operator<<(std::ostream& out, SetLanguage l) {
+  l.applyLanguage(out);
+  return out;
+}
+
+}/* CVC4::language namespace */
+}/* CVC4 namespace */