1 files changed, 14 insertions, 0 deletions
diff --git a/error.h b/error.h
index f332ae4c..23386823 100644
--- a/error.h
+++ b/error.h
@@ -18,6 +18,20 @@ class error : public std::exception
   }
 };
 
+class compute_error : public error
+{
+ public:
+  compute_error(const std::string& reason) throw() : error(reason) {}
+  virtual ~compute_error() throw() {}
+};
+
+class expr_error : public error
+{
+ public:
+  expr_error(const std::string& reason) throw() : error(reason) {}
+  virtual ~expr_error() throw() {}
+};
+
 class parse_error : public error
 {
   unsigned int line;