1 files changed, 19 insertions, 1 deletions
diff --git a/tutorius/constraints.py b/tutorius/constraints.py
index 36abdfb..455ede3 100644
--- a/tutorius/constraints.py
+++ b/tutorius/constraints.py
@@ -204,4 +204,22 @@ class FileConstraint(Constraint):
         if not os.path.isfile(value):
             raise FileConstraintError("Non-existing file : %s"%value)
         return
-    
+
+
+class SameTypeConstraintError(Exception):
+    pass
+     
+class SameTypeConstraint(Constraint):
+    """
+    Ensures that the list is not empty and that properties of the list have the same type. 
+    """
+   
+    def validate(self, value):  
+        if len(value)==0:
+            raise SameTypeConstraintError("The list is empty")
+        for i in value:
+            if i.type != value[0].type: 
+                raise SameTypeConstraintError("Properties have diffferent type")
+        return
+                 
+