diff --git a/schala-lang/language/src/reduced_ir/mod.rs b/schala-lang/language/src/reduced_ir/mod.rs
index 7035052..b13da75 100644
--- a/schala-lang/language/src/reduced_ir/mod.rs
+++ b/schala-lang/language/src/reduced_ir/mod.rs
@@ -201,25 +201,18 @@ impl<'a> Reducer<'a> {
                     rval: Box::new(self.expression(rhs)),
                 }
             },
-            Some(op) => {
-                Expression::Call {
-                    f: Box::new(Expression::Callable(Function::Builtin(op))),
-                    args: vec![self.expression(lhs), self.expression(rhs)],
-                }
-            }
-            None => {
-                //TODO handle a user-defined operation
-                ReductionError("User-defined operations not supported".to_string())
-            }
+            Some(op) => Expression::Call {
+                f: Box::new(Expression::Callable(Function::Builtin(op))),
+                args: vec![self.expression(lhs), self.expression(rhs)],
+            },
+            //TODO handle a user-defined operation
+            None => ReductionError("User-defined operations not supported".to_string())
         }
     }
 
     fn value(&mut self, qualified_name: &ast::QualifiedName) -> Expression {
         use SymbolSpec::*;
 
-        let ast::QualifiedName { id: _, components, .. } = qualified_name;
-        let _ = components;
-
         let symbol = match self.symbol_table.lookup_symbol(&qualified_name.id) {
             Some(s) => s,
             None => return Expression::ReductionError(format!("No symbol found for name: {:?}", qualified_name))
diff --git a/schala-lang/language/src/reduced_ir/types.rs b/schala-lang/language/src/reduced_ir/types.rs
index 147e117..37af6b6 100644
--- a/schala-lang/language/src/reduced_ir/types.rs
+++ b/schala-lang/language/src/reduced_ir/types.rs
@@ -81,7 +81,12 @@ pub enum Function {
     Lambda {
         arity: u8,
         body: Vec<Statement>
-    }
+    },
+    DataConstructor {
+        type_id: Rc<String>, //TODO this can't last
+        arity: u32,
+        tag: u32
+    },
 }
 
 #[derive(Debug, Clone)]
diff --git a/schala-lang/language/src/tree_walk_eval/mod.rs b/schala-lang/language/src/tree_walk_eval/mod.rs
index 200af03..a868b39 100644
--- a/schala-lang/language/src/tree_walk_eval/mod.rs
+++ b/schala-lang/language/src/tree_walk_eval/mod.rs
@@ -278,6 +278,7 @@ impl<'a> State<'a> {
               let body = body.clone(); //TODO again ideally, no cloning here
               self.apply_function(body, args)
           }
+          Function::DataConstructor { .. } => panic!(),
       }
   }