Merge pull request #147 from 01mf02/default-owned

Correct `Default` implementation for `Owned` filters.

jaq-interpret/src/filter.rs

@@ -8,9 +8,15 @@ use jaq_syn::filter::FoldType;
 use jaq_syn::{MathOp, OrdOp};
 
 /// Function from a value to a stream of value results.
-#[derive(Debug, Default, Clone)]
+#[derive(Debug, Clone)]
 pub struct Owned(Id, Vec<Ast>);
 
+impl Default for Owned {
+    fn default() -> Self {
+        Self(Id(0), Vec::from([Ast::Id]))
+    }
+}
+
 #[derive(Debug, Copy, Clone)]
 pub struct Ref<'a>(Id, &'a [Ast]);