Make type annotation optional to allow serializing SimpleValue

1 files changed, 34 insertions, 0 deletions

diff --git a/serde_dhall/src/options/mod.rs b/serde_dhall/src/options/mod.rs
index 384f318..9241c45 100644
--- a/serde_dhall/src/options/mod.rs
+++ b/serde_dhall/src/options/mod.rs
@@ -1,2 +1,36 @@
+use crate::{SimpleType, StaticType};
+
 pub(crate) mod de;
 pub(crate) mod ser;
+
+#[derive(Debug, Clone, Copy)]
+pub struct NoAnnot;
+#[derive(Debug, Clone, Copy)]
+pub struct ManualAnnot<'ty>(&'ty SimpleType);
+#[derive(Debug, Clone, Copy)]
+pub struct StaticAnnot;
+
+pub trait TypeAnnot: Copy {}
+pub trait HasAnnot<A: TypeAnnot> {
+    fn get_annot(a: A) -> Option<SimpleType>;
+}
+
+impl TypeAnnot for NoAnnot {}
+impl TypeAnnot for ManualAnnot<'_> {}
+impl TypeAnnot for StaticAnnot {}
+
+impl<T> HasAnnot<NoAnnot> for T {
+    fn get_annot(_: NoAnnot) -> Option<SimpleType> {
+        None
+    }
+}
+impl<T> HasAnnot<ManualAnnot<'_>> for T {
+    fn get_annot(a: ManualAnnot<'_>) -> Option<SimpleType> {
+        Some(a.0.clone())
+    }
+}
+impl<T: StaticType> HasAnnot<StaticAnnot> for T {
+    fn get_annot(_: StaticAnnot) -> Option<SimpleType> {
+        Some(T::static_type())
+    }
+}