1 files changed, 43 insertions, 0 deletions
diff --git a/dhall/src/traits/deserialize.rs b/dhall/src/traits/deserialize.rs
new file mode 100644
index 0000000..8d1f565
--- /dev/null
+++ b/dhall/src/traits/deserialize.rs
@@ -0,0 +1,43 @@
+use crate::error::*;
+use crate::expr::*;
+
+pub trait Deserialize<'a>: Sized {
+    fn from_str(s: &'a str, ty: Option<&Type>) -> Result<Self>;
+}
+
+impl<'a> Deserialize<'a> for Parsed {
+    /// Simply parses the provided string. Ignores the
+    /// provided type.
+    fn from_str(s: &'a str, _ty: Option<&Type>) -> Result<Self> {
+        Ok(Parsed::parse_str(s).map_err(|_| ())?)
+    }
+}
+
+impl<'a> Deserialize<'a> for Resolved {
+    /// Parses and resolves the provided string. Ignores the
+    /// provided type.
+    fn from_str(s: &'a str, ty: Option<&Type>) -> Result<Self> {
+        Ok(Parsed::from_str(s, ty)?.resolve().map_err(|_| ())?)
+    }
+}
+
+impl<'a> Deserialize<'a> for Typed {
+    /// Parses, resolves and typechecks the provided string.
+    fn from_str(s: &'a str, ty: Option<&Type>) -> Result<Self> {
+        // TODO: compare with provided type
+        Ok(Resolved::from_str(s, ty)?.typecheck().map_err(|_| ())?)
+    }
+}
+
+impl<'a> Deserialize<'a> for Normalized {
+    /// Parses, resolves, typechecks and normalizes the provided string.
+    fn from_str(s: &'a str, ty: Option<&Type>) -> Result<Self> {
+        Ok(Typed::from_str(s, ty)?.normalize())
+    }
+}
+
+impl<'a> Deserialize<'a> for Type {
+    fn from_str(s: &'a str, ty: Option<&Type>) -> Result<Self> {
+        Ok(Normalized::from_str(s, ty)?.into_type())
+    }
+}