1 files changed, 53 insertions, 0 deletions
diff --git a/dhall/src/api/traits/deserialize.rs b/dhall/src/api/traits/deserialize.rs
new file mode 100644
index 0000000..9673cf9
--- /dev/null
+++ b/dhall/src/api/traits/deserialize.rs
@@ -0,0 +1,53 @@
+use crate::error::*;
+use crate::phase::*;
+
+/// A data structure that can be deserialized from a Dhall expression
+///
+/// This is automatically implemented for any type that [serde][serde]
+/// can deserialize.
+///
+/// This trait cannot be implemented manually.
+pub trait Deserialize<'de>: Sized {
+    /// See [dhall::de::from_str][crate::de::from_str]
+    fn from_str(s: &'de str, ty: Option<&Type>) -> Result<Self>;
+}
+
+impl<'de> Deserialize<'de> for Parsed {
+    /// Simply parses the provided string. Ignores the
+    /// provided type.
+    fn from_str(s: &'de str, _: Option<&Type>) -> Result<Self> {
+        Ok(Parsed::parse_str(s)?)
+    }
+}
+
+impl<'de> Deserialize<'de> for Resolved {
+    /// Parses and resolves the provided string. Ignores the
+    /// provided type.
+    fn from_str(s: &'de str, ty: Option<&Type>) -> Result<Self> {
+        Ok(Parsed::from_str(s, ty)?.resolve()?)
+    }
+}
+
+impl<'de> Deserialize<'de> for Typed {
+    /// Parses, resolves and typechecks the provided string.
+    fn from_str(s: &'de str, ty: Option<&Type>) -> Result<Self> {
+        let resolved = Resolved::from_str(s, ty)?;
+        match ty {
+            None => Ok(resolved.typecheck()?),
+            Some(t) => Ok(resolved.typecheck_with(t)?),
+        }
+    }
+}
+
+impl<'de> Deserialize<'de> for Normalized {
+    /// Parses, resolves, typechecks and normalizes the provided string.
+    fn from_str(s: &'de str, ty: Option<&Type>) -> Result<Self> {
+        Ok(Typed::from_str(s, ty)?.normalize())
+    }
+}
+
+impl<'de> Deserialize<'de> for Type {
+    fn from_str(s: &'de str, ty: Option<&Type>) -> Result<Self> {
+        Ok(Normalized::from_str(s, ty)?.to_type())
+    }
+}