1 files changed, 25 insertions, 27 deletions

diff --git a/dhall/src/api/serde.rs b/serde_dhall/src/serde.rs
index e1c8eef..26708c1 100644
--- a/dhall/src/api/serde.rs
+++ b/serde_dhall/src/serde.rs
@@ -1,8 +1,11 @@
-use crate::api::de::{Deserialize, Value};
-use crate::error::{Error, Result};
-use dhall_syntax::{ExprF, SubExpr, X};
 use std::borrow::Cow;
 
+use dhall::phase::NormalizedExpr;
+use dhall_syntax::ExprF;
+
+use crate::de::{Deserialize, Error, Result};
+use crate::Value;
+
 impl<'a, T> Deserialize for T
 where
     T: serde::Deserialize<'a>,
@@ -12,16 +15,7 @@ where
     }
 }
 
-struct Deserializer<'a>(Cow<'a, SubExpr<X, X>>);
-
-impl serde::de::Error for Error {
-    fn custom<T>(msg: T) -> Self
-    where
-        T: std::fmt::Display,
-    {
-        Error::Deserialize(msg.to_string())
-    }
-}
+struct Deserializer<'a>(Cow<'a, NormalizedExpr>);
 
 impl<'de: 'a, 'a> serde::de::IntoDeserializer<'de, Error> for Deserializer<'a> {
     type Deserializer = Deserializer<'a>;
@@ -39,20 +33,24 @@ impl<'de: 'a, 'a> serde::Deserializer<'de> for Deserializer<'a> {
         use std::convert::TryInto;
         use ExprF::*;
         match self.0.as_ref().as_ref() {
-            NaturalLit(n) => match (*n).try_into() {
-                Ok(n64) => visitor.visit_u64(n64),
-                Err(_) => match (*n).try_into() {
-                    Ok(n32) => visitor.visit_u32(n32),
-                    Err(_) => unimplemented!(),
-                },
-            },
-            IntegerLit(n) => match (*n).try_into() {
-                Ok(n64) => visitor.visit_i64(n64),
-                Err(_) => match (*n).try_into() {
-                    Ok(n32) => visitor.visit_i32(n32),
-                    Err(_) => unimplemented!(),
-                },
-            },
+            NaturalLit(n) => {
+                if let Ok(n64) = (*n).try_into() {
+                    visitor.visit_u64(n64)
+                } else if let Ok(n32) = (*n).try_into() {
+                    visitor.visit_u32(n32)
+                } else {
+                    unimplemented!()
+                }
+            }
+            IntegerLit(n) => {
+                if let Ok(n64) = (*n).try_into() {
+                    visitor.visit_i64(n64)
+                } else if let Ok(n32) = (*n).try_into() {
+                    visitor.visit_i32(n32)
+                } else {
+                    unimplemented!()
+                }
+            }
             RecordLit(m) => visitor.visit_map(
                 serde::de::value::MapDeserializer::new(m.iter().map(
                     |(k, v)| (k.as_ref(), Deserializer(Cow::Borrowed(v))),