Thread lifetimes through other newtypes

Closes #55

1 files changed, 36 insertions, 44 deletions

diff --git a/dhall/src/expr.rs b/dhall/src/expr.rs
index e3a2fe5..3987896 100644
--- a/dhall/src/expr.rs
+++ b/dhall/src/expr.rs
@@ -4,25 +4,6 @@ use std::marker::PhantomData;
 
 macro_rules! derive_other_traits {
     ($ty:ident) => {
-        impl std::cmp::PartialEq for $ty {
-            fn eq(&self, other: &Self) -> bool {
-                self.0 == other.0
-            }
-        }
-
-        impl std::fmt::Display for $ty {
-            fn fmt(
-                &self,
-                f: &mut std::fmt::Formatter,
-            ) -> Result<(), std::fmt::Error> {
-                self.0.fmt(f)
-            }
-        }
-    };
-}
-
-macro_rules! derive_other_traits_ {
-    ($ty:ident) => {
         impl<'a> std::cmp::PartialEq for $ty<'a> {
             fn eq(&self, other: &Self) -> bool {
                 self.0 == other.0
@@ -46,85 +27,96 @@ pub struct Parsed<'a>(
     pub(crate) ImportRoot,
     pub(crate) PhantomData<&'a ()>,
 );
-derive_other_traits_!(Parsed);
+derive_other_traits!(Parsed);
 
 #[derive(Debug, Clone, Eq)]
 pub struct Resolved<'a>(
-    pub(crate) SubExpr<X, Normalized>,
+    pub(crate) SubExpr<X, Normalized<'static>>,
     pub(crate) PhantomData<&'a ()>,
 );
-derive_other_traits_!(Resolved);
+derive_other_traits!(Resolved);
 
 #[derive(Debug, Clone, Eq)]
-pub struct Typed(pub(crate) SubExpr<X, Normalized>, pub(crate) Option<Type>);
+pub struct Typed<'a>(
+    pub(crate) SubExpr<X, Normalized<'static>>,
+    pub(crate) Option<Type<'static>>,
+    pub(crate) PhantomData<&'a ()>,
+);
 derive_other_traits!(Typed);
 
 #[derive(Debug, Clone, Eq)]
-pub struct Normalized(pub(crate) SubExpr<X, X>, pub(crate) Option<Type>);
+pub struct Normalized<'a>(
+    pub(crate) SubExpr<X, X>,
+    pub(crate) Option<Type<'static>>,
+    pub(crate) PhantomData<&'a ()>,
+);
 derive_other_traits!(Normalized);
 
 /// An expression of type `Type` (like `Bool` or `Natural -> Text`, but not `Type`)
 #[derive(Debug, Clone, Eq)]
-pub struct SimpleType(pub(crate) SubExpr<X, X>);
+pub struct SimpleType<'a>(
+    pub(crate) SubExpr<X, X>,
+    pub(crate) PhantomData<&'a ()>,
+);
 derive_other_traits!(SimpleType);
 
 #[derive(Debug, Clone, PartialEq, Eq)]
-pub struct Type(pub(crate) TypeInternal);
+pub struct Type<'a>(pub(crate) TypeInternal<'a>);
 
 #[derive(Debug, Clone, PartialEq, Eq)]
-pub(crate) enum TypeInternal {
-    Expr(Box<Normalized>),
+pub(crate) enum TypeInternal<'a> {
+    Expr(Box<Normalized<'a>>),
     // The type of `Sort`
     SuperType,
 }
 
 // Exposed for the macros
 #[doc(hidden)]
-impl From<SimpleType> for SubExpr<X, X> {
-    fn from(x: SimpleType) -> SubExpr<X, X> {
+impl<'a> From<SimpleType<'a>> for SubExpr<X, X> {
+    fn from(x: SimpleType<'a>) -> SubExpr<X, X> {
         x.0
     }
 }
 
 // Exposed for the macros
 #[doc(hidden)]
-impl From<SubExpr<X, X>> for SimpleType {
-    fn from(x: SubExpr<X, X>) -> SimpleType {
-        SimpleType(x)
+impl<'a> From<SubExpr<X, X>> for SimpleType<'a> {
+    fn from(x: SubExpr<X, X>) -> SimpleType<'a> {
+        SimpleType(x, PhantomData)
     }
 }
 
 // Exposed for the macros
 #[doc(hidden)]
-impl From<Normalized> for Typed {
-    fn from(x: Normalized) -> Typed {
-        Typed(x.0.absurd(), x.1)
+impl<'a> From<Normalized<'a>> for Typed<'a> {
+    fn from(x: Normalized<'a>) -> Typed<'a> {
+        Typed(x.0.absurd(), x.1, x.2)
     }
 }
 
-impl Typed {
-    pub(crate) fn as_expr(&self) -> &SubExpr<X, Normalized> {
+impl<'a> Typed<'a> {
+    pub(crate) fn as_expr(&self) -> &SubExpr<X, Normalized<'a>> {
         &self.0
     }
-    pub(crate) fn into_expr(self) -> SubExpr<X, Normalized> {
+    pub(crate) fn into_expr(self) -> SubExpr<X, Normalized<'a>> {
         self.0
     }
 }
 
-impl Normalized {
+impl<'a> Normalized<'a> {
     pub(crate) fn as_expr(&self) -> &SubExpr<X, X> {
         &self.0
     }
     pub(crate) fn into_expr<T>(self) -> SubExpr<X, T> {
         self.0.absurd()
     }
-    pub(crate) fn into_type(self) -> Type {
+    pub(crate) fn into_type(self) -> Type<'a> {
         crate::expr::Type(TypeInternal::Expr(Box::new(self)))
     }
 }
 
-impl SimpleType {
-    pub(crate) fn into_type(self) -> Type {
-        Normalized(self.0, Some(Type::const_type())).into_type()
+impl<'a> SimpleType<'a> {
+    pub(crate) fn into_type(self) -> Type<'a> {
+        Normalized(self.0, Some(Type::const_type()), PhantomData).into_type()
     }
 }