Promote shift and subst_shift to traits

1 files changed, 1 insertions, 0 deletions

diff --git a/dhall/src/phase/normalize.rs b/dhall/src/phase/normalize.rs
index 5dfcfb6..e9fc570 100644
--- a/dhall/src/phase/normalize.rs
+++ b/dhall/src/phase/normalize.rs
@@ -5,6 +5,7 @@ use dhall_syntax::{BinOp, Builtin, ExprF, InterpolatedTextContents, Label, X};
 use crate::core::context::NormalizationContext;
 use crate::core::thunk::{Thunk, TypeThunk};
 use crate::core::value::Value;
+use crate::core::var::Subst;
 use crate::phase::{NormalizedSubExpr, ResolvedSubExpr, Typed};
 
 pub(crate) type InputSubExpr = ResolvedSubExpr;