From 588127bf4105d8d4629304521abc3d992326a63a Mon Sep 17 00:00:00 2001
From: Nadrieril
Date: Thu, 18 Apr 2019 19:34:38 +0200
Subject: subst_shift in a single pass

---
 dhall_core/src/context.rs | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

(limited to 'dhall_core/src/context.rs')

diff --git a/dhall_core/src/context.rs b/dhall_core/src/context.rs
index 877843d..b500226 100644
--- a/dhall_core/src/context.rs
+++ b/dhall_core/src/context.rs
@@ -43,6 +43,20 @@ impl<K: Hash + Eq + Clone, T> Context<K, T> {
                 .collect(),
         )
     }
+
+    pub fn lookup_all<'a>(&'a self, k: &K) -> impl Iterator<Item = &T> {
+        self.0.get(k).into_iter().flat_map(|v| v.iter())
+    }
+
+    pub fn iter<'a>(&'a self) -> impl Iterator<Item = (&K, &T)> {
+        self.0
+            .iter()
+            .flat_map(|(k, vs)| vs.iter().map(move |v| (k, v)))
+    }
+
+    pub fn iter_keys<'a>(&'a self) -> impl Iterator<Item = (&K, &Vec<T>)> {
+        self.0.iter()
+    }
 }
 
 impl<K: Hash + Eq + Clone, T: Clone> Context<K, T> {
-- 
cgit v1.2.3


From 486a26eb7cea0c99818fde2c3fd933f7aca40b52 Mon Sep 17 00:00:00 2001
From: Nadrieril
Date: Thu, 18 Apr 2019 22:08:25 +0200
Subject: Use a context for substitution in normalization

---
 dhall_core/src/context.rs | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

(limited to 'dhall_core/src/context.rs')

diff --git a/dhall_core/src/context.rs b/dhall_core/src/context.rs
index b500226..91eec69 100644
--- a/dhall_core/src/context.rs
+++ b/dhall_core/src/context.rs
@@ -32,7 +32,13 @@ impl<K: Hash + Eq + Clone, T> Context<K, T> {
     /// lookup k n (insert j v c) = lookup k  n      c  -- k /= j
     /// ```
     pub fn lookup<'a>(&'a self, k: &K, n: usize) -> Option<&'a T> {
-        self.0.get(k).and_then(|v| v.get(v.len() - 1 - n))
+        self.0.get(k).and_then(|v| {
+            if n < v.len() {
+                v.get(v.len() - 1 - n)
+            } else {
+                None
+            }
+        })
     }
 
     pub fn map<U, F: Fn(&T) -> U>(&self, f: F) -> Context<K, U> {
-- 
cgit v1.2.3


From 0682a84eadc383e1d5747576298c9160737e0e99 Mon Sep 17 00:00:00 2001
From: Nadrieril
Date: Thu, 18 Apr 2019 22:20:40 +0200
Subject: Label is redundant in EnvItem::Skip

---
 dhall_core/src/context.rs | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

(limited to 'dhall_core/src/context.rs')

diff --git a/dhall_core/src/context.rs b/dhall_core/src/context.rs
index 91eec69..55bfff5 100644
--- a/dhall_core/src/context.rs
+++ b/dhall_core/src/context.rs
@@ -41,11 +41,13 @@ impl<K: Hash + Eq + Clone, T> Context<K, T> {
         })
     }
 
-    pub fn map<U, F: Fn(&T) -> U>(&self, f: F) -> Context<K, U> {
+    pub fn map<U, F: Fn(&K, &T) -> U>(&self, f: F) -> Context<K, U> {
         Context(
             self.0
                 .iter()
-                .map(|(k, v)| ((*k).clone(), v.iter().map(&f).collect()))
+                .map(|(k, vs)| {
+                    ((*k).clone(), vs.iter().map(|v| f(k, v)).collect())
+                })
                 .collect(),
         )
     }
-- 
cgit v1.2.3