From 5b2cc1df77e9258e8d14e9de56e317184544af6b Mon Sep 17 00:00:00 2001
From: Connor Skees <connor1skees@gmail.com>
Date: Wed, 8 Jul 2020 20:50:18 -0400
Subject: [PATCH] use btreemap to back scope

---
 src/common.rs |  2 +-
 src/scope.rs  | 14 +++++++-------
 2 files changed, 8 insertions(+), 8 deletions(-)

diff --git a/src/common.rs b/src/common.rs
index 882793c..c52a593 100644
--- a/src/common.rs
+++ b/src/common.rs
@@ -110,7 +110,7 @@ impl ListSeparator {
 ///
 /// This struct protects that invariant by normalizing all
 /// underscores into hypens.
-#[derive(Debug, Clone, Eq, PartialEq, Hash)]
+#[derive(Debug, Clone, Eq, PartialEq, Hash, PartialOrd, Ord)]
 pub(crate) struct Identifier(String);
 
 impl From<String> for Identifier {
diff --git a/src/scope.rs b/src/scope.rs
index 90e30f7..733b9cd 100644
--- a/src/scope.rs
+++ b/src/scope.rs
@@ -1,4 +1,4 @@
-use std::collections::HashMap;
+use std::collections::BTreeMap;
 
 use codemap::Spanned;
 
@@ -12,18 +12,18 @@ use crate::{
 
 #[derive(Debug, Default)]
 pub(crate) struct Scope {
-    vars: HashMap<Identifier, Spanned<Value>>,
-    mixins: HashMap<Identifier, Mixin>,
-    functions: HashMap<Identifier, Function>,
+    vars: BTreeMap<Identifier, Spanned<Value>>,
+    mixins: BTreeMap<Identifier, Mixin>,
+    functions: BTreeMap<Identifier, Function>,
 }
 
 impl Scope {
     #[must_use]
     pub fn new() -> Self {
         Self {
-            vars: HashMap::new(),
-            mixins: HashMap::new(),
-            functions: HashMap::new(),
+            vars: BTreeMap::new(),
+            mixins: BTreeMap::new(),
+            functions: BTreeMap::new(),
         }
     }