1 files changed, 29 insertions, 32 deletions

diff --git a/dhall/src/phase/binary.rs b/dhall/src/phase/binary.rs
index 249d7c7..5110241 100644
--- a/dhall/src/phase/binary.rs
+++ b/dhall/src/phase/binary.rs
@@ -131,11 +131,11 @@ fn cbor_value_to_dhall(data: &cbor::Value) -> Result<ParsedExpr, DecodeError> {
                 Merge(x, y, Some(z))
             }
             [U64(7), Object(map)] => {
-                let map = cbor_map_to_dhall_map(map)?;
+                let map = cbor_map_to_dhall_map(map.iter())?;
                 RecordType(map)
             }
             [U64(8), Object(map)] => {
-                let map = cbor_map_to_dhall_map(map)?;
+                let map = cbor_map_to_dhall_map(map.iter())?;
                 RecordLit(map)
             }
             [U64(9), x, String(l)] => {
@@ -144,11 +144,11 @@ fn cbor_value_to_dhall(data: &cbor::Value) -> Result<ParsedExpr, DecodeError> {
                 Field(x, l)
             }
             [U64(11), Object(map)] => {
-                let map = cbor_map_to_dhall_opt_map(map)?;
+                let map = cbor_map_to_dhall_opt_map(map.iter())?;
                 UnionType(map)
             }
             [U64(12), String(l), x, Object(map)] => {
-                let map = cbor_map_to_dhall_opt_map(map)?;
+                let map = cbor_map_to_dhall_opt_map(map.iter())?;
                 let x = cbor_value_to_dhall(&x)?;
                 let l = Label::from(l.as_str());
                 UnionLit(l, x, map)
@@ -331,34 +331,31 @@ fn cbor_value_to_dhall(data: &cbor::Value) -> Result<ParsedExpr, DecodeError> {
     }))
 }
 
-fn cbor_map_to_dhall_map(
-    map: &std::collections::BTreeMap<cbor::ObjectKey, cbor::Value>,
-) -> Result<std::collections::BTreeMap<Label, ParsedExpr>, DecodeError> {
-    map.iter()
-        .map(|(k, v)| -> Result<(_, _), _> {
-            let k = k.as_string().ok_or_else(|| {
-                DecodeError::WrongFormatError("map/key".to_owned())
-            })?;
-            let v = cbor_value_to_dhall(v)?;
-            Ok((Label::from(k.as_ref()), v))
-        })
-        .collect::<Result<_, _>>()
+fn cbor_map_to_dhall_map<'a>(
+    map: impl Iterator<Item = (&'a cbor::ObjectKey, &'a cbor::Value)>,
+) -> Result<Vec<(Label, ParsedExpr)>, DecodeError> {
+    map.map(|(k, v)| -> Result<(_, _), _> {
+        let k = k.as_string().ok_or_else(|| {
+            DecodeError::WrongFormatError("map/key".to_owned())
+        })?;
+        let v = cbor_value_to_dhall(v)?;
+        Ok((Label::from(k.as_ref()), v))
+    })
+    .collect::<Result<_, _>>()
 }
 
-fn cbor_map_to_dhall_opt_map(
-    map: &std::collections::BTreeMap<cbor::ObjectKey, cbor::Value>,
-) -> Result<std::collections::BTreeMap<Label, Option<ParsedExpr>>, DecodeError>
-{
-    map.iter()
-        .map(|(k, v)| -> Result<(_, _), _> {
-            let k = k.as_string().ok_or_else(|| {
-                DecodeError::WrongFormatError("map/key".to_owned())
-            })?;
-            let v = match v {
-                cbor::Value::Null => None,
-                _ => Some(cbor_value_to_dhall(v)?),
-            };
-            Ok((Label::from(k.as_ref()), v))
-        })
-        .collect::<Result<_, _>>()
+fn cbor_map_to_dhall_opt_map<'a>(
+    map: impl Iterator<Item = (&'a cbor::ObjectKey, &'a cbor::Value)>,
+) -> Result<Vec<(Label, Option<ParsedExpr>)>, DecodeError> {
+    map.map(|(k, v)| -> Result<(_, _), _> {
+        let k = k.as_string().ok_or_else(|| {
+            DecodeError::WrongFormatError("map/key".to_owned())
+        })?;
+        let v = match v {
+            cbor::Value::Null => None,
+            _ => Some(cbor_value_to_dhall(v)?),
+        };
+        Ok((Label::from(k.as_ref()), v))
+    })
+    .collect::<Result<_, _>>()
 }