From 0427acd18cc06adec49783818107d1d5e2afc2ab Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Bla=C5=BE=20Hrastnik?= <blaz@mxxn.io>
Date: Sun, 13 Sep 2020 23:12:14 +0900
Subject: [PATCH] Avoid collect() by accepting iterators into
 Transaction::change.

---
 helix-core/src/commands.rs    | 2 +-
 helix-core/src/transaction.rs | 8 +++++---
 2 files changed, 6 insertions(+), 4 deletions(-)

diff --git a/helix-core/src/commands.rs b/helix-core/src/commands.rs
index 3bebd7b46..8dc817da8 100644
--- a/helix-core/src/commands.rs
+++ b/helix-core/src/commands.rs
@@ -155,7 +155,7 @@ pub fn open_below(state: &mut State, _count: usize) {
         0,
     );
 
-    let transaction = Transaction::change(state, changes.collect()).with_selection(selection);
+    let transaction = Transaction::change(state, changes).with_selection(selection);
 
     transaction.apply(state);
     // TODO: need to store into history if successful
diff --git a/helix-core/src/transaction.rs b/helix-core/src/transaction.rs
index 12ed523e4..4ecc575a8 100644
--- a/helix-core/src/transaction.rs
+++ b/helix-core/src/transaction.rs
@@ -353,8 +353,10 @@ impl Transaction {
     }
 
     /// Generate a transaction from a set of changes.
-    // TODO: take an owned iter instead of Vec
-    pub fn change(state: &State, changes: Vec<Change>) -> Self {
+    pub fn change<I>(state: &State, changes: I) -> Self
+    where
+        I: IntoIterator<Item = Change> + ExactSizeIterator,
+    {
         let len = state.doc.len_chars();
         let mut acc = Vec::with_capacity(2 * changes.len() + 1);
 
@@ -381,7 +383,7 @@ impl Transaction {
     where
         F: Fn(&SelectionRange) -> Change,
     {
-        Self::change(state, state.selection.ranges.iter().map(f).collect())
+        Self::change(state, state.selection.ranges.iter().map(f))
     }
 
     /// Insert text at each selection head.