From: Matthias Kruk <m@m10k.eu>
Date: Wed, 2 Feb 2022 11:20:12 +0000 (+0900)
Subject: include/array: Improve performance of array_to_lines()
X-Git-Url: https://git.corax.cc/?a=commitdiff_plain;h=7a62d607cd963ae917dc96e6c51f67c6bb650e2b;p=toolbox

include/array: Improve performance of array_to_lines()

`array_to_lines()` calls `echo` for every element in the array, which
is wasteful and scales very poorly.

This commit modifies `array_to_lines()` so that it uses a single call
to `printf` to print all array elements.

This issue was pointed out by reddit user u/oh5nxo.
---

diff --git a/include/array.sh b/include/array.sh
index 7008b59..de5b820 100644
--- a/include/array.sh
+++ b/include/array.sh
@@ -37,11 +37,11 @@ array_contains() {
 
 array_to_lines() {
 	local array=("$@")
-	local item
 
-	for item in "${array[@]}"; do
-		echo "$item"
-	done
+	# Don't print an empty line if array is empty
+	if (( ${#array[@]} > 0 )); then
+		printf "%s\n" "${array[@]}"
+	fi
 }
 
 array_sort() {