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finish porting listing specs (!!) - hsmusic-wiki - HSMusic - static wiki software cataloguing collaborative creation
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author(quasar) nebula <qznebula@protonmail.com>2022-07-19 12:43:09 -0300
committer(quasar) nebula <qznebula@protonmail.com>2022-07-19 12:43:09 -0300
commit1455b384058184796279c629c21a754cd8fb4482 (patch)
treeabf277454e86ba73fac20716a824ce09203feec8 /src/util
parentf474ba28a5a46f39dd51e9d1838c18f07cd14a3d (diff)
finish porting listing specs (!!)
Diffstat (limited to 'src/util')
-rw-r--r--src/util/sugar.js14
1 files changed, 14 insertions, 0 deletions
diff --git a/src/util/sugar.js b/src/util/sugar.js
index 2883d949..754f1991 100644
--- a/src/util/sugar.js
+++ b/src/util/sugar.js
@@ -30,6 +30,20 @@ export function* splitArray(array, fn) {
   }
 }
 
+// Sums the values in an array, optionally taking a function which maps each
+// item to a number (handy for accessing a certain property on an array of like
+// objects). This also coalesces null values to zero, so if the mapping function
+// returns null (or values in the array are nullish), they'll just be skipped in
+// the sum.
+export function accumulateSum(array, fn = x => x) {
+  return array.reduce(
+    (accumulator, value, index, array) =>
+      accumulator +
+        fn(value, index, array) ?? 0,
+    0
+  );
+}
+
 export const mapInPlace = (array, fn) =>
   array.splice(0, array.length, ...array.map(fn));