From ab7591e45e7e31b4e2c0e2f81e224672145993fa Mon Sep 17 00:00:00 2001
From: "(quasar) nebula" <qznebula@protonmail.com>
Date: Sun, 1 Oct 2023 17:01:21 -0300
Subject: data, test: refactor utilities into own file

Primarily for more precies test coverage mapping, but also to make
navigation a bit easier and consolidate complex functions with
lots of imports out of the same space as other, more simple or
otherwise specialized files.
---
 src/data/composite/data/withUnflattenedList.js | 62 ++++++++++++++++++++++++++
 1 file changed, 62 insertions(+)
 create mode 100644 src/data/composite/data/withUnflattenedList.js

(limited to 'src/data/composite/data/withUnflattenedList.js')

diff --git a/src/data/composite/data/withUnflattenedList.js b/src/data/composite/data/withUnflattenedList.js
new file mode 100644
index 00000000..3cfc247b
--- /dev/null
+++ b/src/data/composite/data/withUnflattenedList.js
@@ -0,0 +1,62 @@
+// After mapping the contents of a flattened array in-place (being careful to
+// retain the original indices by replacing unmatched results with null instead
+// of filtering them out), this function allows for recombining them. It will
+// filter out null and undefined items by default (pass {filter: false} to
+// disable this).
+
+import {input, templateCompositeFrom} from '#composite';
+import {isWholeNumber, validateArrayItems} from '#validators';
+
+export default templateCompositeFrom({
+  annotation: `withUnflattenedList`,
+
+  inputs: {
+    list: input({
+      type: 'array',
+      defaultDependency: '#flattenedList',
+    }),
+
+    indices: input({
+      validate: validateArrayItems(isWholeNumber),
+      defaultDependency: '#flattenedIndices',
+    }),
+
+    filter: input({
+      type: 'boolean',
+      defaultValue: true,
+    }),
+  },
+
+  outputs: ['#unflattenedList'],
+
+  steps: () => [
+    {
+      dependencies: [input('list'), input('indices'), input('filter')],
+      compute(continuation, {
+        [input('list')]: list,
+        [input('indices')]: indices,
+        [input('filter')]: filter,
+      }) {
+        const unflattenedList = [];
+
+        for (let i = 0; i < indices.length; i++) {
+          const startIndex = indices[i];
+          const endIndex =
+            (i === indices.length - 1
+              ? list.length
+              : indices[i + 1]);
+
+          const values = list.slice(startIndex, endIndex);
+          unflattenedList.push(
+            (filter
+              ? values.filter(value => value !== null && value !== undefined)
+              : values));
+        }
+
+        return continuation({
+          ['#unflattenedList']: unflattenedList,
+        });
+      },
+    },
+  ],
+});
-- 
cgit 1.3.0-6-gf8a5