From 1a3e407f9373cad9567b03619a4c6a3ccb41fb67 Mon Sep 17 00:00:00 2001
From: Ewan Breakey <ebreakey@gmail.com>
Date: Wed, 19 Jul 2023 16:13:47 +1000
Subject: [PATCH 1/2] Implement intersperse utility

---
 .changeset/good-terms-deliver.md |  5 +++++
 lib/arrays/intersperseArray.ts   | 36 ++++++++++++++++++++++++++++++++
 2 files changed, 41 insertions(+)
 create mode 100644 .changeset/good-terms-deliver.md
 create mode 100644 lib/arrays/intersperseArray.ts

diff --git a/.changeset/good-terms-deliver.md b/.changeset/good-terms-deliver.md
new file mode 100644
index 0000000..9506383
--- /dev/null
+++ b/.changeset/good-terms-deliver.md
@@ -0,0 +1,5 @@
+---
+"@giraugh/tools": minor
+---
+
+Implement intersperseArray utility
diff --git a/lib/arrays/intersperseArray.ts b/lib/arrays/intersperseArray.ts
new file mode 100644
index 0000000..16dcba9
--- /dev/null
+++ b/lib/arrays/intersperseArray.ts
@@ -0,0 +1,36 @@
+/**
+ * Intersperse a seperator element between every element of a given array
+ * @param arr the array to intersperse into
+ * @param sep a seperator element to distribute throughout `arr`
+ * @returns `arr` with `sep` interspersed between every pair of elements
+ *
+ * @example
+ * intersperseArray([[1, 2], [3, 4], [5, 6]], []) // [[1, 2], [], [3, 4], [], [5, 6]]
+
+ * @example
+ * intersperseArray(['alpha', 'beta', 'gamma'], '!') // ['alpha', '!', 'beta', '!', 'gamma']
+ */
+export const intersperseArray = <T>(arr: T[], sep: T): T[] => {
+  const gen = function*() {
+    while (arr.length > 0) {
+      yield arr.shift()!
+      if (arr.length > 0) yield sep
+    }
+  }
+  return Array.from(gen())
+}
+
+
+if (import.meta.vitest) {
+  const { expect, it } = import.meta.vitest
+
+  it('works for example 1', () => {
+    const inter = intersperseArray([[1, 2, 3], [4, 5, 6], [7, 8, 9]], [])
+    expect(inter).toEqual([[1, 2, 3], [], [4, 5, 6], [], [7, 8, 9]])
+  })
+
+  it('works for example 2', () => {
+    const inter = intersperseArray(['alpha', 'beta', 'gamma'], '!')
+    expect(inter).toEqual(['alpha', '!', 'beta', '!', 'gamma'])
+  })
+}

From bb5cff83deaef8f76d525fb657c7f43b4f0ec270 Mon Sep 17 00:00:00 2001
From: Ewan Breakey <ebreakey@gmail.com>
Date: Wed, 19 Jul 2023 22:29:14 +1000
Subject: [PATCH 2/2] Update lib/arrays/intersperseArray.ts

Co-authored-by: Benji Grant <benjamin.grantGRA0007@gmail.com>
---
 lib/arrays/intersperseArray.ts | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/lib/arrays/intersperseArray.ts b/lib/arrays/intersperseArray.ts
index 16dcba9..f6d6aa3 100644
--- a/lib/arrays/intersperseArray.ts
+++ b/lib/arrays/intersperseArray.ts
@@ -33,4 +33,12 @@ if (import.meta.vitest) {
     const inter = intersperseArray(['alpha', 'beta', 'gamma'], '!')
     expect(inter).toEqual(['alpha', '!', 'beta', '!', 'gamma'])
   })
+  
+  it('does nothing to an empty array', () => {
+    expect(intersperseArray([] as string[], 'hello')).toEqual([])
+  })
+  
+  it('does nothing to an array with one element', () => {
+    expect(intersperseArray(['suave'], '$')).toEqual(['suave'])
+  })
 }