From cd7835617a86068d76de3badaec0f94c44307094 Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Wed, 30 Jul 2025 15:08:47 +0000
Subject: [PATCH 1/4] Initial plan


From 7cd023a06cc0970dda71d0082a0c1417f1fa8960 Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Wed, 30 Jul 2025 15:38:58 +0000
Subject: [PATCH 2/4] Add time and space complexity documentation to core
 collection operators

Co-authored-by: T-Gro <46543583+T-Gro@users.noreply.github.com>
---
 src/FSharp.Core/array.fsi      | 10 +++++++++-
 src/FSharp.Core/list.fsi       | 10 +++++++++-
 src/FSharp.Core/prim-types.fsi |  4 ++++
 src/FSharp.Core/set.fsi        |  4 ++++
 4 files changed, 26 insertions(+), 2 deletions(-)

diff --git a/src/FSharp.Core/array.fsi b/src/FSharp.Core/array.fsi
index 18a4463277e..0ae2be5c515 100644
--- a/src/FSharp.Core/array.fsi
+++ b/src/FSharp.Core/array.fsi
@@ -46,6 +46,8 @@ module Array =
     ///
     /// <exception cref="T:System.ArgumentNullException">Thrown when either of the input arrays is null.</exception>
     ///
+    /// <remarks>Time complexity: O(n + m) where n and m are the lengths of the input arrays. Space complexity: O(n + m).</remarks>
+    ///
     /// <example id="append-1">
     /// <code lang="fsharp">
     /// Array.append [| 1; 2 |] [| 3; 4 |]
@@ -278,6 +280,8 @@ module Array =
     ///
     /// <exception cref="T:System.ArgumentNullException">Thrown when the input sequence is null.</exception>
     ///
+    /// <remarks>Time complexity: O(n) where n is the total number of elements in all arrays. Space complexity: O(n).</remarks>
+    ///
     /// <example id="concat-1">
     /// <code lang="fsharp">
     /// let inputs = [ [| 1; 2 |]; [| 3 |]; [| 4; 5 |] ]
@@ -1234,6 +1238,8 @@ module Array =
     /// <exception cref="T:System.ArgumentNullException">Thrown when the input array is null.</exception>
     /// <exception cref="T:System.ArgumentException">Thrown when the input array is empty.</exception>
     ///
+    /// <remarks>Time complexity: O(1). Space complexity: O(1).</remarks>
+    ///
     /// <example id="head-1">
     /// <code lang="fsharp">
     /// let inputs = [| "banana"; "pear" |]
@@ -1530,7 +1536,7 @@ module Array =
     ///
     /// <returns>The length of the array.</returns>
     ///
-    /// <remarks>The notation <c>array.Length</c> is preferred.</remarks>
+    /// <remarks>Time complexity: O(1). Space complexity: O(1). The notation <c>array.Length</c> is preferred.</remarks>
     ///
     /// <exception cref="T:System.NullReferenceException">Thrown when the input array is null.</exception>
     ///
@@ -2582,6 +2588,8 @@ module Array =
     ///
     /// <returns>A new array containing the elements of the original except the first element.</returns>
     ///
+    /// <remarks>Time complexity: O(n) where n is the length of the array. Space complexity: O(n).</remarks>
+    ///
     /// <example id="tail-1">
     /// <code lang="fsharp">
     /// let inputs = [| "a"; "bb"; "ccc" |]
diff --git a/src/FSharp.Core/list.fsi b/src/FSharp.Core/list.fsi
index c77e26ddaf0..42d0ad9d079 100644
--- a/src/FSharp.Core/list.fsi
+++ b/src/FSharp.Core/list.fsi
@@ -46,6 +46,8 @@ module List =
     ///
     /// <returns>The resulting list.</returns>
     /// 
+    /// <remarks>Time complexity: O(n) where n is the length of the first list. Space complexity: O(n).</remarks>
+    /// 
     /// <example id="append-1">
     /// <code lang="fsharp">
     /// List.append [ 1..3 ] [ 4..7 ]
@@ -345,6 +347,8 @@ module List =
     ///
     /// <returns>The resulting concatenated list.</returns>
     /// 
+    /// <remarks>Time complexity: O(n) where n is the total number of elements in all lists. Space complexity: O(n).</remarks>
+    /// 
     /// <example id="concat-1">
     /// <code lang="fsharp">
     /// let input = [ [1;2]
@@ -1013,6 +1017,8 @@ module List =
     ///
     /// <returns>The first element of the list.</returns>
     ///
+    /// <remarks>Time complexity: O(1). Space complexity: O(1).</remarks>
+    ///
     /// <example id="head-1">
     /// <code lang="fsharp">
     /// let inputs = ["banana"; "pear"]
@@ -1251,7 +1257,7 @@ module List =
     ///
     /// <returns>The length of the list.</returns>
     ///
-    /// <remarks>The notation <c>array.Length</c> is preferred.</remarks>
+    /// <remarks>Time complexity: O(n) where n is the length of the list. Space complexity: O(1). The notation <c>array.Length</c> is preferred.</remarks>
     ///
     /// <example id="length-1">
     /// <code lang="fsharp">
@@ -2088,6 +2094,8 @@ module List =
     ///
     /// <returns>The list after removing the first element.</returns>
     ///
+    /// <remarks>Time complexity: O(1). Space complexity: O(1).</remarks>
+    ///
     /// <example id="tail-1">
     /// <code lang="fsharp">
     /// let inputs = ["a"; "bb"; "ccc"]
diff --git a/src/FSharp.Core/prim-types.fsi b/src/FSharp.Core/prim-types.fsi
index 6697e108d2c..b755328f0c5 100644
--- a/src/FSharp.Core/prim-types.fsi
+++ b/src/FSharp.Core/prim-types.fsi
@@ -2674,6 +2674,8 @@ namespace Microsoft.FSharp.Collections
     [<CompiledName("FSharpList`1")>]
     type List<'T> =
         | ([]): 'T list
+        /// <summary>Cons operator for adding an element to the front of a list.</summary>
+        /// <remarks>Time complexity: O(1). Space complexity: O(1).</remarks>
         | (::): Head: 'T * Tail: 'T list -> 'T list
 
         /// <summary>Returns an empty list of a particular type</summary>
@@ -3800,6 +3802,8 @@ namespace Microsoft.FSharp.Core
         ///
         /// <returns>The concatenation of the lists.</returns>
         /// 
+        /// <remarks>Time complexity: O(n) where n is the length of the first list. Space complexity: O(n).</remarks>
+        /// 
         /// <example id="list-concat-example">
         /// <code lang="fsharp">
         /// let l1 = ['a'; 'b'; 'c']
diff --git a/src/FSharp.Core/set.fsi b/src/FSharp.Core/set.fsi
index d60432fcd0b..6a6267318e0 100644
--- a/src/FSharp.Core/set.fsi
+++ b/src/FSharp.Core/set.fsi
@@ -297,6 +297,8 @@ module Set =
     ///
     /// <returns>A new set containing <c>value</c>.</returns>
     ///
+    /// <remarks>Time complexity: O(log n) where n is the size of the set. Space complexity: O(log n) due to path copying in the balanced tree.</remarks>
+    ///
     /// <example id="set-add">
     /// <code lang="fsharp">
     /// let set = Set.empty.Add(1).Add(1).Add(2)
@@ -680,6 +682,8 @@ module Set =
     ///
     /// <returns>The input set with <c>value</c> removed.</returns>
     ///
+    /// <remarks>Time complexity: O(log n) where n is the size of the set. Space complexity: O(log n) due to path copying in the balanced tree.</remarks>
+    ///
     /// <example id="set-remove">
     /// <code lang="fsharp">
     /// let set = Set.empty.Add(1).Add(2).Add(3)

From 157bbf8cbd3e6751c705e3f104cc8376c43a7559 Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Wed, 30 Jul 2025 15:46:34 +0000
Subject: [PATCH 3/4] Complete time and space complexity documentation for
 collection operators

Co-authored-by: T-Gro <46543583+T-Gro@users.noreply.github.com>
---
 src/FSharp.Core/map.fsi | 4 ++++
 src/FSharp.Core/seq.fsi | 4 +++-
 src/FSharp.Core/set.fsi | 4 ++++
 3 files changed, 11 insertions(+), 1 deletion(-)

diff --git a/src/FSharp.Core/map.fsi b/src/FSharp.Core/map.fsi
index 2fdabdbb29f..911161f778a 100644
--- a/src/FSharp.Core/map.fsi
+++ b/src/FSharp.Core/map.fsi
@@ -230,6 +230,8 @@ module Map =
     ///
     /// <returns>The resulting map.</returns>
     ///
+    /// <remarks>Time complexity: O(log n) where n is the size of the map. Space complexity: O(log n) due to path copying in the balanced tree.</remarks>
+    ///
     /// <example id="add-1">
     /// <code lang="fsharp">
     /// let input = Map [ (1, "a"); (2, "b") ]
@@ -643,6 +645,8 @@ module Map =
     ///
     /// <returns>The resulting map.</returns>
     ///
+    /// <remarks>Time complexity: O(log n) where n is the size of the map. Space complexity: O(log n) due to path copying in the balanced tree.</remarks>
+    ///
     /// <example id="remove-1">
     /// <code lang="fsharp">
     /// let sample = Map [ (1, "a"); (2, "b") ]
diff --git a/src/FSharp.Core/seq.fsi b/src/FSharp.Core/seq.fsi
index 24189d3730c..5d51023286c 100644
--- a/src/FSharp.Core/seq.fsi
+++ b/src/FSharp.Core/seq.fsi
@@ -38,7 +38,9 @@ module Seq =
     ///
     /// <remarks>The returned sequence may be passed between threads safely. However,
     /// individual IEnumerator values generated from the returned sequence should not be accessed
-    /// concurrently.</remarks>
+    /// concurrently.
+    /// 
+    /// Time complexity: O(1) - sequences are lazily evaluated. Space complexity: O(1).</remarks>
     ///
     /// <param name="source1">The first sequence.</param>
     /// <param name="source2">The second sequence.</param>
diff --git a/src/FSharp.Core/set.fsi b/src/FSharp.Core/set.fsi
index 6a6267318e0..5a9920514a2 100644
--- a/src/FSharp.Core/set.fsi
+++ b/src/FSharp.Core/set.fsi
@@ -541,6 +541,8 @@ module Set =
     ///
     /// <returns>The intersection of <c>set1</c> and <c>set2</c>.</returns>
     ///
+    /// <remarks>Time complexity: O(n + m) where n and m are the sizes of the input sets. Space complexity: O(min(n, m)).</remarks>
+    ///
     /// <example id="set-intersect">
     /// <code lang="fsharp">
     /// let set1 = Set.empty.Add(1).Add(2).Add(3)
@@ -584,6 +586,8 @@ module Set =
     ///
     /// <returns>The union of <c>set1</c> and <c>set2</c>.</returns>
     ///
+    /// <remarks>Time complexity: O(n + m) where n and m are the sizes of the input sets. Space complexity: O(n + m).</remarks>
+    ///
     /// <example id="set-union">
     /// <code lang="fsharp">
     /// let set1 = Set.empty.Add(1).Add(2).Add(3)

From 8c49a0978445de7b52e750f11dcafd07996c35a0 Mon Sep 17 00:00:00 2001
From: GH Actions <actions@github.com>
Date: Thu, 31 Jul 2025 08:49:01 +0000
Subject: [PATCH 4/4] Apply patch from /run fantomas

---
 src/FSharp.Core/seq.fsi | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/FSharp.Core/seq.fsi b/src/FSharp.Core/seq.fsi
index 5d51023286c..fd5e59c616f 100644
--- a/src/FSharp.Core/seq.fsi
+++ b/src/FSharp.Core/seq.fsi
@@ -39,7 +39,7 @@ module Seq =
     /// <remarks>The returned sequence may be passed between threads safely. However,
     /// individual IEnumerator values generated from the returned sequence should not be accessed
     /// concurrently.
-    /// 
+    ///
     /// Time complexity: O(1) - sequences are lazily evaluated. Space complexity: O(1).</remarks>
     ///
     /// <param name="source1">The first sequence.</param>