From 45d1e4f4aa75c2e6df486e82d831903113122980 Mon Sep 17 00:00:00 2001
From: aranchelk <carlhaken@gmail.com>
Date: Sun, 8 Jun 2025 06:55:31 -0700
Subject: [PATCH 1/2] Improve documentation for Map functions with bounds
 params (#74)

* Make it clear that the bounds are inclusive. Previously this was ambiguous in the prose and only indicated by the examples.
* Generally tighten up the writing.
---
 src/Data/Map/Internal.purs | 14 ++++++--------
 1 file changed, 6 insertions(+), 8 deletions(-)

diff --git a/src/Data/Map/Internal.purs b/src/Data/Map/Internal.purs
index 81cc398..39ae443 100644
--- a/src/Data/Map/Internal.purs
+++ b/src/Data/Map/Internal.purs
@@ -365,10 +365,9 @@ findMin = case _ of
       Leaf -> Just { key: k, value: v }
       _ -> findMin l
 
--- | Fold over the entries of a given map where the key is between a lower and
--- | an upper bound. Passing `Nothing` as either the lower or upper bound
--- | argument means that the fold has no lower or upper bound, i.e. the fold
--- | starts from (or ends with) the smallest (or largest) key in the map.
+-- | Fold over the entries of a given map that have keys within a lower and
+-- | upper bound (including keys equal to those bounds). `Nothing` is treated as
+-- | unbounded.
 -- |
 -- | ```purescript
 -- | foldSubmap (Just 1) (Just 2) (\_ v -> [v])
@@ -420,10 +419,9 @@ foldSubmapBy appendFn memptyValue kmin kmax f =
   in
     go
 
--- | Returns a new map containing all entries of the given map which lie
--- | between a given lower and upper bound, treating `Nothing` as no bound i.e.
--- | including the smallest (or largest) key in the map, no matter how small
--- | (or large) it is. For example:
+-- | Returns a new map containing all entries with keys that fall within a
+-- | specified lower and upper bound (including keys equal to those bounds).
+-- | `Nothing` is treated as unbounded.
 -- |
 -- | ```purescript
 -- | submap (Just 1) (Just 2)

From 92a7c20fda232d0eb30d5ef0da87991fd27b0703 Mon Sep 17 00:00:00 2001
From: Thomas Cumming <mail@tomcumming.co.uk>
Date: Sat, 11 Apr 2026 23:11:57 +0100
Subject: [PATCH 2/2] Add set limit to range operation using submap (#75)

---
 CHANGELOG.md            | 1 +
 src/Data/Set.purs       | 6 ++++++
 test/Test/Data/Set.purs | 5 +++++
 3 files changed, 12 insertions(+)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 091f307..0adb6e8 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -7,6 +7,7 @@ Notable changes to this project are documented in this file. The format is based
 Breaking changes:
 
 New features:
+- Add `Data.Set.range` which works like `Data.Map.submap`.
 
 Bugfixes:
 
diff --git a/src/Data/Set.purs b/src/Data/Set.purs
index ef35ff6..7bd2755 100644
--- a/src/Data/Set.purs
+++ b/src/Data/Set.purs
@@ -18,6 +18,7 @@ module Data.Set
   , size
   , findMin
   , findMax
+  , range
   , union
   , unions
   , difference
@@ -136,6 +137,11 @@ findMin (Set m) = Prelude.map _.key (M.findMin m)
 findMax :: forall a. Set a -> Maybe a
 findMax (Set m) = Prelude.map _.key (M.findMax m)
 
+-- | Return the set limited to the lower and upper bounds (including keys equal
+-- | to those bounds).
+range :: forall a. Ord a => Maybe a -> Maybe a -> Set a -> Set a
+range kmin kmax (Set m) = Set (M.submap kmin kmax m)
+
 -- | Form the union of two sets
 -- |
 -- | Running time: `O(n + m)`
diff --git a/test/Test/Data/Set.purs b/test/Test/Data/Set.purs
index 0269206..2128b7a 100644
--- a/test/Test/Data/Set.purs
+++ b/test/Test/Data/Set.purs
@@ -37,3 +37,8 @@ setTests = do
 
   log "toggle - deletes item"
   assert $ S.toggle 1 (S.fromFoldable [1]) == S.empty
+
+  log "range"
+  do let s1 = S.fromFoldable [1,2,3,4,5]
+         s2 = S.fromFoldable [2,3]
+     assert $ S.range (Just 2) (Just 3) s1 == s2