feat: initial commit

spago.yaml

@@ -3,22 +3,12 @@ package:
     strict: true
     pedantic_packages: true
   dependencies:
-    - prelude
-    - aff
-    - effect
-    - either
+    - enums
     - maybe
-    - foldable-traversable
-    - console
-    - newtype
-    - strings
-    - stringutils
-    - transformers
-    - tuples
-    - typelevel-prelude
-  name: project
+    - prelude
+  name: range
 workspace:
   extra_packages: {}
   package_set:
     url: https://raw.githubusercontent.com/purescript/package-sets/psc-0.15.10-20230930/packages.json
-    hash: sha256-nTsd44o7/hrTdk0c6dh0wyBqhFFDJJIeKdQU6L1zv/A=
+    hash: sha256-hp58GPoH+qX3eUsk2ecoHBZpQ50rFeZCCMTdKkYTr/Y=

src/Data.Range.purs

@@ -0,0 +1,94 @@
+module Data.Range where
+
+import Prelude
+
+import Data.Enum (class Enum, pred, succ)
+import Data.Generic.Rep (class Generic)
+import Data.Maybe (Maybe(..))
+import Data.Show.Generic (genericShow)
+
+data RangeOrExact a
+  = RangeNotExact (Range a)
+  | RangeExact a
+
+data Bound a
+  = BoundIncluding a
+  | BoundExcluding a
+
+derive instance Generic (Bound a) _
+derive instance Ord a => Ord (Bound a)
+derive instance Eq a => Eq (Bound a)
+instance Show a => Show (Bound a) where
+  show = genericShow
+
+boundModify :: forall a. (a -> a) -> Bound a -> Bound a
+boundModify f (BoundIncluding a) = BoundIncluding $ f a
+boundModify f (BoundExcluding a) = BoundExcluding $ f a
+
+boundBottomContains :: forall a. Ord a => Bound a -> a -> Boolean
+boundBottomContains (BoundIncluding ba) a = a >= ba
+boundBottomContains (BoundExcluding ba) a = a > ba
+
+boundTopContains :: forall a. Ord a => Bound a -> a -> Boolean
+boundTopContains (BoundIncluding ba) a = a <= ba
+boundTopContains (BoundExcluding ba) a = a < ba
+
+data Range a
+  = RangeAbove (Bound a)
+  | RangeBelow (Bound a)
+  | RangeBetween (Bound a) (Bound a)
+
+derive instance Generic (Range a) _
+derive instance Ord a => Ord (Range a)
+derive instance Eq a => Eq (Range a)
+instance Show a => Show (Range a) where
+  show = genericShow
+
+instance Semigroup (Range a) where
+  append (RangeAbove a) (RangeBelow b) = RangeBetween a b
+  append (RangeBelow a) (RangeAbove b) = RangeBetween a b
+  append a _ = a
+
+modifyLower :: forall a. (a -> a) -> Range a -> Range a
+modifyLower _ r@(RangeAbove _) = r
+modifyLower f (RangeBelow b) = RangeBelow (boundModify f b)
+modifyLower f (RangeBetween b top') = RangeBetween (boundModify f b) top'
+
+modifyUpper :: forall a. (a -> a) -> Range a -> Range a
+modifyUpper _ r@(RangeBelow _) = r
+modifyUpper f (RangeAbove b) = RangeAbove (boundModify f b)
+modifyUpper f (RangeBetween bot' b) = RangeBetween bot' (boundModify f b)
+
+incl :: forall a. a -> Bound a
+incl = BoundIncluding
+
+excl :: forall a. a -> Bound a
+excl = BoundExcluding
+
+above :: forall a. Bound a -> Range a
+above = RangeAbove
+
+below :: forall a. Bound a -> Range a
+below = RangeBelow
+
+between :: forall a. Bound a -> Bound a -> Range a
+between = RangeBetween
+
+bottom :: forall a. Enum a => Range a -> Maybe a
+bottom (RangeBetween (BoundIncluding a) _) = Just a
+bottom (RangeBetween (BoundExcluding a) _) = succ a
+bottom (RangeAbove (BoundIncluding a)) = Just a
+bottom (RangeAbove (BoundExcluding a)) = succ a
+bottom _ = Nothing
+
+top :: forall a. Enum a => Range a -> Maybe a
+top (RangeBetween _ (BoundIncluding a)) = Just a
+top (RangeBetween _ (BoundExcluding a)) = pred a
+top (RangeBelow (BoundIncluding a)) = Just a
+top (RangeBelow (BoundExcluding a)) = pred a
+top _ = Nothing
+
+contains :: forall a. Ord a => Range a -> a -> Boolean
+contains (RangeBetween bot' top') a = boundBottomContains bot' a && boundTopContains top' a
+contains (RangeAbove bot') a = boundBottomContains bot' a
+contains (RangeBelow top') a = boundTopContains top' a

src/Main.purs

@@ -1,7 +0,0 @@
-module Main where
-
-import Prelude
-import Effect (Effect)
-
-main :: Effect Unit
-main = pure unit