[Repo Assist] feat: add ofList, ofArray, tryFind, find, choose, collect, partition, sort, sortWith, sortBy, rev to DList

src/FSharpx.Collections/DList.fs

@@ -279,3 +279,54 @@ module DList =
 
     let inline toArray(l: DList<'T>) : 'T[] =
         Seq.toArray l
+
+    ///O(n). Build a DList from the given list.
+    let inline ofList(l: 'T list) : DList<'T> = ofSeq l
+
+    ///O(n). Build a DList from the given array.
+    let inline ofArray(a: 'T array) : DList<'T> = ofSeq a
+
+    ///O(n), worst case. Returns the first element for which the given function returns <c>Some</c>.
+    let tryFind (predicate: 'T -> bool) (l: DList<'T>) : 'T option =
+        Seq.tryFind predicate l
+
+    ///O(n), worst case. Returns the first element for which the given function returns <c>true</c>.
+    /// Raises <c>KeyNotFoundException</c> if no such element exists.
+    let find (predicate: 'T -> bool) (l: DList<'T>) : 'T =
+        Seq.find predicate l
+
+    ///O(n). Applies the given function to each element and returns a DList of the values returned
+    /// by the function where the function returned <c>Some</c>.
+    let choose (mapping: 'T -> 'U option) (l: DList<'T>) : DList<'U> =
+        foldBack
+            (fun x acc ->
+                match mapping x with
+                | Some v -> cons v acc
+                | None -> acc)
+            l
+            empty
+
+    ///O(n). For each element, applies the given function to produce a DList, then concatenates all results.
+    let collect (mapping: 'T -> DList<'U>) (l: DList<'T>) : DList<'U> =
+        foldBack (fun x acc -> append (mapping x) acc) l empty
+
+    ///O(n). Splits the DList into two DLists: the first contains elements for which the predicate
+    /// returns <c>true</c>; the second contains those for which it returns <c>false</c>.
+    let partition (predicate: 'T -> bool) (l: DList<'T>) : DList<'T> * DList<'T> =
+        foldBack (fun x (yes, no) -> if predicate x then cons x yes, no else yes, cons x no) l (empty, empty)
+
+    ///O(n log n). Returns a new DList sorted using the default comparison.
+    let sort(l: DList<'T>) : DList<'T> =
+        l |> toArray |> Array.sort |> ofArray
+
+    ///O(n log n). Returns a new DList sorted using the given comparison function.
+    let sortWith (comparer: 'T -> 'T -> int) (l: DList<'T>) : DList<'T> =
+        l |> toArray |> Array.sortWith comparer |> ofArray
+
+    ///O(n log n). Returns a new DList sorted by the given projection.
+    let sortBy (projection: 'T -> 'Key) (l: DList<'T>) : DList<'T> =
+        l |> toArray |> Array.sortBy projection |> ofArray
+
+    ///O(n). Returns the DList in reversed order.
+    let rev(l: DList<'T>) : DList<'T> =
+        fold (fun acc x -> cons x acc) empty l

src/FSharpx.Collections/DList.fsi

@@ -121,3 +121,37 @@ module DList =
 
     ///O(n). Returns an array of the DList elements.
     val inline toArray: DList<'T> -> 'T[]
+
+    ///O(n). Build a DList from the given list.
+    val inline ofList: list<'T> -> DList<'T>
+
+    ///O(n). Build a DList from the given array.
+    val inline ofArray: 'T[] -> DList<'T>
+
+    ///O(n), worst case. Returns the first element for which the given function returns Some.
+    val tryFind: ('T -> bool) -> DList<'T> -> 'T option
+
+    ///O(n), worst case. Returns the first element for which the given function returns true.
+    /// Raises KeyNotFoundException if no such element exists.
+    val find: ('T -> bool) -> DList<'T> -> 'T
+
+    ///O(n). Returns a DList of the values v where the mapping function returns Some(v).
+    val choose: ('T -> 'U option) -> DList<'T> -> DList<'U>
+
+    ///O(n). For each element, applies the mapping to produce a DList, then concatenates all results.
+    val collect: ('T -> DList<'U>) -> DList<'T> -> DList<'U>
+
+    ///O(n). Splits the DList into two DLists on the predicate: true elements first, false elements second.
+    val partition: ('T -> bool) -> DList<'T> -> DList<'T> * DList<'T>
+
+    ///O(n log n). Returns a new DList sorted using the default comparison.
+    val sort: DList<'T> -> DList<'T> when 'T: comparison
+
+    ///O(n log n). Returns a new DList sorted using the given comparison function.
+    val sortWith: ('T -> 'T -> int) -> DList<'T> -> DList<'T>
+
+    ///O(n log n). Returns a new DList sorted by the given projection.
+    val sortBy: ('T -> 'Key) -> DList<'T> -> DList<'T> when 'Key: comparison
+
+    ///O(n). Returns the DList in reversed order.
+    val rev: DList<'T> -> DList<'T>

tests/FSharpx.Collections.Tests/DListTest.fs

@@ -494,4 +494,90 @@ module DListTests =
                   config10k
                   "DList.toArray matches Seq.toArray 0"
                   (Prop.forAll(Arb.fromGen intGensStart1.[0])
-                   <| fun (q, l) -> DList.toArray q = Array.ofList l) ]
+                   <| fun (q, l) -> DList.toArray q = Array.ofList l)
+
+              testPropertyWithConfig
+                  config10k
+                  "DList.ofList round-trips with toList"
+                  (Prop.forAll(Arb.fromGen intGensStart1.[0])
+                   <| fun (_, l) -> DList.ofList l |> DList.toList = l)
+
+              testPropertyWithConfig
+                  config10k
+                  "DList.ofArray round-trips with toArray"
+                  (Prop.forAll(Arb.fromGen intGensStart1.[0])
+                   <| fun (_, l) -> DList.ofArray(Array.ofList l) |> DList.toArray = Array.ofList l)
+
+              testPropertyWithConfig
+                  config10k
+                  "DList.tryFind matches List.tryFind"
+                  (Prop.forAll(Arb.fromGen intGensStart1.[0])
+                   <| fun (q, l) -> DList.tryFind (fun x -> x % 3 = 0) q = List.tryFind (fun x -> x % 3 = 0) l)
+
+              testPropertyWithConfig
+                  config10k
+                  "DList.find matches List.find when element exists"
+                  (Prop.forAll(Arb.fromGen intGensStart1.[0])
+                   <| fun (q, l) ->
+                       match List.tryFind (fun x -> x % 2 = 0) l with
+                       | Some expected -> DList.find (fun x -> x % 2 = 0) q = expected
+                       | None -> true)
+
+              testPropertyWithConfig
+                  config10k
+                  "DList.choose matches List.choose"
+                  (Prop.forAll(Arb.fromGen intGensStart1.[0])
+                   <| fun (q, l) ->
+                       let mapping x =
+                           if x % 2 = 0 then Some(x * 2) else None
+
+                       DList.choose mapping q |> DList.toList = List.choose mapping l)
+
+              testPropertyWithConfig
+                  config10k
+                  "DList.collect matches List.collect"
+                  (Prop.forAll(Arb.fromGen intGensStart1.[0])
+                   <| fun (q, l) ->
+                       let mapping x =
+                           DList.ofList [ x; x * 2 ]
+
+                       DList.collect mapping q |> DList.toList = List.collect (fun x -> [ x; x * 2 ]) l)
+
+              testPropertyWithConfig
+                  config10k
+                  "DList.partition splits correctly"
+                  (Prop.forAll(Arb.fromGen intGensStart1.[0])
+                   <| fun (q, l) ->
+                       let trueD, falseD = DList.partition (fun x -> x % 2 = 0) q
+                       let trueL, falseL = List.partition (fun x -> x % 2 = 0) l
+                       DList.toList trueD = trueL && DList.toList falseD = falseL)
+
+              testPropertyWithConfig
+                  config10k
+                  "DList.sort matches List.sort"
+                  (Prop.forAll(Arb.fromGen intGensStart1.[0])
+                   <| fun (q, l) -> DList.sort q |> DList.toList = List.sort l)
+
+              testPropertyWithConfig
+                  config10k
+                  "DList.sortWith compare matches List.sort"
+                  (Prop.forAll(Arb.fromGen intGensStart1.[0])
+                   <| fun (q, l) -> DList.sortWith compare q |> DList.toList = List.sort l)
+
+              testPropertyWithConfig
+                  config10k
+                  "DList.sortBy id matches List.sort"
+                  (Prop.forAll(Arb.fromGen intGensStart1.[0])
+                   <| fun (q, l) -> DList.sortBy id q |> DList.toList = List.sort l)
+
+              testPropertyWithConfig
+                  config10k
+                  "DList.rev reverses the list"
+                  (Prop.forAll(Arb.fromGen intGensStart1.[0])
+                   <| fun (q, l) -> DList.rev q |> DList.toList = List.rev l)
+
+              testPropertyWithConfig
+                  config10k
+                  "DList.rev . DList.rev = id"
+                  (Prop.forAll(Arb.fromGen intGensStart1.[0])
+                   <| fun (q, _) -> DList.rev(DList.rev q) |> DList.toList = DList.toList q) ]