replicate creates n instances of the given element

dotnet · Jul 29, 2015 · 0656124 · 0656124
1 parent 578a2a4
commit 0656124
Showing 1 changed file with 11 additions and 0 deletions.
diff --git a/src/fsharp/FSharp.Core.PropertyTests/ListProperties.fs b/src/fsharp/FSharp.Core.PropertyTests/ListProperties.fs
@@ -343,6 +343,17 @@ let ``reduceBack works like foldBack with given seed`` () =
     Check.QuickThrowOnFailure reduceBack_and_foldBack<string>
     Check.QuickThrowOnFailure reduceBack_and_foldBack<NormalFloat>
 
+let replicate<'a when 'a : comparison> (x:'a) (count:NonNegativeInt) =
+    let count = int count
+    let xs = List.replicate count x
+    xs.Length = count && List.forall ((=) x) xs
+
+[<Test>]
+let ``replicate creates n instances of the given element`` () =
+    Check.QuickThrowOnFailure replicate<int>
+    Check.QuickThrowOnFailure replicate<string>
+    Check.QuickThrowOnFailure replicate<NormalFloat>
+
 let mapFold_and_map_and_fold<'a when 'a : comparison> (xs : list<'a>) mapF foldF start =
     let f s x = 
         let x' = mapF x