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Implement Seq.fold2
commit 3c379b6deba89aeccd0af4d3744f69076f6cc34d Merge: f197816 6e6f68c Author: latkin <latkin@microsoft.com> Date: Sun Oct 12 10:23:58 2014 -0700 Merge branch 'fold2' of https://git01.codeplex.com/forks/forki/fsharp into PR commit 6e6f68ce8b1b0dbf7deb92cf1c6887792118821d Author: Steffen Forkmann <steffen.forkmann@msu-solutions.de> Date: Fri Jul 4 14:49:20 2014 +0200 Adding surface are for fold2 commit ac88069f9d2ed8196e5cdbd5294d891d52942b47 Author: Steffen Forkmann <steffen.forkmann@msu-solutions.de> Date: Fri Jul 4 14:45:05 2014 +0200 Changing Seq.fold2 - sequences need not have equal lengths commit 74adf606599ba4b648142c532249f782501f0758 Author: Steffen Forkmann <steffen.forkmann@msu-solutions.de> Date: Thu Jul 3 23:06:41 2014 +0200 Check exceptions for Seq.fold2 commit 2be78be51151b83cc9f294254b9de7b20fd71b79 Author: Steffen Forkmann <steffen.forkmann@msu-solutions.de> Date: Thu Jul 3 23:02:49 2014 +0200 Implementing Seq.fold2
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‎src/fsharp/FSharp.Core.Unittests/FSharp.Core/Microsoft.FSharp.Collections/SeqModule.fs‎

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@@ -667,6 +667,40 @@ type SeqModule() =
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CheckThrowsArgumentNullException (fun () -> Seq.fold funcInt 1 nullSeq |> ignore)
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()
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[<Test>]
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member this.Fold2() =
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Assert.AreEqual([(3,5); (2,3); (1,1)],Seq.fold2 (fun acc x y -> (x,y)::acc) [] (seq [ 1..3 ]) (seq [1..2..6]))
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// integer List
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let funcInt x y z = x + y + z
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let resultInt = Seq.fold2 funcInt 9 (seq [ 1..10 ]) (seq [1..2..20])
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Assert.AreEqual(164, resultInt)
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// string List
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let funcStr x y z = x + y + z
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let resultStr = Seq.fold2 funcStr "*" ["a"; "b"; "c" ; "d" ] ["A"; "B"; "C" ; "D" ]
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Assert.AreEqual("*aAbBcCdD", resultStr)
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// empty List
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let emptyArr:int list = [ ]
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let resultEpt = Seq.fold2 funcInt 5 emptyArr emptyArr
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Assert.AreEqual(5, resultEpt)
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Assert.AreEqual(0,Seq.fold2 funcInt 0 Seq.empty (seq [1]))
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Assert.AreEqual(-1,Seq.fold2 funcInt -1 (seq [1]) Seq.empty)
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Assert.AreEqual(2,Seq.fold2 funcInt 0 (seq [1;2]) (seq [1]))
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Assert.AreEqual(4,Seq.fold2 funcInt 0 (seq [1]) (seq [3;6]))
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// null Seq
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let nullSeq:seq<'a> = null
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CheckThrowsArgumentNullException (fun () -> Seq.fold2 funcInt 0 nullSeq (seq [1]) |> ignore)
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CheckThrowsArgumentNullException (fun () -> Seq.fold2 funcInt 0 (seq [1]) nullSeq |> ignore)
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()
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[<Test>]
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member this.ForAll() =

‎src/fsharp/FSharp.Core.Unittests/SurfaceArea.4.0.fs‎

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@@ -449,6 +449,7 @@ Microsoft.FSharp.Collections.SeqModule: T Sum[T](System.Collections.Generic.IEnu
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Microsoft.FSharp.Collections.SeqModule: TResult AverageBy[T,TResult](Microsoft.FSharp.Core.FSharpFunc`2[T,TResult], System.Collections.Generic.IEnumerable`1[T])
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Microsoft.FSharp.Collections.SeqModule: TResult Pick[T,TResult](Microsoft.FSharp.Core.FSharpFunc`2[T,Microsoft.FSharp.Core.FSharpOption`1[TResult]], System.Collections.Generic.IEnumerable`1[T])
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Microsoft.FSharp.Collections.SeqModule: TResult SumBy[T,TResult](Microsoft.FSharp.Core.FSharpFunc`2[T,TResult], System.Collections.Generic.IEnumerable`1[T])
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Microsoft.FSharp.Collections.SeqModule: TState Fold2[T1,T2,TState](Microsoft.FSharp.Core.FSharpFunc`2[TState,Microsoft.FSharp.Core.FSharpFunc`2[T1,Microsoft.FSharp.Core.FSharpFunc`2[T2,TState]]], TState, System.Collections.Generic.IEnumerable`1[T1], System.Collections.Generic.IEnumerable`1[T2])
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Microsoft.FSharp.Collections.SeqModule: TState Fold[T,TState](Microsoft.FSharp.Core.FSharpFunc`2[TState,Microsoft.FSharp.Core.FSharpFunc`2[T,TState]], TState, System.Collections.Generic.IEnumerable`1[T])
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Microsoft.FSharp.Collections.SeqModule: T[] ToArray[T](System.Collections.Generic.IEnumerable`1[T])
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Microsoft.FSharp.Collections.SeqModule: Void Iterate2[T1,T2](Microsoft.FSharp.Core.FSharpFunc`2[T1,Microsoft.FSharp.Core.FSharpFunc`2[T2,Microsoft.FSharp.Core.Unit]], System.Collections.Generic.IEnumerable`1[T1], System.Collections.Generic.IEnumerable`1[T2])

‎src/fsharp/FSharp.Core.Unittests/SurfaceArea.Portable.fs‎

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@@ -443,6 +443,7 @@ Microsoft.FSharp.Collections.SeqModule: T Sum[T](System.Collections.Generic.IEnu
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Microsoft.FSharp.Collections.SeqModule: TResult AverageBy[T,TResult](Microsoft.FSharp.Core.FSharpFunc`2[T,TResult], System.Collections.Generic.IEnumerable`1[T])
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Microsoft.FSharp.Collections.SeqModule: TResult Pick[T,TResult](Microsoft.FSharp.Core.FSharpFunc`2[T,Microsoft.FSharp.Core.FSharpOption`1[TResult]], System.Collections.Generic.IEnumerable`1[T])
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Microsoft.FSharp.Collections.SeqModule: TResult SumBy[T,TResult](Microsoft.FSharp.Core.FSharpFunc`2[T,TResult], System.Collections.Generic.IEnumerable`1[T])
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Microsoft.FSharp.Collections.SeqModule: TState Fold2[T1,T2,TState](Microsoft.FSharp.Core.FSharpFunc`2[TState,Microsoft.FSharp.Core.FSharpFunc`2[T1,Microsoft.FSharp.Core.FSharpFunc`2[T2,TState]]], TState, System.Collections.Generic.IEnumerable`1[T1], System.Collections.Generic.IEnumerable`1[T2])
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Microsoft.FSharp.Collections.SeqModule: TState Fold[T,TState](Microsoft.FSharp.Core.FSharpFunc`2[TState,Microsoft.FSharp.Core.FSharpFunc`2[T,TState]], TState, System.Collections.Generic.IEnumerable`1[T])
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Microsoft.FSharp.Collections.SeqModule: T[] ToArray[T](System.Collections.Generic.IEnumerable`1[T])
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Microsoft.FSharp.Collections.SeqModule: Void Iterate2[T1,T2](Microsoft.FSharp.Core.FSharpFunc`2[T1,Microsoft.FSharp.Core.FSharpFunc`2[T2,Microsoft.FSharp.Core.Unit]], System.Collections.Generic.IEnumerable`1[T1], System.Collections.Generic.IEnumerable`1[T2])

‎src/fsharp/FSharp.Core/seq.fs‎

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@@ -1044,7 +1044,23 @@ namespace Microsoft.FSharp.Collections
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use e = source.GetEnumerator()
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let mutable state = x
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while e.MoveNext() do
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state <- f state e.Current;
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state <- f state e.Current;
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state
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[<CompiledName("Fold2")>]
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let fold2<'T1,'T2,'State> f (state:'State) (source1: seq<'T1>) (source2: seq<'T2>) =
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checkNonNull "source1" source1
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checkNonNull "source2" source2
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use e1 = source1.GetEnumerator()
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use e2 = source2.GetEnumerator()
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let f = OptimizedClosures.FSharpFunc<_,_,_,_>.Adapt(f)
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let mutable state = state
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while e1.MoveNext() && e2.MoveNext() do
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state <- f.Invoke(state, e1.Current, e2.Current)
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state
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[<CompiledName("Reduce")>]

‎src/fsharp/FSharp.Core/seq.fsi‎

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@@ -351,6 +351,19 @@ namespace Microsoft.FSharp.Collections
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[<CompiledName("Fold")>]
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val fold<'T,'State> : folder:('State -> 'T -> 'State) -> state:'State -> source:seq<'T> -> 'State
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/// <summary>Applies a function to corresponding elements of two collections, threading an accumulator argument
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/// through the computation. The two sequences need not have equal lengths:
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/// when one sequence is exhausted any remaining elements in the other sequence are ignored.
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/// If the input function is <c>f</c> and the elements are <c>i0...iN</c> and <c>j0...jN</c>
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/// then computes <c>f (... (f s i0 j0)...) iN jN</c>.</summary>
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/// <param name="folder">The function to update the state given the input elements.</param>
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/// <param name="state">The initial state.</param>
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/// <param name="source1">The first input sequence.</param>
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/// <param name="source2">The second input sequence.</param>
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/// <returns>The final state value.</returns>
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[<CompiledName("Fold2")>]
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val fold2<'T1,'T2,'State> : folder:('State -> 'T1 -> 'T2 -> 'State) -> state:'State -> source1:seq<'T1> -> source2:seq<'T2> -> 'State
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/// <summary>Tests if all elements of the sequence satisfy the given predicate.</summary>
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///
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/// <remarks>The predicate is applied to the elements of the input sequence. If any application

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