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The operation

let f : seq<int> -> unit = Query.compile (Query.ofSeq >> Query.iter (fun _ -> ()))

fails with the following error:

System.Exception: Not supported source Nessos.LinqOptimizer.Base.IQueryExpr
   at Microsoft.FSharp.Core.PrintfModule.PrintFormatToStringThenFail@1365.Invoke(String message)
   at Nessos.LinqOptimizer.Core.FSharpExpressionOptimizerHelpers.sourceOfExpr(Expression expr, QueryExprType sourceType) in C:\Development\VS 2013\LinqOptimizer\src\LinqOptimizer.Core\FSharpExpressionOptimizer.fs:line 33
   at Nessos.LinqOptimizer.Core.FSharpExpressionOptimizerHelpers.toQueryExpr(Expression expr) in C:\Development\VS 2013\LinqOptimizer\src\LinqOptimizer.Core\FSharpExpressionOptimizer.fs:line 186
   at Nessos.LinqOptimizer.Core.FSharpExpressionOptimizer.ToQueryExpr(Expression expr) in C:\Development\VS 2013\LinqOptimizer\src\LinqOptimizer.Core\FSharpExpressionOptimizer.fs:line 236
   at Nessos.LinqOptimizer.FSharp.Query.compile[T](Expression`1 template, FSharpOption`1 enableNonPublicMemberAccess) in C:\Development\VS 2013\LinqOptimizer\src\LinqOptimizer.FSharp\FSharpQuery.fs:line 360
   at <StartupCode$FSI_0006>.$FSI_0006.main@() in C:\Development\VS 2013\LinqOptimizer\tests\LinqOptimizer.Tests.FSharp\QueryExpr.fs:line 275
Stopped due to error

Would be useful to include countBy, maxBy and head combinators.

Hi !

I saw in the source code that the method ThenBy was commented for IParallelQueryExpr. I wanted to know when this method will be available.

Thanks.

Is there a wiki or user guide showing the full list of commands that this library can optimize or any user reference guide showing a full list? I'm new to using this library and I'm having trouble figuring out how it works exactly. I can see in the home page that you seem to add AsQueryExpr() to any item you are using for a linq query and there is also a parallel version AsParallelQueryExpr(). Is there a rule of thumb for when to use the parallel version vs the regular version?

Hello

The page https://github.com/nessos/LinqOptimizer/wiki/Performance has a benchmark link that leads to a 404 page.

The source code of the benchmarks can be found in the benchmarks branch.

Could you please have a look?

The LinqOptimizer.FSharp package includes a copy of FSHarp.Core. It should not be there since this is a library?

No real issue, just wanted to share this comment from Brian Beckman:

https://twitter.com/lorentzframe/status/506107739538722817

I created a repository with benchmarks that compare the performance of several LINQ-to-Objects implementations. It can be found at https://github.com/NetFabric/LinqBenchmarks

It includes both LinqOptimizer and Streams. I think I implemented them as you have in here but I'm getting the huge hit in performance because of the first iteration.

Am I doing something wrong?