Clojure Q&A - Recent activity in ClojureCLR

Commented: Porting .NET 4.8 application using Clojure CLR to .NET 8

Wed, 29 Apr 2026 02:52:51 +0000

System.Text.Json comes in only as a transitive dependency. Not sure what other libs require it -- could be several. Installed version is 10.0.7. Could be a version issue? Not sure how to even figure these things out in your scenario. (I had to do some serious tweaking to get all the right libraries in place for my little C++ console app.)

Commented: Threading macro with update and when produces incorrect results

Wed, 10 Dec 2025 11:20:49 +0000

I tried the following in Clojure 1.12.2 (Windows) and 1.12.3-alpha4 (Windows and Linux):

```
(def p1 {:name "James" :age 26})
(def p2 {:name "Fred" :age nil})
(def p3 {:name "Fred"})

(-> p1 (update :age #(when % (inc %))))   ; => {:name "James", :age 27}
(-> p2 (update :age #(when % (inc %))))   ; => {:name "Fred", :age nil}
(-> p3 (update :age #(when % (inc %))))   ; => {:name "Fred", :age nil}
```

I thought the `p2` and `p3` examples matched the description given and would fail. They do not. Could you provide a more specific example that illustrates the problem?   Your description says the error occurs in web handlers? Does this only occur in that context?

Answered: How to use core.async from cljr command line tool?

Tue, 02 Dec 2025 04:00:56 +0000

The recommendations have implemented (other than the archiving of clr.tools.analyzer).

clr.core.async version 1.7.701 has been released.
It and all its dependencies have been properly deps.edn-ified.
I've been doing all the testing via cljr, so I have some confidence it works.

Answered: Does cljr -Sdeps work for other people?

Wed, 05 Nov 2025 19:34:05 +0000

Fixed a month ago in clr.core.cli. Was a problem with a .sh file on Linux and another issue.
Forgot to write back here. It all works now.

Retagged: Does clojure-clr work on Android?

Sat, 06 Sep 2025 18:26:58 +0000

EDIT: Answer is YES. Below is my long-winded exploration.

I see one of the reasons for clojure-clr-next is it will work on more platforms, is Android one of those?

I'm using Termux to operate dotnet on Android.

Both the clojure-clr global dotnet tool and locally compiled clojure-clr fail with exit code 1, no exceptions or anything. I tried dotnet-trace and it gets a partial trace, but no minidump. Puzzling as with the partial trace, the documentation indicates an expectation of a minidump, maybe there is some unmet condition to emit the minidump I'm not aware of yet (env variables for it didn't work).

In the trace here is an early line followed by some of the last lines:
`
"system.linq!System.Linq.Enumerable.SelectManyS\ingleSelectorIterator\u003cSystem.Reflection.As\sembly,System.Type\u003e.MoveNext()"

[...]
"system.collections!System.Collections.Generic.\
SortedSet\u003cSystem.Collections.Generic.KeyVa\luePair\u003cSystem.Int32,clojure.lang.CljCompi\ler.Ast.FnMethod\u003e\u003e.AddIfNotPresent(Sy\stem.Collections.Generic.KeyValuePair`2\u003cin\t,

[...last line...]
"ManagedModule!System.Buffers.SharedArrayPool\u\003cSystem.Byte\u003e.Trim()"
`

So maybe something to do with reflection, or that SharedArrayPool?

I tried inserting some logging to Clojure.Main, but nothing logged as it appears to fail before CljMain.Main() is called. Possibly fails during setting up attributes on one of the classes, in one of the Symbol.intern() or RT.var() calls or somewhere else?

Couldn't run the dotnet msbuild build.proj -t:Test -p:TestTargetFramework=net8.0, fails with:
Clojure.Main -> /data/data/com.termux/files/home/dev/clojure-clr/Clojure/Clojure.Main/bin/Debug/net8.0/Clojure.Main.dll ClojureCompileAssets = '' ClojureMainAssets = '' ClojureTestsAssets = '' /data/data/com.termux/files/home/dev/clojure-clr/Clojure/build.proj(177,5): error MSB3073: The command "dotnet run --project /data/data/com.termux/files/home/dev/clojure-clr/Clojure/Clojure.Main --framework net8.0 -c Debug -p:TargetOS=linux-bionic -p:TargetPlatform=arm64 -p:TargetFramework=net8.0 -p:TargetFrameworks='net8.0' -- run_test.clj" exited with code 1.
I had to edit build.proj a bit to get custom -p:TargetFrameworks and such to pass through, but still fails with exit code 1.

Well I'll continue poking around in this uncharted territory.

Edited: Porting clojure libraries w/ java interop to clojure-clr

Sat, 23 Aug 2025 22:28:29 +0000

I've been browsing around to understand the ecosystem.

I see some libraries are ported to use CLR interop, like core.logic, some are part way finished, like core.async.

Here is one maintainer's concerns, they would much like to point CLR users at a fork with CLR interop maintained by someone else:
https://github.com/weavejester/medley/pull/96
https://github.com/weavejester/medley/pull/65

For fun I examined how to use formal logic to do the code translation. Using Spec, and core.logic for code generation perhaps. I think it would require a lot of knowledge representation.

It might be easier, for these non-core/crucial libraries to use LLMs to do the code translation, and direct the outputs into a set of forks. Perhaps the core libraries used as training data on what to do. This author has some great insights and details on a plausible workflow(s) including with the utility of editor integration. He has done interop translation and work with clojure:
https://m.youtube.com/watch?v=oNhqqiKuUmw

As it is only the interop which requires translation (subsets of clojure files), with a skilled hand there might be better results than some of what he illustrates.

I looked around for a spec for the dotnet core API. I saw one they used to maintain but couldn't find a recent one. Though, all this LLM stuff is beyond me at this time. I thought to share some of my exploration.

EDIT: Found the dotnet API spec/reference for netstandard 2.1.0, I think someone wrote they since moved it into dotnet/runtime but I couldn't find it there, dunno if this helps: https://github.com/dotnet/standard/blob/v2.1.0/src/netstandard/ref/System.IO.cs

Commented: CLR behavior of tools.namespace does not match the JVM implementation

Sun, 08 Dec 2024 18:39:59 +0000

I don't think anything more needs to be done. If there are any other discrepancies between CLR/JVM, they haven't surfaced themselves yet.

Commented: Is it still possible to compile cljr files to dll/exe on dotent 6 and above?

Thu, 02 May 2024 06:03:09 +0000

Thanks for the info.

Commented: Newbie question about namespaces and strategy for C# -> CLJ in general

Thu, 04 Jan 2024 10:32:31 +0000

Thanks for this, it works like a charm. Also potentially gave me some understanding the "internals" of Clojure : ) (RT.init, RT.var etc.).
I think the wiki could be improved with some more clear examples like yours above.
https://github.com/clojure/clojure-clr/wiki/Using-ClojureCLR-in-a-C%23-project

I'll try learn more and maybe contribute some day...

Answered: clojure-clr nrepl - .NET Standard 2.1. does not work with .NET 7

Tue, 23 May 2023 02:15:54 +0000

Thank you for the very clear example. It was easy to track down. When I added support for .cljr files, I missed a location -- that's what is failing here. (Embedded resource in loaded assembly.)

https://clojure.atlassian.net/jira/software/c/projects/CLJCLR/issues/CLJCLR-155

I'll get a fix into the next alpha -- very soon.

Commented: Semantics of as-file differs from Clojure

Wed, 29 Mar 2023 01:09:48 +0000

The suggested fix does not really work. `FileSystemObject` is an abstract class. One is going to have to create either `FileInfo` or a `DirectoryInfo` object -- you pick the one that has the functionality you need. For this purpose, I left 'as-file` as-is and added `as-dir`.

In addition, as a rough approximation to `clojure.java.io/file`, I added `file-info` and `dir-info`. They will take multiple arguments, stringify them, and join them with the directory separator char interposed. It will convert any 'wrong' separator chars to the correct one for the platform -- once you enter the land of `DirectoryInfo` and `FileInfo`, it is hard to remain agnostic. Thus you could do something mixed mode like `(file-info "a/b" "c\\d")`.

This will be in the alpha6 of 1.12.0 when it comes out, probably later this week.

Answered: Using proxy to extend MemoryStream fails on Close

Tue, 17 Jan 2023 13:43:36 +0000

Issue created. Two other instances have been reported (including my own encounter).
From my initial digging, it is related to overloads of methods such as Write on arguments of types such as ReadOnlySpan. I'm going to guess a problem with stack-allocated object that are not handled properly in IL-generation.

JIRA issue CLRCLR-132 created for this.

Commented: slurp without encoding prints erroneous warning

Sat, 07 Jan 2023 15:41:26 +0000

Commit for this pushed. Will be out in the next alpha release, coming soon.

Commented: Cannot install Clojure.Main 1.10.0-rc1 dotnet tool

Sat, 10 Apr 2021 22:39:33 +0000

RC2 has been released for testing.

Answer selected: How do I tag a game object in arcadia?

Mon, 29 Jul 2019 12:51:42 +0000

Haven’t tested this, but it should work:

According to the Unity Scripting API you can simply set the tag property of a GameObject to a string after specifying it via the Tags and Layers manager.

In Arcadia you can use set! to accomplish this:

(set! (. game-object tag) "SomeTag")

Answered: ClojureClr assembly loading from referenced dll