On the other hand, we need to discuss the current location of the pretty printer, I've added it into tools/, which might not be suitable. However, it makes sense to have the base of the pretty printer in tools/ as it should be treated as an additional tool to the compiler.

I agree. This is fine.

Hi Din,

Just getting up to speed, but already a couple of questions:

• Do you think that Text and SoftLine should perhaps contain Tokens instead of Strings?
• Speaking of tokens, doc comments can be span multiple lines. Is that a problem?
• Do you see a way to support alignment of => e.g. in pattern match cases? It does not look straightforward to me...

Hey Magnus,

Of course we can further discuss these in the meeting, but here some thoughts to your questions.

• Do you think that Text and SoftLine should perhaps contain Tokens instead of Strings?

I would like to keep the abstraction or at least have the Doc as near to the original paper implementation as possible. Just out of curiosity, what benefits would implementing it with Token bring?

• Speaking of tokens, doc comments can be span multiple lines. Is that a problem?

Currently not no. I've rebuilt some structures in some local commits which I will show you in the meeting. However, currently multi-line comments do not cause any problem.

• Do you see a way to support alignment of => e.g. in pattern match cases? It does not look straightforward to me...

Out of the box with only Wadler itself it would not work. However, if I remember correctly Alignment could be achieved with extending Wadler with Leijen to include align.

I would like to keep the abstraction or at least have the Doc as near to the original paper implementation as possible. Just out of curiosity, what benefits would implementing it with Token bring?

Not sure yet, but perhaps:

• A lot more information than a string would have.
• Source positions which may be useful for computing specific text edits.

Out of the box with only Wadler itself it would not work. However, if I remember correctly Alignment could be achieved with extending Wadler with Leijen to include align.

Roger 👍

As discussed with Magnus, we simply try to pattern match instead of already planning a big ruling engine (we incrementally try to refactor and improve). Please note that this progress currently has many hiccups and might break functional code. Example of such breaking:

import java.lang.Runnable
import java.lang.Thread

def newRunnable(): Runnable \ IO = new Runnable {
    // Note: In Flix `run` is a keyword so we must escape it with $.
    def run(_this: Runnable): Unit \ IO = {
        println("Running...")
    }
}

def main(): Unit \ IO =
    new Thread(newRunnable()).start()

As stated in the comment // Note: In Flix run is a keyword so we must escape it with $. it must add a $ in front of run, which causes the PrettyPrinter to break the existing code.

!!!jar

Building JAR...

The JAR is available HERE.

@magnus-madsen You might want to invoke the jar build again. I did not push everything, sorry, so the jar up there might be outdated.

!!!jar

Building JAR...

The JAR is available HERE.

!!!jar

Building JAR...

The JAR is available HERE.

Hello @mweyland and @dandolo

First of all, thanks again. After all you might want to test the actual formatter and see, how it looks and feels. Therefore, I requested Magnus to invoke the jar build action to provide a executable for you.

I'll provide two short instructions on how you can use this jar file.

• First, download the jar and unzip it. Then execute it with java -jar out.jar of course, you might want to run it in a project and append the format

$ cd <flix-project>

# Formatting the whole project.
$ java -jar <path-to-jar>/out.jar format

# Formatting a specific file (e.g. Main.flix)
$ java -jar <path-to-jar>/out.jar format src/Main.flix 

• After all, you might want to use it in Visual Studio Code (Because this feels more real and is cooler in my opinion). This can be done by moving the jar file into the flix project, into the project root, and open the project in Visual Studio Code.

$ cd <flix-project>

# Option 1: copy out.jar
$ cp <path-to-jar>/out.jar .

# Option 2: move out.jar
$ mv <path-to-jar>/out.jar .

# Open Visual Studio code
$ code .

It is to note all this can be done graphically as well of course. Aside from that the code command might be named differently for Visual Studio Code.

And for Visual Studio Code you might need this extension, https://marketplace.visualstudio.com/items?itemName=flix.flix . It can happen that there might some conflicts with which compiler it takes.

In case you have some issues and are not able to play around with it, feel free to contact me any time and I'll try to help with finding a solution. And of course if you find any issues with formatting, feel free to open an issue or just note them down if possible, hopefully you don't find to many^^

PS: The jar file can be found in the comment before this one.

Cheers gwydd :)