rascal | A simple functional interpreted language | Functional Programming library

I want to show the data of table in a form for updating it.

So I'm using this code :

How can I create a set containing a loc, int and string? In the example below it seems my map is converted to the container type ' value'. I would like to use the characteristics of a set; Only one element should be contained in the set and the order does not matter . In the example below the same elements are contained in what I was hoping to be a set.

In java I would use: System.getProperty("os.name") to get Java to return the operating system. Is something similar possible in Rascal? My goal is to write a method to write text files to a folder that works OS-independent. Something like;

Rascal is currently hosting my simple web server. Here I have an input for users using HTML textarea tag, and a submit button. However, I can't figure out how to request that input data from users when they have submitted it. I also don't see much documentation about it, so any help would be appreciated!

I am pretty new to this, but I have started coding Rascal and I have been stuck for a long time. I am trying to get the grammar of a parse tree, but I can't seem to manage to retrieve it.

You know the yellow boxes with grammars when you hover your mouse above the parse tree here? http://tutor.rascal-mpl.org/Recipes/Visualization/ParseTree/ParseTree.html#/Recipes/Visualization/ParseTree/ParseTree.html

I want to somehow get that. I am trying to visualize the parsetree on html. And I somehow think it is best to get the grammar and then draw the tree into html myself, or is there a better way of doing it?

Any help is appreciated!!

I am trying to use rascal.js with my node.js app to publish messages via RabbitMQ.

To simplify things:

I got the standard rascal.js file which looks similar to their docs. And I got a controller.js file which receives http request for saving some data. Then this controller.js file calls 2 functions on different files. "SendMail" and "NotifyUser". Both of those functions needs to publish messages to specific queues.

The question how can I access the Rascal.js publish logic from those 2 files? I could not find any examples. Maybe the publish logic suppose to be activated differently? By triggers or events of sort?

And so far the only solution I could use was creating another separate function in my rascal.js file which opens a connection specifically for publishing. It uses input params to determine the name of the queue and the message to be published to it and at the end it closes the connection. This seems to be a bad solution since every request will open a new connection with rascal.js.

this is my first post in this subject - How to manage publish connection per request on rabbitmq(rascal.js)

I am using Rascal.Js(it uses amqplib) for my messaging logic with rabbitMq on node.js app.

I am using something similar to their example on my project startup, which creates a permanent instance and "registers" all of my subscribers and redirects messages when they arrive to the queue (in the background).

My issue is with the publishers. There are http requests from outside which should trigger my publishers. A user clicks on create button of sorts which leads to certain flow of actions. At some point it reaches the point at which I need to use a publisher.

And here I am not sure about the right approach. Do I need to open a new connection every time I need to publish a message? and close it after it ends? Or maybe I should implement this in a way that it keeps the same connection open for all of the publishers? (I actually not so sure how to create it in a way that it can be accessed from other parts of my app).

At the moment I am using the following :

I'm writing a paper and want to cite Rascal. Which is the preferred paper I should cite? Or should I just cite a link to the website? There are no publications mentioned on the website. The Wikipedia entry mentions a publication from 2013 (13th SCAM). Shall I use this one?

The docs for Node only mention following methods:

Equal, GreaterThan, GreaterThanOrEqual, LessThan, LessThanOrEqual, NotEqual, Slice, Subscription

It does mention how to access child by index using Subscription, but how can I find out the count of children node has to iterate over them?

Here is my use case: