GSN Editor

This extension includes a grammar and a corresponding language server that facilitates syntax highlighting, grammar checks, and code completion for the GSN Assurance Language. This language is a Domain Specific Language (DSL) based on Goal Structuring Notation (GSN).

In addition to the textual DSL, the extension offers a graphical editor that displays the GSN models as Directed Acyclic Graphs (DAGs).

Getting started

System Requirements

This extension requires a Java 8+ installation available in path as java (or via the JAVA_HOME env. var). A version that's confirmed to work is:

openjdk version "11.0.20.1" 2023-08-24

Example models

A GSN model consists of one or more .gsn files contained in a single folder. Entities can be cross-referenced between files by defining namespaces and reference nodes.

Below, there is a simple example illustrating some entity types (goal, strategy, context). To begin, create a folder named myModel and a file named myModel.gsn, then copy and paste the model below into that file.

For more examples check out the sample-models under the repository root.

GOALS gauss
    goal Statement
        uuid adaa653c-737a-4080-bf74-4f0fa0da3495
        summary "The sum of the natural numbers less or equal to n equals to Sn = n*(n + 1) / 2"
        strategy Mathematical_Induction
            uuid 3c168586-1c57-4269-9187-35dfe3123691
            summary "test"
            goal Base
                uuid 53cfa782-7250-45bf-b24c-1a32a4e6ac38
                summary "Holds for n = 1"
                solution S1
                    uuid 9038480f-ae65-4c2c-b399-0e4aeaa44cb1
                    summary "S1 = 1*(1 + 1) / 2 = 1"
            goal Inductive_Step
                uuid 0f9bb9a7-abaa-467f-9798-b59fb42e26fe
                summary "Holds for n = k + 1"
                assumption Assuming
                    uuid 391acf6d-d507-4a3b-a88f-537e09ce25de
                    summary "Holds for n = k"
                solution Sk_plus_1
                    uuid aa4e0fc7-a74f-45fc-bb59-75a3dd82067c
                    summary "Sk + 1 = (k + 1)(k + 2)/2

Sk + 1
= Sk + (k + 1)
= k*(k + 1) / 2 + (k + 1)
= (k + 1)*(k + 2) / 2"

After opening the file in VSCode, granted this extension is installed and functioning correctly, keywords and symbols will be highlighted in accordance to your current theme.

Make sure the file has been saved, then bring up the command panel (Ctrl/Cmd + Shift + P) and type gsn. Select GSN: Graph View and the graphical editor will open up in a separate tab.

You can continue to expand on the model using either the graphical editor or the textual editor. Changes made in either perspective within the same VSCode instance will automatically be reflected in the other. (Edits in the textual .gsn-files must be saved in order for the editor to pick up the changes.)

Tutorial Videos

These videos were recorded using v0.11.2 of the extension.

• Getting started - UI overview
• References and Multiple files
• State, artifacts, views, labels and groups

Public Release History

v0.14.9

• Updated more compact grammar introduced

v0.12.0

• Public release of GSN Assurance extension for VSCode.
• GSN Assurance extension includes
  • a Graphical Editor for Assurance models based on GSN
  • an XText based language server that supports the above graphical-editor as well as textual development of GSN based assurance models (.gsn files) in VSCode editor.

Known Issues

Acknowledgements

This work was supported by the DARPA Assured Autonomy program and Air Force Research Laboratory. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of DARPA or AFRL.

Contact

caid-dev@vanderbilt.edu