{log} for VS Code

VS Code extension for {log}.

Highlights

• Language support: syntax highlighting & snippets for .pl / .slog.
• Verification: generate and (optionally) check verification conditions (VCs), surface errors as diagnostics.
• Simulation: run default or custom simulation operations, with optional ground solutions.
• Configuration: toolbar indicators, a side-panel settings view, and bidirectional config file sync.

Prerequisites

• VS Code (v1.102 or latter) installed.
• Java SE (v21 or latter) installed and available on your PATH.
• SWI-Prolog (v10.0.1 or latter) installed and available on your PATH.

Installation

From the Visual Studio Code Marketplace

1. Open Visual Studio Code.
2. Navigate to the Extensions view (Ctrl+Shift+X on Windows/Linux, Cmd+Shift+X on macOS).
3. Search for Setlog and click Install.

From a VSIX file

1. Download the latest released .vsix file from the repo.
   • On the right side panel select Releases → link below Other to download the latest available .vsix file.
   1. Install it:
   • GUI: Extensions → Install from VSIX… → choose the file → Install.
   • CLI:

     code --install-extension path/to/vscode-setlog-X.Y.Z.vsix
     

After installation

The extension activates automatically every time you open any .pl or .slog file.

After opening a file, you should see (1) the new extension toolbar buttons in the editor title bar and (2) the new side panel with the icon {L} that shows the current settings of the extension.

Toolbar buttons (editor title bar)

When editing a .pl / .slog file, the following buttons appear in the top-right corner of the editor:

Side panel ({log} Tools)

Click the {log} Tools icon in the Activity Bar (left sidebar) to open the configuration panel. All settings are clickable and update immediately.

Getting started

1. Open a workspace/folder containing your {log} files.
2. Open a .pl (or .slog) file. The extension activates automatically.
3. Use the toolbar buttons or the Command Palette (Ctrl+Shift+P):
   • {log}: Consult File — load and check your specification
   • {log}: Verify Conditions — generate and optionally check VCs
   • {log}: Check VCs — check an existing *-vc.pl file
   • {log}: Simulate — run a simulation with default or custom operation
4. Results appear in dedicated Output Channels:
   • Setlog Consult Results
   • Setlog VCG Results
   • Setlog check VCS Results
   • Setlog Simulation Results
5. Errors appear in the Problems panel. Clicking a diagnostic jumps to the source line.

Workflows

Below a summary of the most representative use cases you may face with. Consult the User Guide for more details.

Consulting a file

To check the syntax and types of your specification:

• Click the CON button in the editor toolbar, or
• Simply save the file (auto-consult is enabled by default).

A successful consult shows the clauses stored and __R = success. in the output channel.

Generating and checking VCs

1. Open your specification file (e.g. bb.pl).
2. Click the VCG button in the toolbar.
3. Choose "Yes, check VCs" to immediately verify, or "No" to only generate the *-vc.pl file.
4. Results (e.g. birthdayBookInit_sat_birthdayBookInv ... OK) appear in the VCG output channel.
5. You can later re-check VCs by opening the *-vc.pl file and clicking the Check VCs button that appears.

Running a simulation

1. Create a simulation file (e.g. bb-sim.pl):

   :- notype_check.
   :- consult('bb.pl').
   
   simulate_adding_someone(K, B, K_, B_, FoundDate, NewName, NewDate, Msg1, Msg2, Msg3) :-
       birthdayBookInit(K, B) &
       addBirthday(K, B, messi, 2406, K1, B1, Msg1) &
       addBirthday(K1, B1, pele, 2310, K2, B2, Msg2) &
       findBirthday(K2, B2, messi, FoundDate, K2, B2) &
       addBirthday(K2, B2, NewName, NewDate, K_, B_, Msg3).
   

2. Open the file and click the SIM button, or click Run Simulation above the predicate (CodeLens).
3. Choose Use Default Operation or Provide Custom Operation.
4. Results appear in the Simulation output channel.

Tip: Enable Groundsol in the side panel to get concrete values instead of constraints.

Using the interactive terminal

Click the >- icon in the toolbar to open a dedicated {log} terminal. This is useful for:

• Typing goals directly at the {log}=> prompt
• Using groundsol interactively before running simulations
• Exploring your specification step by step

Configuration

The {L} side panel shows the current configuration on which the extension operates.

Clicking on each setting of the configuration allows to change its value.

Configuration file

To allow to share a configuration along with the {log} specification and related simulation files, the extension provides a feature to export the configuration settings into a file.

This file must be named setlogj.conf and contain a value for each configuration setting.

Once a setlogj.conf is set, the extension makes a bidirectional sync between the indicated setlogj.conf file and the {log} settings. This allows to change the configuration either by editing the file content or using the {L} side panel.

The extension provides features to support the life cycle of a setlogj.conf files. Clicking on the Config setting it allows to:

• Set: links an existing setlog.conf file with the {log} settings
• Create: creates a new setlog.conf with default values
• Edit: changes the content of the setlog.conf being used
• Reset: sets the content of the setlog.conf file to its default value
• Default: removes binding with setlog.conf and sets {log} settings to their default values.

Config file keys

Example

# setlogj configuration file
tout 60000
vcgTimeout 60000
mode quiet
typeCheck true
noHistory false
help false
json false
outputFile
maxDepth 10
groundsol true
executionMode rsetlog
autoConsult true

Important: Configuration for the {log} version is handled separately and is not included in setlog.conf. See the following section for more information

Configuring the {log} version

As {log} is a standalone product and may evolve at a different pace than this VS Code extension, users can change the specific version of {log} being used.

The {L} side panel allows you to see which version of {log} is currently active.

To switch to a different version, simply click on the current version and browse to the setlog.pl file for the version you wish to use. You may also enter the file path directly.

To return to the built-in version that comes with the extension (the default), select the Clear Path option.

The {L} icon in the toolbar allows you to perform these same operations. When a custom version of {log} is set, the icon turns purple. While using the built-in version, it remains green.

Troubleshooting

• "Please open a Setlog file first": The extension does not detect a .pl or .slog file. Click on your code editor area so VS Code focuses on the file.
• "Java not found": Ensure java -version works in your terminal and Java is on your PATH.
• SWI-Prolog path errors: Use {log}: Set SWI-Prolog Path from the Command Palette to configure the path to your swipl binary.
• Output missing: Check the Setlog … Results output channels and the Problems panel.
• Language server didn't start: Look in Help → Toggle Developer Tools → Console and the extension host log.
• Headless/CI tests: Use xvfb-run -a on Linux.
• Extension not activating: Ensure the file extension is .pl or .slog. The extension activates on onLanguage:setlog.

Uninstall & cleanup

The process for disabling or uninstalling the {log} VS Code extension is the same as for any other extension.

Temporary files are stored within VS Code's global storage specific for this extension.

Upon deactivation or uninstallation, the extension executes java -jar server/setlogj.jar deltmp to remove the temporary folders.

If Java is missing or the command is blocked, VS Code will still clear the extension's storage directory upon uninstallation.

Contributing

We love contributions! Whether you're fixing a bug, improving documentation, or suggesting a new feature, your help makes this project better for everyone. To maintain a high quality of code and a friendly environment, please check out our Contributing Guidelines before you get started.

Notice

It is licensed under Apache License, Version 2.0.

Setlog-vscode was created by Mykyta Yampolskyi, and Alfredo Capozucca.

It is currently maintained by Alexandre Tinouert.

See CONTRIBUTING.md to know how you can contribute to the project.