LFortran Language Client (VSCode)

Integrates VSCode with LFortran's language server. The extension is extremely lightweight and delegates all the heavy lifting to the language server.

Installation

Before you install this extension, please be sure to install lfortran per the installation instructions. Unless you intend to develop lfortran, it is recommended to install it with Conda.

Once you have installed lfortran, it is recommended to install this extension via the VSCode Marketplace.

Version Compatibility with LFortran

There are two independent constraints.

First constraint is that for a given version of lfortran-vscode-client in the left column, you need at least the version of LFortran in the right column:

The second constraint is that for a given version of LFortran in the left column, you need at least the version of lfortran-vscode-client in the right column:

When lfortran-vscode-client introduces a change the requires some feature in LFortran, we bump the LFortran version in the first table. When LFortran adds a change that requires some feature in the lfortran-vscode-client, then we bump the lfortran-vscode-client verison in the second table. When a new version of lfortran-vscode-client is released, only the first table has to be updated. When a new version of LFortran is released, only the second table needs to be updated.

Building from source

If you would like to build this extension from source, please install lfortran as described, above. Then, follow these instructions:

# Clone the repository if you have not already:
git clone https://github.com/lfortran/lfortran-vscode-client.git

cd lfortran-vscode-client

# If you already had it cloned, update your repo:
git checkout main
git pull origin main

# Install the NPM dependencies:
npm install

# Remove old build artifacts:
rm -rf out *.vsix

# Bundle the package:
npx vsce package

# Uninstall any older version of the extension from VSCode:
code --uninstall-extension lcompilers.lfortran

# Install the package you just created:
code --install-extension *.vsix

Usage

Once you have installed the extension, it should begin working immediately when a Fortran file is opened or edited. More specifically, any time a file is opened or edited with one of the following file extensions, this VSCode extension will be activated: .f; .for; .f90; .f95; .f03.

Code Validation

LFortran will automatically check a document for syntactic and semantic errors and warn about potential issues. Errors will be highlighted and described in the Problems terminal (View -> Problems).

Goto Definitions

To jump to a symbol's definition, either place the cursor over it and press F12 or right-click it and select Go to Definition from the context menu.

Hover Previews

When the cursor hovers over a symbol, a preview of its definition will be placed next to it.

Configuration

You may configure the extension by clicking the Extensions tab, followed by clicking the gear icon on the bottom-right of the LFortran list item, and lastly by clicking the Settings menu item. Most of the settings are common to all workspaces but the compiler flags may be modified at the resource level.

Debugging

If you would like to debug the extension, please do the following:

1. Open the extension's output terminal by selecting View -> Terminal from the menu bar. Then, select the Output tab and choose LFortran from the combo box near the top-right.
2. Open the extension's settings and enable at least a debug log level.
3. If you would like trace-level logging, you may set the log level to either trace or all to enable the most granular level of logging within the extension, or leave the log level alone and enable request tracing under LFortran > Trace: Server. If you enable verbose request tracing, the JSON payloads will be pretty-printed if you have enabled LFortran > Log: Pretty Print.
4. The language server mirrors its logs to a log file. Its default location is a file named lfortran-language-server.log that is located relative to the root of your workspace.