Awsum language support for IntelliJ IDEA

IntelliJ Platform plugin for the Awsum programming language (.aww files). A thin LSP client to the awsum lsp server bundled with the Awsum compiler — every diagnostic, code action, format edit, document symbol, and workspace symbol is computed inside the awsum compiler binary and pushed over LSP.

Works in IntelliJ IDEA (free tier) and every Ultimate-tier JetBrains IDE (Rider, CLion, WebStorm, PyCharm Pro, GoLand, …). The native LSP API has been open to all users since IDEA 2025.2, and Community / Ultimate were merged into one product in 2025.3.

Features

• Syntax highlighting — TextMate grammar shared with awsum-vscode.
• Format on save / reformat code — textDocument/formatting, same algorithm as awsum format.
• Inline diagnostics — textDocument/publishDiagnostics, pushed on open / save / change (debounced 500 ms server-side). error vs warning severity honoured by the IDEA Problems panel.
• Quick fixes (intention actions) — textDocument/codeAction. Compiler-supplied fixes only; the plugin does no language-aware reasoning.
• Document outline (Structure view, breadcrumbs) — textDocument/documentSymbol.
• Workspace symbol search (Cmd+O / Ctrl+Shift+N) — workspace/symbol. The server walks every .aww under the workspace folders received at initialize.

Install

1. Install the Awsum compiler (see awsum-lang/awsum) and ensure awsum is on your PATH.
2. Install the plugin from the JetBrains Marketplace (search "Awsum"), or sideload a locally-built .zip: Settings → Plugins → ⚙ → Install Plugin from Disk… → pick build/distributions/awsum-intellij-A.B.C.zip.

If awsum is not on your PATH, IntelliJ inherits PATH from the shell that launched it. Either launch IDEA from a terminal where awsum resolves, or use Toolbox / Spotlight with a PATH configured via your shell's startup files. There is no extension-level setting for the binary path today.

Actions

Action	Default keybinding	What it does
Restart Awsum LSP server	—	Stops the awsum lsp process and starts a new one with the same settings. Useful after a local stack install of a new awsum build, or to clear any in-memory state on the server.

Invoke via Help → Find Action… (Cmd+Shift+A / Ctrl+Shift+A) and type the action name. Bind it to a keybinding via Settings → Keymap if you use it often.

Versioning

awsum-intellij A.B.C is built and tested against awsum A.B.C. Mismatched versions are not supported — at startup the LSP server compares the plugin's expected version against its own and shows a non-blocking notification on mismatch, with an action button that opens the install page.

The lockstep policy is shared across all three IDE plugins (awsum-vscode, awsum-zed, awsum-intellij) — see CHANGELOG.md for the reasoning.

Development

./gradlew buildPlugin    # build/distributions/awsum-intellij-A.B.C.zip
./gradlew runIde         # launch sandbox IDEA with the plugin loaded
./gradlew verifyPlugin   # IntelliJ Plugin Verifier

JDK 21 is required; settings.gradle.kts declares foojay-resolver-convention so Gradle auto-downloads Adoptium Temurin 21 if no local JDK 21 is available.

Structure

src/main/kotlin/dev/awsumlang/intellij/
  AwsumLspServerSupportProvider.kt    # extension point; spawns descriptor on .aww open
  AwsumLspServerDescriptor.kt         # `awsum lsp --stdio`, version handshake, format-via-server override
  AwsumTextMateBundleProvider.kt      # exposes the bundled TextMate grammar to IDEA
src/main/resources/
  META-INF/plugin.xml                 # plugin manifest (id, vendor, extension registrations)
  textmate/awsum/                     # VSCode-style TextMate bundle (package.json + grammar + language-configuration)

Architecture

• Single source of truth. awsum-intellij does no language-aware processing. All semantics live in awsum/src/Awsum/Lsp.hs (the LSP server) and the modules it reuses (Awsum.Diagnostic, Awsum.Symbols, Awsum.Format, Awsum.ElaborateLower, …).
• No custom providers. Everything routes through the IntelliJ Platform's native LSP API (com.intellij.platform.lsp.api.LspServerSupportProvider, ProjectWideLspServerDescriptor, LspCustomization). Anything you'd want to add for IDEA is best added on the LSP server side first — that way awsum-vscode, awsum-zed, and any other LSP client benefit too.

Related

• Compiler: awsum-lang/awsum
• VSCode extension: awsum-lang/awsum-vscode
• Zed extension: awsum-lang/awsum-zed
• Examples: awsum-lang/awsum-examples
• Website: awsum-lang.org

AI use

This IntelliJ Platform plugin is developed with substantial usage of generative AI. Every generated change is reviewed, edited, and accepted by a human before it lands in the repository, and no output is shipped unedited.

License

Apache 2.0 — see LICENSE and NOTICE.