Fidan — VS Code Extension

First-class VS Code support for the Fidan programming language. Powered by the fidan lsp language server.

Features

Feature	Status
Syntax highlighting (TextMate grammar)	✅
Semantic token highlighting	✅
Bracket, comment, and indent rules	✅
Code snippets	✅
Format on save (`fidan format`)	✅ via LSP
Error & warning diagnostics	✅ via LSP
Hover	✅ via LSP
Auto-completion	✅ via LSP
Go to definition	✅ via LSP
Find references	✅ via LSP
Inline type hints	✅ via LSP
Quick fixes / code actions	✅ via LSP
Run / Build / Test / Check / Fix from the editor	✅
Integrated REPL	✅
Profiling	✅
Sandbox mode with fine-grained permissions	✅

Requirements

The fidan binary must be on your PATH, or point the extension at it via fidan.server.path.

Build from source:

git clone https://github.com/fidan-lang/fidan.git
cd fidan
cargo build --release
# Add target/release/ to your PATH

Commands

All commands are available from the Command Palette (Ctrl+Shift+P). Run and Test also appear as title-bar icons when a .fdn file is active.

Command	Description
`Fidan: Run Current File`	Run the active `.fdn` file in an integrated terminal
`Fidan: Build File`	Compile to a native binary via Cranelift AOT
`Fidan: Check File`	Type-check without producing output
`Fidan: Fix File`	Apply auto-fixable diagnostics
`Fidan: Format Current File`	Format the active file through the language server
`Fidan: Run Tests in Current File`	Discover and run all `test { }` blocks
`Fidan: Profile Current File`	Run with profiling instrumentation
`Fidan: Open REPL`	Open a `fidan repl` session
`Fidan: New Project`	Scaffold a new Fidan project
`Fidan: Explain Diagnostic Code`	Look up a diagnostic code (for example `E0109`)
`Fidan: Explain Current Line(s)`	Explain the selected line range
`Fidan: Restart Language Server`	Kill and restart the LSP process
`Fidan: Show Language Server Output`	Open the LSP output channel

Extension Settings

Language Server

Setting	Default	Description
`fidan.server.path`	`"fidan"`	Path to the `fidan` binary
`fidan.server.extraArgs`	`[]`	Extra arguments forwarded to `fidan lsp`
`fidan.trace.server`	`"off"`	LSP trace level: `off` \| `messages` \| `verbose`

Formatting

Setting	Default	Description
`fidan.format.indentWidth`	`4`	Spaces per indent level used for LSP formatting defaults
`fidan.format.maxLineLen`	`100`	Target maximum line length for formatting defaults
`fidan.format.onSave`	`true`	Format automatically on save

.fidanfmt files are still respected by the formatter itself; these settings are the editor-side defaults and CLI overrides.

Run

Setting	Default	Description
`fidan.run.terminalName`	`"Fidan"`	Name of the integrated terminal
`fidan.run.reload`	`false`	Pass `--reload` (watch and re-run on change)
`fidan.run.strict`	`false`	Treat select warnings as errors
`fidan.run.trace`	`"none"`	Panic stack-trace mode: `none` \| `short` \| `full` \| `compact`
`fidan.run.jitThreshold`	`500`	Cranelift JIT call threshold (`0` = disable JIT)
`fidan.run.suppress`	`[]`	Diagnostic codes to suppress
`fidan.run.emit`	`[]`	Emit intermediate IRs: `tokens` \| `ast` \| `hir` \| `mir`
`fidan.run.maxErrors`	`0`	Stop after N errors (`0` = no limit)

Sandbox

When fidan.run.sandbox is true, file/env/net/spawn access is denied by default. Grant permissions individually:

Setting	Default	Description
`fidan.run.sandbox`	`false`	Enable sandbox mode
`fidan.run.sandbox.allowRead`	`[]`	Allowed read path prefixes (`["*"]` = all)
`fidan.run.sandbox.allowWrite`	`[]`	Allowed write path prefixes
`fidan.run.sandbox.allowEnv`	`false`	Allow environment variable access
`fidan.run.sandbox.allowNet`	`false`	Allow network access
`fidan.run.sandbox.allowSpawn`	`false`	Allow spawning child processes
`fidan.run.sandbox.timeLimit`	`0`	Wall-time limit in seconds (`0` = none)
`fidan.run.sandbox.memLimit`	`0`	Memory limit in MB (`0` = none)

Check

Setting	Default	Description
`fidan.check.strict`	`false`	Pass `--strict` to `fidan check`
`fidan.check.maxErrors`	`0`	Stop after N errors
`fidan.check.suppress`	`[]`	Suppressed diagnostic codes

Build & Profile

Setting	Default	Description
`fidan.build.release`	`false`	Build in release mode
`fidan.build.outputPath`	`""`	Output binary path (empty = default `out/`)
`fidan.build.emit`	`[]`	Emit intermediate IRs during build
`fidan.profile.outputFile`	`""`	Write profiling data to a JSON file

License

Licensed under the Apache License 2.0 — see LICENSE for the full text.

Additional terms apply regarding trademark use and commercial distribution of the Fidan language; see NOTICE.

Fidan

The Fidan Dev Team