Seen Language for Visual Studio Code
Official extension for the Seen programming language -- syntax highlighting, LSP, debugging, and multi-language keyword support.
Features
- Syntax Highlighting -- TextMate grammar for
.seen files with support for SIMD types, GPU annotations, async/await, and all 6 keyword languages
- IntelliSense -- Code completion and type information via the built-in LSP
- Error Diagnostics -- Real-time error checking as you type
- Go to Definition / Find References -- Navigate your codebase
- Code Formatting -- Format with
Shift+Alt+F (uses seen fmt)
- Debugging -- Breakpoints, stepping, variable inspection
- REPL -- Interactive Seen session in the terminal
- Build Integration -- Build, run, and test from the editor
- Multi-Language Keywords -- Switch between English, Arabic, Spanish, Russian, Chinese, and Japanese keywords
Quick Start
- Install the extension (search "Seen Language" in the marketplace, or install from
.vsix)
- Install the Seen compiler (syntax highlighting works without it)
- Open a
.seen file and start coding
Commands
| Command |
Shortcut |
Description |
| Seen: Build Project |
Ctrl+Shift+B |
Compile the current project |
| Seen: Run Project |
F5 |
Execute the program |
| Seen: Run Tests |
-- |
Run all test functions |
| Seen: Format Document |
Shift+Alt+F |
Format the current file |
| Seen: Check Project |
-- |
Type-check without compiling |
| Seen: Initialize New Project |
-- |
Scaffold a new Seen project |
| Seen: Open REPL |
-- |
Launch interactive REPL |
| Seen: Switch Project Language |
-- |
Change keyword language |
| Seen: Translate to Another Language |
-- |
Translate code keywords |
Snippets
| Prefix |
Description |
main |
Main function entry point |
fun / funv |
Function with/without return type |
class |
Class with constructor |
struct / data |
Struct / data record |
enum |
Enum declaration |
trait / impl |
Trait declaration / implementation |
if / ife |
If / if-else |
for / while |
Loops |
match / when |
Pattern matching |
let / var |
Variable bindings |
test |
Test function with @test |
extern |
External function (FFI) |
closure |
Closure expression \|x\| expr |
parallel_for |
Parallel for loop |
compute |
GPU compute kernel with @compute |
derive |
@derive(...) annotation |
trycatch |
Try-catch block |
defer |
Defer block |
println |
Print with newline |
lambda |
Lambda expression |
static / method / ext |
Static / instance / extension methods |
import |
Import statement |
Configuration
{
"seen.compiler.path": "seen",
"seen.lsp.enabled": true,
"seen.formatting.enable": true,
"seen.target.default": "native",
"seen.language.default": "en"
}
| Setting |
Default |
Description |
seen.compiler.path |
"seen" |
Path to the Seen compiler |
seen.lsp.enabled |
true |
Enable language server |
seen.lsp.trace.server |
"off" |
LSP tracing (off, messages, verbose) |
seen.formatting.enable |
true |
Enable code formatting |
seen.target.default |
"native" |
Compilation target |
seen.language.default |
"en" |
Keyword language (en, ar, es, ru, zh, ja) |
Troubleshooting
Extension not detecting compiler -- Set seen.compiler.path to the full path of your seen binary, or ensure it's in your PATH.
LSP not starting -- Check the Output panel ("Seen Language Server"). Make sure your project has a Seen.toml file. Try setting seen.lsp.trace.server to "verbose".
Syntax highlighting looks wrong -- Reload the window (Ctrl+Shift+P > "Reload Window"). If using non-English keywords, set seen.language.default to match.
Development
cd vscode-seen
npm install
# Press F5 in VS Code to launch extension development host
To package:
npm run package
code --install-extension seen-*.vsix
Requirements
- VS Code 1.75.0+
- Seen compiler (optional -- syntax highlighting works without it)
License
MIT -- see LICENSE.
Source: github.com/codeyousef/seenlang
