🎯 Felico Playground

Fun, Friendly, Fast - In That Order

Type Check (Experimental)

Code

Output

REPL Commands

:help - Show help message
:clear - Clear all definitions and reset state
:type <expr> - Show the type of an expression
:check - Toggle type checking

Keyboard Shortcuts

Ctrl/Cmd + Enter - Run code immediately
Ctrl/Cmd + K - Clear output
Tab - Insert 4 spaces

Features

Auto-run - Code compiles and runs automatically as you type
Type checking (experimental - toggle on/off)
Error highlighting and messages
Example programs to get started
Copy code and output to clipboard
Download code as .felico file

Note About Type Checking

Type checking is experimental and may report false errors. If you encounter type errors with print or println, try unchecking the "Type Check" box. The interpreter will still run your code correctly.

Language Syntax

// Variables
let x = 42;
let name = "Felico";

// Functions
fn add(a: i64, b: i64) -> i64 {
    return a + b;
}

// Control flow
if x > 0 {
    println("positive");
}

while x > 0 {
    x = x - 1;
}